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>
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 269ee27..f422aec 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -134,7 +134,6 @@
#define DMA_MAPPING_ERROR (~(dma_addr_t)0)
-extern const struct dma_map_ops dma_direct_ops;
extern const struct dma_map_ops dma_virt_ops;
extern const struct dma_map_ops dma_dummy_ops;
@@ -222,6 +221,69 @@
}
#endif
+static inline bool dma_is_direct(const struct dma_map_ops *ops)
+{
+ return likely(!ops);
+}
+
+/*
+ * All the dma_direct_* declarations are here just for the indirect call bypass,
+ * and must not be used directly drivers!
+ */
+dma_addr_t dma_direct_map_page(struct device *dev, struct page *page,
+ unsigned long offset, size_t size, enum dma_data_direction dir,
+ unsigned long attrs);
+int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
+ enum dma_data_direction dir, unsigned long attrs);
+
+#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
+ defined(CONFIG_SWIOTLB)
+void dma_direct_sync_single_for_device(struct device *dev,
+ dma_addr_t addr, size_t size, enum dma_data_direction dir);
+void dma_direct_sync_sg_for_device(struct device *dev,
+ struct scatterlist *sgl, int nents, enum dma_data_direction dir);
+#else
+static inline void dma_direct_sync_single_for_device(struct device *dev,
+ dma_addr_t addr, size_t size, enum dma_data_direction dir)
+{
+}
+static inline void dma_direct_sync_sg_for_device(struct device *dev,
+ struct scatterlist *sgl, int nents, enum dma_data_direction dir)
+{
+}
+#endif
+
+#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
+ defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL) || \
+ defined(CONFIG_SWIOTLB)
+void dma_direct_unmap_page(struct device *dev, dma_addr_t addr,
+ size_t size, enum dma_data_direction dir, unsigned long attrs);
+void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl,
+ int nents, enum dma_data_direction dir, unsigned long attrs);
+void dma_direct_sync_single_for_cpu(struct device *dev,
+ dma_addr_t addr, size_t size, enum dma_data_direction dir);
+void dma_direct_sync_sg_for_cpu(struct device *dev,
+ struct scatterlist *sgl, int nents, enum dma_data_direction dir);
+#else
+static inline void dma_direct_unmap_page(struct device *dev, dma_addr_t addr,
+ size_t size, enum dma_data_direction dir, unsigned long attrs)
+{
+}
+static inline void dma_direct_unmap_sg(struct device *dev,
+ struct scatterlist *sgl, int nents, enum dma_data_direction dir,
+ unsigned long attrs)
+{
+}
+static inline void dma_direct_sync_single_for_cpu(struct device *dev,
+ dma_addr_t addr, size_t size, enum dma_data_direction dir)
+{
+}
+static inline void dma_direct_sync_sg_for_cpu(struct device *dev,
+ struct scatterlist *sgl, int nents, enum dma_data_direction dir)
+{
+}
+#endif
+
static inline dma_addr_t dma_map_single_attrs(struct device *dev, void *ptr,
size_t size,
enum dma_data_direction dir,
@@ -232,9 +294,12 @@
BUG_ON(!valid_dma_direction(dir));
debug_dma_map_single(dev, ptr, size);
- addr = ops->map_page(dev, virt_to_page(ptr),
- offset_in_page(ptr), size,
- dir, attrs);
+ if (dma_is_direct(ops))
+ addr = dma_direct_map_page(dev, virt_to_page(ptr),
+ offset_in_page(ptr), size, dir, attrs);
+ else
+ addr = ops->map_page(dev, virt_to_page(ptr),
+ offset_in_page(ptr), size, dir, attrs);
debug_dma_map_page(dev, virt_to_page(ptr),
offset_in_page(ptr), size,
dir, addr, true);
@@ -249,7 +314,9 @@
const struct dma_map_ops *ops = get_dma_ops(dev);
BUG_ON(!valid_dma_direction(dir));
- if (ops->unmap_page)
+ if (dma_is_direct(ops))
+ dma_direct_unmap_page(dev, addr, size, dir, attrs);
+ else if (ops->unmap_page)
ops->unmap_page(dev, addr, size, dir, attrs);
debug_dma_unmap_page(dev, addr, size, dir, true);
}
@@ -272,7 +339,10 @@
int ents;
BUG_ON(!valid_dma_direction(dir));
- ents = ops->map_sg(dev, sg, nents, dir, attrs);
+ if (dma_is_direct(ops))
+ ents = dma_direct_map_sg(dev, sg, nents, dir, attrs);
+ else
+ ents = ops->map_sg(dev, sg, nents, dir, attrs);
BUG_ON(ents < 0);
debug_dma_map_sg(dev, sg, nents, ents, dir);
@@ -287,7 +357,9 @@
BUG_ON(!valid_dma_direction(dir));
debug_dma_unmap_sg(dev, sg, nents, dir);
- if (ops->unmap_sg)
+ if (dma_is_direct(ops))
+ dma_direct_unmap_sg(dev, sg, nents, dir, attrs);
+ else if (ops->unmap_sg)
ops->unmap_sg(dev, sg, nents, dir, attrs);
}
@@ -301,7 +373,10 @@
dma_addr_t addr;
BUG_ON(!valid_dma_direction(dir));
- addr = ops->map_page(dev, page, offset, size, dir, attrs);
+ if (dma_is_direct(ops))
+ addr = dma_direct_map_page(dev, page, offset, size, dir, attrs);
+ else
+ addr = ops->map_page(dev, page, offset, size, dir, attrs);
debug_dma_map_page(dev, page, offset, size, dir, addr, false);
return addr;
@@ -322,7 +397,7 @@
BUG_ON(pfn_valid(PHYS_PFN(phys_addr)));
addr = phys_addr;
- if (ops->map_resource)
+ if (ops && ops->map_resource)
addr = ops->map_resource(dev, phys_addr, size, dir, attrs);
debug_dma_map_resource(dev, phys_addr, size, dir, addr);
@@ -337,7 +412,7 @@
const struct dma_map_ops *ops = get_dma_ops(dev);
BUG_ON(!valid_dma_direction(dir));
- if (ops->unmap_resource)
+ if (ops && ops->unmap_resource)
ops->unmap_resource(dev, addr, size, dir, attrs);
debug_dma_unmap_resource(dev, addr, size, dir);
}
@@ -349,7 +424,9 @@
const struct dma_map_ops *ops = get_dma_ops(dev);
BUG_ON(!valid_dma_direction(dir));
- if (ops->sync_single_for_cpu)
+ if (dma_is_direct(ops))
+ dma_direct_sync_single_for_cpu(dev, addr, size, dir);
+ else if (ops->sync_single_for_cpu)
ops->sync_single_for_cpu(dev, addr, size, dir);
debug_dma_sync_single_for_cpu(dev, addr, size, dir);
}
@@ -368,7 +445,9 @@
const struct dma_map_ops *ops = get_dma_ops(dev);
BUG_ON(!valid_dma_direction(dir));
- if (ops->sync_single_for_device)
+ if (dma_is_direct(ops))
+ dma_direct_sync_single_for_device(dev, addr, size, dir);
+ else if (ops->sync_single_for_device)
ops->sync_single_for_device(dev, addr, size, dir);
debug_dma_sync_single_for_device(dev, addr, size, dir);
}
@@ -387,7 +466,9 @@
const struct dma_map_ops *ops = get_dma_ops(dev);
BUG_ON(!valid_dma_direction(dir));
- if (ops->sync_sg_for_cpu)
+ if (dma_is_direct(ops))
+ dma_direct_sync_sg_for_cpu(dev, sg, nelems, dir);
+ else if (ops->sync_sg_for_cpu)
ops->sync_sg_for_cpu(dev, sg, nelems, dir);
debug_dma_sync_sg_for_cpu(dev, sg, nelems, dir);
}
@@ -399,7 +480,9 @@
const struct dma_map_ops *ops = get_dma_ops(dev);
BUG_ON(!valid_dma_direction(dir));
- if (ops->sync_sg_for_device)
+ if (dma_is_direct(ops))
+ dma_direct_sync_sg_for_device(dev, sg, nelems, dir);
+ else if (ops->sync_sg_for_device)
ops->sync_sg_for_device(dev, sg, nelems, dir);
debug_dma_sync_sg_for_device(dev, sg, nelems, dir);