From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Sasha Levin <sashal@kernel.org>,
iommu@lists.linux-foundation.org, Christoph Hellwig <hch@lst.de>
Subject: [PATCH AUTOSEL 5.8 31/63] dma-pool: Only allocate from CMA when in same memory zone
Date: Mon, 24 Aug 2020 12:34:31 -0400 [thread overview]
Message-ID: <20200824163504.605538-31-sashal@kernel.org> (raw)
In-Reply-To: <20200824163504.605538-1-sashal@kernel.org>
From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
[ Upstream commit d7e673ec2c8e0ea39c4c70fc490d67d7fbda869d ]
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. To get around this double check CMA's placement before
allocating from it.
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/dma/pool.c | 31 ++++++++++++++++++++++++++++++-
1 file changed, 30 insertions(+), 1 deletion(-)
diff --git a/kernel/dma/pool.c b/kernel/dma/pool.c
index 5d071d4a3cbaa..06582b488e317 100644
--- a/kernel/dma/pool.c
+++ b/kernel/dma/pool.c
@@ -3,7 +3,9 @@
* Copyright (C) 2012 ARM Ltd.
* Copyright (C) 2020 Google LLC
*/
+#include <linux/cma.h>
#include <linux/debugfs.h>
+#include <linux/dma-contiguous.h>
#include <linux/dma-direct.h>
#include <linux/dma-noncoherent.h>
#include <linux/init.h>
@@ -55,6 +57,29 @@ static void dma_atomic_pool_size_add(gfp_t gfp, size_t size)
pool_size_kernel += size;
}
+static bool cma_in_zone(gfp_t gfp)
+{
+ unsigned long size;
+ phys_addr_t end;
+ struct cma *cma;
+
+ cma = dev_get_cma_area(NULL);
+ if (!cma)
+ return false;
+
+ size = cma_get_size(cma);
+ if (!size)
+ return false;
+
+ /* CMA can't cross zone boundaries, see cma_activate_area() */
+ end = cma_get_base(cma) + size - 1;
+ if (IS_ENABLED(CONFIG_ZONE_DMA) && (gfp & GFP_DMA))
+ return end <= DMA_BIT_MASK(zone_dma_bits);
+ if (IS_ENABLED(CONFIG_ZONE_DMA32) && (gfp & GFP_DMA32))
+ return end <= DMA_BIT_MASK(32);
+ return true;
+}
+
static int atomic_pool_expand(struct gen_pool *pool, size_t pool_size,
gfp_t gfp)
{
@@ -68,7 +93,11 @@ static int atomic_pool_expand(struct gen_pool *pool, size_t pool_size,
do {
pool_size = 1 << (PAGE_SHIFT + order);
- page = alloc_pages(gfp, order);
+ if (cma_in_zone(gfp))
+ page = dma_alloc_from_contiguous(NULL, 1 << order,
+ order, false);
+ if (!page)
+ page = alloc_pages(gfp, order);
} while (!page && order-- > 0);
if (!page)
goto out;
--
2.25.1
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prev parent reply other threads:[~2020-08-24 16:35 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20200824163504.605538-1-sashal@kernel.org>
2020-08-24 16:34 ` [PATCH AUTOSEL 5.8 30/63] dma-pool: fix coherent pool allocations for IOMMU mappings Sasha Levin
2020-08-24 16:34 ` Sasha Levin [this message]
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