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| author |   Christoph Hellwig <hch@lst.de> | 2018-12-06 13:39:32 -0800 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2018-12-13 21:06:18 +0100 |
| commit | 356da6d0cde3323236977fce54c1f9612a742036 (patch) | |
| tree | 87ad8176833266fbaa038780d67aebcc490d0d64 /arch/arm | |
| parent | vmd: use the proper dma_* APIs instead of direct methods calls (diff) | |
| download | linux-dev-356da6d0cde3323236977fce54c1f9612a742036.tar.xz linux-dev-356da6d0cde3323236977fce54c1f9612a742036.zip | |
dma-mapping: bypass indirect calls for dma-direct
Avoid expensive indirect calls in the fast path DMA mapping
operations by directly calling the dma_direct_* ops if we are using
the directly mapped DMA operations.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Tested-by: Jesper Dangaard Brouer <brouer@redhat.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/include/asm/dma-mapping.h | 2 | ||||
| -rw-r--r-- | arch/arm/mm/dma-mapping-nommu.c | 14 |
2 files changed, 4 insertions, 12 deletions
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h index 965b7c846ecb..31d3b96f0f4b 100644 --- a/arch/arm/include/asm/dma-mapping.h +++ b/arch/arm/include/asm/dma-mapping.h @@ -18,7 +18,7 @@ extern const struct dma_map_ops arm_coherent_dma_ops; static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus) { - return IS_ENABLED(CONFIG_MMU) ? &arm_dma_ops : &dma_direct_ops; + return IS_ENABLED(CONFIG_MMU) ? &arm_dma_ops : NULL; } #ifdef __arch_page_to_dma diff --git a/arch/arm/mm/dma-mapping-nommu.c b/arch/arm/mm/dma-mapping-nommu.c index 712416ecd8e6..f304b10e23a4 100644 --- a/arch/arm/mm/dma-mapping-nommu.c +++ b/arch/arm/mm/dma-mapping-nommu.c @@ -22,7 +22,7 @@ #include "dma.h" /* - * dma_direct_ops is used if + * The generic direct mapping code is used if * - MMU/MPU is off * - cpu is v7m w/o cache support * - device is coherent @@ -209,16 +209,9 @@ const struct dma_map_ops arm_nommu_dma_ops = { }; EXPORT_SYMBOL(arm_nommu_dma_ops); -static const struct dma_map_ops *arm_nommu_get_dma_map_ops(bool coherent) -{ - return coherent ? &dma_direct_ops : &arm_nommu_dma_ops; -} - void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, const struct iommu_ops *iommu, bool coherent) { - const struct dma_map_ops *dma_ops; - if (IS_ENABLED(CONFIG_CPU_V7M)) { /* * Cache support for v7m is optional, so can be treated as @@ -234,7 +227,6 @@ void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, dev->archdata.dma_coherent = (get_cr() & CR_M) ? coherent : true; } - dma_ops = arm_nommu_get_dma_map_ops(dev->archdata.dma_coherent); - - set_dma_ops(dev, dma_ops); + if (!dev->archdata.dma_coherent) + set_dma_ops(dev, &arm_nommu_dma_ops); } |