[PATCH 10/31] powerpc/iommu: handle page-less SG entries

Christoph Hellwig
2015-08-12T07:05:29Z

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