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| author | Bastian Hecht <bhecht@de.adit-jv.com> | 2016-09-28 08:51:57 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-09-28 17:53:16 +0200 |
| commit | dd01c75f1df311793de6ef217c72036552000c9a (patch) | |
| tree | 0da39cc93ddfb308acd94a627663033a7f421bc2 /drivers/base | |
| parent | 9ca5d4fd08d1c560a46ff649221a891065039891 (diff) | |
| download | linux-dd01c75f1df311793de6ef217c72036552000c9a.tar.gz linux-dd01c75f1df311793de6ef217c72036552000c9a.tar.xz | |
drivers: dma-coherent: Move spinlock in dma_alloc_from_coherent()
We don't need to hold the spinlock while zeroing the allocated memory.
In case we handle big buffers this is a severe issue as other CPUs might
be spinning half a second or longer.
Signed-off-by: Bastian Hecht <bhecht@de.adit-jv.com>
Signed-off-by: George G. Davis <george_davis@mentor.com>
Signed-off-by: Mark Craske <Mark_Craske@mentor.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base')
| -rw-r--r-- | drivers/base/dma-coherent.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/base/dma-coherent.c b/drivers/base/dma-coherent.c index 2789f7a95b93..640a7e63c453 100644 --- a/drivers/base/dma-coherent.c +++ b/drivers/base/dma-coherent.c @@ -165,6 +165,7 @@ int dma_alloc_from_coherent(struct device *dev, ssize_t size, int order = get_order(size); unsigned long flags; int pageno; + int dma_memory_map; if (!dev) return 0; @@ -187,11 +188,12 @@ int dma_alloc_from_coherent(struct device *dev, ssize_t size, */ *dma_handle = mem->device_base + (pageno << PAGE_SHIFT); *ret = mem->virt_base + (pageno << PAGE_SHIFT); - if (mem->flags & DMA_MEMORY_MAP) + dma_memory_map = (mem->flags & DMA_MEMORY_MAP); + spin_unlock_irqrestore(&mem->spinlock, flags); + if (dma_memory_map) memset(*ret, 0, size); else memset_io(*ret, 0, size); - spin_unlock_irqrestore(&mem->spinlock, flags); return 1; |