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| author | Christoph Hellwig <hch@lst.de> | 2018-03-28 15:35:35 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-03-28 17:34:23 +0200 |
| commit | e89f5b37015309a8bdf0b21d08007580b92f92a4 (patch) | |
| tree | 194c925657ddd394d26ccc1ae707ffdac31c8534 /lib | |
| parent | ea2301b6220117398a1de4f4bc853fbe886d5e08 (diff) | |
| download | linux-stable-e89f5b37015309a8bdf0b21d08007580b92f92a4.tar.gz linux-stable-e89f5b37015309a8bdf0b21d08007580b92f92a4.tar.bz2 linux-stable-e89f5b37015309a8bdf0b21d08007580b92f92a4.zip | |
dma-mapping: Don't clear GFP_ZERO in dma_alloc_attrs
Revert the clearing of __GFP_ZERO in dma_alloc_attrs and move it to
dma_direct_alloc for now. While most common architectures always zero dma
cohereny allocations (and x86 did so since day one) this is not documented
and at least arc and s390 do not zero without the explicit __GFP_ZERO
argument.
Fixes: 57bf5a8963f8 ("dma-mapping: clear harmful GFP_* flags in common code")
Reported-by: Evgeniy Didin <Evgeniy.Didin@synopsys.com>
Reported-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Evgeniy Didin <Evgeniy.Didin@synopsys.com>
Cc: iommu@lists.linux-foundation.org
Link: https://lkml.kernel.org/r/20180328133535.17302-2-hch@lst.de
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/dma-direct.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/lib/dma-direct.c b/lib/dma-direct.c index 1277d293d4da..c0bba30fef0a 100644 --- a/lib/dma-direct.c +++ b/lib/dma-direct.c @@ -59,6 +59,9 @@ void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, struct page *page = NULL; void *ret; + /* we always manually zero the memory once we are done: */ + gfp &= ~__GFP_ZERO; + /* GFP_DMA32 and GFP_DMA are no ops without the corresponding zones: */ if (dev->coherent_dma_mask <= DMA_BIT_MASK(ARCH_ZONE_DMA_BITS)) gfp |= GFP_DMA; |