[PATCH 15/15] dma-mapping: bypass indirect calls for dma-direct

Christoph Hellwig
2018-12-07T19:07:20Z

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>
---
arch/alpha/include/asm/dma-mapping.h | 2 +-
arch/arc/mm/cache.c | 2 +-
arch/arm/include/asm/dma-mapping.h | 2 +-
arch/arm/mm/dma-mapping-nommu.c | 14 +---
arch/arm64/mm/dma-mapping.c | 3 -
arch/ia64/hp/common/hwsw_iommu.c | 2 +-
arch/ia64/hp/common/sba_iommu.c | 4 +-
arch/ia64/kernel/dma-mapping.c | 1 -
arch/mips/include/asm/dma-mapping.h | 2 +-
arch/parisc/kernel/setup.c | 4 -
arch/sparc/include/asm/dma-mapping.h | 4 +-
arch/x86/kernel/pci-dma.c | 2 +-
drivers/gpu/drm/vmwgfx/vmwgfx_drv.c | 2 +-
drivers/iommu/amd_iommu.c | 13 +---
include/asm-generic/dma-mapping.h | 2 +-
include/linux/dma-direct.h | 17 ----
include/linux/dma-mapping.h | 111 +++++++++++++++++++++++----
include/linux/dma-noncoherent.h | 5 +-
kernel/dma/direct.c | 37 ++-------
kernel/dma/mapping.c | 40 ++++++----
20 files changed, 150 insertions(+), 119 deletions(-)

diff --git a/arch/alpha/include/asm/dma-mapping.h b/arch/alpha/include/asm/dma-mapping.h
index 8beeafd4f68e..0ee6a5c99b16 100644
--- a/arch/alpha/include/asm/dma-mapping.h
+++ b/arch/alpha/include/asm/dma-mapping.h
@@ -7,7 +7,7 @@ extern const struct dma_map_ops alpha_pci_ops;
static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
{
#ifdef CONFIG_ALPHA_JENSEN
- return &dma_direct_ops;
+ return NULL;
#else
return &alpha_pci_ops;
#endif
diff --git a/arch/arc/mm/cache.c b/arch/arc/mm/cache.c
index f2701c13a66b..e188bb3ede53 100644
--- a/arch/arc/mm/cache.c
+++ b/arch/arc/mm/cache.c
@@ -1280,7 +1280,7 @@ void __init arc_cache_init_master(void)
/*
* In case of IOC (say IOC+SLC case), pointers above could still be set
* but end up not being relevant as the first function in chain is not
- * called at all for @dma_direct_ops
+ * called at all for devices using coherent DMA.
* arch_sync_dma_for_cpu() -> dma_cache_*() -> __dma_cache_*()
*/
}
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);
}
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index ab1e417204d0..95eda81e3f2d 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -462,9 +462,6 @@ static void __iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
const struct iommu_ops *iommu, bool coherent)
{
- if (!dev->dma_ops)
- dev->dma_ops = &dma_direct_ops;
-
dev->dma_coherent = coherent;
__iommu_setup_dma_ops(dev, dma_base, size, iommu);

diff --git a/arch/ia64/hp/common/hwsw_iommu.c b/arch/ia64/hp/common/hwsw_iommu.c
index f40ca499b246..8840ed97712f 100644
--- a/arch/ia64/hp/common/hwsw_iommu.c
+++ b/arch/ia64/hp/common/hwsw_iommu.c
@@ -38,7 +38,7 @@ static inline int use_swiotlb(struct device *dev)
const struct dma_map_ops *hwsw_dma_get_ops(struct device *dev)
{
if (use_swiotlb(dev))
- return &dma_direct_ops;
+ return NULL;
return &sba_dma_ops;
}
EXPORT_SYMBOL(hwsw_dma_get_ops);
diff --git a/arch/ia64/hp/common/sba_iommu.c b/arch/ia64/hp/common/sba_iommu.c
index 5ee74820a0f6..5a361e51cb1e 100644
--- a/arch/ia64/hp/common/sba_iommu.c
+++ b/arch/ia64/hp/common/sba_iommu.c
@@ -2078,7 +2078,7 @@ sba_init(void)
* a successful kdump kernel boot is to use the swiotlb.
*/
if (is_kdump_kernel()) {
- dma_ops = &dma_direct_ops;
+ dma_ops = NULL;
if (swiotlb_late_init_with_default_size(64 * (1<<20)) != 0)
panic("Unable to initialize software I/O TLB:"
" Try machvec=dig boot option");
@@ -2100,7 +2100,7 @@ sba_init(void)
* If we didn't find something sba_iommu can claim, we
* need to setup the swiotlb and switch to the dig machvec.
*/
- dma_ops = &dma_direct_ops;
+ dma_ops = NULL;
if (swiotlb_late_init_with_default_size(64 * (1<<20)) != 0)
panic("Unable to find SBA IOMMU or initialize "
"software I/O TLB: Try machvec=dig boot option");
diff --git a/arch/ia64/kernel/dma-mapping.c b/arch/ia64/kernel/dma-mapping.c
index 80cd3e1ea95a..ad7d9963de34 100644
--- a/arch/ia64/kernel/dma-mapping.c
+++ b/arch/ia64/kernel/dma-mapping.c
@@ -36,7 +36,6 @@ long arch_dma_coherent_to_pfn(struct device *dev, void *cpu_addr,

void __init swiotlb_dma_init(void)
{
- dma_ops = &dma_direct_ops;
swiotlb_init(1);
}
#endif
diff --git a/arch/mips/include/asm/dma-mapping.h b/arch/mips/include/asm/dma-mapping.h
index 69f914667f3e..20dfaad3a55d 100644
--- a/arch/mips/include/asm/dma-mapping.h
+++ b/arch/mips/include/asm/dma-mapping.h
@@ -11,7 +11,7 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
#if defined(CONFIG_MACH_JAZZ)
return &jazz_dma_ops;
#else
- return &dma_direct_ops;
+ return NULL;
#endif
}

diff --git a/arch/parisc/kernel/setup.c b/arch/parisc/kernel/setup.c
index cd227f1cf629..54818cd78bd0 100644
--- a/arch/parisc/kernel/setup.c
+++ b/arch/parisc/kernel/setup.c
@@ -99,10 +99,6 @@ void __init dma_ops_init(void)

case pcxl2:
pa7300lc_init();
- case pcxl: /* falls through */
- case pcxs:
- case pcxt:
- hppa_dma_ops = &dma_direct_ops;
break;
default:
break;
diff --git a/arch/sparc/include/asm/dma-mapping.h b/arch/sparc/include/asm/dma-mapping.h
index b0bb2fcaf1c9..59f5a0f17316 100644
--- a/arch/sparc/include/asm/dma-mapping.h
+++ b/arch/sparc/include/asm/dma-mapping.h
@@ -14,11 +14,11 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
{
#ifdef CONFIG_SPARC_LEON
if (sparc_cpu_model = sparc_leon)
- return &dma_direct_ops;
+ return NULL;
#endif
#if defined(CONFIG_SPARC32) && defined(CONFIG_PCI)
if (bus = &pci_bus_type)
- return &dma_direct_ops;
+ return NULL;
#endif
return dma_ops;
}
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index f4562fcec681..d460998ae828 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -17,7 +17,7 @@

static bool disable_dac_quirk __read_mostly;

-const struct dma_map_ops *dma_ops = &dma_direct_ops;
+const struct dma_map_ops *dma_ops;
EXPORT_SYMBOL(dma_ops);

#ifdef CONFIG_IOMMU_DEBUG
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
index 61a84b958d67..50637f372e9f 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -581,7 +581,7 @@ static int vmw_dma_select_mode(struct vmw_private *dev_priv)

dev_priv->map_mode = vmw_dma_map_populate;

- if (dma_ops->sync_single_for_cpu)
+ if (dma_ops && dma_ops->sync_single_for_cpu)
dev_priv->map_mode = vmw_dma_alloc_coherent;
#ifdef CONFIG_SWIOTLB
if (swiotlb_nr_tbl() = 0)
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index c5d6c7c42b0a..567221cca13c 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -2184,7 +2184,7 @@ static int amd_iommu_add_device(struct device *dev)
dev_name(dev));

iommu_ignore_device(dev);
- dev->dma_ops = &dma_direct_ops;
+ dev->dma_ops = NULL;
goto out;
}
init_iommu_group(dev);
@@ -2770,17 +2770,6 @@ int __init amd_iommu_init_dma_ops(void)
swiotlb = (iommu_pass_through || sme_me_mask) ? 1 : 0;
iommu_detected = 1;

- /*
- * In case we don't initialize SWIOTLB (actually the common case
- * when AMD IOMMU is enabled and SME is not active), make sure there
- * are global dma_ops set as a fall-back for devices not handled by
- * this driver (for example non-PCI devices). When SME is active,
- * make sure that swiotlb variable remains set so the global dma_ops
- * continue to be SWIOTLB.
- */
- if (!swiotlb)
- dma_ops = &dma_direct_ops;
-
if (amd_iommu_unmap_flush)
pr_info("AMD-Vi: IO/TLB flush on unmap enabled\n");
else
diff --git a/include/asm-generic/dma-mapping.h b/include/asm-generic/dma-mapping.h
index 880a292d792f..c13f46109e88 100644
--- a/include/asm-generic/dma-mapping.h
+++ b/include/asm-generic/dma-mapping.h
@@ -4,7 +4,7 @@

static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
{
- return &dma_direct_ops;
+ return NULL;
}

#endif /* _ASM_GENERIC_DMA_MAPPING_H */
diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h
index 3b0a3ea3876d..b7338702592a 100644
--- a/include/linux/dma-direct.h
+++ b/include/linux/dma-direct.h
@@ -60,22 +60,5 @@ void dma_direct_free_pages(struct device *dev, size_t size, void *cpu_addr,
struct page *__dma_direct_alloc_pages(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs);
void __dma_direct_free_pages(struct device *dev, size_t size, struct page *page);
-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);
-void dma_direct_unmap_page(struct device *dev, dma_addr_t addr,
- 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);
-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_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);
-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);
int dma_direct_supported(struct device *dev, u64 mask);
#endif /* _LINUX_DMA_DIRECT_H */
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 269ee27fc3d9..f422aec0f53c 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -134,7 +134,6 @@ struct dma_map_ops {

#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 @@ static inline const struct dma_map_ops *get_dma_ops(struct device *dev)
}
#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 @@ static inline dma_addr_t dma_map_single_attrs(struct device *dev, void *ptr,

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 @@ static inline void dma_unmap_single_attrs(struct device *dev, dma_addr_t addr,
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 @@ static inline int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
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 @@ static inline void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg

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 @@ static inline dma_addr_t dma_map_page_attrs(struct device *dev,
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 @@ static inline dma_addr_t dma_map_resource(struct device *dev,
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 @@ static inline void dma_unmap_resource(struct device *dev, dma_addr_t addr,
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 @@ static inline void dma_sync_single_for_cpu(struct device *dev, dma_addr_t addr,
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 @@ static inline void dma_sync_single_for_device(struct device *dev,
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 @@ dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
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 @@ dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
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);

diff --git a/include/linux/dma-noncoherent.h b/include/linux/dma-noncoherent.h
index 306557331d7d..69b36ed31a99 100644
--- a/include/linux/dma-noncoherent.h
+++ b/include/linux/dma-noncoherent.h
@@ -38,7 +38,10 @@ pgprot_t arch_dma_mmap_pgprot(struct device *dev, pgprot_t prot,
void arch_dma_cache_sync(struct device *dev, void *vaddr, size_t size,
enum dma_data_direction direction);
#else
-#define arch_dma_cache_sync NULL
+static inline void arch_dma_cache_sync(struct device *dev, void *vaddr,
+ size_t size, enum dma_data_direction direction)
+{
+}
#endif /* CONFIG_DMA_NONCOHERENT_CACHE_SYNC */

#ifdef CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 85d8286a0ba2..79da61b49fa4 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -223,6 +223,7 @@ void dma_direct_sync_single_for_device(struct device *dev,
if (!dev_is_dma_coherent(dev))
arch_sync_dma_for_device(dev, paddr, size, dir);
}
+EXPORT_SYMBOL(dma_direct_sync_single_for_device);

void dma_direct_sync_sg_for_device(struct device *dev,
struct scatterlist *sgl, int nents, enum dma_data_direction dir)
@@ -240,6 +241,7 @@ void dma_direct_sync_sg_for_device(struct device *dev,
dir);
}
}
+EXPORT_SYMBOL(dma_direct_sync_sg_for_device);
#endif

#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
@@ -258,6 +260,7 @@ void dma_direct_sync_single_for_cpu(struct device *dev,
if (unlikely(is_swiotlb_buffer(paddr)))
swiotlb_tbl_sync_single(dev, paddr, size, dir, SYNC_FOR_CPU);
}
+EXPORT_SYMBOL(dma_direct_sync_single_for_cpu);

void dma_direct_sync_sg_for_cpu(struct device *dev,
struct scatterlist *sgl, int nents, enum dma_data_direction dir)
@@ -277,6 +280,7 @@ void dma_direct_sync_sg_for_cpu(struct device *dev,
if (!dev_is_dma_coherent(dev))
arch_sync_dma_for_cpu_all(dev);
}
+EXPORT_SYMBOL(dma_direct_sync_sg_for_cpu);

void dma_direct_unmap_page(struct device *dev, dma_addr_t addr,
size_t size, enum dma_data_direction dir, unsigned long attrs)
@@ -289,6 +293,7 @@ void dma_direct_unmap_page(struct device *dev, dma_addr_t addr,
if (unlikely(is_swiotlb_buffer(phys)))
swiotlb_tbl_unmap_single(dev, phys, size, dir, attrs);
}
+EXPORT_SYMBOL(dma_direct_unmap_page);

void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl,
int nents, enum dma_data_direction dir, unsigned long attrs)
@@ -300,11 +305,7 @@ void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl,
dma_direct_unmap_page(dev, sg->dma_address, sg_dma_len(sg), dir,
attrs);
}
-#else
-void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl,
- int nents, enum dma_data_direction dir, unsigned long attrs)
-{
-}
+EXPORT_SYMBOL(dma_direct_unmap_sg);
#endif

static inline bool dma_direct_possible(struct device *dev, dma_addr_t dma_addr,
@@ -331,6 +332,7 @@ dma_addr_t dma_direct_map_page(struct device *dev, struct page *page,
arch_sync_dma_for_device(dev, phys, size, dir);
return dma_addr;
}
+EXPORT_SYMBOL(dma_direct_map_page);

int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
enum dma_data_direction dir, unsigned long attrs)
@@ -352,6 +354,7 @@ int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
dma_direct_unmap_sg(dev, sgl, i, dir, attrs | DMA_ATTR_SKIP_CPU_SYNC);
return 0;
}
+EXPORT_SYMBOL(dma_direct_map_sg);

/*
* Because 32-bit DMA masks are so common we expect every architecture to be
@@ -372,27 +375,3 @@ int dma_direct_supported(struct device *dev, u64 mask)

return mask >= phys_to_dma(dev, min_mask);
}
-
-const struct dma_map_ops dma_direct_ops = {
- .alloc = dma_direct_alloc,
- .free = dma_direct_free,
- .map_page = dma_direct_map_page,
- .map_sg = dma_direct_map_sg,
-#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
- defined(CONFIG_SWIOTLB)
- .sync_single_for_device = dma_direct_sync_single_for_device,
- .sync_sg_for_device = dma_direct_sync_sg_for_device,
-#endif
-#if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
- defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL) || \
- defined(CONFIG_SWIOTLB)
- .sync_single_for_cpu = dma_direct_sync_single_for_cpu,
- .sync_sg_for_cpu = dma_direct_sync_sg_for_cpu,
- .unmap_page = dma_direct_unmap_page,
- .unmap_sg = dma_direct_unmap_sg,
-#endif
- .get_required_mask = dma_direct_get_required_mask,
- .dma_supported = dma_direct_supported,
- .cache_sync = arch_dma_cache_sync,
-};
-EXPORT_SYMBOL(dma_direct_ops);
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 <linux/memblock.h> /* for max_pfn */
#include <linux/acpi.h>
+#include <linux/dma-direct.h>
#include <linux/dma-noncoherent.h>
#include <linux/export.h>
#include <linux/gfp.h>
@@ -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);
--
2.19.1