diff options
| -rw-r--r-- | drivers/dma-buf/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/dma-buf/udmabuf.c | 22 |
2 files changed, 16 insertions, 7 deletions
diff --git a/drivers/dma-buf/Kconfig b/drivers/dma-buf/Kconfig index b46eb8a552d7..fee04fdb0822 100644 --- a/drivers/dma-buf/Kconfig +++ b/drivers/dma-buf/Kconfig @@ -36,6 +36,7 @@ config UDMABUF depends on DMA_SHARED_BUFFER depends on MEMFD_CREATE || COMPILE_TEST depends on MMU + select VMAP_PFN help A driver to let userspace turn memfd regions into dma-bufs. Qemu can use this to create host dmabufs for guest framebuffers. diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c index ba9dbc7caf71..aa182a9dcdfa 100644 --- a/drivers/dma-buf/udmabuf.c +++ b/drivers/dma-buf/udmabuf.c @@ -103,21 +103,29 @@ static int mmap_udmabuf(struct dma_buf *buf, struct vm_area_struct *vma) static int vmap_udmabuf(struct dma_buf *buf, struct iosys_map *map) { struct udmabuf *ubuf = buf->priv; - struct page **pages; + unsigned long *pfns; void *vaddr; pgoff_t pg; dma_resv_assert_held(buf->resv); - pages = kvmalloc_array(ubuf->pagecount, sizeof(*pages), GFP_KERNEL); - if (!pages) + /** + * HVO may free tail pages, so just use pfn to map each folio + * into vmalloc area. + */ + pfns = kvmalloc_array(ubuf->pagecount, sizeof(*pfns), GFP_KERNEL); + if (!pfns) return -ENOMEM; - for (pg = 0; pg < ubuf->pagecount; pg++) - pages[pg] = &ubuf->folios[pg]->page; + for (pg = 0; pg < ubuf->pagecount; pg++) { + unsigned long pfn = folio_pfn(ubuf->folios[pg]); - vaddr = vm_map_ram(pages, ubuf->pagecount, -1); - kvfree(pages); + pfn += ubuf->offsets[pg] >> PAGE_SHIFT; + pfns[pg] = pfn; + } + + vaddr = vmap_pfn(pfns, ubuf->pagecount, PAGE_KERNEL); + kvfree(pfns); if (!vaddr) return -EINVAL; |