[PATCH v1 02/10] powerpc/kernel/iommu: Align size for IOMMU_PAGE_SIZE on iommu_*_coherent()

[Leonardo Bras]

Both iommu_alloc_coherent() and iommu_free_coherent() assume that once
size is aligned to PAGE_SIZE it will be aligned to IOMMU_PAGE_SIZE.

Update those functions to guarantee alignment with requested size
using IOMMU_PAGE_ALIGN() before doing iommu_alloc() / iommu_free().

Also, on iommu_range_alloc(), replace ALIGN(n, 1 << tbl->it_page_shift)
with IOMMU_PAGE_ALIGN(n, tbl), which seems easier to read.

Signed-off-by: Leonardo Bras <leobra...@gmail.com>
---
 arch/powerpc/kernel/iommu.c | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index 9704f3f76e63..d7086087830f 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -237,10 +237,9 @@ static unsigned long iommu_range_alloc(struct device *dev,
        }
 
        if (dev)
-               boundary_size = ALIGN(dma_get_seg_boundary(dev) + 1,
-                                     1 << tbl->it_page_shift);
+               boundary_size = IOMMU_PAGE_ALIGN(dma_get_seg_boundary(dev) + 1, 
tbl);
        else
-               boundary_size = ALIGN(1UL << 32, 1 << tbl->it_page_shift);
+               boundary_size = IOMMU_PAGE_ALIGN(1UL << 32, tbl);
        /* 4GB boundary for iseries_hv_alloc and iseries_hv_map */
 
        n = iommu_area_alloc(tbl->it_map, limit, start, npages, tbl->it_offset,
@@ -858,6 +857,7 @@ void *iommu_alloc_coherent(struct device *dev, struct 
iommu_table *tbl,
        unsigned int order;
        unsigned int nio_pages, io_order;
        struct page *page;
+       size_t size_io = size;
 
        size = PAGE_ALIGN(size);
        order = get_order(size);
@@ -884,8 +884,9 @@ void *iommu_alloc_coherent(struct device *dev, struct 
iommu_table *tbl,
        memset(ret, 0, size);
 
        /* Set up tces to cover the allocated range */
-       nio_pages = size >> tbl->it_page_shift;
-       io_order = get_iommu_order(size, tbl);
+       size_io = IOMMU_PAGE_ALIGN(size_io, tbl);
+       nio_pages = size_io >> tbl->it_page_shift;
+       io_order = get_iommu_order(size_io, tbl);
        mapping = iommu_alloc(dev, tbl, ret, nio_pages, DMA_BIDIRECTIONAL,
                              mask >> tbl->it_page_shift, io_order, 0);
        if (mapping == DMA_MAPPING_ERROR) {
@@ -900,11 +901,11 @@ void iommu_free_coherent(struct iommu_table *tbl, size_t 
size,
                         void *vaddr, dma_addr_t dma_handle)
 {
        if (tbl) {
-               unsigned int nio_pages;
+               size_t size_io = IOMMU_PAGE_ALIGN(size, tbl);
+               unsigned int nio_pages = size_io >> tbl->it_page_shift;
 
-               size = PAGE_ALIGN(size);
-               nio_pages = size >> tbl->it_page_shift;
                iommu_free(tbl, dma_handle, nio_pages);
+
                size = PAGE_ALIGN(size);
                free_pages((unsigned long)vaddr, get_order(size));
        }
-- 
2.25.4