a mmap issue for videobuf-dma-sg: it will alloc a new page for mmaping
when it encounter page fault at video_vm_ops->fault().
a new implementation for mmap, it translate the vmalloc to page at
video_vm_ops->fault().
in v2, if mem->dma.vmalloc is NULL at video_vm_ops->fault(), it will
alloc memory by vmalloc_32().
Signed-off-by: Figo.zhang <figo1802@xxxxxxxxx>
---
drivers/media/video/videobuf-dma-sg.c | 51
+++++++++++++++++++++++++++------
1 files changed, 42 insertions(+), 9 deletions(-)
diff --git a/drivers/media/video/videobuf-dma-sg.c
b/drivers/media/video/videobuf-dma-sg.c
index 8359e6b..767483d 100644
--- a/drivers/media/video/videobuf-dma-sg.c
+++ b/drivers/media/video/videobuf-dma-sg.c
@@ -201,10 +201,11 @@ int videobuf_dma_init_kernel(struct
videobuf_dmabuf *dma, int direction,
dprintk(1, "init kernel [%d pages]\n", nr_pages);
dma->direction = direction;
- dma->vmalloc = vmalloc_32(nr_pages << PAGE_SHIFT);
- if (NULL == dma->vmalloc) {
- dprintk(1, "vmalloc_32(%d pages) failed\n", nr_pages);
- return -ENOMEM;
+ if (!dma->vmalloc)
+ dma->vmalloc = vmalloc_32(nr_pages << PAGE_SHIFT);
+ if (NULL == dma->vmalloc) {
+ dprintk(1, "vmalloc_32(%d pages) failed\n", nr_pages);
+ return -ENOMEM;
}
dprintk(1, "vmalloc is at addr 0x%08lx, size=%d\n",
@@ -397,16 +398,48 @@ static void videobuf_vm_close(struct
vm_area_struct *vma)
*/
static int videobuf_vm_fault(struct vm_area_struct *vma, struct
vm_fault *vmf)
{
- struct page *page;
+ struct page *page = NULL;
+ struct videobuf_mapping *map = vma->vm_private_data;
+ struct videobuf_queue *q = map->q;
+ struct videobuf_dma_sg_memory *mem = NULL;
+
+ unsigned long offset;
+ unsigned long page_nr;
+ int first;
dprintk(3, "fault: fault @ %08lx [vma %08lx-%08lx]\n",
(unsigned long)vmf->virtual_address,
vma->vm_start, vma->vm_end);
- page = alloc_page(GFP_USER | __GFP_DMA32);
- if (!page)
- return VM_FAULT_OOM;
- clear_user_highpage(page, (unsigned long)vmf->virtual_address);
+ mutex_lock(&q->vb_lock);
+
+ offset = (unsigned long)vmf->virtual_address - vma->vm_start;
+ page_nr = offset >> PAGE_SHIFT;
+
+ for (first = 0; first < VIDEO_MAX_FRAME; first++) {
+ if (NULL == q->bufs[first])
+ continue;
+
+ MAGIC_CHECK(mem->magic, MAGIC_SG_MEM);
+
+ if (q->bufs[first]->map == map)
+ break;
+ }
+
+ mem = q->bufs[first]->priv;
+ if (!mem)
+ return VM_FAULT_SIGBUS;
+ if (!mem->dma.vmalloc) {
+ mem->dma.vmalloc = vmalloc_32(PAGE_ALIGN(q->bufs[first]->size));
+ if (NULL == mem->dma.vmalloc) {
+ dprintk(1, "%s: vmalloc_32() failed\n", __func__);
+ return VM_FAULT_OOM;
+ }
+ } else
+ page = vmalloc_to_page(mem->dma.vmalloc+
+ (offset & (~PAGE_MASK)));
+ mutex_unlock(&q->vb_lock);
+
vmf->page = page;
return 0;
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
