From be8466abbfa9b235d630b26ada6bd30fed916742 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Tue, 22 Apr 2025 10:44:55 +0200 Subject: [PATCH] 5.15-stable patches added patches: xen-swiotlb-relax-alignment-requirements.patch --- queue-5.15/series | 1 + ...swiotlb-relax-alignment-requirements.patch | 78 +++++++++++++++++++ 2 files changed, 79 insertions(+) create mode 100644 queue-5.15/xen-swiotlb-relax-alignment-requirements.patch diff --git a/queue-5.15/series b/queue-5.15/series index 92c09f2d05..c1bf4b7e4f 100644 --- a/queue-5.15/series +++ b/queue-5.15/series @@ -210,3 +210,4 @@ x86-pvh-call-c-code-via-the-kernel-virtual-mapping.patch powerpc-rtas-prevent-spectre-v1-gadget-construction-in-sys_rtas.patch phy-tegra-xusb-fix-return-value-of-tegra_xusb_find_port_node-function.patch wifi-ath10k-avoid-null-pointer-error-during-sdio-remove.patch +xen-swiotlb-relax-alignment-requirements.patch diff --git a/queue-5.15/xen-swiotlb-relax-alignment-requirements.patch b/queue-5.15/xen-swiotlb-relax-alignment-requirements.patch new file mode 100644 index 0000000000..b9aa3f1b4f --- /dev/null +++ b/queue-5.15/xen-swiotlb-relax-alignment-requirements.patch @@ -0,0 +1,78 @@ +From 85fcb57c983f423180ba6ec5d0034242da05cc54 Mon Sep 17 00:00:00 2001 +From: Juergen Gross +Date: Mon, 10 Feb 2025 08:43:39 +0100 +Subject: xen/swiotlb: relax alignment requirements + +From: Juergen Gross + +commit 85fcb57c983f423180ba6ec5d0034242da05cc54 upstream. + +When mapping a buffer for DMA via .map_page or .map_sg DMA operations, +there is no need to check the machine frames to be aligned according +to the mapped areas size. All what is needed in these cases is that the +buffer is contiguous at machine level. + +So carve out the alignment check from range_straddles_page_boundary() +and move it to a helper called by xen_swiotlb_alloc_coherent() and +xen_swiotlb_free_coherent() directly. + +Fixes: 9f40ec84a797 ("xen/swiotlb: add alignment check for dma buffers") +Reported-by: Jan Vejvalka +Tested-by: Jan Vejvalka +Signed-off-by: Juergen Gross +Reviewed-by: Stefano Stabellini +Signed-off-by: Juergen Gross +Signed-off-by: Harshvardhan Jha +Signed-off-by: Greg Kroah-Hartman +--- + drivers/xen/swiotlb-xen.c | 18 +++++++++++------- + 1 file changed, 11 insertions(+), 7 deletions(-) + +--- a/drivers/xen/swiotlb-xen.c ++++ b/drivers/xen/swiotlb-xen.c +@@ -75,19 +75,21 @@ static inline phys_addr_t xen_dma_to_phy + return xen_bus_to_phys(dev, dma_to_phys(dev, dma_addr)); + } + ++static inline bool range_requires_alignment(phys_addr_t p, size_t size) ++{ ++ phys_addr_t algn = 1ULL << (get_order(size) + PAGE_SHIFT); ++ phys_addr_t bus_addr = pfn_to_bfn(XEN_PFN_DOWN(p)) << XEN_PAGE_SHIFT; ++ ++ return IS_ALIGNED(p, algn) && !IS_ALIGNED(bus_addr, algn); ++} ++ + 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; +@@ -306,7 +308,8 @@ xen_swiotlb_alloc_coherent(struct device + phys = dma_to_phys(hwdev, *dma_handle); + dev_addr = xen_phys_to_dma(hwdev, phys); + if (((dev_addr + size - 1 <= dma_mask)) && +- !range_straddles_page_boundary(phys, size)) ++ !range_straddles_page_boundary(phys, size) && ++ !range_requires_alignment(phys, size)) + *dma_handle = dev_addr; + else { + if (xen_create_contiguous_region(phys, order, +@@ -347,6 +350,7 @@ xen_swiotlb_free_coherent(struct device + + if (!WARN_ON((dev_addr + size - 1 > dma_mask) || + range_straddles_page_boundary(phys, size)) && ++ !range_requires_alignment(phys, size) && + TestClearPageXenRemapped(page)) + xen_destroy_contiguous_region(phys, order); + -- 2.47.3