diff options
author | Nicolin Chen <nicoleotsuka@gmail.com> | 2020-09-01 15:16:45 -0700 |
---|---|---|
committer | Christoph Hellwig <hch@lst.de> | 2020-09-03 18:12:15 +0200 |
commit | 1e9d90dbed120ec98517428ffff4dacd9797e39d (patch) | |
tree | d743be6b54427bb62e36e6d1ae2f6fc243cd70b7 /arch | |
parent | 2281f797f5524abb8fff66bf8540b4f4687332a2 (diff) | |
download | linux-1e9d90dbed120ec98517428ffff4dacd9797e39d.tar.bz2 |
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 <hch@lst.de>
Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Acked-by: Niklas Schnelle <schnelle@linux.ibm.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/alpha/kernel/pci_iommu.c | 7 | ||||
-rw-r--r-- | arch/ia64/hp/common/sba_iommu.c | 3 | ||||
-rw-r--r-- | arch/powerpc/kernel/iommu.c | 11 | ||||
-rw-r--r-- | arch/s390/pci/pci_dma.c | 6 | ||||
-rw-r--r-- | arch/sparc/kernel/iommu-common.c | 10 | ||||
-rw-r--r-- | arch/sparc/kernel/iommu.c | 3 | ||||
-rw-r--r-- | arch/sparc/kernel/pci_sun4v.c | 3 | ||||
-rw-r--r-- | arch/x86/kernel/amd_gart_64.c | 3 |
8 files changed, 12 insertions, 34 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, |