From b763f24aed409296eb76d085c279b2c40462f8a1 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 19 Nov 2019 17:38:58 +0100 Subject: [PATCH] dma-direct: exclude dma_direct_map_resource from the min_low_pfn check commit 68a33b1794665ba8a1d1ef1d3bfcc7c587d380a6 upstream. The valid memory address check in dma_capable only makes sense when mapping normal memory, not when using dma_map_resource to map a device resource. Add a new boolean argument to dma_capable to exclude that check for the dma_map_resource case. Fixes: b12d66278dd6 ("dma-direct: check for overflows on 32 bit DMA addresses") Reported-by: Marek Szyprowski Signed-off-by: Christoph Hellwig Acked-by: Marek Szyprowski Tested-by: Marek Szyprowski --- arch/x86/kernel/amd_gart_64.c | 4 ++-- drivers/xen/swiotlb-xen.c | 4 ++-- include/linux/dma-direct.h | 5 +++-- kernel/dma/direct.c | 4 ++-- kernel/dma/swiotlb.c | 2 +- 5 files changed, 10 insertions(+), 9 deletions(-) --- a/arch/x86/kernel/amd_gart_64.c +++ b/arch/x86/kernel/amd_gart_64.c @@ -185,13 +185,13 @@ static void iommu_full(struct device *de static inline int need_iommu(struct device *dev, unsigned long addr, size_t size) { - return force_iommu || !dma_capable(dev, addr, size); + return force_iommu || !dma_capable(dev, addr, size, true); } static inline int nonforced_iommu(struct device *dev, unsigned long addr, size_t size) { - return !dma_capable(dev, addr, size); + return !dma_capable(dev, addr, size, true); } /* Map a single continuous physical area into the IOMMU. --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -381,7 +381,7 @@ static dma_addr_t xen_swiotlb_map_page(s * we can safely return the device addr and not worry about bounce * buffering it. */ - if (dma_capable(dev, dev_addr, size) && + if (dma_capable(dev, dev_addr, size, true) && !range_straddles_page_boundary(phys, size) && !xen_arch_need_swiotlb(dev, phys, dev_addr) && swiotlb_force != SWIOTLB_FORCE) @@ -403,7 +403,7 @@ static dma_addr_t xen_swiotlb_map_page(s /* * Ensure that the address returned is DMA'ble */ - if (unlikely(!dma_capable(dev, dev_addr, size))) { + if (unlikely(!dma_capable(dev, dev_addr, size, true))) { swiotlb_tbl_unmap_single(dev, map, size, size, dir, attrs | DMA_ATTR_SKIP_CPU_SYNC); return DMA_MAPPING_ERROR; --- a/include/linux/dma-direct.h +++ b/include/linux/dma-direct.h @@ -51,14 +51,15 @@ static inline phys_addr_t dma_to_phys(st return __sme_clr(__dma_to_phys(dev, daddr)); } -static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size) +static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size, + bool is_ram) { dma_addr_t end = addr + size - 1; if (!dev->dma_mask) return false; - if (!IS_ENABLED(CONFIG_ARCH_DMA_ADDR_T_64BIT) && + if (is_ram && !IS_ENABLED(CONFIG_ARCH_DMA_ADDR_T_64BIT) && min(addr, end) < phys_to_dma(dev, PFN_PHYS(min_low_pfn))) return false; --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -326,7 +326,7 @@ static inline bool dma_direct_possible(s size_t size) { return swiotlb_force != SWIOTLB_FORCE && - dma_capable(dev, dma_addr, size); + dma_capable(dev, dma_addr, size, true); } dma_addr_t dma_direct_map_page(struct device *dev, struct page *page, @@ -375,7 +375,7 @@ dma_addr_t dma_direct_map_resource(struc { dma_addr_t dma_addr = paddr; - if (unlikely(!dma_capable(dev, dma_addr, size))) { + if (unlikely(!dma_capable(dev, dma_addr, size, false))) { report_addr(dev, dma_addr, size); return DMA_MAPPING_ERROR; } --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -682,7 +682,7 @@ bool swiotlb_map(struct device *dev, phy /* Ensure that the address returned is DMA'ble */ *dma_addr = __phys_to_dma(dev, *phys); - if (unlikely(!dma_capable(dev, *dma_addr, size))) { + if (unlikely(!dma_capable(dev, *dma_addr, size, true))) { swiotlb_tbl_unmap_single(dev, *phys, size, size, dir, attrs | DMA_ATTR_SKIP_CPU_SYNC); return false;