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V4L/DVB (7552): videbuf-vmalloc: Corrects mmap code

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There were some bugs on videobuf-vmalloc.

Basically, remap were called with a wrong parameter. Due to that, a later remap
were needed, generating the need of some hacks on videobuf-vmalloc and
videobuf-core.

This patch fixes the remap and removes the hacks.

TODO:

- V4L2_MEMORY_USERPTR is not implemented yet. This method should be
  properly implemented, in order to work with a few userspace applications.

- The driver also doesn't implement V4L2_MEMORY_OVERLAY. This method is used
  only by a few applications, and are becaming obsolete, due to the increment
  of cpu performance. So, most apps prefer to retrieve data to an internal
  buffer, doing some processing like de-interlacing.

Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
This commit is contained in:
Mauro Carvalho Chehab 2008-04-13 14:58:21 -03:00
parent fbde31d54b
commit 968ced78a5
2 changed files with 108 additions and 75 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
drivers/media/video/videobuf-core.c
View File

@ -91,20 +91,6 @@ int videobuf_iolock(struct videobuf_queue *q, struct videobuf_buffer *vb,
MAGIC_CHECK(vb->magic, MAGIC_BUFFER);
MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
/* This is required to avoid OOPS on some cases,
since mmap_mapper() method should be called before _iolock.
On some cases, the mmap_mapper() is called only after scheduling.
*/
if (vb->memory == V4L2_MEMORY_MMAP) {
wait_event_timeout(vb->done, q->is_mmapped,
msecs_to_jiffies(100));
if (!q->is_mmapped) {
printk(KERN_ERR
"Error: mmap_mapper() never called!\n");
return -EINVAL;
}
}
return CALL(q, iolock, q, vb, fbuf);
}

169
drivers/media/video/videobuf-vmalloc.c
View File

@ -124,45 +124,75 @@ static int __videobuf_iolock (struct videobuf_queue* q,
struct videobuf_buffer *vb,
struct v4l2_framebuffer *fbuf)
{
int pages;
struct videobuf_vmalloc_memory *mem=vb->priv;
struct videobuf_vmalloc_memory *mem = vb->priv;
BUG_ON(!mem);
MAGIC_CHECK(mem->magic,MAGIC_VMAL_MEM);
MAGIC_CHECK(mem->magic, MAGIC_VMAL_MEM);
pages = PAGE_ALIGN(vb->size) >> PAGE_SHIFT;
switch (vb->memory) {
case V4L2_MEMORY_MMAP:
dprintk(1, "%s memory method MMAP\n", __func__);
/* Currently, doesn't support V4L2_MEMORY_OVERLAY */
if ((vb->memory != V4L2_MEMORY_MMAP) &&
(vb->memory != V4L2_MEMORY_USERPTR) ) {
printk(KERN_ERR "Method currently unsupported.\n");
return -EINVAL;
}
/* FIXME: should be tested with kernel mmap mem */
mem->vmalloc=vmalloc_user (PAGE_ALIGN(vb->size));
if (NULL == mem->vmalloc) {
printk(KERN_ERR "vmalloc (%d pages) failed\n",pages);
return -ENOMEM;
}
dprintk(1,"vmalloc is at addr 0x%08lx, size=%d\n",
(unsigned long)mem->vmalloc,
pages << PAGE_SHIFT);
/* It seems that some kernel versions need to do remap *after*
the mmap() call
*/
if (mem->vma) {
int retval=remap_vmalloc_range(mem->vma, mem->vmalloc,0);
kfree(mem->vma);
mem->vma=NULL;
if (retval<0) {
dprintk(1,"mmap app bug: remap_vmalloc_range area %p error %d\n",
mem->vmalloc,retval);
return retval;
/* All handling should be done by __videobuf_mmap_mapper() */
if (!mem->vmalloc) {
printk(KERN_ERR "memory is not alloced/mmapped.\n");
return -EINVAL;
}
break;
case V4L2_MEMORY_USERPTR:
{
int pages = PAGE_ALIGN(vb->size);
dprintk(1, "%s memory method USERPTR\n", __func__);
#if 1
if (vb->baddr) {
printk(KERN_ERR "USERPTR is currently not supported\n");
return -EINVAL;
}
#endif
/* The only USERPTR currently supported is the one needed for
read() method.
*/
mem->vmalloc = vmalloc_user(pages);
if (!mem->vmalloc) {
printk(KERN_ERR "vmalloc (%d pages) failed\n", pages);
return -ENOMEM;
}
dprintk(1, "vmalloc is at addr %p (%d pages)\n",
mem->vmalloc, pages);
#if 0
int rc;
/* Kernel userptr is used also by read() method. In this case,
there's no need to remap, since data will be copied to user
*/
if (!vb->baddr)
return 0;
/* FIXME: to properly support USERPTR, remap should occur.
The code bellow won't work, since mem->vma = NULL
*/
/* Try to remap memory */
rc = remap_vmalloc_range(mem->vma, (void *)vb->baddr, 0);
if (rc < 0) {
printk(KERN_ERR "mmap: remap failed with error %d. ", rc);
return -ENOMEM;
}
#endif
break;
}
case V4L2_MEMORY_OVERLAY:
default:
dprintk(1, "%s memory method OVERLAY/unknown\n", __func__);
/* Currently, doesn't support V4L2_MEMORY_OVERLAY */
printk(KERN_ERR "Memory method currently unsupported.\n");
return -EINVAL;
}
return 0;
@ -178,6 +208,7 @@ static int __videobuf_mmap_free(struct videobuf_queue *q)
{
unsigned int i;
dprintk(1, "%s\n", __func__);
for (i = 0; i < VIDEO_MAX_FRAME; i++) {
if (q->bufs[i]) {
if (q->bufs[i]->map)
@ -194,10 +225,11 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q,
struct videobuf_vmalloc_memory *mem;
struct videobuf_mapping *map;
unsigned int first;
int retval;
int retval, pages;
unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
if (! (vma->vm_flags & VM_WRITE) || ! (vma->vm_flags & VM_SHARED))
dprintk(1, "%s\n", __func__);
if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED))
return -EINVAL;
/* look for first buffer to map */
@ -217,46 +249,55 @@ static int __videobuf_mmap_mapper(struct videobuf_queue *q,
}
/* create mapping + update buffer list */
map = q->bufs[first]->map = kzalloc(sizeof(struct videobuf_mapping),GFP_KERNEL);
map = kzalloc(sizeof(struct videobuf_mapping), GFP_KERNEL);
if (NULL == map)
return -ENOMEM;
q->bufs[first]->map = map;
map->start = vma->vm_start;
map->end = vma->vm_end;
map->q = q;
q->bufs[first]->baddr = vma->vm_start;
mem = q->bufs[first]->priv;
BUG_ON(!mem);
MAGIC_CHECK(mem->magic, MAGIC_VMAL_MEM);
pages = PAGE_ALIGN(vma->vm_end - vma->vm_start);
mem->vmalloc = vmalloc_user(pages);
if (!mem->vmalloc) {
printk(KERN_ERR "vmalloc (%d pages) failed\n", pages);
goto error;
}
dprintk(1, "vmalloc is at addr %p (%d pages)\n",
mem->vmalloc, pages);
/* Try to remap memory */
retval = remap_vmalloc_range(vma, mem->vmalloc, 0);
if (retval < 0) {
printk(KERN_ERR "mmap: remap failed with error %d. ", retval);
vfree(mem->vmalloc);
goto error;
}
vma->vm_ops = &videobuf_vm_ops;
vma->vm_flags |= VM_DONTEXPAND | VM_RESERVED;
vma->vm_private_data = map;
mem=q->bufs[first]->priv;
BUG_ON (!mem);
MAGIC_CHECK(mem->magic,MAGIC_VMAL_MEM);
/* Try to remap memory */
retval=remap_vmalloc_range(vma, mem->vmalloc,0);
if (retval<0) {
dprintk(1,"mmap: postponing remap_vmalloc_range\n");
mem->vma=kmalloc(sizeof(*vma),GFP_KERNEL);
if (!mem->vma) {
kfree(map);
q->bufs[first]->map=NULL;
return -ENOMEM;
}
memcpy(mem->vma,vma,sizeof(*vma));
}
dprintk(1,"mmap %p: q=%p %08lx-%08lx (%lx) pgoff %08lx buf %d\n",
map,q,vma->vm_start,vma->vm_end,
map, q, vma->vm_start, vma->vm_end,
(long int) q->bufs[first]->bsize,
vma->vm_pgoff,first);
vma->vm_pgoff, first);
videobuf_vm_open(vma);
return (0);
return 0;
error:
mem = NULL;
kfree(map);
return -ENOMEM;
}
static int __videobuf_copy_to_user ( struct videobuf_queue *q,
@ -347,13 +388,19 @@ EXPORT_SYMBOL_GPL(videobuf_to_vmalloc);
void videobuf_vmalloc_free (struct videobuf_buffer *buf)
{
struct videobuf_vmalloc_memory *mem=buf->priv;
BUG_ON (!mem);
struct videobuf_vmalloc_memory *mem = buf->priv;
MAGIC_CHECK(mem->magic,MAGIC_VMAL_MEM);
if (!mem)
return;
MAGIC_CHECK(mem->magic, MAGIC_VMAL_MEM);
vfree(mem->vmalloc);
mem->vmalloc=NULL;
mem->vmalloc = NULL;
/* FIXME: need to do buf->priv = NULL? */
return;
}