diff options
| -rw-r--r-- | drivers/comedi/comedi_buf.c | 43 | ||||
| -rw-r--r-- | drivers/comedi/comedi_fops.c | 43 |
2 files changed, 42 insertions, 44 deletions
diff --git a/drivers/comedi/comedi_buf.c b/drivers/comedi/comedi_buf.c index 5807007bb3dd..002c0e76baff 100644 --- a/drivers/comedi/comedi_buf.c +++ b/drivers/comedi/comedi_buf.c @@ -27,14 +27,12 @@ static void comedi_buf_map_kref_release(struct kref *kref) if (bm->page_list) { if (bm->dma_dir != DMA_NONE) { - /* - * DMA buffer was allocated as a single block. - * Address is in page_list[0]. - */ - buf = &bm->page_list[0]; - dma_free_coherent(bm->dma_hw_dev, - PAGE_SIZE * bm->n_pages, - buf->virt_addr, buf->dma_addr); + for (i = 0; i < bm->n_pages; i++) { + buf = &bm->page_list[i]; + dma_free_coherent(bm->dma_hw_dev, PAGE_SIZE, + buf->virt_addr, + buf->dma_addr); + } } else { for (i = 0; i < bm->n_pages; i++) { buf = &bm->page_list[i]; @@ -88,26 +86,14 @@ comedi_buf_map_alloc(struct comedi_device *dev, enum dma_data_direction dma_dir, goto err; if (bm->dma_dir != DMA_NONE) { - void *virt_addr; - dma_addr_t dma_addr; - - /* - * Currently, the DMA buffer needs to be allocated as a - * single block so that it can be mmap()'ed. - */ - virt_addr = dma_alloc_coherent(bm->dma_hw_dev, - PAGE_SIZE * n_pages, &dma_addr, - GFP_KERNEL); - if (!virt_addr) - goto err; - for (i = 0; i < n_pages; i++) { buf = &bm->page_list[i]; - buf->virt_addr = virt_addr + (i << PAGE_SHIFT); - buf->dma_addr = dma_addr + (i << PAGE_SHIFT); + buf->virt_addr = + dma_alloc_coherent(bm->dma_hw_dev, PAGE_SIZE, + &buf->dma_addr, GFP_KERNEL); + if (!buf->virt_addr) + break; } - - bm->n_pages = i; } else { for (i = 0; i < n_pages; i++) { buf = &bm->page_list[i]; @@ -117,11 +103,10 @@ comedi_buf_map_alloc(struct comedi_device *dev, enum dma_data_direction dma_dir, SetPageReserved(virt_to_page(buf->virt_addr)); } - - bm->n_pages = i; - if (i < n_pages) - goto err; } + bm->n_pages = i; + if (i < n_pages) + goto err; return bm; diff --git a/drivers/comedi/comedi_fops.c b/drivers/comedi/comedi_fops.c index 37cfef36c1ad..3383a7ce27ff 100644 --- a/drivers/comedi/comedi_fops.c +++ b/drivers/comedi/comedi_fops.c @@ -2387,13 +2387,27 @@ static int comedi_mmap(struct file *file, struct vm_area_struct *vma) goto done; } if (bm->dma_dir != DMA_NONE) { + unsigned long vm_start = vma->vm_start; + unsigned long vm_end = vma->vm_end; + /* - * DMA buffer was allocated as a single block. - * Address is in page_list[0]. + * Buffer pages are not contiguous, so temporarily modify VMA + * start and end addresses for each buffer page. */ - buf = &bm->page_list[0]; - retval = dma_mmap_coherent(bm->dma_hw_dev, vma, buf->virt_addr, - buf->dma_addr, n_pages * PAGE_SIZE); + for (i = 0; i < n_pages; ++i) { + buf = &bm->page_list[i]; + vma->vm_start = start; + vma->vm_end = start + PAGE_SIZE; + retval = dma_mmap_coherent(bm->dma_hw_dev, vma, + buf->virt_addr, + buf->dma_addr, PAGE_SIZE); + if (retval) + break; + + start += PAGE_SIZE; + } + vma->vm_start = vm_start; + vma->vm_end = vm_end; } else { for (i = 0; i < n_pages; ++i) { unsigned long pfn; @@ -2407,19 +2421,18 @@ static int comedi_mmap(struct file *file, struct vm_area_struct *vma) start += PAGE_SIZE; } + } #ifdef CONFIG_MMU - /* - * Leaving behind a partial mapping of a buffer we're about to - * drop is unsafe, see remap_pfn_range_notrack(). - * We need to zap the range here ourselves instead of relying - * on the automatic zapping in remap_pfn_range() because we call - * remap_pfn_range() in a loop. - */ - if (retval) - zap_vma_ptes(vma, vma->vm_start, size); + /* + * Leaving behind a partial mapping of a buffer we're about to drop is + * unsafe, see remap_pfn_range_notrack(). We need to zap the range + * here ourselves instead of relying on the automatic zapping in + * remap_pfn_range() because we call remap_pfn_range() in a loop. + */ + if (retval) + zap_vma_ptes(vma, vma->vm_start, size); #endif - } if (retval == 0) { vma->vm_ops = &comedi_vm_ops; |