Discussion:
[PATCH 3/8] v4l: videobuf2: add vmalloc allocator
Marek Szyprowski
2010-12-16 14:24:00 UTC
Permalink
From: Pawel Osciak <***@samsung.com>

Add an implementation of contiguous virtual memory allocator and handling
routines for videobuf2, implemented on top of vmalloc()/vfree() calls.

Signed-off-by: Pawel Osciak <***@samsung.com>
Signed-off-by: Kyungmin Park <***@samsung.com>
Signed-off-by: Marek Szyprowski <***@samsung.com>
CC: Pawel Osciak <***@osciak.com>
---
drivers/media/video/Kconfig | 5 +
drivers/media/video/Makefile | 1 +
drivers/media/video/videobuf2-vmalloc.c | 132 +++++++++++++++++++++++++++++++
include/media/videobuf2-vmalloc.h | 20 +++++
4 files changed, 158 insertions(+), 0 deletions(-)
create mode 100644 drivers/media/video/videobuf2-vmalloc.c
create mode 100644 include/media/videobuf2-vmalloc.h

diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
index 3c239fa..2606f49 100644
--- a/drivers/media/video/Kconfig
+++ b/drivers/media/video/Kconfig
@@ -55,6 +55,11 @@ config VIDEOBUF2_CORE
config VIDEOBUF2_MEMOPS
tristate

+config VIDEOBUF2_VMALLOC
+ select VIDEOBUF2_CORE
+ select VIDEOBUF2_MEMOPS
+ tristate
+
#
# Multimedia Video device configuration
#
diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
index a97a2a0..538bee9 100644
--- a/drivers/media/video/Makefile
+++ b/drivers/media/video/Makefile
@@ -116,6 +116,7 @@ obj-$(CONFIG_VIDEO_BTCX) += btcx-risc.o

obj-$(CONFIG_VIDEOBUF2_CORE) += videobuf2-core.o
obj-$(CONFIG_VIDEOBUF2_MEMOPS) += videobuf2-memops.o
+obj-$(CONFIG_VIDEOBUF2_VMALLOC) += videobuf2-vmalloc.o

obj-$(CONFIG_V4L2_MEM2MEM_DEV) += v4l2-mem2mem.o

diff --git a/drivers/media/video/videobuf2-vmalloc.c b/drivers/media/video/videobuf2-vmalloc.c
new file mode 100644
index 0000000..b5e6936
--- /dev/null
+++ b/drivers/media/video/videobuf2-vmalloc.c
@@ -0,0 +1,132 @@
+/*
+ * videobuf2-vmalloc.c - vmalloc memory allocator for videobuf2
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ *
+ * Author: Pawel Osciak <***@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+#include <media/videobuf2-core.h>
+#include <media/videobuf2-memops.h>
+
+struct vb2_vmalloc_buf {
+ void *vaddr;
+ unsigned long size;
+ atomic_t refcount;
+ struct vb2_vmarea_handler handler;
+};
+
+static void vb2_vmalloc_put(void *buf_priv);
+
+static void *vb2_vmalloc_alloc(void *alloc_ctx, unsigned long size)
+{
+ struct vb2_vmalloc_buf *buf;
+
+ buf = kzalloc(sizeof *buf, GFP_KERNEL);
+ if (!buf)
+ return NULL;
+
+ buf->size = size;
+ buf->vaddr = vmalloc_user(buf->size);
+ buf->handler.refcount = &buf->refcount;
+ buf->handler.put = vb2_vmalloc_put;
+ buf->handler.arg = buf;
+
+ if (!buf->vaddr) {
+ printk(KERN_ERR "vmalloc of size %ld failed\n", buf->size);
+ kfree(buf);
+ return NULL;
+ }
+
+ atomic_inc(&buf->refcount);
+ printk(KERN_DEBUG "Allocated vmalloc buffer of size %ld at vaddr=%p\n",
+ buf->size, buf->vaddr);
+
+ return buf;
+}
+
+static void vb2_vmalloc_put(void *buf_priv)
+{
+ struct vb2_vmalloc_buf *buf = buf_priv;
+
+ if (atomic_dec_and_test(&buf->refcount)) {
+ printk(KERN_DEBUG "%s: Freeing vmalloc mem at vaddr=%p\n",
+ __func__, buf->vaddr);
+ vfree(buf->vaddr);
+ kfree(buf);
+ }
+}
+
+static void *vb2_vmalloc_vaddr(void *buf_priv)
+{
+ struct vb2_vmalloc_buf *buf = buf_priv;
+
+ BUG_ON(!buf);
+
+ if (!buf->vaddr) {
+ printk(KERN_ERR "Address of an unallocated plane requested\n");
+ return NULL;
+ }
+
+ return buf->vaddr;
+}
+
+static unsigned int vb2_vmalloc_num_users(void *buf_priv)
+{
+ struct vb2_vmalloc_buf *buf = buf_priv;
+ return atomic_read(&buf->refcount);
+}
+
+static int vb2_vmalloc_mmap(void *buf_priv, struct vm_area_struct *vma)
+{
+ struct vb2_vmalloc_buf *buf = buf_priv;
+ int ret;
+
+ if (!buf) {
+ printk(KERN_ERR "No memory to map\n");
+ return -EINVAL;
+ }
+
+ ret = remap_vmalloc_range(vma, buf->vaddr, 0);
+ if (ret) {
+ printk(KERN_ERR "Remapping vmalloc memory, error: %d\n", ret);
+ return ret;
+ }
+
+ /*
+ * Make sure that vm_areas for 2 buffers won't be merged together
+ */
+ vma->vm_flags |= VM_DONTEXPAND;
+
+ /*
+ * Use common vm_area operations to track buffer refcount.
+ */
+ vma->vm_private_data = &buf->handler;
+ vma->vm_ops = &vb2_common_vm_ops;
+
+ vma->vm_ops->open(vma);
+
+ return 0;
+}
+
+const struct vb2_mem_ops vb2_vmalloc_memops = {
+ .alloc = vb2_vmalloc_alloc,
+ .put = vb2_vmalloc_put,
+ .vaddr = vb2_vmalloc_vaddr,
+ .mmap = vb2_vmalloc_mmap,
+ .num_users = vb2_vmalloc_num_users,
+};
+EXPORT_SYMBOL_GPL(vb2_vmalloc_memops);
+
+MODULE_DESCRIPTION("vmalloc memory handling routines for videobuf2");
+MODULE_AUTHOR("Pawel Osciak");
+MODULE_LICENSE("GPL");
diff --git a/include/media/videobuf2-vmalloc.h b/include/media/videobuf2-vmalloc.h
new file mode 100644
index 0000000..a76b8af
--- /dev/null
+++ b/include/media/videobuf2-vmalloc.h
@@ -0,0 +1,20 @@
+/*
+ * videobuf2-vmalloc.h - vmalloc memory allocator for videobuf2
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ *
+ * Author: Pawel Osciak <***@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.
+ */
+
+#ifndef _MEDIA_VIDEOBUF2_VMALLOC_H
+#define _MEDIA_VIDEOBUF2_VMALLOC_H
+
+#include <media/videobuf2-core.h>
+
+extern const struct vb2_mem_ops vb2_vmalloc_memops;
+
+#endif
--
1.7.1.569.g6f426
Marek Szyprowski
2010-12-16 14:24:01 UTC
Permalink
From: Pawel Osciak <***@samsung.com>

Add an implementation of DMA coherent memory allocator and handling
routines for videobuf2, implemented on top of dma_alloc_coherent() call.

Signed-off-by: Pawel Osciak <***@samsung.com>
Signed-off-by: Kyungmin Park <***@samsung.com>
Signed-off-by: Marek Szyprowski <***@samsung.com>
CC: Pawel Osciak <***@osciak.com>
---
drivers/media/video/Kconfig | 5 +
drivers/media/video/Makefile | 1 +
drivers/media/video/videobuf2-dma-contig.c | 186 ++++++++++++++++++++++++++++
include/media/videobuf2-dma-contig.h | 29 +++++
4 files changed, 221 insertions(+), 0 deletions(-)
create mode 100644 drivers/media/video/videobuf2-dma-contig.c
create mode 100644 include/media/videobuf2-dma-contig.h

diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
index 2606f49..a9e90e4 100644
--- a/drivers/media/video/Kconfig
+++ b/drivers/media/video/Kconfig
@@ -55,6 +55,11 @@ config VIDEOBUF2_CORE
config VIDEOBUF2_MEMOPS
tristate

+config VIDEOBUF2_DMA_CONTIG
+ select VIDEOBUF2_CORE
+ select VIDEOBUF2_MEMOPS
+ tristate
+
config VIDEOBUF2_VMALLOC
select VIDEOBUF2_CORE
select VIDEOBUF2_MEMOPS
diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
index 538bee9..8eb7973 100644
--- a/drivers/media/video/Makefile
+++ b/drivers/media/video/Makefile
@@ -117,6 +117,7 @@ obj-$(CONFIG_VIDEO_BTCX) += btcx-risc.o
obj-$(CONFIG_VIDEOBUF2_CORE) += videobuf2-core.o
obj-$(CONFIG_VIDEOBUF2_MEMOPS) += videobuf2-memops.o
obj-$(CONFIG_VIDEOBUF2_VMALLOC) += videobuf2-vmalloc.o
+obj-$(CONFIG_VIDEOBUF2_DMA_CONTIG) += videobuf2-dma-contig.o

obj-$(CONFIG_V4L2_MEM2MEM_DEV) += v4l2-mem2mem.o

diff --git a/drivers/media/video/videobuf2-dma-contig.c b/drivers/media/video/videobuf2-dma-contig.c
new file mode 100644
index 0000000..7fe7fce
--- /dev/null
+++ b/drivers/media/video/videobuf2-dma-contig.c
@@ -0,0 +1,186 @@
+/*
+ * videobuf2-dma-contig.c - DMA contig memory allocator for videobuf2
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ *
+ * Author: Pawel Osciak <***@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/dma-mapping.h>
+
+#include <media/videobuf2-core.h>
+#include <media/videobuf2-memops.h>
+
+struct vb2_dc_conf {
+ struct device *dev;
+};
+
+struct vb2_dc_buf {
+ struct vb2_dc_conf *conf;
+ void *vaddr;
+ dma_addr_t paddr;
+ unsigned long size;
+ struct vm_area_struct *vma;
+ atomic_t refcount;
+ struct vb2_vmarea_handler handler;
+};
+
+static void vb2_dma_contig_put(void *buf_priv);
+
+static void *vb2_dma_contig_alloc(void *alloc_ctx, unsigned long size)
+{
+ struct vb2_dc_conf *conf = alloc_ctx;
+ struct vb2_dc_buf *buf;
+
+ buf = kzalloc(sizeof *buf, GFP_KERNEL);
+ if (!buf)
+ return ERR_PTR(-ENOMEM);
+
+ buf->vaddr = dma_alloc_coherent(conf->dev, size, &buf->paddr,
+ GFP_KERNEL);
+ if (!buf->vaddr) {
+ dev_err(conf->dev, "dma_alloc_coherent of size %ld failed\n",
+ buf->size);
+ kfree(buf);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ buf->conf = conf;
+ buf->size = size;
+
+ buf->handler.refcount = &buf->refcount;
+ buf->handler.put = vb2_dma_contig_put;
+ buf->handler.arg = buf;
+
+ atomic_inc(&buf->refcount);
+
+ return buf;
+}
+
+static void vb2_dma_contig_put(void *buf_priv)
+{
+ struct vb2_dc_buf *buf = buf_priv;
+
+ if (atomic_dec_and_test(&buf->refcount)) {
+ dma_free_coherent(buf->conf->dev, buf->size, buf->vaddr,
+ buf->paddr);
+ kfree(buf);
+ }
+}
+
+static void *vb2_dma_contig_cookie(void *buf_priv)
+{
+ struct vb2_dc_buf *buf = buf_priv;
+
+ return (void *)buf->paddr;
+}
+
+static void *vb2_dma_contig_vaddr(void *buf_priv)
+{
+ struct vb2_dc_buf *buf = buf_priv;
+ if (!buf)
+ return 0;
+
+ return buf->vaddr;
+}
+
+static unsigned int vb2_dma_contig_num_users(void *buf_priv)
+{
+ struct vb2_dc_buf *buf = buf_priv;
+
+ return atomic_read(&buf->refcount);
+}
+
+static int vb2_dma_contig_mmap(void *buf_priv, struct vm_area_struct *vma)
+{
+ struct vb2_dc_buf *buf = buf_priv;
+
+ if (!buf) {
+ printk(KERN_ERR "No buffer to map\n");
+ return -EINVAL;
+ }
+
+ return vb2_mmap_pfn_range(vma, buf->paddr, buf->size,
+ &vb2_common_vm_ops, &buf->handler);
+}
+
+static void *vb2_dma_contig_get_userptr(void *alloc_ctx, unsigned long vaddr,
+ unsigned long size, int write)
+{
+ struct vb2_dc_buf *buf;
+ struct vm_area_struct *vma;
+ dma_addr_t paddr = 0;
+ int ret;
+
+ buf = kzalloc(sizeof *buf, GFP_KERNEL);
+ if (!buf)
+ return ERR_PTR(-ENOMEM);
+
+ ret = vb2_get_contig_userptr(vaddr, size, &vma, &paddr);
+ if (ret) {
+ printk(KERN_ERR "Failed acquiring VMA for vaddr 0x%08lx\n",
+ vaddr);
+ kfree(buf);
+ return ERR_PTR(ret);
+ }
+
+ buf->size = size;
+ buf->paddr = paddr;
+ buf->vma = vma;
+
+ return buf;
+}
+
+static void vb2_dma_contig_put_userptr(void *mem_priv)
+{
+ struct vb2_dc_buf *buf = mem_priv;
+
+ if (!buf)
+ return;
+
+ vb2_put_vma(buf->vma);
+ kfree(buf);
+}
+
+const struct vb2_mem_ops vb2_dma_contig_memops = {
+ .alloc = vb2_dma_contig_alloc,
+ .put = vb2_dma_contig_put,
+ .cookie = vb2_dma_contig_cookie,
+ .vaddr = vb2_dma_contig_vaddr,
+ .mmap = vb2_dma_contig_mmap,
+ .get_userptr = vb2_dma_contig_get_userptr,
+ .put_userptr = vb2_dma_contig_put_userptr,
+ .num_users = vb2_dma_contig_num_users,
+};
+EXPORT_SYMBOL_GPL(vb2_dma_contig_memops);
+
+void *vb2_dma_contig_init_ctx(struct device *dev)
+{
+ struct vb2_dc_conf *conf;
+
+ conf = kzalloc(sizeof *conf, GFP_KERNEL);
+ if (!conf)
+ return ERR_PTR(-ENOMEM);
+
+ conf->dev = dev;
+
+ return conf;
+}
+EXPORT_SYMBOL_GPL(vb2_dma_contig_init_ctx);
+
+void vb2_dma_contig_cleanup_ctx(void *alloc_ctx)
+{
+ kfree(alloc_ctx);
+}
+EXPORT_SYMBOL_GPL(vb2_dma_contig_cleanup_ctx);
+
+MODULE_DESCRIPTION("DMA-contig memory handling routines for videobuf2");
+MODULE_AUTHOR("Pawel Osciak");
+MODULE_LICENSE("GPL");
+
diff --git a/include/media/videobuf2-dma-contig.h b/include/media/videobuf2-dma-contig.h
new file mode 100644
index 0000000..fb7ca84
--- /dev/null
+++ b/include/media/videobuf2-dma-contig.h
@@ -0,0 +1,29 @@
+/*
+ * videobuf2-dma-coherent.h - DMA coherent memory allocator for videobuf2
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ *
+ * Author: Pawel Osciak <***@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.
+ */
+
+#ifndef _MEDIA_VIDEOBUF2_DMA_COHERENT_H
+#define _MEDIA_VIDEOBUF2_DMA_COHERENT_H
+
+#include <media/videobuf2-core.h>
+
+static inline unsigned long vb2_dma_contig_plane_paddr(
+ struct vb2_buffer *vb, unsigned int plane_no)
+{
+ return (unsigned long)vb2_plane_cookie(vb, plane_no);
+}
+
+void *vb2_dma_contig_init_ctx(struct device *dev);
+void vb2_dma_contig_cleanup_ctx(void *alloc_ctx);
+
+extern const struct vb2_mem_ops vb2_dma_contig_memops;
+
+#endif
--
1.7.1.569.g6f426
Marek Szyprowski
2010-12-16 14:23:59 UTC
Permalink
Add generic memory handling routines for userspace pointer handling,
contiguous memory verification and mapping.

Signed-off-by: Marek Szyprowski <***@samsung.com>
Signed-off-by: Pawel Osciak <***@samsung.com>
Signed-off-by: Kyungmin Park <***@samsung.com>
CC: Pawel Osciak <***@osciak.com>
---
drivers/media/video/Kconfig | 3 +
drivers/media/video/Makefile | 1 +
drivers/media/video/videobuf2-memops.c | 233 ++++++++++++++++++++++++++++++++
include/media/videobuf2-memops.h | 45 ++++++
4 files changed, 282 insertions(+), 0 deletions(-)
create mode 100644 drivers/media/video/videobuf2-memops.c
create mode 100644 include/media/videobuf2-memops.h

diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
index 4a81a00..3c239fa 100644
--- a/drivers/media/video/Kconfig
+++ b/drivers/media/video/Kconfig
@@ -52,6 +52,9 @@ config V4L2_MEM2MEM_DEV
config VIDEOBUF2_CORE
tristate

+config VIDEOBUF2_MEMOPS
+ tristate
+
#
# Multimedia Video device configuration
#
diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
index 77c4f85..a97a2a0 100644
--- a/drivers/media/video/Makefile
+++ b/drivers/media/video/Makefile
@@ -115,6 +115,7 @@ obj-$(CONFIG_VIDEOBUF_DVB) += videobuf-dvb.o
obj-$(CONFIG_VIDEO_BTCX) += btcx-risc.o

obj-$(CONFIG_VIDEOBUF2_CORE) += videobuf2-core.o
+obj-$(CONFIG_VIDEOBUF2_MEMOPS) += videobuf2-memops.o

obj-$(CONFIG_V4L2_MEM2MEM_DEV) += v4l2-mem2mem.o

diff --git a/drivers/media/video/videobuf2-memops.c b/drivers/media/video/videobuf2-memops.c
new file mode 100644
index 0000000..dde5b51
--- /dev/null
+++ b/drivers/media/video/videobuf2-memops.c
@@ -0,0 +1,233 @@
+/*
+ * videobuf2-memops.c - generic memory handling routines for videobuf2
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ *
+ * Author: Pawel Osciak <***@samsung.com>
+ * Marek Szyprowski <***@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.
+ */
+
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/dma-mapping.h>
+#include <linux/vmalloc.h>
+#include <linux/cma.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/file.h>
+#include <linux/slab.h>
+
+#include <media/videobuf2-core.h>
+#include <media/videobuf2-memops.h>
+
+/**
+ * vb2_get_vma() - acquire and lock the virtual memory area
+ * @vma: given virtual memory area
+ *
+ * This function attempts to acquire an area mapped in the userspace for
+ * the duration of a hardware operation. The area is "locked" by performing
+ * the same set of operation that are done when process calls fork() and
+ * memory areas are duplicated.
+ *
+ * Returns a copy of a virtual memory region on success or NULL.
+ */
+struct vm_area_struct *vb2_get_vma(struct vm_area_struct *vma)
+{
+ struct vm_area_struct *vma_copy;
+
+ vma_copy = kmalloc(sizeof(*vma_copy), GFP_KERNEL);
+ if (vma_copy == NULL)
+ return NULL;
+
+ if (vma->vm_ops && vma->vm_ops->open)
+ vma->vm_ops->open(vma);
+
+ if (vma->vm_file)
+ get_file(vma->vm_file);
+
+ memcpy(vma_copy, vma, sizeof(*vma));
+
+ vma_copy->vm_mm = NULL;
+ vma_copy->vm_next = NULL;
+ vma_copy->vm_prev = NULL;
+
+ return vma_copy;
+}
+
+/**
+ * vb2_put_userptr() - release a userspace virtual memory area
+ * @vma: virtual memory region associated with the area to be released
+ *
+ * This function releases the previously acquired memory area after a hardware
+ * operation.
+ */
+void vb2_put_vma(struct vm_area_struct *vma)
+{
+ if (!vma)
+ return;
+
+ if (vma->vm_file)
+ fput(vma->vm_file);
+
+ if (vma->vm_ops && vma->vm_ops->close)
+ vma->vm_ops->close(vma);
+
+ kfree(vma);
+}
+
+/**
+ * vb2_get_contig_userptr() - lock physically contigous userspace mapped memory
+ * @vaddr: starting virtual address of the area to be verified
+ * @size: size of the area
+ * @res_paddr: will return physical address for the given vaddr
+ * @res_vma: will return locked copy of struct vm_area for the given area
+ *
+ * This function will go through memory area of size @size mapped at @vaddr and
+ * verify that the underlying physical pages are contiguous. If they are
+ * contigous the virtual memory area is locked and a @res_vma is filled with
+ * the copy and @res_pa set to the physical address of the buffer.
+ *
+ * Returns 0 on success.
+ */
+int vb2_get_contig_userptr(unsigned long vaddr, unsigned long size,
+ struct vm_area_struct **res_vma, dma_addr_t *res_pa)
+{
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+ unsigned long offset, start, end;
+ unsigned long this_pfn, prev_pfn;
+ dma_addr_t pa = 0;
+ int ret = -EFAULT;
+
+ start = vaddr;
+ offset = start & ~PAGE_MASK;
+ end = start + size;
+
+ down_read(&mm->mmap_sem);
+ vma = find_vma(mm, start);
+
+ if (vma == NULL || vma->vm_end < end)
+ goto done;
+
+ for (prev_pfn = 0; start < end; start += PAGE_SIZE) {
+ ret = follow_pfn(vma, start, &this_pfn);
+ if (ret)
+ goto done;
+
+ if (prev_pfn == 0)
+ pa = this_pfn << PAGE_SHIFT;
+ else if (this_pfn != prev_pfn + 1) {
+ ret = -EFAULT;
+ goto done;
+ }
+ prev_pfn = this_pfn;
+ }
+
+ /*
+ * Memory is contigous, lock vma and return to the caller
+ */
+ *res_vma = vb2_get_vma(vma);
+ if (*res_vma == NULL) {
+ ret = -ENOMEM;
+ goto done;
+ }
+ *res_pa = pa + offset;
+ ret = 0;
+
+done:
+ up_read(&mm->mmap_sem);
+ return ret;
+}
+
+/**
+ * vb2_mmap_pfn_range() - map physical pages to userspace
+ * @vma: virtual memory region for the mapping
+ * @paddr: starting physical address of the memory to be mapped
+ * @size: size of the memory to be mapped
+ * @vm_ops: vm operations to be assigned to the created area
+ * @priv: private data to be associated with the area
+ *
+ * Returns 0 on success.
+ */
+int vb2_mmap_pfn_range(struct vm_area_struct *vma, unsigned long paddr,
+ unsigned long size,
+ const struct vm_operations_struct *vm_ops,
+ void *priv)
+{
+ int ret;
+
+ size = min_t(unsigned long, vma->vm_end - vma->vm_start, size);
+
+ vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+ ret = remap_pfn_range(vma, vma->vm_start, paddr >> PAGE_SHIFT,
+ size, vma->vm_page_prot);
+ if (ret) {
+ printk(KERN_ERR "Remapping memory failed, error: %d\n", ret);
+ return ret;
+ }
+
+ vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED;
+ vma->vm_private_data = priv;
+ vma->vm_ops = vm_ops;
+
+ vma->vm_ops->open(vma);
+
+ printk(KERN_DEBUG "%s: mapped paddr 0x%08lx at 0x%08lx, size %ld\n",
+ __func__, paddr, vma->vm_start, size);
+
+ return 0;
+}
+
+/**
+ * vb2_common_vm_open() - increase refcount of the vma
+ * @vma: virtual memory region for the mapping
+ *
+ * This function adds another user to the provided vma. It expects
+ * struct vb2_vmarea_handler pointer in vma->vm_private_data.
+ */
+static void vb2_common_vm_open(struct vm_area_struct *vma)
+{
+ struct vb2_vmarea_handler *h = vma->vm_private_data;
+
+ printk(KERN_DEBUG "%s: %p, refcount: %d, vma: %08lx-%08lx\n",
+ __func__, h, atomic_read(h->refcount), vma->vm_start,
+ vma->vm_end);
+
+ atomic_inc(h->refcount);
+}
+
+/**
+ * vb2_common_vm_close() - decrease refcount of the vma
+ * @vma: virtual memory region for the mapping
+ *
+ * This function releases the user from the provided vma. It expects
+ * struct vb2_vmarea_handler pointer in vma->vm_private_data.
+ */
+static void vb2_common_vm_close(struct vm_area_struct *vma)
+{
+ struct vb2_vmarea_handler *h = vma->vm_private_data;
+
+ printk(KERN_DEBUG "%s: %p, refcount: %d, vma: %08lx-%08lx\n",
+ __func__, h, atomic_read(h->refcount), vma->vm_start,
+ vma->vm_end);
+
+ h->put(h->arg);
+}
+
+/**
+ * vb2_common_vm_ops - common vm_ops used for tracking refcount of mmaped
+ * video buffers
+ */
+const struct vm_operations_struct vb2_common_vm_ops = {
+ .open = vb2_common_vm_open,
+ .close = vb2_common_vm_close,
+};
+EXPORT_SYMBOL_GPL(vb2_common_vm_ops);
+
+MODULE_DESCRIPTION("common memory handling routines for videobuf2");
+MODULE_AUTHOR("Pawel Osciak");
+MODULE_LICENSE("GPL");
diff --git a/include/media/videobuf2-memops.h b/include/media/videobuf2-memops.h
new file mode 100644
index 0000000..fee1703
--- /dev/null
+++ b/include/media/videobuf2-memops.h
@@ -0,0 +1,45 @@
+/*
+ * videobuf2-memops.h - generic memory handling routines for videobuf2
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ *
+ * Author: Pawel Osciak <***@samsung.com>
+ * Marek Szyprowski <***@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.
+ */
+
+#ifndef _MEDIA_VIDEOBUF2_MEMOPS_H
+#define _MEDIA_VIDEOBUF2_MEMOPS_H
+
+#include <media/videobuf2-core.h>
+
+/**
+ * vb2_vmarea_handler - common vma refcount tracking handler
+ * @refcount: pointer to refcount entry in the buffer
+ * @put: callback to function that decreases buffer refcount
+ * @arg: argument for @put callback
+ */
+struct vb2_vmarea_handler {
+ atomic_t *refcount;
+ void (*put)(void *arg);
+ void *arg;
+};
+
+extern const struct vm_operations_struct vb2_common_vm_ops;
+
+int vb2_get_contig_userptr(unsigned long vaddr, unsigned long size,
+ struct vm_area_struct **res_vma, dma_addr_t *res_pa);
+
+int vb2_mmap_pfn_range(struct vm_area_struct *vma, unsigned long paddr,
+ unsigned long size,
+ const struct vm_operations_struct *vm_ops,
+ void *priv);
+
+struct vm_area_struct *vb2_get_vma(struct vm_area_struct *vma);
+void vb2_put_vma(struct vm_area_struct *vma);
+
+
+#endif
--
1.7.1.569.g6f426
Marek Szyprowski
2010-12-16 14:24:04 UTC
Permalink
Make vivi use videobuf2 in place of videobuf.

Signed-off-by: Pawel Osciak <***@samsung.com>
Signed-off-by: Marek Szyprowski <***@samsung.com>
Signed-off-by: Kyungmin Park <***@samsung.com>
CC: Pawel Osciak <***@osciak.com>
---
drivers/media/video/Kconfig | 2 +-
drivers/media/video/vivi.c | 369 +++++++++++++++++++++++--------------------
2 files changed, 200 insertions(+), 171 deletions(-)

diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
index bfa08b1..4dda7bf 100644
--- a/drivers/media/video/Kconfig
+++ b/drivers/media/video/Kconfig
@@ -563,7 +563,7 @@ config VIDEO_VIVI
depends on VIDEO_DEV && VIDEO_V4L2 && !SPARC32 && !SPARC64
depends on FRAMEBUFFER_CONSOLE || STI_CONSOLE
select FONT_8x16
- select VIDEOBUF_VMALLOC
+ select VIDEOBUF2_VMALLOC
default n
---help---
Enables a virtual video driver. This device shows a color bar
diff --git a/drivers/media/video/vivi.c b/drivers/media/video/vivi.c
index 9797e5a..674337f 100644
--- a/drivers/media/video/vivi.c
+++ b/drivers/media/video/vivi.c
@@ -7,6 +7,9 @@
* John Sokol <sokol--a.t--videotechnology.com>
* http://v4l.videotechnology.com/
*
+ * Conversion to videobuf2 by Pawel Osciak & Marek Szyprowski
+ * Copyright (c) 2010 Samsung Electronics
+ *
* This program is free software; you can redistribute it and/or modify
* it under the terms of the BSD Licence, GNU General Public License
* as published by the Free Software Foundation; either version 2 of the
@@ -23,10 +26,8 @@
#include <linux/mutex.h>
#include <linux/videodev2.h>
#include <linux/kthread.h>
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2, 6, 20)
#include <linux/freezer.h>
-#endif
-#include <media/videobuf-vmalloc.h>
+#include <media/videobuf2-vmalloc.h>
#include <media/v4l2-device.h>
#include <media/v4l2-ioctl.h>
#include <media/v4l2-common.h>
@@ -42,7 +43,7 @@
#define MAX_HEIGHT 1200

#define VIVI_MAJOR_VERSION 0
-#define VIVI_MINOR_VERSION 7
+#define VIVI_MINOR_VERSION 8
#define VIVI_RELEASE 0
#define VIVI_VERSION \
KERNEL_VERSION(VIVI_MAJOR_VERSION, VIVI_MINOR_VERSION, VIVI_RELEASE)
@@ -133,16 +134,11 @@ static struct vivi_fmt *get_format(struct v4l2_format *f)
return &formats[k];
}

-struct sg_to_addr {
- int pos;
- struct scatterlist *sg;
-};
-
/* buffer for one video frame */
struct vivi_buffer {
/* common v4l buffer stuff -- must be first */
- struct videobuf_buffer vb;
-
+ struct vb2_buffer vb;
+ struct list_head list;
struct vivi_fmt *fmt;
};

@@ -190,9 +186,11 @@ struct vivi_dev {
/* video capture */
struct vivi_fmt *fmt;
unsigned int width, height;
- struct videobuf_queue vb_vidq;
+ struct vb2_queue vb_vidq;
+ enum v4l2_field field;
+ unsigned int field_count;

- unsigned long generating;
+ unsigned int open_count;
u8 bars[9][3];
u8 line[MAX_WIDTH * 4];
};
@@ -443,10 +441,10 @@ static void gen_text(struct vivi_dev *dev, char *basep,

static void vivi_fillbuff(struct vivi_dev *dev, struct vivi_buffer *buf)
{
- int hmax = buf->vb.height;
- int wmax = buf->vb.width;
+ int wmax = dev->width;
+ int hmax = dev->height;
struct timeval ts;
- void *vbuf = videobuf_to_vmalloc(&buf->vb);
+ void *vbuf = vb2_plane_vaddr(&buf->vb, 0);
unsigned ms;
char str[100];
int h, line = 1;
@@ -483,11 +481,11 @@ static void vivi_fillbuff(struct vivi_dev *dev, struct vivi_buffer *buf)

dev->mv_count += 2;

- /* Advice that buffer was filled */
- buf->vb.field_count++;
+ buf->vb.v4l2_buf.field = dev->field;
+ dev->field_count++;
+ buf->vb.v4l2_buf.sequence = dev->field_count >> 1;
do_gettimeofday(&ts);
- buf->vb.ts = ts;
- buf->vb.state = VIDEOBUF_DONE;
+ buf->vb.v4l2_buf.timestamp = ts;
}

static void vivi_thread_tick(struct vivi_dev *dev)
@@ -504,23 +502,17 @@ static void vivi_thread_tick(struct vivi_dev *dev)
goto unlock;
}

- buf = list_entry(dma_q->active.next,
- struct vivi_buffer, vb.queue);
-
- /* Nobody is waiting on this buffer, return */
- if (!waitqueue_active(&buf->vb.done))
- goto unlock;
+ buf = list_entry(dma_q->active.next, struct vivi_buffer, list);
+ list_del(&buf->list);

- list_del(&buf->vb.queue);
-
- do_gettimeofday(&buf->vb.ts);
+ do_gettimeofday(&buf->vb.v4l2_buf.timestamp);

/* Fill buffer */
vivi_fillbuff(dev, buf);
dprintk(dev, 1, "filled buffer %p\n", buf);

- wake_up(&buf->vb.done);
- dprintk(dev, 2, "[%p/%d] wakeup\n", buf, buf->vb. i);
+ vb2_buffer_done(&buf->vb, VB2_BUF_STATE_DONE);
+ dprintk(dev, 2, "[%p/%d] done\n", buf, buf->vb.v4l2_buf.index);
unlock:
spin_unlock_irqrestore(&dev->slock, flags);
}
@@ -571,17 +563,12 @@ static int vivi_thread(void *data)
return 0;
}

-static void vivi_start_generating(struct file *file)
+static int vivi_start_generating(struct vivi_dev *dev)
{
- struct vivi_dev *dev = video_drvdata(file);
struct vivi_dmaqueue *dma_q = &dev->vidq;

dprintk(dev, 1, "%s\n", __func__);

- if (test_and_set_bit(0, &dev->generating))
- return;
- file->private_data = dev;
-
/* Resets frame counters */
dev->ms = 0;
dev->mv_count = 0;
@@ -593,146 +580,200 @@ static void vivi_start_generating(struct file *file)

if (IS_ERR(dma_q->kthread)) {
v4l2_err(&dev->v4l2_dev, "kernel_thread() failed\n");
- clear_bit(0, &dev->generating);
- return;
+ return PTR_ERR(dma_q->kthread);
}
/* Wakes thread */
wake_up_interruptible(&dma_q->wq);

dprintk(dev, 1, "returning from %s\n", __func__);
+ return 0;
}

-static void vivi_stop_generating(struct file *file)
+static void vivi_stop_generating(struct vivi_dev *dev)
{
- struct vivi_dev *dev = video_drvdata(file);
struct vivi_dmaqueue *dma_q = &dev->vidq;

dprintk(dev, 1, "%s\n", __func__);

- if (!file->private_data)
- return;
- if (!test_and_clear_bit(0, &dev->generating))
- return;
-
/* shutdown control thread */
if (dma_q->kthread) {
kthread_stop(dma_q->kthread);
dma_q->kthread = NULL;
}
- videobuf_stop(&dev->vb_vidq);
- videobuf_mmap_free(&dev->vb_vidq);
-}

-static int vivi_is_generating(struct vivi_dev *dev)
-{
- return test_bit(0, &dev->generating);
+ /*
+ * Typical driver might need to wait here until dma engine stops.
+ * In this case we can abort imiedetly, so it's just a noop.
+ */
+
+ /* Release all active buffers */
+ while (!list_empty(&dma_q->active)) {
+ struct vivi_buffer *buf;
+ buf = list_entry(dma_q->active.next, struct vivi_buffer, list);
+ list_del(&buf->list);
+ vb2_buffer_done(&buf->vb, VB2_BUF_STATE_ERROR);
+ dprintk(dev, 2, "[%p/%d] done\n", buf, buf->vb.v4l2_buf.index);
+ }
}
-
/* ------------------------------------------------------------------
Videobuf operations
------------------------------------------------------------------*/
-static int
-buffer_setup(struct videobuf_queue *vq, unsigned int *count, unsigned int *size)
+static int queue_setup(struct vb2_queue *vq, unsigned int *nbuffers,
+ unsigned int *nplanes, unsigned long sizes[],
+ void *alloc_ctxs[])
{
- struct vivi_dev *dev = vq->priv_data;
+ struct vivi_dev *dev = vb2_get_drv_priv(vq);
+ unsigned long size;
+
+ size = dev->width * dev->height * 2;

- *size = dev->width * dev->height * 2;
+ if (0 == *nbuffers)
+ *nbuffers = 32;

- if (0 == *count)
- *count = 32;
+ while (size * *nbuffers > vid_limit * 1024 * 1024)
+ (*nbuffers)--;

- while (*size * *count > vid_limit * 1024 * 1024)
- (*count)--;
+ *nplanes = 1;

- dprintk(dev, 1, "%s, count=%d, size=%d\n", __func__,
- *count, *size);
+ sizes[0] = size;
+
+ /*
+ * videobuf2-vmalloc allocator is context-less so no need to set
+ * alloc_ctxs array.
+ */
+
+ dprintk(dev, 1, "%s, count=%d, size=%ld\n", __func__,
+ *nbuffers, size);

return 0;
}

-static void free_buffer(struct videobuf_queue *vq, struct vivi_buffer *buf)
+static int buffer_init(struct vb2_buffer *vb)
{
- struct vivi_dev *dev = vq->priv_data;
+ struct vivi_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
+
+ BUG_ON(NULL == dev->fmt);

- dprintk(dev, 1, "%s, state: %i\n", __func__, buf->vb.state);
+ /*
+ * This callback is called once per buffer, after its allocation.
+ *
+ * Vivi does not allow changing format during streaming, but it is
+ * possible to do so when streaming is paused (i.e. in streamoff state).
+ * Buffers however are not freed when going into streamoff and so
+ * buffer size verification has to be done in buffer_prepare, on each
+ * qbuf.
+ * It would be best to move verification code here to buf_init and
+ * s_fmt though.
+ */

- videobuf_vmalloc_free(&buf->vb);
- dprintk(dev, 1, "free_buffer: freed\n");
- buf->vb.state = VIDEOBUF_NEEDS_INIT;
+ return 0;
}

-static int
-buffer_prepare(struct videobuf_queue *vq, struct videobuf_buffer *vb,
- enum v4l2_field field)
+static int buffer_prepare(struct vb2_buffer *vb)
{
- struct vivi_dev *dev = vq->priv_data;
+ struct vivi_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
struct vivi_buffer *buf = container_of(vb, struct vivi_buffer, vb);
- int rc;
+ unsigned long size;

- dprintk(dev, 1, "%s, field=%d\n", __func__, field);
+ dprintk(dev, 1, "%s, field=%d\n", __func__, vb->v4l2_buf.field);

BUG_ON(NULL == dev->fmt);

+ /*
+ * Theses properties only change when queue is idle, see s_fmt.
+ * The below checks should not be performed here, on each
+ * buffer_prepare (i.e. on each qbuf). Most of the code in this function
+ * should thus be moved to buffer_init and s_fmt.
+ */
if (dev->width < 48 || dev->width > MAX_WIDTH ||
dev->height < 32 || dev->height > MAX_HEIGHT)
return -EINVAL;

- buf->vb.size = dev->width * dev->height * 2;
- if (0 != buf->vb.baddr && buf->vb.bsize < buf->vb.size)
+ size = dev->width * dev->height * 2;
+ if (vb2_plane_size(vb, 0) < size) {
+ dprintk(dev, 1, "%s data will not fit into plane (%lu < %lu)\n",
+ __func__, vb2_plane_size(vb, 0), size);
return -EINVAL;
+ }

- /* These properties only change when queue is idle, see s_fmt */
- buf->fmt = dev->fmt;
- buf->vb.width = dev->width;
- buf->vb.height = dev->height;
- buf->vb.field = field;
+ vb2_set_plane_payload(&buf->vb, 0, size);
+
+ buf->fmt = dev->fmt;

precalculate_bars(dev);
precalculate_line(dev);

- if (VIDEOBUF_NEEDS_INIT == buf->vb.state) {
- rc = videobuf_iolock(vq, &buf->vb, NULL);
- if (rc < 0)
- goto fail;
- }
+ return 0;
+}

- buf->vb.state = VIDEOBUF_PREPARED;
+static int buffer_finish(struct vb2_buffer *vb)
+{
+ struct vivi_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
+ dprintk(dev, 1, "%s\n", __func__);
return 0;
+}
+
+static void buffer_cleanup(struct vb2_buffer *vb)
+{
+ struct vivi_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
+ dprintk(dev, 1, "%s\n", __func__);

-fail:
- free_buffer(vq, buf);
- return rc;
}

-static void
-buffer_queue(struct videobuf_queue *vq, struct videobuf_buffer *vb)
+static void buffer_queue(struct vb2_buffer *vb)
{
- struct vivi_dev *dev = vq->priv_data;
+ struct vivi_dev *dev = vb2_get_drv_priv(vb->vb2_queue);
struct vivi_buffer *buf = container_of(vb, struct vivi_buffer, vb);
struct vivi_dmaqueue *vidq = &dev->vidq;
+ unsigned long flags = 0;

dprintk(dev, 1, "%s\n", __func__);

- buf->vb.state = VIDEOBUF_QUEUED;
- list_add_tail(&buf->vb.queue, &vidq->active);
+ spin_lock_irqsave(&dev->slock, flags);
+ list_add_tail(&buf->list, &vidq->active);
+ spin_unlock_irqrestore(&dev->slock, flags);
}

-static void buffer_release(struct videobuf_queue *vq,
- struct videobuf_buffer *vb)
+static int start_streaming(struct vb2_queue *vq)
{
- struct vivi_dev *dev = vq->priv_data;
- struct vivi_buffer *buf = container_of(vb, struct vivi_buffer, vb);
+ struct vivi_dev *dev = vb2_get_drv_priv(vq);
+ dprintk(dev, 1, "%s\n", __func__);
+ return vivi_start_generating(dev);
+}

+/* abort streaming and wait for last buffer */
+static int stop_streaming(struct vb2_queue *vq)
+{
+ struct vivi_dev *dev = vb2_get_drv_priv(vq);
dprintk(dev, 1, "%s\n", __func__);
+ vivi_stop_generating(dev);
+ return 0;
+}

- free_buffer(vq, buf);
+static void vivi_lock(struct vb2_queue *vq)
+{
+ struct vivi_dev *dev = vb2_get_drv_priv(vq);
+ mutex_lock(&dev->mutex);
}

-static struct videobuf_queue_ops vivi_video_qops = {
- .buf_setup = buffer_setup,
- .buf_prepare = buffer_prepare,
- .buf_queue = buffer_queue,
- .buf_release = buffer_release,
+static void vivi_unlock(struct vb2_queue *vq)
+{
+ struct vivi_dev *dev = vb2_get_drv_priv(vq);
+ mutex_unlock(&dev->mutex);
+}
+
+
+static struct vb2_ops vivi_video_qops = {
+ .queue_setup = queue_setup,
+ .buf_init = buffer_init,
+ .buf_prepare = buffer_prepare,
+ .buf_finish = buffer_finish,
+ .buf_cleanup = buffer_cleanup,
+ .buf_queue = buffer_queue,
+ .start_streaming = start_streaming,
+ .stop_streaming = stop_streaming,
+ .wait_prepare = vivi_unlock,
+ .wait_finish = vivi_lock,
};

/* ------------------------------------------------------------------
@@ -774,7 +815,7 @@ static int vidioc_g_fmt_vid_cap(struct file *file, void *priv,

f->fmt.pix.width = dev->width;
f->fmt.pix.height = dev->height;
- f->fmt.pix.field = dev->vb_vidq.field;
+ f->fmt.pix.field = dev->field;
f->fmt.pix.pixelformat = dev->fmt->fourcc;
f->fmt.pix.bytesperline =
(f->fmt.pix.width * dev->fmt->depth) >> 3;
@@ -820,91 +861,60 @@ static int vidioc_s_fmt_vid_cap(struct file *file, void *priv,
struct v4l2_format *f)
{
struct vivi_dev *dev = video_drvdata(file);
+ struct vb2_queue *q = &dev->vb_vidq;

int ret = vidioc_try_fmt_vid_cap(file, priv, f);
if (ret < 0)
return ret;

- if (vivi_is_generating(dev)) {
+ if (vb2_is_streaming(q)) {
dprintk(dev, 1, "%s device busy\n", __func__);
- ret = -EBUSY;
- goto out;
+ return -EBUSY;
}

dev->fmt = get_format(f);
dev->width = f->fmt.pix.width;
dev->height = f->fmt.pix.height;
- dev->vb_vidq.field = f->fmt.pix.field;
- ret = 0;
-out:
- return ret;
+ dev->field = f->fmt.pix.field;
+
+ return 0;
}

static int vidioc_reqbufs(struct file *file, void *priv,
struct v4l2_requestbuffers *p)
{
struct vivi_dev *dev = video_drvdata(file);
-
- return videobuf_reqbufs(&dev->vb_vidq, p);
+ return vb2_reqbufs(&dev->vb_vidq, p);
}

static int vidioc_querybuf(struct file *file, void *priv, struct v4l2_buffer *p)
{
struct vivi_dev *dev = video_drvdata(file);
-
- return videobuf_querybuf(&dev->vb_vidq, p);
+ return vb2_querybuf(&dev->vb_vidq, p);
}

static int vidioc_qbuf(struct file *file, void *priv, struct v4l2_buffer *p)
{
struct vivi_dev *dev = video_drvdata(file);
-
- return videobuf_qbuf(&dev->vb_vidq, p);
+ return vb2_qbuf(&dev->vb_vidq, p);
}

static int vidioc_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p)
{
struct vivi_dev *dev = video_drvdata(file);
-
- return videobuf_dqbuf(&dev->vb_vidq, p,
- file->f_flags & O_NONBLOCK);
-}
-
-#ifdef CONFIG_VIDEO_V4L1_COMPAT
-static int vidiocgmbuf(struct file *file, void *priv, struct video_mbuf *mbuf)
-{
- struct vivi_dev *dev = video_drvdata(file);
-
- return videobuf_cgmbuf(&dev->vb_vidq, mbuf, 8);
+ return vb2_dqbuf(&dev->vb_vidq, p, file->f_flags & O_NONBLOCK);
}
-#endif

static int vidioc_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
{
struct vivi_dev *dev = video_drvdata(file);
- int ret;
-
- if (i != V4L2_BUF_TYPE_VIDEO_CAPTURE)
- return -EINVAL;
- ret = videobuf_streamon(&dev->vb_vidq);
- if (ret)
- return ret;
-
- vivi_start_generating(file);
- return 0;
+ return vb2_streamon(&dev->vb_vidq, i);
}

static int vidioc_streamoff(struct file *file, void *priv, enum v4l2_buf_type i)
{
struct vivi_dev *dev = video_drvdata(file);
- int ret;
-
- if (i != V4L2_BUF_TYPE_VIDEO_CAPTURE)
- return -EINVAL;
- ret = videobuf_streamoff(&dev->vb_vidq);
- if (!ret)
- vivi_stop_generating(file);
- return ret;
+ return vb2_streamoff(&dev->vb_vidq, i);
}

static int vidioc_s_std(struct file *file, void *priv, v4l2_std_id *i)
@@ -1027,26 +1037,33 @@ static int vidioc_s_ctrl(struct file *file, void *priv,
File operations for the device
------------------------------------------------------------------*/

+static int vivi_open(struct file *file)
+{
+ struct vivi_dev *dev = video_drvdata(file);
+
+ dprintk(dev, 1, "%s, %p\n", __func__, file);
+ dev->open_count++;
+ return 0;
+}
+
static ssize_t
vivi_read(struct file *file, char __user *data, size_t count, loff_t *ppos)
{
struct vivi_dev *dev = video_drvdata(file);

- vivi_start_generating(file);
- return videobuf_read_stream(&dev->vb_vidq, data, count, ppos, 0,
- file->f_flags & O_NONBLOCK);
+ dprintk(dev, 1, "read called\n");
+ return vb2_read(&dev->vb_vidq, data, count, ppos,
+ file->f_flags & O_NONBLOCK);
}

static unsigned int
vivi_poll(struct file *file, struct poll_table_struct *wait)
{
struct vivi_dev *dev = video_drvdata(file);
- struct videobuf_queue *q = &dev->vb_vidq;
+ struct vb2_queue *q = &dev->vb_vidq;

dprintk(dev, 1, "%s\n", __func__);
-
- vivi_start_generating(file);
- return videobuf_poll_stream(file, q, wait);
+ return vb2_poll(q, file, wait);
}

static int vivi_close(struct file *file)
@@ -1054,10 +1071,11 @@ static int vivi_close(struct file *file)
struct video_device *vdev = video_devdata(file);
struct vivi_dev *dev = video_drvdata(file);

- vivi_stop_generating(file);
+ dprintk(dev, 1, "close called (dev=%s), file %p\n",
+ video_device_node_name(vdev), file);

- dprintk(dev, 1, "close called (dev=%s)\n",
- video_device_node_name(vdev));
+ if (--dev->open_count == 0)
+ vb2_queue_release(&dev->vb_vidq);
return 0;
}

@@ -1068,8 +1086,7 @@ static int vivi_mmap(struct file *file, struct vm_area_struct *vma)

dprintk(dev, 1, "mmap called, vma=0x%08lx\n", (unsigned long)vma);

- ret = videobuf_mmap_mapper(&dev->vb_vidq, vma);
-
+ ret = vb2_mmap(&dev->vb_vidq, vma);
dprintk(dev, 1, "vma start=0x%08lx, size=%ld, ret=%d\n",
(unsigned long)vma->vm_start,
(unsigned long)vma->vm_end - (unsigned long)vma->vm_start,
@@ -1079,6 +1096,7 @@ static int vivi_mmap(struct file *file, struct vm_area_struct *vma)

static const struct v4l2_file_operations vivi_fops = {
.owner = THIS_MODULE,
+ .open = vivi_open,
.release = vivi_close,
.read = vivi_read,
.poll = vivi_poll,
@@ -1105,9 +1123,6 @@ static const struct v4l2_ioctl_ops vivi_ioctl_ops = {
.vidioc_queryctrl = vidioc_queryctrl,
.vidioc_g_ctrl = vidioc_g_ctrl,
.vidioc_s_ctrl = vidioc_s_ctrl,
-#ifdef CONFIG_VIDEO_V4L1_COMPAT
- .vidiocgmbuf = vidiocgmbuf,
-#endif
};

static struct video_device vivi_template = {
@@ -1148,6 +1163,7 @@ static int __init vivi_create_instance(int inst)
{
struct vivi_dev *dev;
struct video_device *vfd;
+ struct vb2_queue *q;
int ret;

dev = kzalloc(sizeof(*dev), GFP_KERNEL);
@@ -1171,12 +1187,20 @@ static int __init vivi_create_instance(int inst)

/* initialize locks */
spin_lock_init(&dev->slock);
- mutex_init(&dev->mutex);

- videobuf_queue_vmalloc_init(&dev->vb_vidq, &vivi_video_qops,
- NULL, &dev->slock, V4L2_BUF_TYPE_VIDEO_CAPTURE,
- V4L2_FIELD_INTERLACED,
- sizeof(struct vivi_buffer), dev, &dev->mutex);
+ /* initialize queue */
+ q = &dev->vb_vidq;
+ memset(q, 0, sizeof(dev->vb_vidq));
+ q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
+ q->io_modes = VB2_MMAP | VB2_USERPTR | VB2_READ;
+ q->drv_priv = dev;
+ q->buf_struct_size = sizeof(struct vivi_buffer);
+ q->ops = &vivi_video_qops;
+ q->mem_ops = &vb2_vmalloc_memops;
+
+ vb2_queue_init(q);
+
+ mutex_init(&dev->mutex);

/* init video dma queues */
INIT_LIST_HEAD(&dev->vidq.active);
@@ -1190,6 +1214,11 @@ static int __init vivi_create_instance(int inst)
*vfd = vivi_template;
vfd->debug = debug;
vfd->v4l2_dev = &dev->v4l2_dev;
+
+ /*
+ * Provide a mutex to v4l2 core. It will be used to protect
+ * all fops and v4l2 ioctls.
+ */
vfd->lock = &dev->mutex;

ret = video_register_device(vfd, VFL_TYPE_GRABBER, video_nr);
--
1.7.1.569.g6f426
Marek Szyprowski
2010-12-16 14:23:58 UTC
Permalink
From: Pawel Osciak <***@samsung.com>

Videobuf2 is a Video for Linux 2 API-compatible driver framework for
multimedia devices. It acts as an intermediate layer between userspace
applications and device drivers. It also provides low-level, modular
memory management functions for drivers.

Videobuf2 eases driver development, reduces drivers' code size and aids in
proper and consistent implementation of V4L2 API in drivers.

Videobuf2 memory management backend is fully modular. This allows custom
memory management routines for devices and platforms with non-standard
memory management requirements to be plugged in, without changing the
high-level buffer management functions and API.

The framework provides:
- implementations of streaming I/O V4L2 ioctls and file operations
- high-level video buffer, video queue and state management functions
- video buffer memory allocation and management

Signed-off-by: Pawel Osciak <***@samsung.com>
Signed-off-by: Marek Szyprowski <***@samsung.com>
Signed-off-by: Kyungmin Park <***@samsung.com>
CC: Pawel Osciak <***@osciak.com>
---
drivers/media/video/Kconfig | 3 +
drivers/media/video/Makefile | 2 +
drivers/media/video/videobuf2-core.c | 1407 ++++++++++++++++++++++++++++++++++
include/media/videobuf2-core.h | 368 +++++++++
4 files changed, 1780 insertions(+), 0 deletions(-)
create mode 100644 drivers/media/video/videobuf2-core.c
create mode 100644 include/media/videobuf2-core.h

diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
index 6830d28..4a81a00 100644
--- a/drivers/media/video/Kconfig
+++ b/drivers/media/video/Kconfig
@@ -49,6 +49,9 @@ config V4L2_MEM2MEM_DEV
tristate
depends on VIDEOBUF_GEN

+config VIDEOBUF2_CORE
+ tristate
+
#
# Multimedia Video device configuration
#
diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
index af79d47..77c4f85 100644
--- a/drivers/media/video/Makefile
+++ b/drivers/media/video/Makefile
@@ -114,6 +114,8 @@ obj-$(CONFIG_VIDEOBUF_VMALLOC) += videobuf-vmalloc.o
obj-$(CONFIG_VIDEOBUF_DVB) += videobuf-dvb.o
obj-$(CONFIG_VIDEO_BTCX) += btcx-risc.o

+obj-$(CONFIG_VIDEOBUF2_CORE) += videobuf2-core.o
+
obj-$(CONFIG_V4L2_MEM2MEM_DEV) += v4l2-mem2mem.o

obj-$(CONFIG_VIDEO_M32R_AR_M64278) += arv.o
diff --git a/drivers/media/video/videobuf2-core.c b/drivers/media/video/videobuf2-core.c
new file mode 100644
index 0000000..ae1c817
--- /dev/null
+++ b/drivers/media/video/videobuf2-core.c
@@ -0,0 +1,1407 @@
+/*
+ * videobuf2-core.c - V4L2 driver helper framework
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ *
+ * Author: Pawel Osciak <***@samsung.com>
+ * Marek Szyprowski <***@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.
+ */
+
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/poll.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+
+#include <media/videobuf2-core.h>
+
+static int debug;
+module_param(debug, int, 0644);
+
+#define dprintk(level, fmt, arg...) \
+ do { \
+ if (debug >= level) \
+ printk(KERN_DEBUG "vb2: " fmt, ## arg); \
+ } while (0)
+
+#define call_memop(q, plane, op, args...) \
+ (((q)->mem_ops->op) ? \
+ ((q)->mem_ops->op(args)) : 0)
+
+#define call_qop(q, op, args...) \
+ (((q)->ops->op) ? ((q)->ops->op(args)) : 0)
+
+/**
+ * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
+ */
+static int __vb2_buf_mem_alloc(struct vb2_buffer *vb,
+ unsigned long *plane_sizes)
+{
+ struct vb2_queue *q = vb->vb2_queue;
+ void *mem_priv;
+ int plane;
+
+ /* Allocate memory for all planes in this buffer */
+ for (plane = 0; plane < vb->num_planes; ++plane) {
+ mem_priv = call_memop(q, plane, alloc, q->alloc_ctx[plane],
+ plane_sizes[plane]);
+ if (!mem_priv)
+ goto free;
+
+ /* Associate allocator private data with this plane */
+ vb->planes[plane].mem_priv = mem_priv;
+ vb->v4l2_planes[plane].length = plane_sizes[plane];
+ }
+
+ return 0;
+free:
+ /* Free already allocated memory if one of the allocations failed */
+ for (; plane > 0; --plane)
+ call_memop(q, plane, put, vb->planes[plane - 1].mem_priv);
+
+ return -ENOMEM;
+}
+
+/**
+ * __vb2_buf_mem_free() - free memory of the given buffer
+ */
+static void __vb2_buf_mem_free(struct vb2_buffer *vb)
+{
+ struct vb2_queue *q = vb->vb2_queue;
+ unsigned int plane;
+
+ for (plane = 0; plane < vb->num_planes; ++plane) {
+ call_memop(q, plane, put, vb->planes[plane].mem_priv);
+ vb->planes[plane].mem_priv = NULL;
+ dprintk(3, "Freed plane %d of buffer %d\n",
+ plane, vb->v4l2_buf.index);
+ }
+}
+
+/**
+ * __vb2_buf_userptr_put() - release userspace memory associated associated
+ * with a USERPTR buffer
+ */
+static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
+{
+ struct vb2_queue *q = vb->vb2_queue;
+ unsigned int plane;
+
+ for (plane = 0; plane < vb->num_planes; ++plane) {
+ void *mem_priv = vb->planes[plane].mem_priv;
+
+ if (mem_priv) {
+ call_memop(q, plane, put_userptr, mem_priv);
+ vb->planes[plane].mem_priv = NULL;
+ }
+ }
+}
+
+/**
+ * __setup_offsets() - setup unique offsets ("cookies") for every plane in
+ * every buffer on the queue
+ */
+static void __setup_offsets(struct vb2_queue *q)
+{
+ unsigned int buffer, plane;
+ struct vb2_buffer *vb;
+ unsigned long off = 0;
+
+ for (buffer = 0; buffer < q->num_buffers; ++buffer) {
+ vb = q->bufs[buffer];
+ if (!vb)
+ continue;
+
+ for (plane = 0; plane < vb->num_planes; ++plane) {
+ vb->v4l2_planes[plane].m.mem_offset = off;
+
+ dprintk(3, "Buffer %d, plane %d offset 0x%08lx\n",
+ buffer, plane, off);
+
+ off += vb->v4l2_planes[plane].length;
+ off = PAGE_ALIGN(off);
+ }
+ }
+}
+
+/**
+ * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
+ * video buffer memory for all buffers/planes on the queue and initializes the
+ * queue
+ *
+ * Returns the number of buffers successfully allocated.
+ */
+static int __vb2_queue_alloc(struct vb2_queue *q, enum v4l2_memory memory,
+ unsigned int num_buffers, unsigned int num_planes,
+ unsigned long plane_sizes[])
+{
+ unsigned int buffer;
+ struct vb2_buffer *vb;
+ int ret;
+
+ for (buffer = 0; buffer < num_buffers; ++buffer) {
+ /* Allocate videobuf buffer structures */
+ vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
+ if (!vb) {
+ dprintk(1, "Memory alloc for buffer struct failed\n");
+ break;
+ }
+
+ /* Length stores number of planes for multiplanar buffers */
+ if (V4L2_TYPE_IS_MULTIPLANAR(q->type))
+ vb->v4l2_buf.length = num_planes;
+
+ vb->state = VB2_BUF_STATE_DEQUEUED;
+ vb->vb2_queue = q;
+ vb->num_planes = num_planes;
+ vb->v4l2_buf.index = buffer;
+ vb->v4l2_buf.type = q->type;
+ vb->v4l2_buf.memory = memory;
+
+ /* Allocate video buffer memory for the MMAP type */
+ if (memory == V4L2_MEMORY_MMAP) {
+ ret = __vb2_buf_mem_alloc(vb, plane_sizes);
+ if (ret) {
+ dprintk(1, "Failed allocating memory for "
+ "buffer %d\n", buffer);
+ kfree(vb);
+ break;
+ }
+ /*
+ * Call the driver-provided buffer initialization
+ * callback, if given. An error in initialization
+ * results in queue setup failure.
+ */
+ ret = call_qop(q, buf_init, vb);
+ if (ret) {
+ dprintk(1, "Buffer %d %p initialization"
+ " failed\n", buffer, vb);
+ __vb2_buf_mem_free(vb);
+ kfree(vb);
+ break;
+ }
+ }
+
+ q->bufs[buffer] = vb;
+ }
+
+ q->num_buffers = buffer;
+
+ __setup_offsets(q);
+
+ dprintk(1, "Allocated %d buffers, %d plane(s) each\n",
+ q->num_buffers, num_planes);
+
+ return buffer;
+}
+
+/**
+ * __vb2_free_mem() - release all video buffer memory for a given queue
+ */
+static void __vb2_free_mem(struct vb2_queue *q)
+{
+ unsigned int buffer;
+ struct vb2_buffer *vb;
+
+ for (buffer = 0; buffer < q->num_buffers; ++buffer) {
+ vb = q->bufs[buffer];
+ if (!vb)
+ continue;
+
+ /* Free MMAP buffers or release USERPTR buffers */
+ if (q->memory == V4L2_MEMORY_MMAP)
+ __vb2_buf_mem_free(vb);
+ else
+ __vb2_buf_userptr_put(vb);
+ }
+}
+
+/**
+ * __vb2_queue_free() - free the queue - video memory and related information
+ * and return the queue to an uninitialized state. Might be called even if the
+ * queue has been already freed.
+ */
+static int __vb2_queue_free(struct vb2_queue *q)
+{
+ unsigned int buffer;
+
+ /* Call driver-provided cleanup function for each buffer, if provided */
+ if (q->ops->buf_cleanup) {
+ for (buffer = 0; buffer < q->num_buffers; ++buffer) {
+ if (NULL == q->bufs[buffer])
+ continue;
+ q->ops->buf_cleanup(q->bufs[buffer]);
+ }
+ }
+
+ /* Release video buffer memory */
+ __vb2_free_mem(q);
+
+ /* Free videobuf buffers */
+ for (buffer = 0; buffer < q->num_buffers; ++buffer) {
+ kfree(q->bufs[buffer]);
+ q->bufs[buffer] = NULL;
+ }
+
+ q->num_buffers = 0;
+ q->memory = 0;
+
+ return 0;
+}
+
+/**
+ * __verify_planes_array() - verify that the planes array passed in struct
+ * v4l2_buffer from userspace can be safely used
+ */
+static int __verify_planes_array(struct vb2_buffer *vb, struct v4l2_buffer *b)
+{
+ /* Is memory for copying plane information present? */
+ if (NULL == b->m.planes) {
+ dprintk(1, "Multi-planar buffer passed but "
+ "planes array not provided\n");
+ return -EINVAL;
+ }
+
+ if (b->length < vb->num_planes || b->length > VIDEO_MAX_PLANES) {
+ dprintk(1, "Incorrect planes array length, "
+ "expected %d, got %d\n", vb->num_planes, b->length);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/**
+ * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be
+ * returned to userspace
+ */
+static int __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
+{
+ struct vb2_queue *q = vb->vb2_queue;
+ int ret = 0;
+
+ /* Copy back data such as timestamp, input, etc. */
+ memcpy(b, &vb->v4l2_buf, offsetof(struct v4l2_buffer, m));
+ b->input = vb->v4l2_buf.input;
+ b->reserved = vb->v4l2_buf.reserved;
+
+ if (V4L2_TYPE_IS_MULTIPLANAR(q->type)) {
+ ret = __verify_planes_array(vb, b);
+ if (ret)
+ return ret;
+
+ /*
+ * Fill in plane-related data if userspace provided an array
+ * for it. The memory and size is verified above.
+ */
+ memcpy(b->m.planes, vb->v4l2_planes,
+ b->length * sizeof(struct v4l2_plane));
+ } else {
+ /*
+ * We use length and offset in v4l2_planes array even for
+ * single-planar buffers, but userspace does not.
+ */
+ b->length = vb->v4l2_planes[0].length;
+ b->bytesused = vb->v4l2_planes[0].bytesused;
+ if (q->memory == V4L2_MEMORY_MMAP)
+ b->m.offset = vb->v4l2_planes[0].m.mem_offset;
+ else if (q->memory == V4L2_MEMORY_USERPTR)
+ b->m.userptr = vb->v4l2_planes[0].m.userptr;
+ }
+
+ b->flags = 0;
+
+ switch (vb->state) {
+ case VB2_BUF_STATE_QUEUED:
+ case VB2_BUF_STATE_ACTIVE:
+ b->flags |= V4L2_BUF_FLAG_QUEUED;
+ break;
+ case VB2_BUF_STATE_ERROR:
+ b->flags |= V4L2_BUF_FLAG_ERROR;
+ /* fall through */
+ case VB2_BUF_STATE_DONE:
+ b->flags |= V4L2_BUF_FLAG_DONE;
+ break;
+ case VB2_BUF_STATE_DEQUEUED:
+ /* nothing */
+ break;
+ }
+
+ if (vb->num_planes_mapped == vb->num_planes)
+ b->flags |= V4L2_BUF_FLAG_MAPPED;
+
+ return ret;
+}
+
+/**
+ * vb2_querybuf() - query video buffer information
+ * @q: videobuf queue
+ * @b: buffer struct passed from userspace to vidioc_querybuf handler
+ * in driver
+ *
+ * Should be called from vidioc_querybuf ioctl handler in driver.
+ * This function will verify the passed v4l2_buffer structure and fill the
+ * relevant information for the userspace.
+ *
+ * The return values from this function are intended to be directly returned
+ * from vidioc_querybuf handler in driver.
+ */
+int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)
+{
+ struct vb2_buffer *vb;
+
+ if (b->type != q->type) {
+ dprintk(1, "querybuf: wrong buffer type\n");
+ return -EINVAL;
+ }
+
+ if (b->index >= q->num_buffers) {
+ dprintk(1, "querybuf: buffer index out of range\n");
+ return -EINVAL;
+ }
+ vb = q->bufs[b->index];
+
+ return __fill_v4l2_buffer(vb, b);
+}
+EXPORT_SYMBOL(vb2_querybuf);
+
+/**
+ * __verify_userptr_ops() - verify that all memory operations required for
+ * USERPTR queue type have been provided
+ */
+static int __verify_userptr_ops(struct vb2_queue *q)
+{
+ if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
+ !q->mem_ops->put_userptr)
+ return -EINVAL;
+
+ return 0;
+}
+
+/**
+ * __verify_mmap_ops() - verify that all memory operations required for
+ * MMAP queue type have been provided
+ */
+static int __verify_mmap_ops(struct vb2_queue *q)
+{
+ if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
+ !q->mem_ops->put || !q->mem_ops->mmap)
+ return -EINVAL;
+
+ return 0;
+}
+
+/**
+ * __buffers_in_use() - return true if any buffers on the queue are in use and
+ * the queue cannot be freed (by the means of REQBUFS(0)) call
+ */
+static bool __buffers_in_use(struct vb2_queue *q)
+{
+ unsigned int buffer, plane;
+ struct vb2_buffer *vb;
+
+ for (buffer = 0; buffer < q->num_buffers; ++buffer) {
+ vb = q->bufs[buffer];
+ for (plane = 0; plane < vb->num_planes; ++plane) {
+ /*
+ * If num_users() has not been provided, call_memop will
+ * return 0, apparently nobody cares of this case anyway.
+ * If num_users() returns more than 1, we are not the
+ * only user of the plane's memory.
+ */
+ if (call_memop(q, plane, num_users,
+ vb->planes[plane].mem_priv) > 1)
+ return true;
+ }
+ }
+
+ return false;
+}
+
+/**
+ * vb2_reqbufs() - Initiate streaming
+ * @q: videobuf2 queue
+ * @req: struct passed from userspace to vidioc_reqbufs handler in driver
+ *
+ * Should be called from vidioc_reqbufs ioctl handler of a driver.
+ * This function:
+ * 1) verifies streaming parameters passed from the userspace,
+ * 2) sets up the queue,
+ * 3) negotiates number of buffers and planes per buffer with the driver
+ * to be used during streaming,
+ * 4) allocates internal buffer structures (struct vb2_buffer), according to
+ * the agreed parameters,
+ * 5) for MMAP memory type, allocates actual video memory, using the
+ * memory handling/allocation routines provided during queue initialization
+ *
+ * If req->count is 0, all the memory will be freed instead.
+ * If the queue has been allocated previously (by a previous vb2_reqbufs) call
+ * and the queue is not busy, memory will be reallocated.
+ *
+ * The return values from this function are intended to be directly returned
+ * from vidioc_reqbufs handler in driver.
+ */
+int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
+{
+ unsigned int num_buffers, num_planes;
+ unsigned long plane_sizes[VIDEO_MAX_PLANES];
+ int ret = 0;
+
+ if (req->memory != V4L2_MEMORY_MMAP
+ && req->memory != V4L2_MEMORY_USERPTR) {
+ dprintk(1, "reqbufs: unsupported memory type\n");
+ return -EINVAL;
+ }
+
+ if (req->type != q->type) {
+ dprintk(1, "reqbufs: requested type is incorrect\n");
+ return -EINVAL;
+ }
+
+ if (q->streaming) {
+ dprintk(1, "reqbufs: streaming active\n");
+ return -EBUSY;
+ }
+
+ /*
+ * Make sure all the required memory ops for given memory type
+ * are available.
+ */
+ if (req->memory == V4L2_MEMORY_MMAP && __verify_mmap_ops(q)) {
+ dprintk(1, "reqbufs: MMAP for current setup unsupported\n");
+ return -EINVAL;
+ }
+
+ if (req->memory == V4L2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
+ dprintk(1, "reqbufs: USERPTR for current setup unsupported\n");
+ return -EINVAL;
+ }
+
+ if (req->count == 0 || q->num_buffers != 0) {
+ /*
+ * We already have buffers allocated, so first check if they
+ * are not in use and can be freed.
+ */
+ if (q->memory == V4L2_MEMORY_MMAP && __buffers_in_use(q)) {
+ dprintk(1, "reqbufs: memory in use, cannot free\n");
+ return -EBUSY;
+ }
+
+ ret = __vb2_queue_free(q);
+ if (ret != 0)
+ return ret;
+ }
+
+ /*
+ * Make sure the requested values and current defaults are sane.
+ */
+ num_buffers = min_t(unsigned int, req->count, VIDEO_MAX_FRAME);
+ memset(plane_sizes, 0, sizeof(plane_sizes));
+ memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
+
+ /*
+ * Ask the driver how many buffers and planes per buffer it requires.
+ * Driver also sets the size and allocator context for each plane.
+ */
+ ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes,
+ plane_sizes, q->alloc_ctx);
+ if (ret)
+ return ret;
+
+ /* Finally, allocate buffers and video memory */
+ ret = __vb2_queue_alloc(q, req->memory, num_buffers, num_planes,
+ plane_sizes);
+ if (ret < 0) {
+ dprintk(1, "Memory allocation failed with error: %d\n", ret);
+ return ret;
+ }
+
+ /*
+ * Check if driver can handle the allocated number of buffers.
+ */
+ if (ret < num_buffers) {
+ unsigned int num_buffers2;
+
+ num_buffers = num_buffers2 = ret;
+ ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes,
+ plane_sizes, q->alloc_ctx);
+ if (ret)
+ goto free_mem;
+
+ if (num_buffers2 < num_buffers) {
+ ret = -ENOMEM;
+ goto free_mem;
+ }
+
+ /*
+ * Ok, driver accepted smaller number of buffers.
+ */
+ ret = num_buffers;
+ }
+
+ q->memory = req->memory;
+
+ /*
+ * Return the number of successfully allocated buffers
+ * to the userspace.
+ */
+ req->count = ret;
+
+ return 0;
+
+free_mem:
+ __vb2_queue_free(q);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(vb2_reqbufs);
+
+/**
+ * vb2_plane_vaddr() - Return a kernel virtual address of a given plane
+ * @vb: vb2_buffer to which the plane in question belongs to
+ * @plane_no: plane number for which the address is to be returned
+ *
+ * This function returns a kernel virtual address of a given plane if
+ * such a mapping exist, NULL otherwise.
+ */
+void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
+{
+ struct vb2_queue *q = vb->vb2_queue;
+
+ if (plane_no > vb->num_planes)
+ return NULL;
+
+ return call_memop(q, plane_no, vaddr, vb->planes[plane_no].mem_priv);
+
+}
+EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
+
+/**
+ * vb2_plane_cookie() - Return allocator specific cookie for the given plane
+ * @vb: vb2_buffer to which the plane in question belongs to
+ * @plane_no: plane number for which the address is to be returned
+ *
+ * This function returns an allocator specific cookie for a given plane if
+ * available, NULL otherwise. The allocator should provide some simple static
+ * inline function which converts this cookie to the allocator specific type
+ * that can be used directly by the driver to access the buffer. This can be
+ * for example physical address, pointer to scatter list or iommu mapping.
+ */
+void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
+{
+ struct vb2_queue *q = vb->vb2_queue;
+
+ if (plane_no > vb->num_planes)
+ return NULL;
+
+ return call_memop(q, plane_no, cookie, vb->planes[plane_no].mem_priv);
+}
+EXPORT_SYMBOL_GPL(vb2_plane_cookie);
+
+/**
+ * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished
+ * @vb: vb2_buffer returned from the driver
+ * @state: either VB2_BUF_STATE_DONE if the operation finished successfully
+ * or VB2_BUF_STATE_ERROR if the operation finished with an error
+ *
+ * This function should be called by the driver after a hardware operation on
+ * a buffer is finished and the buffer may be returned to userspace. The driver
+ * cannot use this buffer anymore until it is queued back to it by videobuf
+ * by the means of buf_queue callback. Only buffers previously queued to the
+ * driver by buf_queue can be passed to this function.
+ */
+void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
+{
+ struct vb2_queue *q = vb->vb2_queue;
+ unsigned long flags;
+
+ if (vb->state != VB2_BUF_STATE_ACTIVE)
+ return;
+
+ if (state != VB2_BUF_STATE_DONE && state != VB2_BUF_STATE_ERROR)
+ return;
+
+ dprintk(4, "Done processing on buffer %d, state: %d\n",
+ vb->v4l2_buf.index, vb->state);
+
+ /* Add the buffer to the done buffers list */
+ spin_lock_irqsave(&q->done_lock, flags);
+ vb->state = state;
+ list_add_tail(&vb->done_entry, &q->done_list);
+ atomic_dec(&q->queued_count);
+ spin_unlock_irqrestore(&q->done_lock, flags);
+
+ /* Inform any processes that may be waiting for buffers */
+ wake_up(&q->done_wq);
+}
+EXPORT_SYMBOL_GPL(vb2_buffer_done);
+
+/**
+ * __fill_vb2_buffer() - fill a vb2_buffer with information provided in
+ * a v4l2_buffer by the userspace
+ */
+static int __fill_vb2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b,
+ struct v4l2_plane *v4l2_planes)
+{
+ unsigned int plane;
+ int ret;
+
+ if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
+ /*
+ * Verify that the userspace gave us a valid array for
+ * plane information.
+ */
+ ret = __verify_planes_array(vb, b);
+ if (ret)
+ return ret;
+
+ /* Fill in driver-provided information for OUTPUT types */
+ if (V4L2_TYPE_IS_OUTPUT(b->type)) {
+ /*
+ * Will have to go up to b->length when API starts
+ * accepting variable number of planes.
+ */
+ for (plane = 0; plane < vb->num_planes; ++plane) {
+ v4l2_planes[plane].bytesused =
+ b->m.planes[plane].bytesused;
+ v4l2_planes[plane].data_offset =
+ b->m.planes[plane].data_offset;
+ }
+ }
+
+ if (b->memory == V4L2_MEMORY_USERPTR) {
+ for (plane = 0; plane < vb->num_planes; ++plane) {
+ v4l2_planes[plane].m.userptr =
+ b->m.planes[plane].m.userptr;
+ v4l2_planes[plane].length =
+ b->m.planes[plane].length;
+ }
+ }
+ } else {
+ /*
+ * Single-planar buffers do not use planes array,
+ * so fill in relevant v4l2_buffer struct fields instead.
+ * In videobuf we use our internal V4l2_planes struct for
+ * single-planar buffers as well, for simplicity.
+ */
+ if (V4L2_TYPE_IS_OUTPUT(b->type))
+ v4l2_planes[0].bytesused = b->bytesused;
+
+ if (b->memory == V4L2_MEMORY_USERPTR) {
+ v4l2_planes[0].m.userptr = b->m.userptr;
+ v4l2_planes[0].length = b->length;
+ }
+ }
+
+ vb->v4l2_buf.field = b->field;
+ vb->v4l2_buf.timestamp = b->timestamp;
+
+ return 0;
+}
+
+/**
+ * __qbuf_userptr() - handle qbuf of a USERPTR buffer
+ */
+static int __qbuf_userptr(struct vb2_buffer *vb, struct v4l2_buffer *b)
+{
+ struct v4l2_plane planes[VIDEO_MAX_PLANES];
+ struct vb2_queue *q = vb->vb2_queue;
+ void *mem_priv;
+ unsigned int plane;
+ int ret;
+ int write = !V4L2_TYPE_IS_OUTPUT(q->type);
+
+ /* Verify and copy relevant information provided by the userspace */
+ ret = __fill_vb2_buffer(vb, b, planes);
+ if (ret)
+ return ret;
+
+ for (plane = 0; plane < vb->num_planes; ++plane) {
+ /* Skip the plane if already verified */
+ if (vb->v4l2_planes[plane].m.userptr == planes[plane].m.userptr
+ && vb->v4l2_planes[plane].length == planes[plane].length)
+ continue;
+
+ dprintk(3, "qbuf: userspace address for plane %d changed, "
+ "reacquiring memory\n", plane);
+
+ /* Release previously acquired memory if present */
+ if (vb->planes[plane].mem_priv)
+ call_memop(q, plane, put_userptr,
+ vb->planes[plane].mem_priv);
+
+ vb->planes[plane].mem_priv = NULL;
+
+ /* Acquire each plane's memory */
+ if (q->mem_ops->get_userptr) {
+ mem_priv = q->mem_ops->get_userptr(q->alloc_ctx[plane],
+ planes[plane].m.userptr,
+ planes[plane].length,
+ write);
+ if (IS_ERR(mem_priv)) {
+ dprintk(1, "qbuf: failed acquiring userspace "
+ "memory for plane %d\n", plane);
+ ret = PTR_ERR(mem_priv);
+ goto err;
+ }
+ vb->planes[plane].mem_priv = mem_priv;
+ }
+ }
+
+ /*
+ * Call driver-specific initialization on the newly acquired buffer,
+ * if provided.
+ */
+ ret = call_qop(q, buf_init, vb);
+ if (ret) {
+ dprintk(1, "qbuf: buffer initialization failed\n");
+ goto err;
+ }
+
+ /*
+ * Now that everything is in order, copy relevant information
+ * provided by userspace.
+ */
+ for (plane = 0; plane < vb->num_planes; ++plane)
+ vb->v4l2_planes[plane] = planes[plane];
+
+ return 0;
+err:
+ /* In case of errors, release planes that were already acquired */
+ for (; plane > 0; --plane) {
+ call_memop(q, plane, put_userptr,
+ vb->planes[plane - 1].mem_priv);
+ vb->planes[plane - 1].mem_priv = NULL;
+ }
+
+ return ret;
+}
+
+/**
+ * __qbuf_mmap() - handle qbuf of an MMAP buffer
+ */
+static int __qbuf_mmap(struct vb2_buffer *vb, struct v4l2_buffer *b)
+{
+ return __fill_vb2_buffer(vb, b, vb->v4l2_planes);
+}
+
+/**
+ * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
+ */
+static void __enqueue_in_driver(struct vb2_buffer *vb)
+{
+ struct vb2_queue *q = vb->vb2_queue;
+
+ vb->state = VB2_BUF_STATE_ACTIVE;
+ atomic_inc(&q->queued_count);
+ q->ops->buf_queue(vb);
+}
+
+/**
+ * vb2_qbuf() - Queue a buffer from userspace
+ * @q: videobuf2 queue
+ * @b: buffer structure passed from userspace to vidioc_qbuf handler
+ * in driver
+ *
+ * Should be called from vidioc_qbuf ioctl handler of a driver.
+ * This function:
+ * 1) verifies the passed buffer,
+ * 2) calls buf_prepare callback in the driver (if provided), in which
+ * driver-specific buffer initialization can be performed,
+ * 3) if streaming is on, queues the buffer in driver by the means of buf_queue
+ * callback for processing.
+ *
+ * The return values from this function are intended to be directly returned
+ * from vidioc_qbuf handler in driver.
+ */
+int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
+{
+ struct vb2_buffer *vb;
+ int ret = 0;
+
+ if (b->type != q->type) {
+ dprintk(1, "qbuf: invalid buffer type\n");
+ return -EINVAL;
+ }
+
+ if (b->index >= q->num_buffers) {
+ dprintk(1, "qbuf: buffer index out of range\n");
+ return -EINVAL;
+ }
+
+ vb = q->bufs[b->index];
+ if (NULL == vb) {
+ /* Should never happen */
+ dprintk(1, "qbuf: buffer is NULL\n");
+ return -EINVAL;
+ }
+
+ if (b->memory != q->memory) {
+ dprintk(1, "qbuf: invalid memory type\n");
+ return -EINVAL;
+ }
+
+ if (vb->state != VB2_BUF_STATE_DEQUEUED) {
+ dprintk(1, "qbuf: buffer already in use\n");
+ return -EINVAL;
+ }
+
+ if (q->memory == V4L2_MEMORY_MMAP)
+ ret = __qbuf_mmap(vb, b);
+ else if (q->memory == V4L2_MEMORY_USERPTR)
+ ret = __qbuf_userptr(vb, b);
+ else {
+ WARN(1, "Invalid queue type\n");
+ return -EINVAL;
+ }
+
+ if (ret)
+ return ret;
+
+ ret = call_qop(q, buf_prepare, vb);
+ if (ret) {
+ dprintk(1, "qbuf: buffer preparation failed\n");
+ return ret;
+ }
+
+ /*
+ * Add to the queued buffers list, a buffer will stay on it until
+ * dequeued in dqbuf.
+ */
+ list_add_tail(&vb->queued_entry, &q->queued_list);
+ vb->state = VB2_BUF_STATE_QUEUED;
+
+ /*
+ * If already streaming, give the buffer to driver for processing.
+ * If not, the buffer will be given to driver on next streamon.
+ */
+ if (q->streaming)
+ __enqueue_in_driver(vb);
+
+ dprintk(1, "qbuf of buffer %d succeeded\n", vb->v4l2_buf.index);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_qbuf);
+
+/**
+ * __vb2_wait_for_done_vb() - wait for a buffer to become available
+ * for dequeuing
+ *
+ * Will sleep if required for nonblocking == false.
+ */
+static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
+{
+ /*
+ * All operation on vb_done_list is performed under vb_done_lock
+ * spinlock protection. However buffers may must be removed from
+ * it and returned to userspace only while holding both driver's
+ * lock and the vb_done_lock spinlock. Thus we can be sure that as
+ * long as we hold lock, the list will remain not empty if this
+ * check succeeds.
+ */
+
+ for (;;) {
+ int ret;
+
+ if (!q->streaming) {
+ dprintk(1, "Streaming off, will not wait for buffers\n");
+ return -EINVAL;
+ }
+
+ if (!list_empty(&q->done_list)) {
+ /*
+ * Found a buffer that we were waiting for.
+ */
+ break;
+ }
+
+ if (nonblocking) {
+ dprintk(1, "Nonblocking and no buffers to dequeue, "
+ "will not wait\n");
+ return -EAGAIN;
+ }
+
+ /*
+ * We are streaming and blocking, wait for another buffer to
+ * become ready or for streamoff. Driver's lock is released to
+ * allow streamoff or qbuf to be called while waiting.
+ */
+ call_qop(q, wait_prepare, q);
+
+ /*
+ * All locks has been released, it is safe to sleep now.
+ */
+ dprintk(3, "Will sleep waiting for buffers\n");
+ ret = wait_event_interruptible(q->done_wq,
+ !list_empty(&q->done_list) || !q->streaming);
+
+ /*
+ * We need to reevaluate both conditions again after reacquiring
+ * the locks or return an error if it occured. In case of error
+ * we return -EINTR, because -ERESTARTSYS should not be returned
+ * to userspace.
+ */
+ call_qop(q, wait_finish, q);
+ if (ret)
+ return -ERESTARTSYS;
+ }
+ return 0;
+}
+
+/**
+ * __vb2_get_done_vb() - get a buffer ready for dequeuing
+ *
+ * Will sleep if required for nonblocking == false.
+ */
+static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
+ int nonblocking)
+{
+ unsigned long flags;
+ int ret;
+
+ /*
+ * Wait for at least one buffer to become available on the done_list.
+ */
+ ret = __vb2_wait_for_done_vb(q, nonblocking);
+ if (ret)
+ return ret;
+
+ /*
+ * Drivers lock has been held since we last verified that done_list is
+ * not empty, so no need for another list_empty(done_list) check.
+ */
+ spin_lock_irqsave(&q->done_lock, flags);
+ *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
+ list_del(&(*vb)->done_entry);
+ spin_unlock_irqrestore(&q->done_lock, flags);
+
+ return 0;
+}
+
+/**
+ * vb2_wait_for_all_buffers() - wait until all buffers will be given back to vb2
+ * @q: videobuf2 queue
+ *
+ * This function will wait until all buffers that have been given to the driver
+ * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call
+ * wait_prepare, wait_finish pair. It is intended to call it with all locks
+ * taken, from stop_steaming() callback.
+ */
+int vb2_wait_for_all_buffers(struct vb2_queue *q)
+{
+ if (!q->streaming) {
+ dprintk(1, "Streaming off, will not wait for buffers\n");
+ return -EINVAL;
+ }
+
+ wait_event(q->done_wq, !atomic_read(&q->queued_count));
+ return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
+
+/**
+ * vb2_dqbuf() - Dequeue a buffer to the userspace
+ * @q: videobuf2 queue
+ * @b: buffer structure passed from userspace to vidioc_dqbuf handler
+ * in driver
+ * @nonblocking: if true, this call will not sleep waiting for a buffer if no
+ * buffers ready for dequeuing are present. Normally the driver
+ * would be passing (file->f_flags & O_NONBLOCK) here
+ *
+ * Should be called from vidioc_dqbuf ioctl handler of a driver.
+ * This function:
+ * 1) verifies the passed buffer,
+ * 2) calls buf_finish callback in the driver (if provided), in which
+ * driver can perform any additional operations that may be required before
+ * returning the buffer to userspace, such as cache sync,
+ * 3) the buffer struct members are filled with relevant information for
+ * the userspace.
+ *
+ * The return values from this function are intended to be directly returned
+ * from vidioc_dqbuf handler in driver.
+ */
+int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
+{
+ struct vb2_buffer *vb = NULL;
+ int ret;
+
+ if (b->type != q->type) {
+ dprintk(1, "dqbuf: invalid buffer type\n");
+ return -EINVAL;
+ }
+
+ ret = __vb2_get_done_vb(q, &vb, nonblocking);
+ if (ret < 0) {
+ dprintk(1, "dqbuf: error getting next done buffer\n");
+ return ret;
+ }
+
+ ret = call_qop(q, buf_finish, vb);
+ if (ret) {
+ dprintk(1, "dqbuf: buffer finish failed\n");
+ return ret;
+ }
+
+ switch (vb->state) {
+ case VB2_BUF_STATE_DONE:
+ dprintk(3, "dqbuf: Returning done buffer\n");
+ break;
+ case VB2_BUF_STATE_ERROR:
+ dprintk(3, "dqbuf: Returning done buffer with errors\n");
+ break;
+ default:
+ dprintk(1, "dqbuf: Invalid buffer state\n");
+ return -EINVAL;
+ }
+
+ /* Fill buffer information for the userspace */
+ __fill_v4l2_buffer(vb, b);
+ /* Remove from videobuf queue */
+ list_del(&vb->queued_entry);
+
+ dprintk(1, "dqbuf of buffer %d, with state %d\n",
+ vb->v4l2_buf.index, vb->state);
+
+ vb->state = VB2_BUF_STATE_DEQUEUED;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_dqbuf);
+
+/**
+ * vb2_streamon - start streaming
+ * @q: videobuf2 queue
+ * @type: type argument passed from userspace to vidioc_streamon handler
+ *
+ * Should be called from vidioc_streamon handler of a driver.
+ * This function:
+ * 1) verifies current state
+ * 2) starts streaming and passes any previously queued buffers to the driver
+ *
+ * The return values from this function are intended to be directly returned
+ * from vidioc_streamon handler in the driver.
+ */
+int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
+{
+ struct vb2_buffer *vb;
+
+ if (type != q->type) {
+ dprintk(1, "streamon: invalid stream type\n");
+ return -EINVAL;
+ }
+
+ if (q->streaming) {
+ dprintk(1, "streamon: already streaming\n");
+ return -EBUSY;
+ }
+
+ /*
+ * Cannot start streaming on an OUTPUT device if no buffers have
+ * been queued yet.
+ */
+ if (V4L2_TYPE_IS_OUTPUT(q->type)) {
+ if (list_empty(&q->queued_list)) {
+ dprintk(1, "streamon: no output buffers queued\n");
+ return -EINVAL;
+ }
+ }
+
+ q->streaming = 1;
+
+ /*
+ * Let driver notice that streaming state has been enabled.
+ */
+ call_qop(q, start_streaming, q);
+
+ /*
+ * If any buffers were queued before streamon,
+ * we can now pass them to driver for processing.
+ */
+ list_for_each_entry(vb, &q->queued_list, queued_entry)
+ __enqueue_in_driver(vb);
+
+ dprintk(3, "Streamon successful\n");
+ return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_streamon);
+
+/**
+ * __vb2_queue_cancel() - cancel and stop (pause) streaming
+ *
+ * Removes all queued buffers from driver's queue and all buffers queued by
+ * userspace from videobuf's queue. Returns to state after reqbufs.
+ */
+static void __vb2_queue_cancel(struct vb2_queue *q)
+{
+ unsigned int i;
+
+ /*
+ * Tell driver to stop all transactions and release all queued
+ * buffers.
+ */
+ if (q->streaming)
+ call_qop(q, stop_streaming, q);
+ q->streaming = 0;
+
+ /*
+ * Remove all buffers from videobuf's list...
+ */
+ INIT_LIST_HEAD(&q->queued_list);
+ /*
+ * ...and done list; userspace will not receive any buffers it
+ * has not already dequeued before initiating cancel.
+ */
+ INIT_LIST_HEAD(&q->done_list);
+ wake_up_all(&q->done_wq);
+
+ /*
+ * Reinitialize all buffers for next use.
+ */
+ for (i = 0; i < q->num_buffers; ++i)
+ q->bufs[i]->state = VB2_BUF_STATE_DEQUEUED;
+}
+
+/**
+ * vb2_streamoff - stop streaming
+ * @q: videobuf2 queue
+ * @type: type argument passed from userspace to vidioc_streamoff handler
+ *
+ * Should be called from vidioc_streamoff handler of a driver.
+ * This function:
+ * 1) verifies current state,
+ * 2) stop streaming and dequeues any queued buffers, including those previously
+ * passed to the driver (after waiting for the driver to finish).
+ *
+ * This call can be used for pausing playback.
+ * The return values from this function are intended to be directly returned
+ * from vidioc_streamoff handler in the driver
+ */
+int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
+{
+ if (type != q->type) {
+ dprintk(1, "streamoff: invalid stream type\n");
+ return -EINVAL;
+ }
+
+ if (!q->streaming) {
+ dprintk(1, "streamoff: not streaming\n");
+ return -EINVAL;
+ }
+
+ /*
+ * Cancel will pause streaming and remove all buffers from the driver
+ * and videobuf, effectively returning control over them to userspace.
+ */
+ __vb2_queue_cancel(q);
+
+ dprintk(3, "Streamoff successful\n");
+ return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_streamoff);
+
+/**
+ * __find_plane_by_offset() - find plane associated with the given offset off
+ */
+static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
+ unsigned int *_buffer, unsigned int *_plane)
+{
+ struct vb2_buffer *vb;
+ unsigned int buffer, plane;
+
+ /*
+ * Go over all buffers and their planes, comparing the given offset
+ * with an offset assigned to each plane. If a match is found,
+ * return its buffer and plane numbers.
+ */
+ for (buffer = 0; buffer < q->num_buffers; ++buffer) {
+ vb = q->bufs[buffer];
+
+ for (plane = 0; plane < vb->num_planes; ++plane) {
+ if (vb->v4l2_planes[plane].m.mem_offset == off) {
+ *_buffer = buffer;
+ *_plane = plane;
+ return 0;
+ }
+ }
+ }
+
+ return -EINVAL;
+}
+
+/**
+ * vb2_mmap() - map video buffers into application address space
+ * @q: videobuf2 queue
+ * @vma: vma passed to the mmap file operation handler in the driver
+ *
+ * Should be called from mmap file operation handler of a driver.
+ * This function maps one plane of one of the available video buffers to
+ * userspace. To map whole video memory allocated on reqbufs, this function
+ * has to be called once per each plane per each buffer previously allocated.
+ *
+ * When the userspace application calls mmap, it passes to it an offset returned
+ * to it earlier by the means of vidioc_querybuf handler. That offset acts as
+ * a "cookie", which is then used to identify the plane to be mapped.
+ * This function finds a plane with a matching offset and a mapping is performed
+ * by the means of a provided memory operation.
+ *
+ * The return values from this function are intended to be directly returned
+ * from the mmap handler in driver.
+ */
+int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
+{
+ unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
+ struct vb2_plane *vb_plane;
+ struct vb2_buffer *vb;
+ unsigned int buffer, plane;
+ int ret;
+
+ if (q->memory != V4L2_MEMORY_MMAP) {
+ dprintk(1, "Queue is not currently set up for mmap\n");
+ return -EINVAL;
+ }
+
+ /*
+ * Check memory area access mode.
+ */
+ if (!(vma->vm_flags & VM_SHARED)) {
+ dprintk(1, "Invalid vma flags, VM_SHARED needed\n");
+ return -EINVAL;
+ }
+ if (V4L2_TYPE_IS_OUTPUT(q->type)) {
+ if (!(vma->vm_flags & VM_WRITE)) {
+ dprintk(1, "Invalid vma flags, VM_WRITE needed\n");
+ return -EINVAL;
+ }
+ } else {
+ if (!(vma->vm_flags & VM_READ)) {
+ dprintk(1, "Invalid vma flags, VM_READ needed\n");
+ return -EINVAL;
+ }
+ }
+
+ /*
+ * Find the plane corresponding to the offset passed by userspace.
+ */
+ ret = __find_plane_by_offset(q, off, &buffer, &plane);
+ if (ret)
+ return ret;
+
+ vb = q->bufs[buffer];
+ vb_plane = &vb->planes[plane];
+
+ ret = q->mem_ops->mmap(vb_plane->mem_priv, vma);
+ if (ret)
+ return ret;
+
+ vb_plane->mapped = 1;
+ vb->num_planes_mapped++;
+
+ dprintk(3, "Buffer %d, plane %d successfully mapped\n", buffer, plane);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_mmap);
+
+
+/**
+ * vb2_poll() - implements poll userspace operation
+ * @q: videobuf2 queue
+ * @file: file argument passed to the poll file operation handler
+ * @wait: wait argument passed to the poll file operation handler
+ *
+ * This function implements poll file operation handler for a driver.
+ * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
+ * be informed that the file descriptor of a video device is available for
+ * reading.
+ * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
+ * will be reported as available for writing.
+ *
+ * The return values from this function are intended to be directly returned
+ * from poll handler in driver.
+ */
+unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
+{
+ unsigned long flags;
+ struct vb2_buffer *vb = NULL;
+
+ /*
+ * There is nothing to wait for if no buffers have already been queued.
+ */
+ if (list_empty(&q->queued_list))
+ return POLLERR;
+
+ poll_wait(file, &q->done_wq, wait);
+
+ /*
+ * Take first buffer available for dequeuing.
+ */
+ spin_lock_irqsave(&q->done_lock, flags);
+ if (!list_empty(&q->done_list))
+ vb = list_first_entry(&q->done_list, struct vb2_buffer,
+ done_entry);
+ spin_unlock_irqrestore(&q->done_lock, flags);
+
+ if (vb && (vb->state == VB2_BUF_STATE_DONE
+ || vb->state == VB2_BUF_STATE_ERROR)) {
+ return (V4L2_TYPE_IS_OUTPUT(q->type)) ? POLLOUT | POLLWRNORM :
+ POLLIN | POLLRDNORM;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_poll);
+
+/**
+ * vb2_queue_init() - initialize a videobuf2 queue
+ * @q: videobuf2 queue; this structure should be allocated in driver
+ * @ops: driver-specific callbacks
+ * @alloc_ctx: memory handler/allocator-specific context to be used;
+ * the given context will be used for memory allocation on all
+ * planes and buffers; it is possible to assign different contexts
+ * per plane, use vb2_set_alloc_ctx() for that
+ * @type: queue type
+ * @drv_priv: driver private data, may be NULL; it can be used by driver in
+ * driver-specific callbacks when issued
+ */
+int vb2_queue_init(struct vb2_queue *q)
+{
+ BUG_ON(!q);
+ BUG_ON(!q->ops);
+ BUG_ON(!q->mem_ops);
+ BUG_ON(!q->io_modes);
+
+ BUG_ON(!q->ops->queue_setup);
+ BUG_ON(!q->ops->buf_queue);
+
+ INIT_LIST_HEAD(&q->queued_list);
+ INIT_LIST_HEAD(&q->done_list);
+ spin_lock_init(&q->done_lock);
+ init_waitqueue_head(&q->done_wq);
+
+ if (q->buf_struct_size == 0)
+ q->buf_struct_size = sizeof(struct vb2_buffer);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_queue_init);
+
+/**
+ * vb2_queue_release() - stop streaming, release the queue and free memory
+ * @q: videobuf2 queue
+ *
+ * This function stops streaming and performs necessary clean ups, including
+ * freeing video buffer memory. The driver is responsible for freeing
+ * the vb2_queue structure itself.
+ */
+void vb2_queue_release(struct vb2_queue *q)
+{
+ __vb2_queue_cancel(q);
+ __vb2_queue_free(q);
+}
+EXPORT_SYMBOL_GPL(vb2_queue_release);
+
+MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
+MODULE_AUTHOR("Pawel Osciak, Marek Szyprowski");
+MODULE_LICENSE("GPL");
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
new file mode 100644
index 0000000..a44903a
--- /dev/null
+++ b/include/media/videobuf2-core.h
@@ -0,0 +1,368 @@
+/*
+ * videobuf2-core.h - V4L2 driver helper framework
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ *
+ * Author: Pawel Osciak <***@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.
+ */
+#ifndef _MEDIA_VIDEOBUF2_CORE_H
+#define _MEDIA_VIDEOBUF2_CORE_H
+
+#include <linux/mm_types.h>
+#include <linux/mutex.h>
+#include <linux/poll.h>
+#include <linux/videodev2.h>
+
+struct vb2_alloc_ctx;
+
+/**
+ * struct vb2_mem_ops - memory handling/memory allocator operations
+ * @alloc: allocate video memory and, optionally, allocator private data,
+ * return NULL on failure or a pointer to allocator private,
+ * per-buffer data on success; the returned private structure
+ * will then be passed as buf_priv argument to other ops in this
+ * structure
+ * @put: inform the allocator that the buffer will no longer be used;
+ * usually will result in the allocator freeing the buffer (if
+ * no other users of this buffer are present); the buf_priv
+ * argument is the allocator private per-buffer structure
+ * previously returned from the alloc callback
+ * @get_userptr: acquire userspace memory for a hardware operation; used for
+ * USERPTR memory types; vaddr is the address passed to the
+ * videobuf layer when queuing a video buffer of USERPTR type;
+ * should return an allocator private per-buffer structure
+ * associated with the buffer on success, NULL on failure;
+ * the returned private structure will then be passed as buf_priv
+ * argument to other ops in this structure
+ * @put_userptr: inform the allocator that a USERPTR buffer will no longer
+ * be used
+ * @vaddr: return a kernel virtual address to a given memory buffer
+ * associated with the passed private structure or NULL if no
+ * such mapping exists
+ * @cookie: return allocator specific cookie for a given memory buffer
+ * associated with the passed private structure or NULL if not
+ * available
+ * @num_users: return the current number of users of a memory buffer;
+ * return 1 if the videobuf layer (or actually the driver using
+ * it) is the only user
+ * @mmap: setup a userspace mapping for a given memory buffer under
+ * the provided virtual memory region
+ *
+ * Required ops for USERPTR types: get_userptr, put_userptr.
+ * Required ops for MMAP types: alloc, put, num_users, mmap.
+ */
+struct vb2_mem_ops {
+ void *(*alloc)(void *alloc_ctx, unsigned long size);
+ void (*put)(void *buf_priv);
+
+ void *(*get_userptr)(void *alloc_ctx, unsigned long vaddr,
+ unsigned long size, int write);
+ void (*put_userptr)(void *buf_priv);
+
+ void *(*vaddr)(void *buf_priv);
+ void *(*cookie)(void *buf_priv);
+
+ unsigned int (*num_users)(void *buf_priv);
+
+ int (*mmap)(void *buf_priv, struct vm_area_struct *vma);
+};
+
+struct vb2_plane {
+ void *mem_priv;
+ int mapped:1;
+};
+
+/**
+ * enum vb2_io_modes - queue access methods
+ * @VB2_MMAP: driver supports MMAP with streaming api
+ * @VB2_USERPTR: driver supports USERPTR with streaming api
+ * @VB2_READ: driver supports read() style access
+ * @VB2_WRITE: driver supports write() style access
+ */
+enum vb2_io_modes {
+ VB2_MMAP = (1 << 0),
+ VB2_USERPTR = (1 << 1),
+ VB2_READ = (1 << 2),
+ VB2_WRITE = (1 << 3),
+};
+
+/**
+ * enum vb2_fileio_flags - flags for selecting a mode of the file io emulator,
+ * by default the 'streaming' style is used by the file io emulator
+ * @VB2_FILEIO_READ_ONCE: report EOF after reading the first buffer
+ * @VB2_FILEIO_WRITE_IMMEDIATE: queue buffer after each write() call
+ */
+enum vb2_fileio_flags {
+ VB2_FILEIO_READ_ONCE = (1 << 0),
+ VB2_FILEIO_WRITE_IMMEDIATE = (1 << 1),
+};
+
+/**
+ * enum vb2_buffer_state - current video buffer state
+ * @VB2_BUF_STATE_DEQUEUED: buffer under userspace control
+ * @VB2_BUF_STATE_QUEUED: buffer queued in videobuf, but not in driver
+ * @VB2_BUF_STATE_ACTIVE: buffer queued in driver and possibly used
+ * in a hardware operation
+ * @VB2_BUF_STATE_DONE: buffer returned from driver to videobuf, but
+ * not yet dequeued to userspace
+ * @VB2_BUF_STATE_ERROR: same as above, but the operation on the buffer
+ * has ended with an error, which will be reported
+ * to the userspace when it is dequeued
+ */
+enum vb2_buffer_state {
+ VB2_BUF_STATE_DEQUEUED,
+ VB2_BUF_STATE_QUEUED,
+ VB2_BUF_STATE_ACTIVE,
+ VB2_BUF_STATE_DONE,
+ VB2_BUF_STATE_ERROR,
+};
+
+struct vb2_queue;
+
+/**
+ * struct vb2_buffer - represents a video buffer
+ * @v4l2_buf: struct v4l2_buffer associated with this buffer; can
+ * be read by the driver and relevant entries can be
+ * changed by the driver in case of CAPTURE types
+ * (such as timestamp)
+ * @v4l2_planes: struct v4l2_planes associated with this buffer; can
+ * be read by the driver and relevant entries can be
+ * changed by the driver in case of CAPTURE types
+ * (such as bytesused); NOTE that even for single-planar
+ * types, the v4l2_planes[0] struct should be used
+ * instead of v4l2_buf for filling bytesused - drivers
+ * should use the vb2_set_plane_payload() function for that
+ * @vb2_queue: the queue to which this driver belongs
+ * @num_planes: number of planes in the buffer
+ * on an internal driver queue
+ * @state: current buffer state; do not change
+ * @queued_entry: entry on the queued buffers list, which holds all
+ * buffers queued from userspace
+ * @done_entry: entry on the list that stores all buffers ready to
+ * be dequeued to userspace
+ * @planes: private per-plane information; do not change
+ * @num_planes_mapped: number of mapped planes; do not change
+ */
+struct vb2_buffer {
+ struct v4l2_buffer v4l2_buf;
+ struct v4l2_plane v4l2_planes[VIDEO_MAX_PLANES];
+
+ struct vb2_queue *vb2_queue;
+
+ unsigned int num_planes;
+
+/* Private: internal use only */
+ enum vb2_buffer_state state;
+
+ struct list_head queued_entry;
+ struct list_head done_entry;
+
+ struct vb2_plane planes[VIDEO_MAX_PLANES];
+ unsigned int num_planes_mapped;
+};
+
+/**
+ * struct vb2_ops - driver-specific callbacks
+ *
+ * @queue_setup: called from a VIDIOC_REQBUFS handler, before
+ * memory allocation; driver should return the required
+ * number of buffers in num_buffers, the required number
+ * of planes per buffer in num_planes and the required
+ * sizes of planes in size_planes array
+ * @wait_prepare: release any locks taken while calling vb2 functions;
+ * it is called before ioctl needs to wait for a new buffer to
+ * arrive; required to avoid deadlock in blocking access type
+ * @wait_finish: reacquire all locks released in the previous callback;
+ * required to continue operation after sleeping while
+ * waiting for a new buffer to arrive
+ * @buf_init: called once after allocating a buffer (in MMAP case)
+ * or after acquiring a new USERPTR buffer; drivers may
+ * perform additional buffer-related initialization;
+ * initialization failure (return != 0) will prevent
+ * queue setup from completing successfully; optional
+ * @buf_prepare: called every time the buffer is queued from userspace;
+ * drivers may perform any initialization required before
+ * each hardware operation in this callback;
+ * if an error is returned, the buffer will not be queued
+ * in driver; optional
+ * @buf_finish: called before every dequeue of the buffer back to
+ * userspace; drivers may perform any operations required
+ * before userspace accesses the buffer; optional
+ * @buf_cleanup: called once before the buffer is freed; drivers may
+ * perform any additional cleanup; optional
+ * @start_streaming: called once before entering 'streaming' state; enables
+ * driver to receive buffers over buf_queue() callback
+ * @stop_streaming: called when 'streaming' state must be disabled; driver
+ * should stop any dma transactions or wait until they
+ * finish and give back all buffers it got from buf_queue()
+ * callback
+ * @buf_queue: passes buffer vb to the driver; driver may start
+ * hardware operation on this buffer; driver should give
+ * the buffer back by calling vb2_buffer_done() function
+ */
+struct vb2_ops {
+ int (*queue_setup)(struct vb2_queue *q, unsigned int *num_buffers,
+ unsigned int *num_planes, unsigned long sizes[],
+ void *alloc_ctxs[]);
+
+ void (*wait_prepare)(struct vb2_queue *q);
+ void (*wait_finish)(struct vb2_queue *q);
+
+ int (*buf_init)(struct vb2_buffer *vb);
+ int (*buf_prepare)(struct vb2_buffer *vb);
+ int (*buf_finish)(struct vb2_buffer *vb);
+ void (*buf_cleanup)(struct vb2_buffer *vb);
+
+ int (*start_streaming)(struct vb2_queue *q);
+ int (*stop_streaming)(struct vb2_queue *q);
+
+ void (*buf_queue)(struct vb2_buffer *vb);
+};
+
+/**
+ * struct vb2_queue - a videobuf queue
+ *
+ * @type: queue type (see V4L2_BUF_TYPE_* in linux/videodev2.h
+ * @io_modes: supported io methods (see vb2_io_modes enum)
+ * @io_flags: additional io flags (see vb2_fileio_flags enum)
+ * @ops: driver-specific callbacks
+ * @mem_ops: memory allocator specific callbacks
+ * @drv_priv: driver private data
+ * @buf_struct_size: size of the driver specific buffer structure; zero means
+ * the driver doesn't want to use custom buffer structure type,
+ * so sizeof(struct vb2_buffer) is used instead
+ *
+ * @memory: current memory type used
+ * @bufs: videobuf buffer structures
+ * @num_buffers: number of allocated/used buffers
+ * @queued_list: list of buffers currently queued from userspace
+ * @queued_count: number of buffers owned by the driver
+ * @done_list: list of buffers ready to be dequeued to userspace
+ * @done_lock: lock to protect done_list list
+ * @done_wq: waitqueue for processes waiting for buffers ready to be dequeued
+ * @alloc_ctx: memory type/allocator-specific contexts for each plane
+ * @streaming: current streaming state
+ */
+struct vb2_queue {
+ enum v4l2_buf_type type;
+ unsigned int io_modes;
+ unsigned int io_flags;
+
+ const struct vb2_ops *ops;
+ const struct vb2_mem_ops *mem_ops;
+ void *drv_priv;
+ unsigned int buf_struct_size;
+
+/* private: internal use only */
+ enum v4l2_memory memory;
+ struct vb2_buffer *bufs[VIDEO_MAX_FRAME];
+ unsigned int num_buffers;
+
+ struct list_head queued_list;
+
+ atomic_t queued_count;
+ struct list_head done_list;
+ spinlock_t done_lock;
+ wait_queue_head_t done_wq;
+
+ void *alloc_ctx[VIDEO_MAX_PLANES];
+
+ unsigned int streaming:1;
+};
+
+void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no);
+void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no);
+
+void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state);
+int vb2_wait_for_all_buffers(struct vb2_queue *q);
+
+int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b);
+int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req);
+
+int vb2_queue_init(struct vb2_queue *q);
+
+void vb2_queue_release(struct vb2_queue *q);
+
+int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b);
+int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking);
+
+int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type);
+int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type);
+
+int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma);
+unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait);
+
+/**
+ * vb2_is_streaming() - return streaming status of the queue
+ * @q: videobuf queue
+ */
+static inline bool vb2_is_streaming(struct vb2_queue *q)
+{
+ return q->streaming;
+}
+
+/**
+ * vb2_is_busy() - return busy status of the queue
+ * @q: videobuf queue
+ *
+ * This function checks if queue has any buffers allocated.
+ */
+static inline bool vb2_is_busy(struct vb2_queue *q)
+{
+ return (q->num_buffers > 0);
+}
+
+/**
+ * vb2_get_drv_priv() - return driver private data associated with the queue
+ * @q: videobuf queue
+ */
+static inline void *vb2_get_drv_priv(struct vb2_queue *q)
+{
+ return q->drv_priv;
+}
+
+/**
+ * vb2_set_plane_payload() - set bytesused for the plane plane_no
+ * @vb: buffer for which plane payload should be set
+ * @plane_no: plane number for which payload should be set
+ * @size: payload in bytes
+ */
+static inline void vb2_set_plane_payload(struct vb2_buffer *vb,
+ unsigned int plane_no, unsigned long size)
+{
+ if (plane_no < vb->num_planes)
+ vb->v4l2_planes[plane_no].bytesused = size;
+}
+
+/**
+ * vb2_get_plane_payload() - set bytesused for the plane plane_no
+ * @vb: buffer for which plane payload should be set
+ * @plane_no: plane number for which payload should be set
+ * @size: payload in bytes
+ */
+static inline unsigned long vb2_get_plane_payload(struct vb2_buffer *vb,
+ unsigned int plane_no)
+{
+ if (plane_no < vb->num_planes)
+ return vb->v4l2_planes[plane_no].bytesused;
+ return 0;
+}
+
+/**
+ * vb2_plane_size() - return plane size in bytes
+ * @vb: buffer for which plane size should be returned
+ * @plane_no: plane number for which size should be returned
+ */
+static inline unsigned long
+vb2_plane_size(struct vb2_buffer *vb, unsigned int plane_no)
+{
+ if (plane_no < vb->num_planes)
+ return vb->v4l2_planes[plane_no].length;
+ return 0;
+}
+
+#endif /* _MEDIA_VIDEOBUF2_CORE_H */
--
1.7.1.569.g6f426
Marek Szyprowski
2010-12-16 14:24:02 UTC
Permalink
From: Andrzej Pietrasiewicz <***@samsung.com>

Add an implementation of DMA scatter/gather allocator and handling
routines for videobuf2.

For mmap operation mode it is implemented on top of
alloc_page + sg_set_page/_free_page.

For userptr operation mode it is impelmented on top of
get_user_pages + sg_set_page/put_page.

Signed-off-by: Andrzej Pietrasiewicz <***@samsung.com>
Signed-off-by: Kyungmin Park <***@samsung.com>
Signed-off-by: Marek Szyprowski <***@samsung.com>
CC: Pawel Osciak <***@osciak.com>
---
drivers/media/video/Kconfig | 6 +
drivers/media/video/Makefile | 1 +
drivers/media/video/videobuf2-dma-sg.c | 292 ++++++++++++++++++++++++++++++++
include/media/videobuf2-dma-sg.h | 32 ++++
4 files changed, 331 insertions(+), 0 deletions(-)
create mode 100644 drivers/media/video/videobuf2-dma-sg.c
create mode 100644 include/media/videobuf2-dma-sg.h

diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
index 0e1c166..e015dfc 100644
--- a/drivers/media/video/Kconfig
+++ b/drivers/media/video/Kconfig
@@ -65,6 +65,12 @@ config VIDEOBUF2_VMALLOC
select VIDEOBUF2_MEMOPS
tristate

+
+config VIDEOBUF2_DMA_SG
+ #depends on HAS_DMA
+ select VIDEOBUF2_CORE
+ select VIDEOBUF2_MEMOPS
+ tristate
#
# Multimedia Video device configuration
#
diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
index 8eb7973..5d7f3c1 100644
--- a/drivers/media/video/Makefile
+++ b/drivers/media/video/Makefile
@@ -118,6 +118,7 @@ obj-$(CONFIG_VIDEOBUF2_CORE) += videobuf2-core.o
obj-$(CONFIG_VIDEOBUF2_MEMOPS) += videobuf2-memops.o
obj-$(CONFIG_VIDEOBUF2_VMALLOC) += videobuf2-vmalloc.o
obj-$(CONFIG_VIDEOBUF2_DMA_CONTIG) += videobuf2-dma-contig.o
+obj-$(CONFIG_VIDEOBUF2_DMA_SG) += videobuf2-dma-sg.o

obj-$(CONFIG_V4L2_MEM2MEM_DEV) += v4l2-mem2mem.o

diff --git a/drivers/media/video/videobuf2-dma-sg.c b/drivers/media/video/videobuf2-dma-sg.c
new file mode 100644
index 0000000..20b5c5d
--- /dev/null
+++ b/drivers/media/video/videobuf2-dma-sg.c
@@ -0,0 +1,292 @@
+/*
+ * videobuf2-dma-sg.c - dma scatter/gather memory allocator for videobuf2
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ *
+ * Author: Andrzej Pietrasiewicz <***@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/mm.h>
+#include <linux/scatterlist.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+
+#include <media/videobuf2-core.h>
+#include <media/videobuf2-memops.h>
+#include <media/videobuf2-dma-sg.h>
+
+struct vb2_dma_sg_buf {
+ void *vaddr;
+ struct page **pages;
+ int write;
+ int offset;
+ struct vb2_dma_sg_desc sg_desc;
+ atomic_t refcount;
+ struct vb2_vmarea_handler handler;
+};
+
+static void vb2_dma_sg_put(void *buf_priv);
+
+static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size)
+{
+ struct vb2_dma_sg_buf *buf;
+ int i;
+
+ buf = kzalloc(sizeof *buf, GFP_KERNEL);
+ if (!buf)
+ return NULL;
+
+ buf->vaddr = NULL;
+ buf->write = 0;
+ buf->offset = 0;
+ buf->sg_desc.size = size;
+ buf->sg_desc.num_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
+
+ buf->sg_desc.sglist = vmalloc(buf->sg_desc.num_pages *
+ sizeof(*buf->sg_desc.sglist));
+ if (!buf->sg_desc.sglist)
+ goto fail_sglist_alloc;
+ memset(buf->sg_desc.sglist, 0, buf->sg_desc.num_pages *
+ sizeof(*buf->sg_desc.sglist));
+ sg_init_table(buf->sg_desc.sglist, buf->sg_desc.num_pages);
+
+ buf->pages = kzalloc(buf->sg_desc.num_pages * sizeof(struct page *),
+ GFP_KERNEL);
+ if (!buf->pages)
+ goto fail_pages_array_alloc;
+
+ for (i = 0; i < buf->sg_desc.num_pages; ++i) {
+ buf->pages[i] = alloc_page(GFP_KERNEL);
+ if (NULL == buf->pages[i])
+ goto fail_pages_alloc;
+ sg_set_page(&buf->sg_desc.sglist[i],
+ buf->pages[i], PAGE_SIZE, 0);
+ }
+
+ buf->handler.refcount = &buf->refcount;
+ buf->handler.put = vb2_dma_sg_put;
+ buf->handler.arg = buf;
+
+ atomic_inc(&buf->refcount);
+
+ printk(KERN_DEBUG "%s: Allocated buffer of %d pages\n",
+ __func__, buf->sg_desc.num_pages);
+
+ if (!buf->vaddr)
+ buf->vaddr = vm_map_ram(buf->pages,
+ buf->sg_desc.num_pages,
+ -1,
+ PAGE_KERNEL);
+ return buf;
+
+fail_pages_alloc:
+ while (--i >= 0)
+ __free_page(buf->pages[i]);
+
+fail_pages_array_alloc:
+ vfree(buf->sg_desc.sglist);
+
+fail_sglist_alloc:
+ kfree(buf);
+ return NULL;
+}
+
+static void vb2_dma_sg_put(void *buf_priv)
+{
+ struct vb2_dma_sg_buf *buf = buf_priv;
+ int i = buf->sg_desc.num_pages;
+
+ if (atomic_dec_and_test(&buf->refcount)) {
+ printk(KERN_DEBUG "%s: Freeing buffer of %d pages\n", __func__,
+ buf->sg_desc.num_pages);
+ if (buf->vaddr)
+ vm_unmap_ram(buf->vaddr, buf->sg_desc.num_pages);
+ vfree(buf->sg_desc.sglist);
+ while (--i >= 0)
+ __free_page(buf->pages[i]);
+ kfree(buf->pages);
+ kfree(buf);
+ }
+}
+
+static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
+ unsigned long size, int write)
+{
+ struct vb2_dma_sg_buf *buf;
+ unsigned long first, last;
+ int num_pages_from_user, i;
+
+ buf = kzalloc(sizeof *buf, GFP_KERNEL);
+ if (!buf)
+ return NULL;
+
+ buf->vaddr = NULL;
+ buf->write = write;
+ buf->offset = vaddr & ~PAGE_MASK;
+ buf->sg_desc.size = size;
+
+ first = (vaddr & PAGE_MASK) >> PAGE_SHIFT;
+ last = ((vaddr + size - 1) & PAGE_MASK) >> PAGE_SHIFT;
+ buf->sg_desc.num_pages = last - first + 1;
+
+ buf->sg_desc.sglist = vmalloc(
+ buf->sg_desc.num_pages * sizeof(*buf->sg_desc.sglist));
+ if (!buf->sg_desc.sglist)
+ goto userptr_fail_sglist_alloc;
+
+ memset(buf->sg_desc.sglist, 0,
+ buf->sg_desc.num_pages * sizeof(*buf->sg_desc.sglist));
+ sg_init_table(buf->sg_desc.sglist, buf->sg_desc.num_pages);
+
+ buf->pages = kzalloc(buf->sg_desc.num_pages * sizeof(struct page *),
+ GFP_KERNEL);
+ if (!buf->pages)
+ goto userptr_fail_pages_array_alloc;
+
+ down_read(&current->mm->mmap_sem);
+ num_pages_from_user = get_user_pages(current, current->mm,
+ vaddr & PAGE_MASK,
+ buf->sg_desc.num_pages,
+ write,
+ 1, /* force */
+ buf->pages,
+ NULL);
+ up_read(&current->mm->mmap_sem);
+ if (num_pages_from_user != buf->sg_desc.num_pages)
+ goto userptr_fail_get_user_pages;
+
+ sg_set_page(&buf->sg_desc.sglist[0], buf->pages[0],
+ PAGE_SIZE - buf->offset, buf->offset);
+ size -= PAGE_SIZE - buf->offset;
+ for (i = 1; i < buf->sg_desc.num_pages; ++i) {
+ sg_set_page(&buf->sg_desc.sglist[i], buf->pages[i],
+ min_t(size_t, PAGE_SIZE, size), 0);
+ size -= min_t(size_t, PAGE_SIZE, size);
+ }
+ return buf;
+
+userptr_fail_get_user_pages:
+ printk(KERN_DEBUG "get_user_pages requested/got: %d/%d]\n",
+ num_pages_from_user, buf->sg_desc.num_pages);
+ while (--num_pages_from_user >= 0)
+ put_page(buf->pages[num_pages_from_user]);
+
+userptr_fail_pages_array_alloc:
+ vfree(buf->sg_desc.sglist);
+
+userptr_fail_sglist_alloc:
+ kfree(buf);
+ return NULL;
+}
+
+/*
+ * @put_userptr: inform the allocator that a USERPTR buffer will no longer
+ * be used
+ */
+static void vb2_dma_sg_put_userptr(void *buf_priv)
+{
+ struct vb2_dma_sg_buf *buf = buf_priv;
+ int i = buf->sg_desc.num_pages;
+
+ printk(KERN_DEBUG "%s: Releasing userspace buffer of %d pages\n",
+ __func__, buf->sg_desc.num_pages);
+ if (buf->vaddr)
+ vm_unmap_ram(buf->vaddr, buf->sg_desc.num_pages);
+ while (--i >= 0) {
+ if (buf->write)
+ set_page_dirty_lock(buf->pages[i]);
+ put_page(buf->pages[i]);
+ }
+ vfree(buf->sg_desc.sglist);
+ kfree(buf->pages);
+ kfree(buf);
+}
+
+static void *vb2_dma_sg_vaddr(void *buf_priv)
+{
+ struct vb2_dma_sg_buf *buf = buf_priv;
+
+ BUG_ON(!buf);
+
+ if (!buf->vaddr)
+ buf->vaddr = vm_map_ram(buf->pages,
+ buf->sg_desc.num_pages,
+ -1,
+ PAGE_KERNEL);
+
+ /* add offset in case userptr is not page-aligned */
+ return buf->vaddr + buf->offset;
+}
+
+static unsigned int vb2_dma_sg_num_users(void *buf_priv)
+{
+ struct vb2_dma_sg_buf *buf = buf_priv;
+
+ return atomic_read(&buf->refcount);
+}
+
+static int vb2_dma_sg_mmap(void *buf_priv, struct vm_area_struct *vma)
+{
+ struct vb2_dma_sg_buf *buf = buf_priv;
+ unsigned long uaddr = vma->vm_start;
+ unsigned long usize = vma->vm_end - vma->vm_start;
+ int i = 0;
+
+ if (!buf) {
+ printk(KERN_ERR "No memory to map\n");
+ return -EINVAL;
+ }
+
+ do {
+ int ret;
+
+ ret = vm_insert_page(vma, uaddr, buf->pages[i++]);
+ if (ret) {
+ printk(KERN_ERR "Remapping memory, error: %d\n", ret);
+ return ret;
+ }
+
+ uaddr += PAGE_SIZE;
+ usize -= PAGE_SIZE;
+ } while (usize > 0);
+
+
+ /*
+ * Use common vm_area operations to track buffer refcount.
+ */
+ vma->vm_private_data = &buf->handler;
+ vma->vm_ops = &vb2_common_vm_ops;
+
+ vma->vm_ops->open(vma);
+
+ return 0;
+}
+
+static void *vb2_dma_sg_cookie(void *buf_priv)
+{
+ struct vb2_dma_sg_buf *buf = buf_priv;
+
+ return &buf->sg_desc;
+}
+
+const struct vb2_mem_ops vb2_dma_sg_memops = {
+ .alloc = vb2_dma_sg_alloc,
+ .put = vb2_dma_sg_put,
+ .get_userptr = vb2_dma_sg_get_userptr,
+ .put_userptr = vb2_dma_sg_put_userptr,
+ .vaddr = vb2_dma_sg_vaddr,
+ .mmap = vb2_dma_sg_mmap,
+ .num_users = vb2_dma_sg_num_users,
+ .cookie = vb2_dma_sg_cookie,
+};
+EXPORT_SYMBOL_GPL(vb2_dma_sg_memops);
+
+MODULE_DESCRIPTION("dma scatter/gather memory handling routines for videobuf2");
+MODULE_AUTHOR("Andrzej Pietrasiewicz");
+MODULE_LICENSE("GPL");
diff --git a/include/media/videobuf2-dma-sg.h b/include/media/videobuf2-dma-sg.h
new file mode 100644
index 0000000..0038526
--- /dev/null
+++ b/include/media/videobuf2-dma-sg.h
@@ -0,0 +1,32 @@
+/*
+ * videobuf2-dma-sg.h - DMA scatter/gather memory allocator for videobuf2
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ *
+ * Author: Andrzej Pietrasiewicz <***@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.
+ */
+
+#ifndef _MEDIA_VIDEOBUF2_DMA_SG_H
+#define _MEDIA_VIDEOBUF2_DMA_SG_H
+
+#include <media/videobuf2-core.h>
+
+struct vb2_dma_sg_desc {
+ unsigned long size;
+ unsigned int num_pages;
+ struct scatterlist *sglist;
+};
+
+static inline struct vb2_dma_sg_desc *vb2_dma_sg_plane_desc(
+ struct vb2_buffer *vb, unsigned int plane_no)
+{
+ return (struct vb2_dma_sg_desc *)vb2_plane_cookie(vb, plane_no);
+}
+
+extern const struct vb2_mem_ops vb2_dma_sg_memops;
+
+#endif
--
1.7.1.569.g6f426
Marek Szyprowski
2010-12-16 14:24:03 UTC
Permalink
Add a generic file io (read and write) emulator for videobuf2. It uses
MMAP memory type buffers and generic vb2 calls: req_bufs, qbuf and
dqbuf. Video date is being copied from mmap buffers to userspace with
standard copy_to_user() function. To add support for file io the driver
needs to provide an additional callback - read_setup or write_setup. It
should provide the default number of buffers used by emulator and flags.

With these flags one can detemine the style of read() or write()
emulation. By default 'streaming' style is used. With
VB2_FILEIO_READ_ONCE flag one can select 'one shot' mode for read()
emulator. With VB2_FILEIO_WRITE_IMMEDIATE flag one can select immediate
conversion of write calls to qbuf for write() emulator, so the vb2 will
not wait until each buffer is filled completely before queueing it to
the driver.

Signed-off-by: Marek Szyprowski <***@samsung.com>
Signed-off-by: Kyungmin Park <***@samsung.com>
CC: Pawel Osciak <***@osciak.com>
---
drivers/media/video/videobuf2-core.c | 399 ++++++++++++++++++++++++++++++++++
include/media/videobuf2-core.h | 9 +
2 files changed, 408 insertions(+), 0 deletions(-)

diff --git a/drivers/media/video/videobuf2-core.c b/drivers/media/video/videobuf2-core.c
index ae1c817..d7452fa 100644
--- a/drivers/media/video/videobuf2-core.c
+++ b/drivers/media/video/videobuf2-core.c
@@ -453,6 +453,11 @@ int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
unsigned long plane_sizes[VIDEO_MAX_PLANES];
int ret = 0;

+ if (q->fileio) {
+ dprintk(1, "reqbufs: file io in progress\n");
+ return -EBUSY;
+ }
+
if (req->memory != V4L2_MEMORY_MMAP
&& req->memory != V4L2_MEMORY_USERPTR) {
dprintk(1, "reqbufs: unsupported memory type\n");
@@ -824,6 +829,11 @@ int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
struct vb2_buffer *vb;
int ret = 0;

+ if (q->fileio) {
+ dprintk(1, "qbuf: file io in progress\n");
+ return -EBUSY;
+ }
+
if (b->type != q->type) {
dprintk(1, "qbuf: invalid buffer type\n");
return -EINVAL;
@@ -1030,6 +1040,11 @@ int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
struct vb2_buffer *vb = NULL;
int ret;

+ if (q->fileio) {
+ dprintk(1, "dqbuf: file io in progress\n");
+ return -EBUSY;
+ }
+
if (b->type != q->type) {
dprintk(1, "dqbuf: invalid buffer type\n");
return -EINVAL;
@@ -1089,6 +1104,11 @@ int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
{
struct vb2_buffer *vb;

+ if (q->fileio) {
+ dprintk(1, "streamon: file io in progress\n");
+ return -EBUSY;
+ }
+
if (type != q->type) {
dprintk(1, "streamon: invalid stream type\n");
return -EINVAL;
@@ -1182,6 +1202,11 @@ static void __vb2_queue_cancel(struct vb2_queue *q)
*/
int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
{
+ if (q->fileio) {
+ dprintk(1, "streamoff: file io in progress\n");
+ return -EBUSY;
+ }
+
if (type != q->type) {
dprintk(1, "streamoff: invalid stream type\n");
return -EINVAL;
@@ -1305,6 +1330,8 @@ int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
}
EXPORT_SYMBOL_GPL(vb2_mmap);

+static int __vb2_init_fileio(struct vb2_queue *q, int read);
+static int __vb2_cleanup_fileio(struct vb2_queue *q);

/**
* vb2_poll() - implements poll userspace operation
@@ -1325,9 +1352,30 @@ EXPORT_SYMBOL_GPL(vb2_mmap);
unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
{
unsigned long flags;
+ unsigned int ret;
struct vb2_buffer *vb = NULL;

/*
+ * Start file io emulator if streaming api has not been used yet.
+ */
+ if (q->num_buffers == 0 && q->fileio == NULL) {
+ if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ)) {
+ ret = __vb2_init_fileio(q, 1);
+ if (ret)
+ return ret;
+ }
+ if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE)) {
+ ret = __vb2_init_fileio(q, 0);
+ if (ret)
+ return ret;
+ /*
+ * Write to OUTPUT queue can be done immediately.
+ */
+ return POLLOUT | POLLWRNORM;
+ }
+ }
+
+ /*
* There is nothing to wait for if no buffers have already been queued.
*/
if (list_empty(&q->queued_list))
@@ -1397,11 +1445,362 @@ EXPORT_SYMBOL_GPL(vb2_queue_init);
*/
void vb2_queue_release(struct vb2_queue *q)
{
+ __vb2_cleanup_fileio(q);
__vb2_queue_cancel(q);
__vb2_queue_free(q);
}
EXPORT_SYMBOL_GPL(vb2_queue_release);

+/**
+ * struct vb2_fileio_buf - buffer context used by file io emulator
+ *
+ * vb2 provides a compatibility layer and emulator of file io (read and
+ * write) calls on top of streaming API. This structure is used for
+ * tracking context related to the buffers.
+ */
+struct vb2_fileio_buf {
+ void *vaddr;
+ unsigned int size;
+ unsigned int pos;
+ unsigned int queued:1;
+};
+
+/**
+ * struct vb2_fileio_data - queue context used by file io emulator
+ *
+ * vb2 provides a compatibility layer and emulator of file io (read and
+ * write) calls on top of streaming API. For proper operation it required
+ * this structure to save the driver state between each call of the read
+ * or write function.
+ */
+struct vb2_fileio_data {
+ struct v4l2_requestbuffers req;
+ struct v4l2_buffer b;
+ struct vb2_fileio_buf bufs[VIDEO_MAX_FRAME];
+ unsigned int index;
+ unsigned int q_count;
+ unsigned int dq_count;
+ unsigned int flags;
+};
+
+/**
+ * __vb2_init_fileio() - initialize file io emulator
+ * @q: videobuf2 queue
+ * @read: mode selector (1 means read, 0 means write)
+ */
+static int __vb2_init_fileio(struct vb2_queue *q, int read)
+{
+ struct vb2_fileio_data *fileio;
+ int i, ret;
+ unsigned int count = 0;
+
+ /*
+ * Sanity check
+ */
+ if ((read && !(q->io_modes & VB2_READ)) ||
+ (!read && !(q->io_modes & VB2_WRITE)))
+ BUG();
+
+ /*
+ * Check if device supports mapping buffers to kernel virtual space.
+ */
+ if (!q->mem_ops->vaddr)
+ return -EBUSY;
+
+ /*
+ * Check if streaming api has not been already activated.
+ */
+ if (q->streaming || q->num_buffers > 0)
+ return -EBUSY;
+
+ /*
+ * Start with count 1, driver can increase it in queue_setup()
+ */
+ count = 1;
+
+ dprintk(3, "setting up file io: mode %s, count %d, flags %08x\n",
+ (read) ? "read" : "write", count, q->io_flags);
+
+ fileio = kzalloc(sizeof(struct vb2_fileio_data), GFP_KERNEL);
+ if (fileio == NULL)
+ return -ENOMEM;
+
+ fileio->flags = q->io_flags;
+
+ /*
+ * Request buffers and use MMAP type to force driver
+ * to allocate buffers by itself.
+ */
+ fileio->req.count = count;
+ fileio->req.memory = V4L2_MEMORY_MMAP;
+ fileio->req.type = q->type;
+ ret = vb2_reqbufs(q, &fileio->req);
+ if (ret)
+ goto err_kfree;
+
+ /*
+ * Check if plane_count is correct
+ * (multiplane buffers are not supported).
+ */
+ if (q->bufs[0]->num_planes != 1) {
+ fileio->req.count = 0;
+ ret = -EBUSY;
+ goto err_reqbufs;
+ }
+
+ /*
+ * Get kernel address of each buffer.
+ */
+ for (i = 0; i < q->num_buffers; i++) {
+ fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
+ if (fileio->bufs[i].vaddr == NULL)
+ goto err_reqbufs;
+ fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
+ }
+
+ /*
+ * Read mode requires pre queuing of all buffers.
+ */
+ if (read) {
+ /*
+ * Queue all buffers.
+ */
+ for (i = 0; i < q->num_buffers; i++) {
+ struct v4l2_buffer *b = &fileio->b;
+ memset(b, 0, sizeof(*b));
+ b->type = q->type;
+ b->memory = q->memory;
+ b->index = i;
+ ret = vb2_qbuf(q, b);
+ if (ret)
+ goto err_reqbufs;
+ fileio->bufs[i].queued = 1;
+ }
+
+ /*
+ * Start streaming.
+ */
+ ret = vb2_streamon(q, q->type);
+ if (ret)
+ goto err_reqbufs;
+ }
+
+ q->fileio = fileio;
+
+ return ret;
+
+err_reqbufs:
+ vb2_reqbufs(q, &fileio->req);
+
+err_kfree:
+ kfree(fileio);
+ return ret;
+}
+
+/**
+ * __vb2_cleanup_fileio() - free resourced used by file io emulator
+ * @q: videobuf2 queue
+ */
+static int __vb2_cleanup_fileio(struct vb2_queue *q)
+{
+ struct vb2_fileio_data *fileio = q->fileio;
+
+ if (fileio) {
+ /*
+ * Hack fileio context to enable direct calls to vb2 ioctl
+ * interface.
+ */
+ q->fileio = NULL;
+
+ vb2_streamoff(q, q->type);
+ fileio->req.count = 0;
+ vb2_reqbufs(q, &fileio->req);
+ kfree(fileio);
+ dprintk(3, "file io emulator closed\n");
+ }
+ return 0;
+}
+
+/**
+ * __vb2_perform_fileio() - perform a single file io (read or write) operation
+ * @q: videobuf2 queue
+ * @data: pointed to target userspace buffer
+ * @count: number of bytes to read or write
+ * @ppos: file handle position tracking pointer
+ * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
+ * @read: access mode selector (1 means read, 0 means write)
+ */
+static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
+ loff_t *ppos, int nonblock, int read)
+{
+ struct vb2_fileio_data *fileio;
+ struct vb2_fileio_buf *buf;
+ int ret, index;
+
+ dprintk(3, "file io: mode %s, offset %ld, count %d, %sblocking\n",
+ read ? "read" : "write", (long)*ppos, count,
+ nonblock ? "non" : "");
+
+ if (!data)
+ return -EINVAL;
+
+ /*
+ * Initialize emulator on first call.
+ */
+ if (!q->fileio) {
+ ret = __vb2_init_fileio(q, read);
+ dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
+ if (ret)
+ return ret;
+ }
+ fileio = q->fileio;
+
+ /*
+ * Hack fileio context to enable direct calls to vb2 ioctl interface.
+ * The pointer will be restored before returning from this function.
+ */
+ q->fileio = NULL;
+
+ index = fileio->index;
+ buf = &fileio->bufs[index];
+
+ /*
+ * Check if we need to dequeue the buffer.
+ */
+ if (buf->queued) {
+ struct vb2_buffer *vb;
+
+ /*
+ * Call vb2_dqbuf to get buffer back.
+ */
+ memset(&fileio->b, 0, sizeof(fileio->b));
+ fileio->b.type = q->type;
+ fileio->b.memory = q->memory;
+ fileio->b.index = index;
+ ret = vb2_dqbuf(q, &fileio->b, nonblock);
+ dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
+ if (ret)
+ goto end;
+ fileio->dq_count += 1;
+
+ /*
+ * Get number of bytes filled by the driver
+ */
+ vb = q->bufs[index];
+ buf->size = vb2_get_plane_payload(vb, 0);
+ buf->queued = 0;
+ }
+
+ /*
+ * Limit count on last few bytes of the buffer.
+ */
+ if (buf->pos + count > buf->size) {
+ count = buf->size - buf->pos;
+ dprintk(5, "reducing read count: %d\n", count);
+ }
+
+ /*
+ * Transfer data to userspace.
+ */
+ dprintk(3, "file io: copying %d bytes - buffer %d, offset %d\n",
+ count, index, buf->pos);
+ if (read)
+ ret = copy_to_user(data, buf->vaddr + buf->pos, count);
+ else
+ ret = copy_from_user(buf->vaddr + buf->pos, data, count);
+ if (ret) {
+ dprintk(3, "file io: error copying data\n");
+ ret = -EFAULT;
+ goto end;
+ }
+
+ /*
+ * Update counters.
+ */
+ buf->pos += count;
+ *ppos += count;
+
+ /*
+ * Queue next buffer if required.
+ */
+ if (buf->pos == buf->size ||
+ (!read && (fileio->flags & VB2_FILEIO_WRITE_IMMEDIATE))) {
+ /*
+ * Check if this is the last buffer to read.
+ */
+ if (read && (fileio->flags & VB2_FILEIO_READ_ONCE) &&
+ fileio->dq_count == 1) {
+ dprintk(3, "file io: read limit reached\n");
+ /*
+ * Restore fileio pointer and release the context.
+ */
+ q->fileio = fileio;
+ return __vb2_cleanup_fileio(q);
+ }
+
+ /*
+ * Call vb2_qbuf and give buffer to the driver.
+ */
+ memset(&fileio->b, 0, sizeof(fileio->b));
+ fileio->b.type = q->type;
+ fileio->b.memory = q->memory;
+ fileio->b.index = index;
+ fileio->b.bytesused = buf->pos;
+ ret = vb2_qbuf(q, &fileio->b);
+ dprintk(5, "file io: vb2_dbuf result: %d\n", ret);
+ if (ret)
+ goto end;
+
+ /*
+ * Buffer has been queued, update the status
+ */
+ buf->pos = 0;
+ buf->queued = 1;
+ buf->size = q->bufs[0]->v4l2_planes[0].length;
+ fileio->q_count += 1;
+
+ /*
+ * Switch to the next buffer
+ */
+ fileio->index = (index + 1) % q->num_buffers;
+
+ /*
+ * Start streaming if required.
+ */
+ if (!read && !q->streaming) {
+ ret = vb2_streamon(q, q->type);
+ if (ret)
+ goto end;
+ }
+ }
+
+ /*
+ * Return proper number of bytes processed.
+ */
+ if (ret == 0)
+ ret = count;
+end:
+ /*
+ * Restore the fileio context and block vb2 ioctl interface.
+ */
+ q->fileio = fileio;
+ return ret;
+}
+
+size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
+ loff_t *ppos, int nonblocking)
+{
+ return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
+}
+EXPORT_SYMBOL_GPL(vb2_read);
+
+size_t vb2_write(struct vb2_queue *q, char __user *data, size_t count,
+ loff_t *ppos, int nonblocking)
+{
+ return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 0);
+}
+EXPORT_SYMBOL_GPL(vb2_write);
+
MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
MODULE_AUTHOR("Pawel Osciak, Marek Szyprowski");
MODULE_LICENSE("GPL");
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index a44903a..bb340a2 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -18,6 +18,7 @@
#include <linux/videodev2.h>

struct vb2_alloc_ctx;
+struct vb2_fileio_data;

/**
* struct vb2_mem_ops - memory handling/memory allocator operations
@@ -54,6 +55,7 @@ struct vb2_alloc_ctx;
*
* Required ops for USERPTR types: get_userptr, put_userptr.
* Required ops for MMAP types: alloc, put, num_users, mmap.
+ * Required ops for read/write access types: alloc, put, num_users, vaddr
*/
struct vb2_mem_ops {
void *(*alloc)(void *alloc_ctx, unsigned long size);
@@ -246,6 +248,7 @@ struct vb2_ops {
* @done_wq: waitqueue for processes waiting for buffers ready to be dequeued
* @alloc_ctx: memory type/allocator-specific contexts for each plane
* @streaming: current streaming state
+ * @fileio: file io emulator internal data, used only if emulator is active
*/
struct vb2_queue {
enum v4l2_buf_type type;
@@ -272,6 +275,8 @@ struct vb2_queue {
void *alloc_ctx[VIDEO_MAX_PLANES];

unsigned int streaming:1;
+
+ struct vb2_fileio_data *fileio;
};

void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no);
@@ -295,6 +300,10 @@ int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type);

int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma);
unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait);
+size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
+ loff_t *ppos, int nonblock);
+size_t vb2_write(struct vb2_queue *q, char __user *data, size_t count,
+ loff_t *ppos, int nonblock);

/**
* vb2_is_streaming() - return streaming status of the queue
--
1.7.1.569.g6f426
Marek Szyprowski
2010-12-16 14:24:05 UTC
Permalink
From: Pawel Osciak <***@samsung.com>

Add support for the CMA contiguous memory allocator to videobuf2.

Signed-off-by: Pawel Osciak <***@samsung.com>
Signed-off-by: Kyungmin Park <***@samsung.com>
Signed-off-by: Marek Szyprowski <***@samsung.com>
CC: Pawel Osciak <***@osciak.com>
---
drivers/media/video/Kconfig | 6 +
drivers/media/video/Makefile | 1 +
drivers/media/video/videobuf2-cma.c | 224 +++++++++++++++++++++++++++++++++++
include/media/videobuf2-cma.h | 39 ++++++
4 files changed, 270 insertions(+), 0 deletions(-)
create mode 100644 drivers/media/video/videobuf2-cma.c
create mode 100644 include/media/videobuf2-cma.h

diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
index 4dda7bf..bb7196b 100644
--- a/drivers/media/video/Kconfig
+++ b/drivers/media/video/Kconfig
@@ -71,6 +71,12 @@ config VIDEOBUF2_DMA_SG
select VIDEOBUF2_CORE
select VIDEOBUF2_MEMOPS
tristate
+
+config VIDEOBUF2_CMA
+ depends on CMA
+ select VIDEOBUF2_CORE
+ select VIDEOBUF2_MEMOPS
+ tristate
#
# Multimedia Video device configuration
#
diff --git a/drivers/media/video/Makefile b/drivers/media/video/Makefile
index 5d7f3c1..082e64c 100644
--- a/drivers/media/video/Makefile
+++ b/drivers/media/video/Makefile
@@ -119,6 +119,7 @@ obj-$(CONFIG_VIDEOBUF2_MEMOPS) += videobuf2-memops.o
obj-$(CONFIG_VIDEOBUF2_VMALLOC) += videobuf2-vmalloc.o
obj-$(CONFIG_VIDEOBUF2_DMA_CONTIG) += videobuf2-dma-contig.o
obj-$(CONFIG_VIDEOBUF2_DMA_SG) += videobuf2-dma-sg.o
+obj-$(CONFIG_VIDEOBUF2_CMA) += videobuf2-cma.o

obj-$(CONFIG_V4L2_MEM2MEM_DEV) += v4l2-mem2mem.o

diff --git a/drivers/media/video/videobuf2-cma.c b/drivers/media/video/videobuf2-cma.c
new file mode 100644
index 0000000..b03154e
--- /dev/null
+++ b/drivers/media/video/videobuf2-cma.c
@@ -0,0 +1,224 @@
+/*
+ * videobuf2-cma.c - CMA memory allocator for videobuf2
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ *
+ * Author: Pawel Osciak <***@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/cma.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/file.h>
+
+#include <media/videobuf2-core.h>
+#include <media/videobuf2-memops.h>
+
+#include <asm/io.h>
+
+struct vb2_cma_conf {
+ struct device *dev;
+ const char *type;
+ unsigned long alignment;
+};
+
+struct vb2_cma_buf {
+ struct vb2_cma_conf *conf;
+ dma_addr_t paddr;
+ unsigned long size;
+ struct vm_area_struct *vma;
+ atomic_t refcount;
+ struct vb2_vmarea_handler handler;
+};
+
+static void vb2_cma_put(void *buf_priv);
+
+static void *vb2_cma_alloc(void *alloc_ctx, unsigned long size)
+{
+ struct vb2_cma_conf *conf = alloc_ctx;
+ struct vb2_cma_buf *buf;
+
+ buf = kzalloc(sizeof *buf, GFP_KERNEL);
+ if (!buf)
+ return ERR_PTR(-ENOMEM);
+
+ buf->paddr = cma_alloc(conf->dev, conf->type, size, conf->alignment);
+ if (IS_ERR((void *)buf->paddr)) {
+ printk(KERN_ERR "cma_alloc of size %ld failed\n", size);
+ kfree(buf);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ buf->conf = conf;
+ buf->size = size;
+
+ buf->handler.refcount = &buf->refcount;
+ buf->handler.put = vb2_cma_put;
+ buf->handler.arg = buf;
+
+ atomic_inc(&buf->refcount);
+
+ return buf;
+}
+
+static void vb2_cma_put(void *buf_priv)
+{
+ struct vb2_cma_buf *buf = buf_priv;
+
+ if (atomic_dec_and_test(&buf->refcount)) {
+ cma_free(buf->paddr);
+ kfree(buf);
+ }
+}
+
+static void *vb2_cma_cookie(void *buf_priv)
+{
+ struct vb2_cma_buf *buf = buf_priv;
+
+ return (void *)buf->paddr;
+}
+
+static unsigned int vb2_cma_num_users(void *buf_priv)
+{
+ struct vb2_cma_buf *buf = buf_priv;
+
+ return atomic_read(&buf->refcount);
+}
+
+static int vb2_cma_mmap(void *buf_priv, struct vm_area_struct *vma)
+{
+ struct vb2_cma_buf *buf = buf_priv;
+
+ if (!buf) {
+ printk(KERN_ERR "No buffer to map\n");
+ return -EINVAL;
+ }
+
+ return vb2_mmap_pfn_range(vma, buf->paddr, buf->size,
+ &vb2_common_vm_ops, &buf->handler);
+}
+
+static void *vb2_cma_get_userptr(void *alloc_ctx, unsigned long vaddr,
+ unsigned long size, int write)
+{
+ struct vb2_cma_buf *buf;
+ struct vm_area_struct *vma;
+ dma_addr_t paddr = 0;
+ int ret;
+
+ buf = kzalloc(sizeof *buf, GFP_KERNEL);
+ if (!buf)
+ return ERR_PTR(-ENOMEM);
+
+ ret = vb2_get_contig_userptr(vaddr, size, &vma, &paddr);
+ if (ret) {
+ printk(KERN_ERR "Failed acquiring VMA for vaddr 0x%08lx\n",
+ vaddr);
+ kfree(buf);
+ return ERR_PTR(ret);
+ }
+
+ buf->size = size;
+ buf->paddr = paddr;
+ buf->vma = vma;
+
+ return buf;
+}
+
+static void vb2_cma_put_userptr(void *mem_priv)
+{
+ struct vb2_cma_buf *buf = mem_priv;
+
+ if (!buf)
+ return;
+
+ vb2_put_vma(buf->vma);
+ kfree(buf);
+}
+
+static void *vb2_cma_vaddr(void *mem_priv)
+{
+ struct vb2_cma_buf *buf = mem_priv;
+ if (!buf)
+ return 0;
+
+ return phys_to_virt(buf->paddr);
+}
+
+const struct vb2_mem_ops vb2_cma_memops = {
+ .alloc = vb2_cma_alloc,
+ .put = vb2_cma_put,
+ .cookie = vb2_cma_cookie,
+ .mmap = vb2_cma_mmap,
+ .get_userptr = vb2_cma_get_userptr,
+ .put_userptr = vb2_cma_put_userptr,
+ .num_users = vb2_cma_num_users,
+ .vaddr = vb2_cma_vaddr,
+};
+EXPORT_SYMBOL_GPL(vb2_cma_memops);
+
+void *vb2_cma_init(struct device *dev, const char *type,
+ unsigned long alignment)
+{
+ struct vb2_cma_conf *conf;
+
+ conf = kzalloc(sizeof *conf, GFP_KERNEL);
+ if (!conf)
+ return ERR_PTR(-ENOMEM);
+
+ conf->dev = dev;
+ conf->type = type;
+ conf->alignment = alignment;
+
+ return conf;
+}
+EXPORT_SYMBOL_GPL(vb2_cma_init);
+
+void vb2_cma_cleanup(void *conf)
+{
+ kfree(conf);
+}
+EXPORT_SYMBOL_GPL(vb2_cma_cleanup);
+
+void **vb2_cma_init_multi(struct device *dev,
+ unsigned int num_planes,
+ const char *types[],
+ unsigned long alignments[])
+{
+ struct vb2_cma_conf *cma_conf;
+ void **alloc_ctxes;
+ unsigned int i;
+
+ alloc_ctxes = kzalloc((sizeof *alloc_ctxes + sizeof *cma_conf)
+ * num_planes, GFP_KERNEL);
+ if (!alloc_ctxes)
+ return ERR_PTR(-ENOMEM);
+
+ cma_conf = (void *)(alloc_ctxes + num_planes);
+
+ for (i = 0; i < num_planes; ++i, ++cma_conf) {
+ alloc_ctxes[i] = cma_conf;
+ cma_conf->dev = dev;
+ cma_conf->type = types[i];
+ cma_conf->alignment = alignments[i];
+ }
+
+ return alloc_ctxes;
+}
+EXPORT_SYMBOL_GPL(vb2_cma_init_multi);
+
+void vb2_cma_cleanup_multi(void **alloc_ctxes)
+{
+ kfree(alloc_ctxes);
+}
+EXPORT_SYMBOL_GPL(vb2_cma_cleanup_multi);
+
+MODULE_DESCRIPTION("CMA allocator handling routines for videobuf2");
+MODULE_AUTHOR("Pawel Osciak");
+MODULE_LICENSE("GPL");
diff --git a/include/media/videobuf2-cma.h b/include/media/videobuf2-cma.h
new file mode 100644
index 0000000..c1582d1
--- /dev/null
+++ b/include/media/videobuf2-cma.h
@@ -0,0 +1,39 @@
+/*
+ * videobuf2-cma.h - CMA memory allocator for videobuf2
+ *
+ * Copyright (C) 2010 Samsung Electronics
+ *
+ * Author: Pawel Osciak <***@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.
+ */
+
+#ifndef _MEDIA_VIDEOBUF2_CMA_H
+#define _MEDIA_VIDEOBUF2_CMA_H
+
+#include <media/videobuf2-core.h>
+
+static inline unsigned long vb2_cma_plane_paddr(struct vb2_buffer *vb,
+ unsigned int plane_no)
+{
+ return (unsigned long)vb2_plane_cookie(vb, plane_no);
+}
+
+struct vb2_alloc_ctx *vb2_cma_init(struct device *dev, const char *type,
+ unsigned long alignment);
+void vb2_cma_cleanup(struct vb2_alloc_ctx *alloc_ctx);
+
+struct vb2_alloc_ctx **vb2_cma_init_multi(struct device *dev,
+ unsigned int num_planes, const char *types[],
+ unsigned long alignments[]);
+void vb2_cma_cleanup_multi(struct vb2_alloc_ctx **alloc_ctxes);
+
+struct vb2_alloc_ctx *vb2_cma_init(struct device *dev, const char *type,
+ unsigned long alignment);
+void vb2_cma_cleanup(struct vb2_alloc_ctx *alloc_ctx);
+
+extern const struct vb2_mem_ops vb2_cma_memops;
+
+#endif
--
1.7.1.569.g6f426
Loading...