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Revert "powerpc/kernel/iommu: Align size for IOMMU_PAGE_SIZE() to save TCEs"

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This reverts commit 3c0468d445.

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: 3c0468d445 ("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
This commit is contained in:
Frederic Barrat
2021-05-26 16:45:40 +02:00
committed by Michael Ellerman
parent 1438709e63
commit 59cc84c802
1 changed files with 5 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
arch/powerpc/kernel/iommu.c
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@@ -898,7 +898,6 @@ void *iommu_alloc_coherent(struct device *dev, struct iommu_table *tbl,
unsigned int order; unsigned int order;
unsigned int nio_pages, io_order; unsigned int nio_pages, io_order;
struct page *page; struct page *page;
size_t size_io = size;
size = PAGE_ALIGN(size); size = PAGE_ALIGN(size);
order = get_order(size); order = get_order(size);
@@ -925,9 +924,8 @@ void *iommu_alloc_coherent(struct device *dev, struct iommu_table *tbl,
memset(ret, 0, size); memset(ret, 0, size);
/* Set up tces to cover the allocated range */ /* Set up tces to cover the allocated range */
size_io = IOMMU_PAGE_ALIGN(size_io, tbl); nio_pages = size >> tbl->it_page_shift;
nio_pages = size_io >> tbl->it_page_shift; io_order = get_iommu_order(size, tbl);
io_order = get_iommu_order(size_io, tbl);
mapping = iommu_alloc(dev, tbl, ret, nio_pages, DMA_BIDIRECTIONAL, mapping = iommu_alloc(dev, tbl, ret, nio_pages, DMA_BIDIRECTIONAL,
mask >> tbl->it_page_shift, io_order, 0); mask >> tbl->it_page_shift, io_order, 0);
if (mapping == DMA_MAPPING_ERROR) { 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) void *vaddr, dma_addr_t dma_handle)
{ {
if (tbl) { if (tbl) {
size_t size_io = IOMMU_PAGE_ALIGN(size, tbl); unsigned int nio_pages;
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); iommu_free(tbl, dma_handle, nio_pages);
size = PAGE_ALIGN(size); size = PAGE_ALIGN(size);
free_pages((unsigned long)vaddr, get_order(size)); free_pages((unsigned long)vaddr, get_order(size));