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dma-pool: do not allocate pool memory from CMA
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There is no guarantee to CMA's placement, so allocating a zone specific
atomic pool from CMA might return memory from a completely different
memory zone. So stop using it.

Fixes: c84dc6e ("dma-pool: add additional coherent pools to map to gfp mask")
Reported-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Tested-by: Jeremy Linton <jeremy.linton@arm.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Nicolas Saenz Julienne authored and Christoph Hellwig committed Jul 14, 2020
1 parent 81e9d89 commit d9765e4
Showing 1 changed file with 2 additions and 9 deletions.
11 changes: 2 additions & 9 deletions kernel/dma/pool.c
Original file line number Diff line number Diff line change
Expand Up @@ -6,7 +6,6 @@
#include <linux/debugfs.h>
#include <linux/dma-direct.h>
#include <linux/dma-noncoherent.h>
#include <linux/dma-contiguous.h>
#include <linux/init.h>
#include <linux/genalloc.h>
#include <linux/set_memory.h>
Expand Down Expand Up @@ -69,12 +68,7 @@ static int atomic_pool_expand(struct gen_pool *pool, size_t pool_size,

do {
pool_size = 1 << (PAGE_SHIFT + order);

if (dev_get_cma_area(NULL))
page = dma_alloc_from_contiguous(NULL, 1 << order,
order, false);
else
page = alloc_pages(gfp, order);
page = alloc_pages(gfp, order);
} while (!page && order-- > 0);
if (!page)
goto out;
Expand Down Expand Up @@ -118,8 +112,7 @@ static int atomic_pool_expand(struct gen_pool *pool, size_t pool_size,
dma_common_free_remap(addr, pool_size);
#endif
free_page: __maybe_unused
if (!dma_release_from_contiguous(NULL, page, 1 << order))
__free_pages(page, order);
__free_pages(page, order);
out:
return ret;
}
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