[patch] v4l: videobuf update

From: Gerd Knorr
Date: Tue Oct 07 2003 - 05:45:57 EST

Hi,

This patch updates the videobuf module used by the bttv, saa7134 and
saa7146 drivers. Related updates for the three drivers will follow.

Changes:
* adds support for overlays (i.e. PCI-PCI DMA transfers).
* adds support for userspace DMA.
* fixes bug in the read() helper function (catch I/O errors).

Please apply,

Gerd

diff -u linux-2.6.0-test6/drivers/media/video/video-buf.c linux/drivers/media/video/video-buf.c
--- linux-2.6.0-test6/drivers/media/video/video-buf.c 2003-10-06 17:45:22.000000000 +0200
+++ linux/drivers/media/video/video-buf.c 2003-10-06 17:48:02.000000000 +0200
@@ -197,6 +197,20 @@
return 0;
}

+int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
+ dma_addr_t addr, int nr_pages)
+{
+ dprintk(1,"init overlay [%d pages @ bus 0x%lx]\n",
+ nr_pages,(unsigned long)addr);
+ dma->direction = direction;
+ if (0 == addr)
+ return -EINVAL;
+
+ dma->bus_addr = addr;
+ dma->nr_pages = nr_pages;
+ return 0;
+}
+
int videobuf_dma_pci_map(struct pci_dev *dev, struct videobuf_dmabuf *dma)
{
int err;
@@ -218,12 +232,23 @@
dma->sglist = videobuf_vmalloc_to_sg
(dma->vmalloc,dma->nr_pages);
}
+ if (dma->bus_addr) {
+ dma->sglist = kmalloc(sizeof(struct scatterlist), GFP_KERNEL);
+ if (NULL != dma->sglist) {
+ dma->sglen = 1;
+ sg_dma_address(&dma->sglist[0]) = dma->bus_addr & ~PAGE_MASK;
+ dma->sglist[0].offset = dma->bus_addr & PAGE_MASK;
+ sg_dma_len(&dma->sglist[0]) = dma->nr_pages * PAGE_SIZE;
+ }
+ }
if (NULL == dma->sglist) {
dprintk(1,"scatterlist is NULL\n");
return -ENOMEM;
}
- dma->sglen = pci_map_sg(dev,dma->sglist,dma->nr_pages,
- dma->direction);
+
+ if (!dma->bus_addr)
+ dma->sglen = pci_map_sg(dev,dma->sglist,dma->nr_pages,
+ dma->direction);
return 0;
}

@@ -232,7 +257,8 @@
if (!dma->sglen)
BUG();

- pci_dma_sync_sg(dev,dma->sglist,dma->nr_pages,dma->direction);
+ if (!dma->bus_addr)
+ pci_dma_sync_sg(dev,dma->sglist,dma->nr_pages,dma->direction);
return 0;
}

@@ -241,7 +267,8 @@
if (!dma->sglen)
return 0;

- pci_unmap_sg(dev,dma->sglist,dma->nr_pages,dma->direction);
+ if (!dma->bus_addr)
+ pci_unmap_sg(dev,dma->sglist,dma->nr_pages,dma->direction);
kfree(dma->sglist);
dma->sglist = NULL;
dma->sglen = 0;
@@ -266,6 +293,9 @@
vfree(dma->vmalloc);
dma->vmalloc = NULL;
}
+ if (dma->bus_addr) {
+ dma->bus_addr = 0;
+ }
dma->direction = PCI_DMA_NONE;
return 0;
}
@@ -309,27 +339,48 @@
}

int
-videobuf_iolock(struct pci_dev *pci, struct videobuf_buffer *vb)
+videobuf_iolock(struct pci_dev *pci, struct videobuf_buffer *vb,
+ struct v4l2_framebuffer *fbuf)
{
int err,pages;
+ dma_addr_t bus;

- if (0 == vb->baddr) {
- /* no userspace addr -- kernel bounce buffer */
+ switch (vb->memory) {
+ case V4L2_MEMORY_MMAP:
+ case V4L2_MEMORY_USERPTR:
+ if (0 == vb->baddr) {
+ /* no userspace addr -- kernel bounce buffer */
+ pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
+ err = videobuf_dma_init_kernel(&vb->dma,PCI_DMA_FROMDEVICE,
+ pages);
+ if (0 != err)
+ return err;
+ } else {
+ /* dma directly to userspace */
+ err = videobuf_dma_init_user(&vb->dma,PCI_DMA_FROMDEVICE,
+ vb->baddr,vb->bsize);
+ if (0 != err)
+ return err;
+ }
+ break;
+ case V4L2_MEMORY_OVERLAY:
+ if (NULL == fbuf)
+ return -EINVAL;
+ /* FIXME: need sanity checks for vb->boff */
+ bus = (dma_addr_t)fbuf->base + vb->boff;
pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
- err = videobuf_dma_init_kernel(&vb->dma,PCI_DMA_FROMDEVICE,
- pages);
- if (0 != err)
- return err;
- } else {
- /* dma directly to userspace */
- err = videobuf_dma_init_user(&vb->dma,PCI_DMA_FROMDEVICE,
- vb->baddr,vb->bsize);
+ err = videobuf_dma_init_overlay(&vb->dma,PCI_DMA_FROMDEVICE,
+ bus, pages);
if (0 != err)
return err;
+ break;
+ default:
+ BUG();
}
err = videobuf_dma_pci_map(pci,&vb->dma);
if (0 != err)
return err;
+
return 0;
}

@@ -447,11 +498,26 @@
{
b->index = vb->i;
b->type = type;
- b->m.offset = vb->boff;
- b->length = vb->bsize;
+
+ b->memory = vb->memory;
+ switch (b->memory) {
+ case V4L2_MEMORY_MMAP:
+ b->m.offset = vb->boff;
+ b->length = vb->bsize;
+ break;
+ case V4L2_MEMORY_USERPTR:
+ b->m.userptr = vb->baddr;
+ b->length = vb->bsize;
+ break;
+ case V4L2_MEMORY_OVERLAY:
+ b->m.offset = vb->boff;
+ break;
+ }
+
b->flags = 0;
if (vb->map)
b->flags |= V4L2_BUF_FLAG_MAPPED;
+
switch (vb->state) {
case STATE_PREPARED:
case STATE_QUEUED:
@@ -467,6 +533,7 @@
/* nothing */
break;
}
+
b->field = vb->field;
b->timestamp = vb->ts;
b->bytesused = vb->size;
@@ -484,6 +551,10 @@
return -EINVAL;
if (req->count < 1)
return -EINVAL;
+ if (req->memory != V4L2_MEMORY_MMAP &&
+ req->memory != V4L2_MEMORY_USERPTR &&
+ req->memory != V4L2_MEMORY_OVERLAY)
+ return -EINVAL;

down(&q->lock);
count = req->count;
@@ -495,10 +566,10 @@
dprintk(1,"reqbufs: bufs=%d, size=0x%x [%d pages total]\n",
count, size, (count*size)>>PAGE_SHIFT);

- retval = videobuf_mmap_setup(file,q,count,size);
+ retval = videobuf_mmap_setup(file,q,count,size,req->memory);
if (retval < 0)
goto done;
- req->type = q->type;
+
req->count = count;

done:
@@ -540,12 +611,29 @@
buf = q->bufs[b->index];
if (NULL == buf)
goto done;
- if (0 == buf->baddr)
+ if (buf->memory != b->memory)
goto done;
if (buf->state == STATE_QUEUED ||
buf->state == STATE_ACTIVE)
goto done;

+ switch (b->memory) {
+ case V4L2_MEMORY_MMAP:
+ if (0 == buf->baddr)
+ goto done;
+ break;
+ case V4L2_MEMORY_USERPTR:
+ if (b->length < buf->bsize)
+ goto done;
+ buf->baddr = b->m.userptr;
+ break;
+ case V4L2_MEMORY_OVERLAY:
+ buf->boff = b->m.offset;
+ break;
+ default:
+ goto done;
+ }
+
field = videobuf_next_field(q);
retval = q->ops->buf_prepare(file,buf,field);
if (0 != retval)
@@ -663,8 +751,9 @@
if (NULL == q->read_buf)
goto done;

- q->read_buf->baddr = (unsigned long)data;
- q->read_buf->bsize = count;
+ q->read_buf->memory = V4L2_MEMORY_USERPTR;
+ q->read_buf->baddr = (unsigned long)data;
+ q->read_buf->bsize = count;
field = videobuf_next_field(q);
retval = q->ops->buf_prepare(file,q->read_buf,field);
if (0 != retval)
@@ -719,6 +808,7 @@
q->read_buf = videobuf_alloc(q->msize);
if (NULL == q->read_buf)
goto done;
+ q->read_buf->memory = V4L2_MEMORY_USERPTR;
field = videobuf_next_field(q);
retval = q->ops->buf_prepare(file,q->read_buf,field);
if (0 != retval)
@@ -780,7 +870,7 @@
count = VIDEO_MAX_FRAME;
size = PAGE_ALIGN(size);

- err = videobuf_mmap_setup(file, q, count, size);
+ err = videobuf_mmap_setup(file, q, count, size, V4L2_MEMORY_USERPTR);
if (err)
return err;
for (i = 0; i < count; i++) {
@@ -850,31 +940,36 @@
break;
}

- if (vbihack) {
- /* dirty, undocumented hack -- pass the frame counter
- * within the last four bytes of each vbi data block.
- * We need that one to maintain backward compatibility
- * to all vbi decoding software out there ... */
- fc = (unsigned int*)q->read_buf->dma.vmalloc;
- fc += (q->read_buf->size>>2) -1;
- *fc = q->read_buf->field_count >> 1;
- dprintk(1,"vbihack: %d\n",*fc);
- }
-
- /* copy stuff */
- bytes = count;
- if (bytes > q->read_buf->size - q->read_off)
- bytes = q->read_buf->size - q->read_off;
- if (copy_to_user(data + retval,
- q->read_buf->dma.vmalloc + q->read_off,
- bytes)) {
- if (0 == retval)
- retval = -EFAULT;
- break;
+ if (q->read_buf->state == STATE_DONE) {
+ if (vbihack) {
+ /* dirty, undocumented hack -- pass the frame counter
+ * within the last four bytes of each vbi data block.
+ * We need that one to maintain backward compatibility
+ * to all vbi decoding software out there ... */
+ fc = (unsigned int*)q->read_buf->dma.vmalloc;
+ fc += (q->read_buf->size>>2) -1;
+ *fc = q->read_buf->field_count >> 1;
+ dprintk(1,"vbihack: %d\n",*fc);
+ }
+
+ /* copy stuff */
+ bytes = count;
+ if (bytes > q->read_buf->size - q->read_off)
+ bytes = q->read_buf->size - q->read_off;
+ if (copy_to_user(data + retval,
+ q->read_buf->dma.vmalloc + q->read_off,
+ bytes)) {
+ if (0 == retval)
+ retval = -EFAULT;
+ break;
+ }
+ count -= bytes;
+ retval += bytes;
+ q->read_off += bytes;
+ } else {
+ /* some error -- skip buffer */
+ q->read_off = q->read_buf->size;
}
- count -= bytes;
- retval += bytes;
- q->read_off += bytes;

/* requeue buffer when done with copying */
if (q->read_off == q->read_buf->size) {
@@ -1004,7 +1099,8 @@
};

int videobuf_mmap_setup(struct file *file, struct videobuf_queue *q,
- unsigned int bcount, unsigned int bsize)
+ unsigned int bcount, unsigned int bsize,
+ enum v4l2_memory memory)
{
unsigned int i;
int err;
@@ -1012,12 +1108,21 @@
err = videobuf_mmap_free(file,q);
if (0 != err)
return err;
-
+
for (i = 0; i < bcount; i++) {
q->bufs[i] = videobuf_alloc(q->msize);
- q->bufs[i]->i = i;
- q->bufs[i]->boff = bsize * i;
- q->bufs[i]->bsize = bsize;
+ q->bufs[i]->i = i;
+ q->bufs[i]->memory = memory;
+ q->bufs[i]->bsize = bsize;
+ switch (memory) {
+ case V4L2_MEMORY_MMAP:
+ q->bufs[i]->boff = bsize * i;
+ break;
+ case V4L2_MEMORY_USERPTR:
+ case V4L2_MEMORY_OVERLAY:
+ /* nothing */
+ break;
+ };
}
dprintk(1,"mmap setup: %d buffers, %d bytes each\n",
bcount,bsize);
@@ -1063,6 +1168,8 @@
for (first = 0; first < VIDEO_MAX_FRAME; first++) {
if (NULL == q->bufs[first])
continue;
+ if (V4L2_MEMORY_MMAP != q->bufs[first]->memory)
+ continue;
if (q->bufs[first]->boff == (vma->vm_pgoff << PAGE_SHIFT))
break;
}
@@ -1076,6 +1183,8 @@
for (size = 0, last = first; last < VIDEO_MAX_FRAME; last++) {
if (NULL == q->bufs[last])
continue;
+ if (V4L2_MEMORY_MMAP != q->bufs[last]->memory)
+ continue;
if (q->bufs[last]->map) {
retval = -EBUSY;
goto done;
@@ -1124,6 +1233,7 @@

EXPORT_SYMBOL_GPL(videobuf_dma_init_user);
EXPORT_SYMBOL_GPL(videobuf_dma_init_kernel);
+EXPORT_SYMBOL_GPL(videobuf_dma_init_overlay);
EXPORT_SYMBOL_GPL(videobuf_dma_pci_map);
EXPORT_SYMBOL_GPL(videobuf_dma_pci_sync);
EXPORT_SYMBOL_GPL(videobuf_dma_pci_unmap);
diff -u linux-2.6.0-test6/include/media/video-buf.h linux/include/media/video-buf.h
--- linux-2.6.0-test6/include/media/video-buf.h 2003-10-06 17:45:24.000000000 +0200
+++ linux/include/media/video-buf.h 2003-10-06 17:48:02.000000000 +0200
@@ -43,17 +43,17 @@
* A small set of helper functions to manage buffers (both userland
* and kernel) for DMA.
*
- * videobuf_init_*_dmabuf()
+ * videobuf_dma_init_*()
* creates a buffer. The userland version takes a userspace
* pointer + length. The kernel version just wants the size and
* does memory allocation too using vmalloc_32().
*
- * videobuf_pci_*_dmabuf()
+ * videobuf_dma_pci_*()
* see Documentation/DMA-mapping.txt, these functions to
* basically the same. The map function does also build a
* scatterlist for the buffer (and unmap frees it ...)
*
- * videobuf_free_dmabuf()
+ * videobuf_dma_free()
* no comment ...
*
*/
@@ -66,6 +66,9 @@
/* for kernel buffers */
void *vmalloc;

+ /* for overlay buffers (pci-pci dma) */
+ dma_addr_t bus_addr;
+
/* common */
struct scatterlist *sglist;
int sglen;
@@ -77,6 +80,8 @@
unsigned long data, unsigned long size);
int videobuf_dma_init_kernel(struct videobuf_dmabuf *dma, int direction,
int nr_pages);
+int videobuf_dma_init_overlay(struct videobuf_dmabuf *dma, int direction,
+ dma_addr_t addr, int nr_pages);
int videobuf_dma_pci_map(struct pci_dev *dev, struct videobuf_dmabuf *dma);
int videobuf_dma_pci_sync(struct pci_dev *dev,
struct videobuf_dmabuf *dma);
@@ -133,6 +138,7 @@
/* info about the buffer */
unsigned int width;
unsigned int height;
+ unsigned int bytesperline; /* use only if != 0 */
unsigned long size;
enum v4l2_field field;
enum videobuf_state state;
@@ -140,7 +146,8 @@
struct list_head stream; /* QBUF/DQBUF list */

/* for mmap'ed buffers */
- size_t boff; /* buffer offset (mmap) */
+ enum v4l2_memory memory;
+ size_t boff; /* buffer offset (mmap + overlay) */
size_t bsize; /* buffer size */
unsigned long baddr; /* buffer addr (userland ptr!) */
struct videobuf_mapping *map;
@@ -185,7 +192,8 @@

void* videobuf_alloc(unsigned int size);
int videobuf_waiton(struct videobuf_buffer *vb, int non_blocking, int intr);
-int videobuf_iolock(struct pci_dev *pci, struct videobuf_buffer *vb);
+int videobuf_iolock(struct pci_dev *pci, struct videobuf_buffer *vb,
+ struct v4l2_framebuffer *fbuf);

void videobuf_queue_init(struct videobuf_queue *q,
struct videobuf_queue_ops *ops,
@@ -221,7 +229,8 @@
poll_table *wait);

int videobuf_mmap_setup(struct file *file, struct videobuf_queue *q,
- unsigned int bcount, unsigned int bsize);
+ unsigned int bcount, unsigned int bsize,
+ enum v4l2_memory memory);
int videobuf_mmap_free(struct file *file, struct videobuf_queue *q);
int videobuf_mmap_mapper(struct vm_area_struct *vma,
struct videobuf_queue *q);

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