diff options
| -rw-r--r-- | kernel/dma/swiotlb.c | 25 |
1 files changed, 16 insertions, 9 deletions
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 26202274784f..71392c9fac10 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -558,29 +558,40 @@ void __init swiotlb_exit(void) * alloc_dma_pages() - allocate pages to be used for DMA * @gfp: GFP flags for the allocation. * @bytes: Size of the buffer. + * @phys_limit: Maximum allowed physical address of the buffer. * * Allocate pages from the buddy allocator. If successful, make the allocated * pages decrypted that they can be used for DMA. * - * Return: Decrypted pages, or %NULL on failure. + * Return: Decrypted pages, %NULL on allocation failure, or ERR_PTR(-EAGAIN) + * if the allocated physical address was above @phys_limit. */ -static struct page *alloc_dma_pages(gfp_t gfp, size_t bytes) +static struct page *alloc_dma_pages(gfp_t gfp, size_t bytes, u64 phys_limit) { unsigned int order = get_order(bytes); struct page *page; + phys_addr_t paddr; void *vaddr; page = alloc_pages(gfp, order); if (!page) return NULL; - vaddr = page_address(page); + paddr = page_to_phys(page); + if (paddr + bytes - 1 > phys_limit) { + __free_pages(page, order); + return ERR_PTR(-EAGAIN); + } + + vaddr = phys_to_virt(paddr); if (set_memory_decrypted((unsigned long)vaddr, PFN_UP(bytes))) goto error; return page; error: - __free_pages(page, order); + /* Intentional leak if pages cannot be encrypted again. */ + if (!set_memory_encrypted((unsigned long)vaddr, PFN_UP(bytes))) + __free_pages(page, order); return NULL; } @@ -618,11 +629,7 @@ static struct page *swiotlb_alloc_tlb(struct device *dev, size_t bytes, else if (phys_limit <= DMA_BIT_MASK(32)) gfp |= __GFP_DMA32; - while ((page = alloc_dma_pages(gfp, bytes)) && - page_to_phys(page) + bytes - 1 > phys_limit) { - /* allocated, but too high */ - __free_pages(page, get_order(bytes)); - + while (IS_ERR(page = alloc_dma_pages(gfp, bytes, phys_limit))) { if (IS_ENABLED(CONFIG_ZONE_DMA32) && phys_limit < DMA_BIT_MASK(64) && !(gfp & (__GFP_DMA32 | __GFP_DMA))) |