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(). pls see http://www.spinics.net/lists/linux-media/msg21243.html a new implementation for mmap, it translate to 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 vmlloc_32(). Signed-off-by: Figo.zhang <figo1802@xxxxxxxxx> --- drivers/media/video/videobuf-dma-sg.c | 50 +++++++++++++++++++++++++++------ 1 files changed, 41 insertions(+), 9 deletions(-) diff --git a/drivers/media/video/videobuf-dma-sg.c b/drivers/media/video/videobuf-dma-sg.c index 8359e6b..f7295da 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 +398,47 @@ 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
