dma-pool: do not allocate pool memory from CMA (d9765e41) · Commits · 戴 / test

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: ("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>

kernel/dma/pool.c

+2 −9

Original line number	Diff line number	Diff line
		@@ -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>
		@@ -69,11 +68,6 @@ 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);
		} while (!page && order-- > 0);
		if (!page)
		@@ -118,7 +112,6 @@ remove_mapping:
		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);
		out:
		return ret;

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