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(). Signed-off-by: Figo.zhang <[email protected]> --- drivers/media/video/videobuf-dma-sg.c | 38 ++++++++++++++++++++++++++++---- 1 files changed, 33 insertions(+), 5 deletions(-) diff --git a/drivers/media/video/videobuf-dma-sg.c b/drivers/media/video/videobuf-dma-sg.c index 8359e6b..c9a8817 100644 --- a/drivers/media/video/videobuf-dma-sg.c +++ b/drivers/media/video/videobuf-dma-sg.c @@ -397,16 +397,44 @@ 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) + page = vmalloc_to_page(mem->dma.vmalloc+ + (offset & (~PAGE_MASK))); + if (mem->dma.pages) + page = mem->dma.pages[page_nr]; + 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 [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
