From 1e9d90dbed120ec98517428ffff4dacd9797e39d Mon Sep 17 00:00:00 2001 From: Nicolin Chen Date: Tue, 1 Sep 2020 15:16:45 -0700 Subject: dma-mapping: introduce dma_get_seg_boundary_nr_pages() We found that callers of dma_get_seg_boundary mostly do an ALIGN with page mask and then do a page shift to get number of pages: ALIGN(boundary + 1, 1 << shift) >> shift However, the boundary might be as large as ULONG_MAX, which means that a device has no specific boundary limit. So either "+ 1" or passing it to ALIGN() would potentially overflow. According to kernel defines: #define ALIGN_MASK(x, mask) (((x) + (mask)) & ~(mask)) #define ALIGN(x, a) ALIGN_MASK(x, (typeof(x))(a) - 1) We can simplify the logic here into a helper function doing: ALIGN(boundary + 1, 1 << shift) >> shift = ALIGN_MASK(b + 1, (1 << s) - 1) >> s = {[b + 1 + (1 << s) - 1] & ~[(1 << s) - 1]} >> s = [b + 1 + (1 << s) - 1] >> s = [b + (1 << s)] >> s = (b >> s) + 1 This patch introduces and applies dma_get_seg_boundary_nr_pages() as an overflow-free helper for the dma_get_seg_boundary() callers to get numbers of pages. It also takes care of the NULL dev case for non-DMA API callers. Suggested-by: Christoph Hellwig Signed-off-by: Nicolin Chen Acked-by: Niklas Schnelle Acked-by: Michael Ellerman (powerpc) Signed-off-by: Christoph Hellwig --- arch/alpha/kernel/pci_iommu.c | 7 +------ arch/ia64/hp/common/sba_iommu.c | 3 +-- arch/powerpc/kernel/iommu.c | 11 ++--------- arch/s390/pci/pci_dma.c | 6 ++---- arch/sparc/kernel/iommu-common.c | 10 +++------- arch/sparc/kernel/iommu.c | 3 +-- arch/sparc/kernel/pci_sun4v.c | 3 +-- arch/x86/kernel/amd_gart_64.c | 3 +-- drivers/parisc/ccio-dma.c | 3 +-- drivers/parisc/sba_iommu.c | 3 +-- include/linux/dma-mapping.h | 19 +++++++++++++++++++ 11 files changed, 33 insertions(+), 38 deletions(-) diff --git a/arch/alpha/kernel/pci_iommu.c b/arch/alpha/kernel/pci_iommu.c index 81037907268d..6f7de4f4e191 100644 --- a/arch/alpha/kernel/pci_iommu.c +++ b/arch/alpha/kernel/pci_iommu.c @@ -141,12 +141,7 @@ iommu_arena_find_pages(struct device *dev, struct pci_iommu_arena *arena, unsigned long boundary_size; base = arena->dma_base >> PAGE_SHIFT; - if (dev) { - boundary_size = dma_get_seg_boundary(dev) + 1; - boundary_size >>= PAGE_SHIFT; - } else { - boundary_size = 1UL << (32 - PAGE_SHIFT); - } + boundary_size = dma_get_seg_boundary_nr_pages(dev, PAGE_SHIFT); /* Search forward for the first mask-aligned sequence of N free ptes */ ptes = arena->ptes; diff --git a/arch/ia64/hp/common/sba_iommu.c b/arch/ia64/hp/common/sba_iommu.c index 656a4888c300..b49b73a95067 100644 --- a/arch/ia64/hp/common/sba_iommu.c +++ b/arch/ia64/hp/common/sba_iommu.c @@ -485,8 +485,7 @@ sba_search_bitmap(struct ioc *ioc, struct device *dev, ASSERT(((unsigned long) ioc->res_hint & (sizeof(unsigned long) - 1UL)) == 0); ASSERT(res_ptr < res_end); - boundary_size = (unsigned long long)dma_get_seg_boundary(dev) + 1; - boundary_size = ALIGN(boundary_size, 1ULL << iovp_shift) >> iovp_shift; + boundary_size = dma_get_seg_boundary_nr_pages(dev, iovp_shift); BUG_ON(ioc->ibase & ~iovp_mask); shift = ioc->ibase >> iovp_shift; diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c index 9704f3f76e63..5b69a6a72a0e 100644 --- a/arch/powerpc/kernel/iommu.c +++ b/arch/powerpc/kernel/iommu.c @@ -172,7 +172,6 @@ static unsigned long iommu_range_alloc(struct device *dev, int largealloc = npages > 15; int pass = 0; unsigned long align_mask; - unsigned long boundary_size; unsigned long flags; unsigned int pool_nr; struct iommu_pool *pool; @@ -236,15 +235,9 @@ again: } } - if (dev) - boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1, - 1 << tbl->it_page_shift); - else - boundary_size = ALIGN(1UL << 32, 1 << tbl->it_page_shift); - /* 4GB boundary for iseries_hv_alloc and iseries_hv_map */ - n = iommu_area_alloc(tbl->it_map, limit, start, npages, tbl->it_offset, - boundary_size >> tbl->it_page_shift, align_mask); + dma_get_seg_boundary_nr_pages(dev, tbl->it_page_shift), + align_mask); if (n == -1) { if (likely(pass == 0)) { /* First try the pool from the start */ diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c index 64b1399a73f0..4a37d8f4de9d 100644 --- a/arch/s390/pci/pci_dma.c +++ b/arch/s390/pci/pci_dma.c @@ -261,13 +261,11 @@ static unsigned long __dma_alloc_iommu(struct device *dev, unsigned long start, int size) { struct zpci_dev *zdev = to_zpci(to_pci_dev(dev)); - unsigned long boundary_size; - boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1, - PAGE_SIZE) >> PAGE_SHIFT; return iommu_area_alloc(zdev->iommu_bitmap, zdev->iommu_pages, start, size, zdev->start_dma >> PAGE_SHIFT, - boundary_size, 0); + dma_get_seg_boundary_nr_pages(dev, PAGE_SHIFT), + 0); } static dma_addr_t dma_alloc_address(struct device *dev, int size) diff --git a/arch/sparc/kernel/iommu-common.c b/arch/sparc/kernel/iommu-common.c index 59cb16691322..23ca75f09277 100644 --- a/arch/sparc/kernel/iommu-common.c +++ b/arch/sparc/kernel/iommu-common.c @@ -166,13 +166,6 @@ unsigned long iommu_tbl_range_alloc(struct device *dev, } } - if (dev) - boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1, - 1 << iommu->table_shift); - else - boundary_size = ALIGN(1ULL << 32, 1 << iommu->table_shift); - - boundary_size = boundary_size >> iommu->table_shift; /* * if the skip_span_boundary_check had been set during init, we set * things up so that iommu_is_span_boundary() merely checks if the @@ -181,6 +174,9 @@ unsigned long iommu_tbl_range_alloc(struct device *dev, if ((iommu->flags & IOMMU_NO_SPAN_BOUND) != 0) { shift = 0; boundary_size = iommu->poolsize * iommu->nr_pools; + } else { + boundary_size = dma_get_seg_boundary_nr_pages(dev, + iommu->table_shift); } n = iommu_area_alloc(iommu->map, limit, start, npages, shift, boundary_size, align_mask); diff --git a/arch/sparc/kernel/iommu.c b/arch/sparc/kernel/iommu.c index 4ae7388b1bff..c3e4e2df26a8 100644 --- a/arch/sparc/kernel/iommu.c +++ b/arch/sparc/kernel/iommu.c @@ -472,8 +472,7 @@ static int dma_4u_map_sg(struct device *dev, struct scatterlist *sglist, outs->dma_length = 0; max_seg_size = dma_get_max_seg_size(dev); - seg_boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1, - IO_PAGE_SIZE) >> IO_PAGE_SHIFT; + seg_boundary_size = dma_get_seg_boundary_nr_pages(dev, IO_PAGE_SHIFT); base_shift = iommu->tbl.table_map_base >> IO_PAGE_SHIFT; for_each_sg(sglist, s, nelems, i) { unsigned long paddr, npages, entry, out_entry = 0, slen; diff --git a/arch/sparc/kernel/pci_sun4v.c b/arch/sparc/kernel/pci_sun4v.c index 14b93c5564e3..6b92dd51c002 100644 --- a/arch/sparc/kernel/pci_sun4v.c +++ b/arch/sparc/kernel/pci_sun4v.c @@ -508,8 +508,7 @@ static int dma_4v_map_sg(struct device *dev, struct scatterlist *sglist, iommu_batch_start(dev, prot, ~0UL); max_seg_size = dma_get_max_seg_size(dev); - seg_boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1, - IO_PAGE_SIZE) >> IO_PAGE_SHIFT; + seg_boundary_size = dma_get_seg_boundary_nr_pages(dev, IO_PAGE_SHIFT); mask = *dev->dma_mask; if (!iommu_use_atu(iommu, mask)) diff --git a/arch/x86/kernel/amd_gart_64.c b/arch/x86/kernel/amd_gart_64.c index e89031e9c847..bccc5357bffd 100644 --- a/arch/x86/kernel/amd_gart_64.c +++ b/arch/x86/kernel/amd_gart_64.c @@ -96,8 +96,7 @@ static unsigned long alloc_iommu(struct device *dev, int size, base_index = ALIGN(iommu_bus_base & dma_get_seg_boundary(dev), PAGE_SIZE) >> PAGE_SHIFT; - boundary_size = ALIGN((u64)dma_get_seg_boundary(dev) + 1, - PAGE_SIZE) >> PAGE_SHIFT; + boundary_size = dma_get_seg_boundary_nr_pages(dev, PAGE_SHIFT); spin_lock_irqsave(&iommu_bitmap_lock, flags); offset = iommu_area_alloc(iommu_gart_bitmap, iommu_pages, next_bit, diff --git a/drivers/parisc/ccio-dma.c b/drivers/parisc/ccio-dma.c index a5507f75b524..ba16b7f8f806 100644 --- a/drivers/parisc/ccio-dma.c +++ b/drivers/parisc/ccio-dma.c @@ -356,8 +356,7 @@ ccio_alloc_range(struct ioc *ioc, struct device *dev, size_t size) ** ggg sacrifices another 710 to the computer gods. */ - boundary_size = ALIGN((unsigned long long)dma_get_seg_boundary(dev) + 1, - 1ULL << IOVP_SHIFT) >> IOVP_SHIFT; + boundary_size = dma_get_seg_boundary_nr_pages(dev, IOVP_SHIFT); if (pages_needed <= 8) { /* diff --git a/drivers/parisc/sba_iommu.c b/drivers/parisc/sba_iommu.c index d4314fba0269..959bda193b96 100644 --- a/drivers/parisc/sba_iommu.c +++ b/drivers/parisc/sba_iommu.c @@ -342,8 +342,7 @@ sba_search_bitmap(struct ioc *ioc, struct device *dev, unsigned long shift; int ret; - boundary_size = ALIGN((unsigned long long)dma_get_seg_boundary(dev) + 1, - 1ULL << IOVP_SHIFT) >> IOVP_SHIFT; + boundary_size = dma_get_seg_boundary_nr_pages(dev, IOVP_SHIFT); #if defined(ZX1_SUPPORT) BUG_ON(ioc->ibase & ~IOVP_MASK); diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h index 52635e91143b..faab0a8210b9 100644 --- a/include/linux/dma-mapping.h +++ b/include/linux/dma-mapping.h @@ -632,6 +632,25 @@ static inline unsigned long dma_get_seg_boundary(struct device *dev) return DMA_BIT_MASK(32); } +/** + * dma_get_seg_boundary_nr_pages - return the segment boundary in "page" units + * @dev: device to guery the boundary for + * @page_shift: ilog() of the IOMMU page size + * + * Return the segment boundary in IOMMU page units (which may be different from + * the CPU page size) for the passed in device. + * + * If @dev is NULL a boundary of U32_MAX is assumed, this case is just for + * non-DMA API callers. + */ +static inline unsigned long dma_get_seg_boundary_nr_pages(struct device *dev, + unsigned int page_shift) +{ + if (!dev) + return (U32_MAX >> page_shift) + 1; + return (dma_get_seg_boundary(dev) >> page_shift) + 1; +} + static inline int dma_set_seg_boundary(struct device *dev, unsigned long mask) { if (dev->dma_parms) { -- cgit