From 356da6d0cde3323236977fce54c1f9612a742036 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 6 Dec 2018 13:39:32 -0800 Subject: 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 Acked-by: Jesper Dangaard Brouer Tested-by: Jesper Dangaard Brouer Tested-by: Tony Luck --- kernel/dma/mapping.c | 40 +++++++++++++++++++++++++--------------- 1 file changed, 25 insertions(+), 15 deletions(-) (limited to 'kernel/dma/mapping.c') diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index 0b18cfbdde95..fc84c81029d9 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -7,6 +7,7 @@ */ #include /* for max_pfn */ #include +#include #include #include #include @@ -229,8 +230,8 @@ int dma_get_sgtable_attrs(struct device *dev, struct sg_table *sgt, unsigned long attrs) { const struct dma_map_ops *ops = get_dma_ops(dev); - BUG_ON(!ops); - if (ops->get_sgtable) + + if (!dma_is_direct(ops) && ops->get_sgtable) return ops->get_sgtable(dev, sgt, cpu_addr, dma_addr, size, attrs); return dma_common_get_sgtable(dev, sgt, cpu_addr, dma_addr, size, @@ -293,8 +294,8 @@ int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma, unsigned long attrs) { const struct dma_map_ops *ops = get_dma_ops(dev); - BUG_ON(!ops); - if (ops->mmap) + + if (!dma_is_direct(ops) && ops->mmap) return ops->mmap(dev, vma, cpu_addr, dma_addr, size, attrs); return dma_common_mmap(dev, vma, cpu_addr, dma_addr, size, attrs); } @@ -324,6 +325,8 @@ u64 dma_get_required_mask(struct device *dev) { const struct dma_map_ops *ops = get_dma_ops(dev); + if (dma_is_direct(ops)) + return dma_direct_get_required_mask(dev); if (ops->get_required_mask) return ops->get_required_mask(dev); return dma_default_get_required_mask(dev); @@ -341,7 +344,6 @@ void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle, const struct dma_map_ops *ops = get_dma_ops(dev); void *cpu_addr; - BUG_ON(!ops); WARN_ON_ONCE(dev && !dev->coherent_dma_mask); if (dma_alloc_from_dev_coherent(dev, size, dma_handle, &cpu_addr)) @@ -352,10 +354,14 @@ void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle, if (!arch_dma_alloc_attrs(&dev)) return NULL; - if (!ops->alloc) + + if (dma_is_direct(ops)) + cpu_addr = dma_direct_alloc(dev, size, dma_handle, flag, attrs); + else if (ops->alloc) + cpu_addr = ops->alloc(dev, size, dma_handle, flag, attrs); + else return NULL; - cpu_addr = ops->alloc(dev, size, dma_handle, flag, attrs); debug_dma_alloc_coherent(dev, size, *dma_handle, cpu_addr); return cpu_addr; } @@ -366,8 +372,6 @@ void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr, { const struct dma_map_ops *ops = get_dma_ops(dev); - BUG_ON(!ops); - if (dma_release_from_dev_coherent(dev, get_order(size), cpu_addr)) return; /* @@ -379,11 +383,14 @@ void dma_free_attrs(struct device *dev, size_t size, void *cpu_addr, */ WARN_ON(irqs_disabled()); - if (!ops->free || !cpu_addr) + if (!cpu_addr) return; debug_dma_free_coherent(dev, size, cpu_addr, dma_handle); - ops->free(dev, size, cpu_addr, dma_handle, attrs); + if (dma_is_direct(ops)) + dma_direct_free(dev, size, cpu_addr, dma_handle, attrs); + else if (ops->free) + ops->free(dev, size, cpu_addr, dma_handle, attrs); } EXPORT_SYMBOL(dma_free_attrs); @@ -397,9 +404,9 @@ int dma_supported(struct device *dev, u64 mask) { const struct dma_map_ops *ops = get_dma_ops(dev); - if (!ops) - return 0; - if (!ops->dma_supported) + if (dma_is_direct(ops)) + return dma_direct_supported(dev, mask); + if (ops->dma_supported) return 1; return ops->dma_supported(dev, mask); } @@ -437,7 +444,10 @@ void dma_cache_sync(struct device *dev, void *vaddr, size_t size, const struct dma_map_ops *ops = get_dma_ops(dev); BUG_ON(!valid_dma_direction(dir)); - if (ops->cache_sync) + + if (dma_is_direct(ops)) + arch_dma_cache_sync(dev, vaddr, size, dir); + else if (ops->cache_sync) ops->cache_sync(dev, vaddr, size, dir); } EXPORT_SYMBOL(dma_cache_sync); -- cgit v1.2.3