[PATCH 10/31] powerpc/iommu: handle page-less SG entries
From: Christoph Hellwig <hch@lst.de>
Date: 2015-08-12 07:09:16
Also in:
linux-arch, linux-media, linux-mips, linux-s390, linuxppc-dev, lkml, sparclinux
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
For the iommu offset we just need and offset into the page. Calculate that using the physical address instead of using the virtual address so that we don't require a virtual mapping. Signed-off-by: Christoph Hellwig <hch@lst.de> --- arch/powerpc/kernel/iommu.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index a8e3490..0f52e40 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c@@ -457,7 +457,7 @@ int ppc_iommu_map_sg(struct device *dev, struct iommu_table *tbl, max_seg_size = dma_get_max_seg_size(dev); for_each_sg(sglist, s, nelems, i) { - unsigned long vaddr, npages, entry, slen; + unsigned long paddr, npages, entry, slen; slen = s->length; /* Sanity check */
@@ -466,22 +466,22 @@ int ppc_iommu_map_sg(struct device *dev, struct iommu_table *tbl, continue; } /* Allocate iommu entries for that segment */ - vaddr = (unsigned long) sg_virt(s); - npages = iommu_num_pages(vaddr, slen, IOMMU_PAGE_SIZE(tbl)); + paddr = sg_phys(s); + npages = iommu_num_pages(paddr, slen, IOMMU_PAGE_SIZE(tbl)); align = 0; if (tbl->it_page_shift < PAGE_SHIFT && slen >= PAGE_SIZE && - (vaddr & ~PAGE_MASK) == 0) + (paddr & ~PAGE_MASK) == 0) align = PAGE_SHIFT - tbl->it_page_shift; entry = iommu_range_alloc(dev, tbl, npages, &handle, mask >> tbl->it_page_shift, align); - DBG(" - vaddr: %lx, size: %lx\n", vaddr, slen); + DBG(" - paddr: %lx, size: %lx\n", paddr, slen); /* Handle failure */ if (unlikely(entry == DMA_ERROR_CODE)) { if (printk_ratelimit()) dev_info(dev, "iommu_alloc failed, tbl %p " - "vaddr %lx npages %lu\n", tbl, vaddr, + "paddr %lx npages %lu\n", tbl, paddr, npages); goto failure; }
@@ -496,7 +496,7 @@ int ppc_iommu_map_sg(struct device *dev, struct iommu_table *tbl, /* Insert into HW table */ build_fail = tbl->it_ops->set(tbl, entry, npages, - vaddr & IOMMU_PAGE_MASK(tbl), + paddr & IOMMU_PAGE_MASK(tbl), direction, attrs); if(unlikely(build_fail)) goto failure;
--
1.9.1