Hi, On Friday 30 July 2010 02:08:02 Figo.zhang wrote: > 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(). You're replacing allocation in videobuf_vm_fault by allocationg in videobuf_vm_fault. I don't see the point. videobuf_vm_fault needs to go away completely. This has been discussed previously: fixing videobuf is not really possible. A videobuf2 implementation is needed and is (slowly) being worked on. I wouldn't bother with this patch, just drop it. > 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; -- Regards, Laurent Pinchart -- 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
