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authorFrederic Barrat <fbarrat@linux.ibm.com>2021-05-26 16:45:40 +0200
committerMichael Ellerman <mpe@ellerman.id.au>2021-06-01 11:17:08 +1000
commit59cc84c802eb923805e7bba425976a3df5ce35d8 (patch)
tree3d84115b08a05ae52da71ebafaa50eb69f3904ba /arch/powerpc
parent1438709e6328925ef496dafd467dbd0353137434 (diff)
Revert "powerpc/kernel/iommu: Align size for IOMMU_PAGE_SIZE() to save TCEs"
This reverts commit 3c0468d4451eb6b4f6604370639f163f9637a479. That commit was breaking alignment guarantees for the DMA address when allocating coherent mappings, as described in Documentation/core-api/dma-api-howto.rst It was also noticed by Mellanox' driver: [ 1515.763621] mlx5_core c002:01:00.0: mlx5_frag_buf_alloc_node:146:(pid 13402): unexpected map alignment: 0x0800000000c61000, page_shift=16 [ 1515.763635] mlx5_core c002:01:00.0: mlx5_cqwq_create:181:(pid 13402): mlx5_frag_buf_alloc_node() failed, -12 Fixes: 3c0468d4451e ("powerpc/kernel/iommu: Align size for IOMMU_PAGE_SIZE() to save TCEs") Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com> Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20210526144540.117795-1-fbarrat@linux.ibm.com
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/kernel/iommu.c11
1 files changed, 5 insertions, 6 deletions
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index 57d6b85e9b96..2af89a5e379f 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -898,7 +898,6 @@ 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);
@@ -925,9 +924,8 @@ void *iommu_alloc_coherent(struct device *dev, struct iommu_table *tbl,
memset(ret, 0, size);
/* Set up tces to cover the allocated range */
- size_io = IOMMU_PAGE_ALIGN(size_io, tbl);
- nio_pages = size_io >> tbl->it_page_shift;
- io_order = get_iommu_order(size_io, tbl);
+ nio_pages = size >> tbl->it_page_shift;
+ io_order = get_iommu_order(size, tbl);
mapping = iommu_alloc(dev, tbl, ret, nio_pages, DMA_BIDIRECTIONAL,
mask >> tbl->it_page_shift, io_order, 0);
if (mapping == DMA_MAPPING_ERROR) {
@@ -942,9 +940,10 @@ void iommu_free_coherent(struct iommu_table *tbl, size_t size,
void *vaddr, dma_addr_t dma_handle)
{
if (tbl) {
- size_t size_io = IOMMU_PAGE_ALIGN(size, tbl);
- unsigned int nio_pages = size_io >> tbl->it_page_shift;
+ unsigned int nio_pages;
+ 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));