diff mbox series

[28/30,for,5.4] dma-pool: do not allocate pool memory from CMA

Message ID 20200925161916.204667-29-pgonda@google.com
State New
Headers show
Series Backport unencrypted non-blocking DMA allocations | expand

Commit Message

Peter Gonda Sept. 25, 2020, 4:19 p.m. UTC 
From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>

upstream d9765e41d8e9ea2251bf73735a2895c8bad546fc commit.

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: c84dc6e68a1d ("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>
Signed-off-by: Peter Gonda <pgonda@google.com>
---
 kernel/dma/pool.c | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)
diff mbox series

Patch

diff --git a/kernel/dma/pool.c b/kernel/dma/pool.c
index d48d9acb585f..6bc74a2d5127 100644
--- a/kernel/dma/pool.c
+++ b/kernel/dma/pool.c
@@ -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>
@@ -69,12 +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;
@@ -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;
 }