From 1bd738f10f566bb47ddaed7957863c81b82ff7b7 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Fri, 13 Sep 2024 12:05:02 +0200 Subject: [PATCH] xen/swiotlb: add alignment check for dma buffers BugLink: https://bugs.launchpad.net/bugs/2089340 [ Upstream commit 9f40ec84a7976d95c34e7cc070939deb103652b0 ] When checking a memory buffer to be consecutive in machine memory, the alignment needs to be checked, too. Failing to do so might result in DMA memory not being aligned according to its requested size, leading to error messages like: 4xxx 0000:2b:00.0: enabling device (0140 -> 0142) 4xxx 0000:2b:00.0: Ring address not aligned 4xxx 0000:2b:00.0: Failed to initialise service qat_crypto 4xxx 0000:2b:00.0: Resetting device qat_dev0 4xxx: probe of 0000:2b:00.0 failed with error -14 Fixes: 9435cce87950 ("xen/swiotlb: Add support for 64KB page granularity") Signed-off-by: Juergen Gross Reviewed-by: Stefano Stabellini Signed-off-by: Juergen Gross Signed-off-by: Sasha Levin Signed-off-by: Portia Stephens Signed-off-by: Stefan Bader --- drivers/xen/swiotlb-xen.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 0e6c6c25d154..892f87300e2c 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -78,9 +78,15 @@ static inline int range_straddles_page_boundary(phys_addr_t p, size_t size) { unsigned long next_bfn, xen_pfn = XEN_PFN_DOWN(p); unsigned int i, nr_pages = XEN_PFN_UP(xen_offset_in_page(p) + size); + phys_addr_t algn = 1ULL << (get_order(size) + PAGE_SHIFT); next_bfn = pfn_to_bfn(xen_pfn); + /* If buffer is physically aligned, ensure DMA alignment. */ + if (IS_ALIGNED(p, algn) && + !IS_ALIGNED((phys_addr_t)next_bfn << XEN_PAGE_SHIFT, algn)) + return 1; + for (i = 1; i < nr_pages; i++) if (pfn_to_bfn(++xen_pfn) != ++next_bfn) return 1;