[PATCH 01/34] alpha: mark jensen as broken

[PATCH 01/34] alpha: mark jensen as broken

[Christoph Hellwig]

CONFIG_ALPHA_JENSEN has failed to compile since commit 6aca0503
("alpha/dma: use common noop dma ops"), so mark it as broken.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/alpha/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index b31b974a03cb..e96adcbcab41 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -209,6 +209,7 @@ config ALPHA_EIGER
 
 config ALPHA_JENSEN
 	bool "Jensen"
+	depends on BROKEN
 	help
 	  DEC PC 150 AXP (aka Jensen): This is a very old Digital system - one
 	  of the first-generation Alpha systems. A number of these systems
-- 
2.14.2

[PATCH 02/34] hexagon: remove unused flush_write_buffers definition

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/hexagon/include/asm/io.h | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/hexagon/include/asm/io.h b/arch/hexagon/include/asm/io.h
index 66f5e9a61efc..9e8621d94ee9 100644
--- a/arch/hexagon/include/asm/io.h
+++ b/arch/hexagon/include/asm/io.h
@@ -330,8 +330,6 @@ static inline void outsl(unsigned long port, const void *buffer, int count)
 	}
 }
 
-#define flush_write_buffers() do { } while (0)
-
 #endif /* __KERNEL__ */
 
 #endif
-- 
2.14.2

[PATCH 03/34] m32r: remove unused flush_write_buffers definition

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/m32r/include/asm/io.h | 2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/m32r/include/asm/io.h b/arch/m32r/include/asm/io.h
index 1b653bb16f9a..a4272d8f0d9c 100644
--- a/arch/m32r/include/asm/io.h
+++ b/arch/m32r/include/asm/io.h
@@ -191,8 +191,6 @@ static inline void _writel(unsigned long l, unsigned long addr)
 
 #define mmiowb()
 
-#define flush_write_buffers() do { } while (0)  /* M32R_FIXME */
-
 static inline void
 memset_io(volatile void __iomem *addr, unsigned char val, int count)
 {
-- 
2.14.2

[PATCH 04/34] powerpc: remove unused flush_write_buffers definition

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/powerpc/include/asm/dma-mapping.h | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/arch/powerpc/include/asm/dma-mapping.h b/arch/powerpc/include/asm/dma-mapping.h
index 5a6cbe11db6f..592c7f418aa0 100644
--- a/arch/powerpc/include/asm/dma-mapping.h
+++ b/arch/powerpc/include/asm/dma-mapping.h
@@ -107,9 +107,6 @@ static inline void set_dma_offset(struct device *dev, dma_addr_t off)
 		dev->archdata.dma_offset = off;
 }
 
-/* this will be removed soon */
-#define flush_write_buffers()
-
 #define HAVE_ARCH_DMA_SET_MASK 1
 extern int dma_set_mask(struct device *dev, u64 dma_mask);
 
-- 
2.14.2

[PATCH 05/34] arc: remove CONFIG_ARC_PLAT_NEEDS_PHYS_TO_DMA

[Christoph Hellwig]

We always use the stub definitions, so remove the unused other code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Vineet Gupta <vgupta@synopsys.com>
---
 arch/arc/Kconfig                   |  3 ---
 arch/arc/include/asm/dma-mapping.h |  7 -------
 arch/arc/mm/dma.c                  | 14 +++++++-------
 3 files changed, 7 insertions(+), 17 deletions(-)

diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index 9d5fd00d9e91..f3a80cf164cc 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -463,9 +463,6 @@ config ARCH_PHYS_ADDR_T_64BIT
 config ARCH_DMA_ADDR_T_64BIT
 	bool
 
-config ARC_PLAT_NEEDS_PHYS_TO_DMA
-	bool
-
 config ARC_KVADDR_SIZE
 	int "Kernel Virtual Address Space size (MB)"
 	range 0 512
diff --git a/arch/arc/include/asm/dma-mapping.h b/arch/arc/include/asm/dma-mapping.h
index 94285031c4fb..7a16824bfe98 100644
--- a/arch/arc/include/asm/dma-mapping.h
+++ b/arch/arc/include/asm/dma-mapping.h
@@ -11,13 +11,6 @@
 #ifndef ASM_ARC_DMA_MAPPING_H
 #define ASM_ARC_DMA_MAPPING_H
 
-#ifndef CONFIG_ARC_PLAT_NEEDS_PHYS_TO_DMA
-#define plat_dma_to_phys(dev, dma_handle) ((phys_addr_t)(dma_handle))
-#define plat_phys_to_dma(dev, paddr) ((dma_addr_t)(paddr))
-#else
-#include <plat/dma.h>
-#endif
-
 extern const struct dma_map_ops arc_dma_ops;
 
 static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c
index e9d93604ad0f..1dcc404b5aec 100644
--- a/arch/arc/mm/dma.c
+++ b/arch/arc/mm/dma.c
@@ -60,7 +60,7 @@ static void *arc_dma_alloc(struct device *dev, size_t size,
 	/* This is linear addr (0x8000_0000 based) */
 	paddr = page_to_phys(page);
 
-	*dma_handle = plat_phys_to_dma(dev, paddr);
+	*dma_handle = paddr;
 
 	/* This is kernel Virtual address (0x7000_0000 based) */
 	if (need_kvaddr) {
@@ -92,7 +92,7 @@ static void *arc_dma_alloc(struct device *dev, size_t size,
 static void arc_dma_free(struct device *dev, size_t size, void *vaddr,
 		dma_addr_t dma_handle, unsigned long attrs)
 {
-	phys_addr_t paddr = plat_dma_to_phys(dev, dma_handle);
+	phys_addr_t paddr = dma_handle;
 	struct page *page = virt_to_page(paddr);
 	int is_non_coh = 1;
 
@@ -111,7 +111,7 @@ static int arc_dma_mmap(struct device *dev, struct vm_area_struct *vma,
 {
 	unsigned long user_count = vma_pages(vma);
 	unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
-	unsigned long pfn = __phys_to_pfn(plat_dma_to_phys(dev, dma_addr));
+	unsigned long pfn = __phys_to_pfn(dma_addr);
 	unsigned long off = vma->vm_pgoff;
 	int ret = -ENXIO;
 
@@ -175,7 +175,7 @@ static dma_addr_t arc_dma_map_page(struct device *dev, struct page *page,
 	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 		_dma_cache_sync(paddr, size, dir);
 
-	return plat_phys_to_dma(dev, paddr);
+	return paddr;
 }
 
 /*
@@ -190,7 +190,7 @@ static void arc_dma_unmap_page(struct device *dev, dma_addr_t handle,
 			       size_t size, enum dma_data_direction dir,
 			       unsigned long attrs)
 {
-	phys_addr_t paddr = plat_dma_to_phys(dev, handle);
+	phys_addr_t paddr = handle;
 
 	if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC))
 		_dma_cache_sync(paddr, size, dir);
@@ -224,13 +224,13 @@ static void arc_dma_unmap_sg(struct device *dev, struct scatterlist *sg,
 static void arc_dma_sync_single_for_cpu(struct device *dev,
 		dma_addr_t dma_handle, size_t size, enum dma_data_direction dir)
 {
-	_dma_cache_sync(plat_dma_to_phys(dev, dma_handle), size, DMA_FROM_DEVICE);
+	_dma_cache_sync(dma_handle, size, DMA_FROM_DEVICE);
 }
 
 static void arc_dma_sync_single_for_device(struct device *dev,
 		dma_addr_t dma_handle, size_t size, enum dma_data_direction dir)
 {
-	_dma_cache_sync(plat_dma_to_phys(dev, dma_handle), size, DMA_TO_DEVICE);
+	_dma_cache_sync(dma_handle, size, DMA_TO_DEVICE);
 }
 
 static void arc_dma_sync_sg_for_cpu(struct device *dev,
-- 
2.14.2

[PATCH 06/34] m32r: remove the unused dma_capable helper

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/m32r/include/asm/dma-mapping.h | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/arch/m32r/include/asm/dma-mapping.h b/arch/m32r/include/asm/dma-mapping.h
index 336ffe60814b..8967fb659691 100644
--- a/arch/m32r/include/asm/dma-mapping.h
+++ b/arch/m32r/include/asm/dma-mapping.h
@@ -14,11 +14,4 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 	return &dma_noop_ops;
 }
 
-static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
-{
-	if (!dev->dma_mask)
-		return false;
-	return addr + size - 1 <= *dev->dma_mask;
-}
-
 #endif /* _ASM_M32R_DMA_MAPPING_H */
-- 
2.14.2

[PATCH 07/34] riscv: remove the unused dma_capable helper

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/riscv/include/asm/dma-mapping.h | 8 --------
 1 file changed, 8 deletions(-)

diff --git a/arch/riscv/include/asm/dma-mapping.h b/arch/riscv/include/asm/dma-mapping.h
index 3eec1000196d..73849e2cc761 100644
--- a/arch/riscv/include/asm/dma-mapping.h
+++ b/arch/riscv/include/asm/dma-mapping.h
@@ -27,12 +27,4 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 	return &dma_noop_ops;
 }
 
-static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
-{
-	if (!dev->dma_mask)
-		return false;
-
-	return addr + size - 1 <= *dev->dma_mask;
-}
-
 #endif	/* __ASM_RISCV_DMA_MAPPING_H */
-- 
2.14.2

[PATCH 08/34] s390: remove the unused dma_capable helper

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/s390/include/asm/dma-mapping.h | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/arch/s390/include/asm/dma-mapping.h b/arch/s390/include/asm/dma-mapping.h
index eaf490f9c5bc..2ec7240c1ada 100644
--- a/arch/s390/include/asm/dma-mapping.h
+++ b/arch/s390/include/asm/dma-mapping.h
@@ -16,11 +16,4 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 	return &dma_noop_ops;
 }
 
-static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
-{
-	if (!dev->dma_mask)
-		return false;
-	return addr + size - 1 <= *dev->dma_mask;
-}
-
 #endif /* _ASM_S390_DMA_MAPPING_H */
-- 
2.14.2

[PATCH 09/34] dma-mapping: take dma_pfn_offset into account in dma_max_pfn

[Christoph Hellwig]

This makes sure the generic version can be used with architectures /
devices that have a DMA offset in the direct mapping.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
---
 include/linux/dma-mapping.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 81ed9b2d84dc..d84951865be7 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -692,7 +692,7 @@ static inline int dma_set_seg_boundary(struct device *dev, unsigned long mask)
 #ifndef dma_max_pfn
 static inline unsigned long dma_max_pfn(struct device *dev)
 {
-	return *dev->dma_mask >> PAGE_SHIFT;
+	return (*dev->dma_mask >> PAGE_SHIFT) + dev->dma_pfn_offset;
 }
 #endif
 
-- 
2.14.2

[PATCH 10/34] arm64: don't override dma_max_pfn

[Christoph Hellwig]

The generic version now takes dma_pfn_offset into account, so there is no
more need for an architecture override.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
---
 arch/arm64/include/asm/dma-mapping.h | 9 ---------
 1 file changed, 9 deletions(-)

diff --git a/arch/arm64/include/asm/dma-mapping.h b/arch/arm64/include/asm/dma-mapping.h
index 0df756b24863..eada887a93bf 100644
--- a/arch/arm64/include/asm/dma-mapping.h
+++ b/arch/arm64/include/asm/dma-mapping.h
@@ -76,14 +76,5 @@ static inline void dma_mark_clean(void *addr, size_t size)
 {
 }
 
-/* Override for dma_max_pfn() */
-static inline unsigned long dma_max_pfn(struct device *dev)
-{
-	dma_addr_t dma_max = (dma_addr_t)*dev->dma_mask;
-
-	return (ulong)dma_to_phys(dev, dma_max) >> PAGE_SHIFT;
-}
-#define dma_max_pfn(dev) dma_max_pfn(dev)
-
 #endif	/* __KERNEL__ */
 #endif	/* __ASM_DMA_MAPPING_H */
-- 
2.14.2

[PATCH 11/34] mips: fix an off-by-one in dma_capable

[Christoph Hellwig]

This makes it match the generic version.

Reported-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/mips/include/asm/dma-mapping.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/include/asm/dma-mapping.h b/arch/mips/include/asm/dma-mapping.h
index 0d9418d264f9..5c334ac15945 100644
--- a/arch/mips/include/asm/dma-mapping.h
+++ b/arch/mips/include/asm/dma-mapping.h
@@ -22,7 +22,7 @@ static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
 	if (!dev->dma_mask)
 		return false;
 
-	return addr + size <= *dev->dma_mask;
+	return addr + size - 1 <= *dev->dma_mask;
 }
 
 static inline void dma_mark_clean(void *addr, size_t size) {}
-- 
2.14.2

[PATCH 12/34] dma-mapping: move swiotlb arch helpers to a new header

[Christoph Hellwig]

phys_to_dma, dma_to_phys and dma_capable are helpers published by
architecture code for use of swiotlb and xen-swiotlb only.  Drivers are
not supposed to use these directly, but use the DMA API instead.

Move these to a new asm/dma-direct.h helper, included by a
linux/dma-direct.h wrapper that provides the default linear mapping
unless the architecture wants to override it.

In the MIPS case the existing dma-coherent.h is reused for now as
untangling it will take a bit of work.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Robin Murphy <robin.murphy@arm.com>
---
 MAINTAINERS                                        |  1 +
 arch/Kconfig                                       |  4 +++
 arch/arm/Kconfig                                   |  1 +
 arch/arm/include/asm/dma-direct.h                  | 36 ++++++++++++++++++++++
 arch/arm/include/asm/dma-mapping.h                 | 31 -------------------
 arch/arm64/include/asm/dma-mapping.h               | 22 -------------
 arch/arm64/mm/dma-mapping.c                        |  2 +-
 arch/ia64/include/asm/dma-mapping.h                | 18 -----------
 arch/mips/Kconfig                                  |  2 ++
 arch/mips/include/asm/dma-direct.h                 |  1 +
 arch/mips/include/asm/dma-mapping.h                |  8 -----
 .../include/asm/mach-cavium-octeon/dma-coherence.h |  8 +++++
 arch/mips/include/asm/mach-generic/dma-coherence.h | 12 --------
 .../include/asm/mach-loongson64/dma-coherence.h    |  8 +++++
 arch/powerpc/Kconfig                               |  1 +
 arch/powerpc/include/asm/dma-direct.h              | 29 +++++++++++++++++
 arch/powerpc/include/asm/dma-mapping.h             | 25 ---------------
 arch/tile/include/asm/dma-mapping.h                | 18 -----------
 arch/unicore32/include/asm/dma-mapping.h           | 18 -----------
 arch/x86/Kconfig                                   |  1 +
 arch/x86/include/asm/dma-direct.h                  | 30 ++++++++++++++++++
 arch/x86/include/asm/dma-mapping.h                 | 26 ----------------
 arch/x86/kernel/amd_gart_64.c                      |  1 +
 arch/x86/kernel/pci-dma.c                          |  2 +-
 arch/x86/kernel/pci-nommu.c                        |  2 +-
 arch/x86/kernel/pci-swiotlb.c                      |  2 +-
 arch/x86/mm/mem_encrypt.c                          |  2 +-
 arch/x86/pci/sta2x11-fixup.c                       |  1 +
 arch/xtensa/include/asm/dma-mapping.h              | 10 ------
 drivers/crypto/marvell/cesa.c                      |  1 +
 drivers/mtd/nand/qcom_nandc.c                      |  1 +
 drivers/xen/swiotlb-xen.c                          |  2 +-
 include/linux/dma-direct.h                         | 32 +++++++++++++++++++
 lib/swiotlb.c                                      |  2 +-
 34 files changed, 165 insertions(+), 195 deletions(-)
 create mode 100644 arch/arm/include/asm/dma-direct.h
 create mode 100644 arch/mips/include/asm/dma-direct.h
 create mode 100644 arch/powerpc/include/asm/dma-direct.h
 create mode 100644 arch/x86/include/asm/dma-direct.h
 create mode 100644 include/linux/dma-direct.h

diff --git a/MAINTAINERS b/MAINTAINERS
index 95c3fa1f520f..d2cfdcce1db5 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4338,6 +4338,7 @@ F:	lib/dma-noop.c
 F:	lib/dma-virt.c
 F:	drivers/base/dma-mapping.c
 F:	drivers/base/dma-coherent.c
+F:	include/linux/dma-direct.h
 F:	include/linux/dma-mapping.h
 
 DME1737 HARDWARE MONITOR DRIVER
diff --git a/arch/Kconfig b/arch/Kconfig
index 400b9e1b2f27..3edf118ad777 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -938,6 +938,10 @@ config STRICT_MODULE_RWX
 	  and non-text memory will be made non-executable. This provides
 	  protection against certain security exploits (e.g. writing to text)
 
+# select if the architecture provides an asm/dma-direct.h header
+config ARCH_HAS_PHYS_TO_DMA
+	bool
+
 config ARCH_HAS_REFCOUNT
 	bool
 	help
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 51c8df561077..00d889a37965 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -8,6 +8,7 @@ config ARM
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_SET_MEMORY
+	select ARCH_HAS_PHYS_TO_DMA
 	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
 	select ARCH_HAS_STRICT_MODULE_RWX if MMU
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
diff --git a/arch/arm/include/asm/dma-direct.h b/arch/arm/include/asm/dma-direct.h
new file mode 100644
index 000000000000..5b0a8a421894
--- /dev/null
+++ b/arch/arm/include/asm/dma-direct.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef ASM_ARM_DMA_DIRECT_H
+#define ASM_ARM_DMA_DIRECT_H 1
+
+static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
+{
+	unsigned int offset = paddr & ~PAGE_MASK;
+	return pfn_to_dma(dev, __phys_to_pfn(paddr)) + offset;
+}
+
+static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dev_addr)
+{
+	unsigned int offset = dev_addr & ~PAGE_MASK;
+	return __pfn_to_phys(dma_to_pfn(dev, dev_addr)) + offset;
+}
+
+static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
+{
+	u64 limit, mask;
+
+	if (!dev->dma_mask)
+		return 0;
+
+	mask = *dev->dma_mask;
+
+	limit = (mask + 1) & ~mask;
+	if (limit && size > limit)
+		return 0;
+
+	if ((addr | (addr + size - 1)) & ~mask)
+		return 0;
+
+	return 1;
+}
+
+#endif /* ASM_ARM_DMA_DIRECT_H */
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index daf837423a76..5fb1b7fbdfbe 100644
--- a/arch/arm/include/asm/dma-mapping.h
+++ b/arch/arm/include/asm/dma-mapping.h
@@ -109,37 +109,6 @@ static inline bool is_device_dma_coherent(struct device *dev)
 	return dev->archdata.dma_coherent;
 }
 
-static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
-{
-	unsigned int offset = paddr & ~PAGE_MASK;
-	return pfn_to_dma(dev, __phys_to_pfn(paddr)) + offset;
-}
-
-static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dev_addr)
-{
-	unsigned int offset = dev_addr & ~PAGE_MASK;
-	return __pfn_to_phys(dma_to_pfn(dev, dev_addr)) + offset;
-}
-
-static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
-{
-	u64 limit, mask;
-
-	if (!dev->dma_mask)
-		return 0;
-
-	mask = *dev->dma_mask;
-
-	limit = (mask + 1) & ~mask;
-	if (limit && size > limit)
-		return 0;
-
-	if ((addr | (addr + size - 1)) & ~mask)
-		return 0;
-
-	return 1;
-}
-
 static inline void dma_mark_clean(void *addr, size_t size) { }
 
 /**
diff --git a/arch/arm64/include/asm/dma-mapping.h b/arch/arm64/include/asm/dma-mapping.h
index eada887a93bf..400fa67d3b5a 100644
--- a/arch/arm64/include/asm/dma-mapping.h
+++ b/arch/arm64/include/asm/dma-mapping.h
@@ -50,28 +50,6 @@ static inline bool is_device_dma_coherent(struct device *dev)
 	return dev->archdata.dma_coherent;
 }
 
-static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
-{
-	dma_addr_t dev_addr = (dma_addr_t)paddr;
-
-	return dev_addr - ((dma_addr_t)dev->dma_pfn_offset << PAGE_SHIFT);
-}
-
-static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dev_addr)
-{
-	phys_addr_t paddr = (phys_addr_t)dev_addr;
-
-	return paddr + ((phys_addr_t)dev->dma_pfn_offset << PAGE_SHIFT);
-}
-
-static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
-{
-	if (!dev->dma_mask)
-		return false;
-
-	return addr + size - 1 <= *dev->dma_mask;
-}
-
 static inline void dma_mark_clean(void *addr, size_t size)
 {
 }
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index b45c5bcaeccb..f3a637b98487 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -24,7 +24,7 @@
 #include <linux/export.h>
 #include <linux/slab.h>
 #include <linux/genalloc.h>
-#include <linux/dma-mapping.h>
+#include <linux/dma-direct.h>
 #include <linux/dma-contiguous.h>
 #include <linux/vmalloc.h>
 #include <linux/swiotlb.h>
diff --git a/arch/ia64/include/asm/dma-mapping.h b/arch/ia64/include/asm/dma-mapping.h
index c1bab526a046..eabee56d995c 100644
--- a/arch/ia64/include/asm/dma-mapping.h
+++ b/arch/ia64/include/asm/dma-mapping.h
@@ -27,22 +27,4 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 	return platform_dma_get_ops(NULL);
 }
 
-static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
-{
-	if (!dev->dma_mask)
-		return 0;
-
-	return addr + size - 1 <= *dev->dma_mask;
-}
-
-static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
-{
-	return paddr;
-}
-
-static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
-{
-	return daddr;
-}
-
 #endif /* _ASM_IA64_DMA_MAPPING_H */
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 350a990fc719..4b0c26b2e9b7 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -429,6 +429,7 @@ config MACH_LOONGSON32
 
 config MACH_LOONGSON64
 	bool "Loongson-2/3 family of machines"
+	select ARCH_HAS_PHYS_TO_DMA
 	select SYS_SUPPORTS_ZBOOT
 	help
 	  This enables the support of Loongson-2/3 family of machines.
@@ -877,6 +878,7 @@ config MIKROTIK_RB532
 config CAVIUM_OCTEON_SOC
 	bool "Cavium Networks Octeon SoC based boards"
 	select CEVT_R4K
+	select ARCH_HAS_PHYS_TO_DMA
 	select ARCH_PHYS_ADDR_T_64BIT
 	select DMA_COHERENT
 	select SYS_SUPPORTS_64BIT_KERNEL
diff --git a/arch/mips/include/asm/dma-direct.h b/arch/mips/include/asm/dma-direct.h
new file mode 100644
index 000000000000..f32f15530aba
--- /dev/null
+++ b/arch/mips/include/asm/dma-direct.h
@@ -0,0 +1 @@
+#include <asm/dma-coherence.h>
diff --git a/arch/mips/include/asm/dma-mapping.h b/arch/mips/include/asm/dma-mapping.h
index 5c334ac15945..676c14cfc580 100644
--- a/arch/mips/include/asm/dma-mapping.h
+++ b/arch/mips/include/asm/dma-mapping.h
@@ -17,14 +17,6 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 	return mips_dma_map_ops;
 }
 
-static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
-{
-	if (!dev->dma_mask)
-		return false;
-
-	return addr + size - 1 <= *dev->dma_mask;
-}
-
 static inline void dma_mark_clean(void *addr, size_t size) {}
 
 #define arch_setup_dma_ops arch_setup_dma_ops
diff --git a/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h b/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h
index 9110988b92a1..138edf6b5b48 100644
--- a/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h
+++ b/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h
@@ -61,6 +61,14 @@ static inline void plat_post_dma_flush(struct device *dev)
 {
 }
 
+static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
+{
+	if (!dev->dma_mask)
+		return false;
+
+	return addr + size - 1 <= *dev->dma_mask;
+}
+
 dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr);
 phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr);
 
diff --git a/arch/mips/include/asm/mach-generic/dma-coherence.h b/arch/mips/include/asm/mach-generic/dma-coherence.h
index 61addb1677e9..8ad7a40ca786 100644
--- a/arch/mips/include/asm/mach-generic/dma-coherence.h
+++ b/arch/mips/include/asm/mach-generic/dma-coherence.h
@@ -70,16 +70,4 @@ static inline void plat_post_dma_flush(struct device *dev)
 }
 #endif
 
-#ifdef CONFIG_SWIOTLB
-static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
-{
-	return paddr;
-}
-
-static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
-{
-	return daddr;
-}
-#endif
-
 #endif /* __ASM_MACH_GENERIC_DMA_COHERENCE_H */
diff --git a/arch/mips/include/asm/mach-loongson64/dma-coherence.h b/arch/mips/include/asm/mach-loongson64/dma-coherence.h
index 1602a9e9e8c2..b1b575f5c6c1 100644
--- a/arch/mips/include/asm/mach-loongson64/dma-coherence.h
+++ b/arch/mips/include/asm/mach-loongson64/dma-coherence.h
@@ -17,6 +17,14 @@
 
 struct device;
 
+static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
+{
+	if (!dev->dma_mask)
+		return false;
+
+	return addr + size - 1 <= *dev->dma_mask;
+}
+
 extern dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr);
 extern phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr);
 static inline dma_addr_t plat_map_dma_mem(struct device *dev, void *addr,
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index c51e6ce42e7a..887285eb684a 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -139,6 +139,7 @@ config PPC
 	select ARCH_HAS_ELF_RANDOMIZE
 	select ARCH_HAS_FORTIFY_SOURCE
 	select ARCH_HAS_GCOV_PROFILE_ALL
+	select ARCH_HAS_PHYS_TO_DMA
 	select ARCH_HAS_PMEM_API                if PPC64
 	select ARCH_HAS_SCALED_CPUTIME		if VIRT_CPU_ACCOUNTING_NATIVE
 	select ARCH_HAS_SG_CHAIN
diff --git a/arch/powerpc/include/asm/dma-direct.h b/arch/powerpc/include/asm/dma-direct.h
new file mode 100644
index 000000000000..a5b59c765426
--- /dev/null
+++ b/arch/powerpc/include/asm/dma-direct.h
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef ASM_POWERPC_DMA_DIRECT_H
+#define ASM_POWERPC_DMA_DIRECT_H 1
+
+static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
+{
+#ifdef CONFIG_SWIOTLB
+	struct dev_archdata *sd = &dev->archdata;
+
+	if (sd->max_direct_dma_addr && addr + size > sd->max_direct_dma_addr)
+		return false;
+#endif
+
+	if (!dev->dma_mask)
+		return false;
+
+	return addr + size - 1 <= *dev->dma_mask;
+}
+
+static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
+{
+	return paddr + get_dma_offset(dev);
+}
+
+static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
+{
+	return daddr - get_dma_offset(dev);
+}
+#endif /* ASM_POWERPC_DMA_DIRECT_H */
diff --git a/arch/powerpc/include/asm/dma-mapping.h b/arch/powerpc/include/asm/dma-mapping.h
index 592c7f418aa0..f6ab51205a85 100644
--- a/arch/powerpc/include/asm/dma-mapping.h
+++ b/arch/powerpc/include/asm/dma-mapping.h
@@ -112,31 +112,6 @@ extern int dma_set_mask(struct device *dev, u64 dma_mask);
 
 extern u64 __dma_get_required_mask(struct device *dev);
 
-static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
-{
-#ifdef CONFIG_SWIOTLB
-	struct dev_archdata *sd = &dev->archdata;
-
-	if (sd->max_direct_dma_addr && addr + size > sd->max_direct_dma_addr)
-		return false;
-#endif
-
-	if (!dev->dma_mask)
-		return false;
-
-	return addr + size - 1 <= *dev->dma_mask;
-}
-
-static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
-{
-	return paddr + get_dma_offset(dev);
-}
-
-static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
-{
-	return daddr - get_dma_offset(dev);
-}
-
 #define ARCH_HAS_DMA_MMAP_COHERENT
 
 #endif /* __KERNEL__ */
diff --git a/arch/tile/include/asm/dma-mapping.h b/arch/tile/include/asm/dma-mapping.h
index 97ad62878290..75b8aaa4e70b 100644
--- a/arch/tile/include/asm/dma-mapping.h
+++ b/arch/tile/include/asm/dma-mapping.h
@@ -44,26 +44,8 @@ static inline void set_dma_offset(struct device *dev, dma_addr_t off)
 	dev->archdata.dma_offset = off;
 }
 
-static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
-{
-	return paddr;
-}
-
-static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
-{
-	return daddr;
-}
-
 static inline void dma_mark_clean(void *addr, size_t size) {}
 
-static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
-{
-	if (!dev->dma_mask)
-		return 0;
-
-	return addr + size - 1 <= *dev->dma_mask;
-}
-
 #define HAVE_ARCH_DMA_SET_MASK 1
 int dma_set_mask(struct device *dev, u64 mask);
 
diff --git a/arch/unicore32/include/asm/dma-mapping.h b/arch/unicore32/include/asm/dma-mapping.h
index ac608c2f6af6..5cb250bf2d8c 100644
--- a/arch/unicore32/include/asm/dma-mapping.h
+++ b/arch/unicore32/include/asm/dma-mapping.h
@@ -25,24 +25,6 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 	return &swiotlb_dma_map_ops;
 }
 
-static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
-{
-	if (dev && dev->dma_mask)
-		return addr + size - 1 <= *dev->dma_mask;
-
-	return 1;
-}
-
-static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
-{
-	return paddr;
-}
-
-static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
-{
-	return daddr;
-}
-
 static inline void dma_mark_clean(void *addr, size_t size) {}
 
 #endif /* __KERNEL__ */
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index d4fc98c50378..f6f4328103c0 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -54,6 +54,7 @@ config X86
 	select ARCH_HAS_FORTIFY_SOURCE
 	select ARCH_HAS_GCOV_PROFILE_ALL
 	select ARCH_HAS_KCOV			if X86_64
+	select ARCH_HAS_PHYS_TO_DMA
 	select ARCH_HAS_PMEM_API		if X86_64
 	# Causing hangs/crashes, see the commit that added this change for details.
 	select ARCH_HAS_REFCOUNT
diff --git a/arch/x86/include/asm/dma-direct.h b/arch/x86/include/asm/dma-direct.h
new file mode 100644
index 000000000000..1295bc622ebe
--- /dev/null
+++ b/arch/x86/include/asm/dma-direct.h
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef ASM_X86_DMA_DIRECT_H
+#define ASM_X86_DMA_DIRECT_H 1
+
+#include <linux/mem_encrypt.h>
+
+#ifdef CONFIG_X86_DMA_REMAP /* Platform code defines bridge-specific code */
+bool dma_capable(struct device *dev, dma_addr_t addr, size_t size);
+dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr);
+phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr);
+#else
+static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
+{
+	if (!dev->dma_mask)
+		return 0;
+
+	return addr + size - 1 <= *dev->dma_mask;
+}
+
+static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
+{
+	return __sme_set(paddr);
+}
+
+static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
+{
+	return __sme_clr(daddr);
+}
+#endif /* CONFIG_X86_DMA_REMAP */
+#endif /* ASM_X86_DMA_DIRECT_H */
diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
index 0350d99bb8fd..dfdc9357a349 100644
--- a/arch/x86/include/asm/dma-mapping.h
+++ b/arch/x86/include/asm/dma-mapping.h
@@ -12,7 +12,6 @@
 #include <asm/io.h>
 #include <asm/swiotlb.h>
 #include <linux/dma-contiguous.h>
-#include <linux/mem_encrypt.h>
 
 #ifdef CONFIG_ISA
 # define ISA_DMA_BIT_MASK DMA_BIT_MASK(24)
@@ -42,31 +41,6 @@ extern void dma_generic_free_coherent(struct device *dev, size_t size,
 				      void *vaddr, dma_addr_t dma_addr,
 				      unsigned long attrs);
 
-#ifdef CONFIG_X86_DMA_REMAP /* Platform code defines bridge-specific code */
-extern bool dma_capable(struct device *dev, dma_addr_t addr, size_t size);
-extern dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr);
-extern phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr);
-#else
-
-static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
-{
-	if (!dev->dma_mask)
-		return 0;
-
-	return addr + size - 1 <= *dev->dma_mask;
-}
-
-static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
-{
-	return __sme_set(paddr);
-}
-
-static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
-{
-	return __sme_clr(daddr);
-}
-#endif /* CONFIG_X86_DMA_REMAP */
-
 static inline unsigned long dma_alloc_coherent_mask(struct device *dev,
 						    gfp_t gfp)
 {
diff --git a/arch/x86/kernel/amd_gart_64.c b/arch/x86/kernel/amd_gart_64.c
index cc0e8bc0ea3f..ecd486cb06ab 100644
--- a/arch/x86/kernel/amd_gart_64.c
+++ b/arch/x86/kernel/amd_gart_64.c
@@ -31,6 +31,7 @@
 #include <linux/io.h>
 #include <linux/gfp.h>
 #include <linux/atomic.h>
+#include <linux/dma-direct.h>
 #include <asm/mtrr.h>
 #include <asm/pgtable.h>
 #include <asm/proto.h>
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index 599d7462eccc..8439e6de6156 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -1,5 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0
-#include <linux/dma-mapping.h>
+#include <linux/dma-direct.h>
 #include <linux/dma-debug.h>
 #include <linux/dmar.h>
 #include <linux/export.h>
diff --git a/arch/x86/kernel/pci-nommu.c b/arch/x86/kernel/pci-nommu.c
index b0caae27e1b7..618285e475c6 100644
--- a/arch/x86/kernel/pci-nommu.c
+++ b/arch/x86/kernel/pci-nommu.c
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: GPL-2.0
 /* Fallback functions when the main IOMMU code is not compiled in. This
    code is roughly equivalent to i386. */
-#include <linux/dma-mapping.h>
+#include <linux/dma-direct.h>
 #include <linux/scatterlist.h>
 #include <linux/string.h>
 #include <linux/gfp.h>
diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c
index 53bd05ea90d8..9d3e35c33d94 100644
--- a/arch/x86/kernel/pci-swiotlb.c
+++ b/arch/x86/kernel/pci-swiotlb.c
@@ -6,7 +6,7 @@
 #include <linux/init.h>
 #include <linux/swiotlb.h>
 #include <linux/bootmem.h>
-#include <linux/dma-mapping.h>
+#include <linux/dma-direct.h>
 #include <linux/mem_encrypt.h>
 
 #include <asm/iommu.h>
diff --git a/arch/x86/mm/mem_encrypt.c b/arch/x86/mm/mem_encrypt.c
index 391b13402e40..09532c935da0 100644
--- a/arch/x86/mm/mem_encrypt.c
+++ b/arch/x86/mm/mem_encrypt.c
@@ -15,7 +15,7 @@
 #include <linux/linkage.h>
 #include <linux/init.h>
 #include <linux/mm.h>
-#include <linux/dma-mapping.h>
+#include <linux/dma-direct.h>
 #include <linux/swiotlb.h>
 #include <linux/mem_encrypt.h>
 
diff --git a/arch/x86/pci/sta2x11-fixup.c b/arch/x86/pci/sta2x11-fixup.c
index 53d600217973..75577c1490c4 100644
--- a/arch/x86/pci/sta2x11-fixup.c
+++ b/arch/x86/pci/sta2x11-fixup.c
@@ -26,6 +26,7 @@
 #include <linux/pci_ids.h>
 #include <linux/export.h>
 #include <linux/list.h>
+#include <linux/dma-direct.h>
 #include <asm/iommu.h>
 
 #define STA2X11_SWIOTLB_SIZE (4*1024*1024)
diff --git a/arch/xtensa/include/asm/dma-mapping.h b/arch/xtensa/include/asm/dma-mapping.h
index 153bf2370988..44098800dad7 100644
--- a/arch/xtensa/include/asm/dma-mapping.h
+++ b/arch/xtensa/include/asm/dma-mapping.h
@@ -23,14 +23,4 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 	return &xtensa_dma_map_ops;
 }
 
-static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
-{
-	return (dma_addr_t)paddr;
-}
-
-static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
-{
-	return (phys_addr_t)daddr;
-}
-
 #endif	/* _XTENSA_DMA_MAPPING_H */
diff --git a/drivers/crypto/marvell/cesa.c b/drivers/crypto/marvell/cesa.c
index 293832488cc9..3a0c40081ffb 100644
--- a/drivers/crypto/marvell/cesa.c
+++ b/drivers/crypto/marvell/cesa.c
@@ -24,6 +24,7 @@
 #include <linux/scatterlist.h>
 #include <linux/slab.h>
 #include <linux/module.h>
+#include <linux/dma-direct.h> /* XXX: drivers shall never use this directly! */
 #include <linux/clk.h>
 #include <linux/of.h>
 #include <linux/of_platform.h>
diff --git a/drivers/mtd/nand/qcom_nandc.c b/drivers/mtd/nand/qcom_nandc.c
index 2656c1ac5646..411cdfd12a85 100644
--- a/drivers/mtd/nand/qcom_nandc.c
+++ b/drivers/mtd/nand/qcom_nandc.c
@@ -23,6 +23,7 @@
 #include <linux/of_device.h>
 #include <linux/delay.h>
 #include <linux/dma/qcom_bam_dma.h>
+#include <linux/dma-direct.h> /* XXX: drivers shall never use this directly! */
 
 /* NANDc reg offsets */
 #define	NAND_FLASH_CMD			0x00
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 82fc54f8eb77..5bb72d3f8337 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -36,7 +36,7 @@
 #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
 
 #include <linux/bootmem.h>
-#include <linux/dma-mapping.h>
+#include <linux/dma-direct.h>
 #include <linux/export.h>
 #include <xen/swiotlb-xen.h>
 #include <xen/page.h>
diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h
new file mode 100644
index 000000000000..2cc1b6558944
--- /dev/null
+++ b/include/linux/dma-direct.h
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_DMA_DIRECT_H
+#define _LINUX_DMA_DIRECT_H 1
+
+#include <linux/dma-mapping.h>
+
+#ifdef CONFIG_ARCH_HAS_PHYS_TO_DMA
+#include <asm/dma-direct.h>
+#else
+static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
+{
+	dma_addr_t dev_addr = (dma_addr_t)paddr;
+
+	return dev_addr - ((dma_addr_t)dev->dma_pfn_offset << PAGE_SHIFT);
+}
+
+static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dev_addr)
+{
+	phys_addr_t paddr = (phys_addr_t)dev_addr;
+
+	return paddr + ((phys_addr_t)dev->dma_pfn_offset << PAGE_SHIFT);
+}
+
+static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
+{
+	if (!dev->dma_mask)
+		return false;
+
+	return addr + size - 1 <= *dev->dma_mask;
+}
+#endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */
+#endif /* _LINUX_DMA_DIRECT_H */
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index cea19aaf303c..6583f3512386 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -18,7 +18,7 @@
  */
 
 #include <linux/cache.h>
-#include <linux/dma-mapping.h>
+#include <linux/dma-direct.h>
 #include <linux/mm.h>
 #include <linux/export.h>
 #include <linux/spinlock.h>
-- 
2.14.2

[PATCH 13/34] dma-mapping: move dma_mark_clean to dma-direct.h

[Christoph Hellwig]

And unlike the other helpers we don't require a <asm/dma-direct.h> as
this helper is a special case for ia64 only, and this keeps it as
simple as possible.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/arm/include/asm/dma-mapping.h       | 2 --
 arch/arm64/include/asm/dma-mapping.h     | 4 ----
 arch/ia64/Kconfig                        | 1 +
 arch/ia64/include/asm/dma.h              | 2 --
 arch/mips/include/asm/dma-mapping.h      | 2 --
 arch/powerpc/include/asm/swiotlb.h       | 2 --
 arch/tile/include/asm/dma-mapping.h      | 2 --
 arch/unicore32/include/asm/dma-mapping.h | 2 --
 arch/x86/include/asm/swiotlb.h           | 2 --
 include/linux/dma-direct.h               | 9 +++++++++
 10 files changed, 10 insertions(+), 18 deletions(-)

diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index 5fb1b7fbdfbe..e5d9020c9ee1 100644
--- a/arch/arm/include/asm/dma-mapping.h
+++ b/arch/arm/include/asm/dma-mapping.h
@@ -109,8 +109,6 @@ static inline bool is_device_dma_coherent(struct device *dev)
 	return dev->archdata.dma_coherent;
 }
 
-static inline void dma_mark_clean(void *addr, size_t size) { }
-
 /**
  * arm_dma_alloc - allocate consistent memory for DMA
  * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
diff --git a/arch/arm64/include/asm/dma-mapping.h b/arch/arm64/include/asm/dma-mapping.h
index 400fa67d3b5a..b7847eb8a7bb 100644
--- a/arch/arm64/include/asm/dma-mapping.h
+++ b/arch/arm64/include/asm/dma-mapping.h
@@ -50,9 +50,5 @@ static inline bool is_device_dma_coherent(struct device *dev)
 	return dev->archdata.dma_coherent;
 }
 
-static inline void dma_mark_clean(void *addr, size_t size)
-{
-}
-
 #endif	/* __KERNEL__ */
 #endif	/* __ASM_DMA_MAPPING_H */
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 49583c5a5d44..4d18fca885ee 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -33,6 +33,7 @@ config IA64
 	select HAVE_MEMBLOCK
 	select HAVE_MEMBLOCK_NODE_MAP
 	select HAVE_VIRT_CPU_ACCOUNTING
+	select ARCH_HAS_DMA_MARK_CLEAN
 	select ARCH_HAS_SG_CHAIN
 	select VIRT_TO_BUS
 	select ARCH_DISCARD_MEMBLOCK
diff --git a/arch/ia64/include/asm/dma.h b/arch/ia64/include/asm/dma.h
index 186850eec934..23604d6a2cb2 100644
--- a/arch/ia64/include/asm/dma.h
+++ b/arch/ia64/include/asm/dma.h
@@ -20,6 +20,4 @@ extern unsigned long MAX_DMA_ADDRESS;
 
 #define free_dma(x)
 
-void dma_mark_clean(void *addr, size_t size);
-
 #endif /* _ASM_IA64_DMA_H */
diff --git a/arch/mips/include/asm/dma-mapping.h b/arch/mips/include/asm/dma-mapping.h
index 676c14cfc580..886e75a383f2 100644
--- a/arch/mips/include/asm/dma-mapping.h
+++ b/arch/mips/include/asm/dma-mapping.h
@@ -17,8 +17,6 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 	return mips_dma_map_ops;
 }
 
-static inline void dma_mark_clean(void *addr, size_t size) {}
-
 #define arch_setup_dma_ops arch_setup_dma_ops
 static inline void arch_setup_dma_ops(struct device *dev, u64 dma_base,
 				      u64 size, const struct iommu_ops *iommu,
diff --git a/arch/powerpc/include/asm/swiotlb.h b/arch/powerpc/include/asm/swiotlb.h
index 01d45a5fd00b..9341ee804d19 100644
--- a/arch/powerpc/include/asm/swiotlb.h
+++ b/arch/powerpc/include/asm/swiotlb.h
@@ -15,8 +15,6 @@
 
 extern const struct dma_map_ops swiotlb_dma_ops;
 
-static inline void dma_mark_clean(void *addr, size_t size) {}
-
 extern unsigned int ppc_swiotlb_enable;
 int __init swiotlb_setup_bus_notifier(void);
 
diff --git a/arch/tile/include/asm/dma-mapping.h b/arch/tile/include/asm/dma-mapping.h
index 75b8aaa4e70b..d25fce101fc0 100644
--- a/arch/tile/include/asm/dma-mapping.h
+++ b/arch/tile/include/asm/dma-mapping.h
@@ -44,8 +44,6 @@ static inline void set_dma_offset(struct device *dev, dma_addr_t off)
 	dev->archdata.dma_offset = off;
 }
 
-static inline void dma_mark_clean(void *addr, size_t size) {}
-
 #define HAVE_ARCH_DMA_SET_MASK 1
 int dma_set_mask(struct device *dev, u64 mask);
 
diff --git a/arch/unicore32/include/asm/dma-mapping.h b/arch/unicore32/include/asm/dma-mapping.h
index 5cb250bf2d8c..f2bfec273aa7 100644
--- a/arch/unicore32/include/asm/dma-mapping.h
+++ b/arch/unicore32/include/asm/dma-mapping.h
@@ -25,7 +25,5 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 	return &swiotlb_dma_map_ops;
 }
 
-static inline void dma_mark_clean(void *addr, size_t size) {}
-
 #endif /* __KERNEL__ */
 #endif
diff --git a/arch/x86/include/asm/swiotlb.h b/arch/x86/include/asm/swiotlb.h
index bdf9aed40403..1c6a6cb230ff 100644
--- a/arch/x86/include/asm/swiotlb.h
+++ b/arch/x86/include/asm/swiotlb.h
@@ -28,8 +28,6 @@ static inline void pci_swiotlb_late_init(void)
 }
 #endif
 
-static inline void dma_mark_clean(void *addr, size_t size) {}
-
 extern void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
 					dma_addr_t *dma_handle, gfp_t flags,
 					unsigned long attrs);
diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h
index 2cc1b6558944..10e924b7cba7 100644
--- a/include/linux/dma-direct.h
+++ b/include/linux/dma-direct.h
@@ -29,4 +29,13 @@ static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
 	return addr + size - 1 <= *dev->dma_mask;
 }
 #endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */
+
+#ifdef CONFIG_ARCH_HAS_DMA_MARK_CLEAN
+void dma_mark_clean(void *addr, size_t size);
+#else
+static inline void dma_mark_clean(void *addr, size_t size)
+{
+}
+#endif /* CONFIG_ARCH_HAS_DMA_MARK_CLEAN */
+
 #endif /* _LINUX_DMA_DIRECT_H */
-- 
2.14.2

[PATCH 14/34] hexagon: use the generic dma_capable helper

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Richard Kuo <rkuo@codeaurora.org>
---
 arch/hexagon/include/asm/dma-mapping.h | 7 -------
 arch/hexagon/kernel/dma.c              | 1 +
 2 files changed, 1 insertion(+), 7 deletions(-)

diff --git a/arch/hexagon/include/asm/dma-mapping.h b/arch/hexagon/include/asm/dma-mapping.h
index 5208de242e79..263f6acbfb0f 100644
--- a/arch/hexagon/include/asm/dma-mapping.h
+++ b/arch/hexagon/include/asm/dma-mapping.h
@@ -37,11 +37,4 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 	return dma_ops;
 }
 
-static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
-{
-	if (!dev->dma_mask)
-		return 0;
-	return addr + size - 1 <= *dev->dma_mask;
-}
-
 #endif
diff --git a/arch/hexagon/kernel/dma.c b/arch/hexagon/kernel/dma.c
index 546792d176a4..ad8347c29dcf 100644
--- a/arch/hexagon/kernel/dma.c
+++ b/arch/hexagon/kernel/dma.c
@@ -19,6 +19,7 @@
  */
 
 #include <linux/dma-mapping.h>
+#include <linux/dma-direct.h>
 #include <linux/bootmem.h>
 #include <linux/genalloc.h>
 #include <asm/dma-mapping.h>
-- 
2.14.2

[PATCH 15/34] powerpc: rename dma_direct_ to dma_nommu_

[Christoph Hellwig]

We want to use the dma_direct_ namespace for a generic implementation,
so rename powerpc to the second best choice: dma_nommu_.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/powerpc/include/asm/dma-mapping.h    |  8 ++--
 arch/powerpc/kernel/dma-iommu.c           |  2 +-
 arch/powerpc/kernel/dma-swiotlb.c         |  6 +--
 arch/powerpc/kernel/dma.c                 | 68 +++++++++++++++----------------
 arch/powerpc/kernel/pci-common.c          |  2 +-
 arch/powerpc/kernel/setup-common.c        |  2 +-
 arch/powerpc/platforms/cell/iommu.c       | 28 ++++++-------
 arch/powerpc/platforms/pasemi/iommu.c     |  2 +-
 arch/powerpc/platforms/pasemi/setup.c     |  2 +-
 arch/powerpc/platforms/powernv/pci-ioda.c |  4 +-
 arch/powerpc/platforms/pseries/iommu.c    |  2 +-
 arch/powerpc/platforms/pseries/vio.c      |  2 +-
 arch/powerpc/sysdev/dart_iommu.c          |  4 +-
 arch/powerpc/sysdev/fsl_pci.c             |  2 +-
 drivers/misc/cxl/vphb.c                   |  2 +-
 15 files changed, 68 insertions(+), 68 deletions(-)

diff --git a/arch/powerpc/include/asm/dma-mapping.h b/arch/powerpc/include/asm/dma-mapping.h
index f6ab51205a85..8fa394520af6 100644
--- a/arch/powerpc/include/asm/dma-mapping.h
+++ b/arch/powerpc/include/asm/dma-mapping.h
@@ -19,13 +19,13 @@
 #include <asm/swiotlb.h>
 
 /* Some dma direct funcs must be visible for use in other dma_ops */
-extern void *__dma_direct_alloc_coherent(struct device *dev, size_t size,
+extern void *__dma_nommu_alloc_coherent(struct device *dev, size_t size,
 					 dma_addr_t *dma_handle, gfp_t flag,
 					 unsigned long attrs);
-extern void __dma_direct_free_coherent(struct device *dev, size_t size,
+extern void __dma_nommu_free_coherent(struct device *dev, size_t size,
 				       void *vaddr, dma_addr_t dma_handle,
 				       unsigned long attrs);
-extern int dma_direct_mmap_coherent(struct device *dev,
+extern int dma_nommu_mmap_coherent(struct device *dev,
 				    struct vm_area_struct *vma,
 				    void *cpu_addr, dma_addr_t handle,
 				    size_t size, unsigned long attrs);
@@ -73,7 +73,7 @@ static inline unsigned long device_to_mask(struct device *dev)
 #ifdef CONFIG_PPC64
 extern struct dma_map_ops dma_iommu_ops;
 #endif
-extern const struct dma_map_ops dma_direct_ops;
+extern const struct dma_map_ops dma_nommu_ops;
 
 static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
diff --git a/arch/powerpc/kernel/dma-iommu.c b/arch/powerpc/kernel/dma-iommu.c
index 66f33e7f8d40..f9fe2080ceb9 100644
--- a/arch/powerpc/kernel/dma-iommu.c
+++ b/arch/powerpc/kernel/dma-iommu.c
@@ -114,7 +114,7 @@ int dma_iommu_mapping_error(struct device *dev, dma_addr_t dma_addr)
 struct dma_map_ops dma_iommu_ops = {
 	.alloc			= dma_iommu_alloc_coherent,
 	.free			= dma_iommu_free_coherent,
-	.mmap			= dma_direct_mmap_coherent,
+	.mmap			= dma_nommu_mmap_coherent,
 	.map_sg			= dma_iommu_map_sg,
 	.unmap_sg		= dma_iommu_unmap_sg,
 	.dma_supported		= dma_iommu_dma_supported,
diff --git a/arch/powerpc/kernel/dma-swiotlb.c b/arch/powerpc/kernel/dma-swiotlb.c
index d0ea7860e02b..f1e99b9cee97 100644
--- a/arch/powerpc/kernel/dma-swiotlb.c
+++ b/arch/powerpc/kernel/dma-swiotlb.c
@@ -47,9 +47,9 @@ static u64 swiotlb_powerpc_get_required(struct device *dev)
  * for everything else.
  */
 const struct dma_map_ops swiotlb_dma_ops = {
-	.alloc = __dma_direct_alloc_coherent,
-	.free = __dma_direct_free_coherent,
-	.mmap = dma_direct_mmap_coherent,
+	.alloc = __dma_nommu_alloc_coherent,
+	.free = __dma_nommu_free_coherent,
+	.mmap = dma_nommu_mmap_coherent,
 	.map_sg = swiotlb_map_sg_attrs,
 	.unmap_sg = swiotlb_unmap_sg_attrs,
 	.dma_supported = swiotlb_dma_supported,
diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c
index 4194bbbbdb10..6d5d04ccf3b4 100644
--- a/arch/powerpc/kernel/dma.c
+++ b/arch/powerpc/kernel/dma.c
@@ -40,7 +40,7 @@ static u64 __maybe_unused get_pfn_limit(struct device *dev)
 	return pfn;
 }
 
-static int dma_direct_dma_supported(struct device *dev, u64 mask)
+static int dma_nommu_dma_supported(struct device *dev, u64 mask)
 {
 #ifdef CONFIG_PPC64
 	u64 limit = get_dma_offset(dev) + (memblock_end_of_DRAM() - 1);
@@ -62,7 +62,7 @@ static int dma_direct_dma_supported(struct device *dev, u64 mask)
 #endif
 }
 
-void *__dma_direct_alloc_coherent(struct device *dev, size_t size,
+void *__dma_nommu_alloc_coherent(struct device *dev, size_t size,
 				  dma_addr_t *dma_handle, gfp_t flag,
 				  unsigned long attrs)
 {
@@ -119,7 +119,7 @@ void *__dma_direct_alloc_coherent(struct device *dev, size_t size,
 #endif
 }
 
-void __dma_direct_free_coherent(struct device *dev, size_t size,
+void __dma_nommu_free_coherent(struct device *dev, size_t size,
 				void *vaddr, dma_addr_t dma_handle,
 				unsigned long attrs)
 {
@@ -130,7 +130,7 @@ void __dma_direct_free_coherent(struct device *dev, size_t size,
 #endif
 }
 
-static void *dma_direct_alloc_coherent(struct device *dev, size_t size,
+static void *dma_nommu_alloc_coherent(struct device *dev, size_t size,
 				       dma_addr_t *dma_handle, gfp_t flag,
 				       unsigned long attrs)
 {
@@ -139,8 +139,8 @@ static void *dma_direct_alloc_coherent(struct device *dev, size_t size,
 	/* The coherent mask may be smaller than the real mask, check if
 	 * we can really use the direct ops
 	 */
-	if (dma_direct_dma_supported(dev, dev->coherent_dma_mask))
-		return __dma_direct_alloc_coherent(dev, size, dma_handle,
+	if (dma_nommu_dma_supported(dev, dev->coherent_dma_mask))
+		return __dma_nommu_alloc_coherent(dev, size, dma_handle,
 						   flag, attrs);
 
 	/* Ok we can't ... do we have an iommu ? If not, fail */
@@ -154,15 +154,15 @@ static void *dma_direct_alloc_coherent(struct device *dev, size_t size,
 				    dev_to_node(dev));
 }
 
-static void dma_direct_free_coherent(struct device *dev, size_t size,
+static void dma_nommu_free_coherent(struct device *dev, size_t size,
 				     void *vaddr, dma_addr_t dma_handle,
 				     unsigned long attrs)
 {
 	struct iommu_table *iommu;
 
-	/* See comments in dma_direct_alloc_coherent() */
-	if (dma_direct_dma_supported(dev, dev->coherent_dma_mask))
-		return __dma_direct_free_coherent(dev, size, vaddr, dma_handle,
+	/* See comments in dma_nommu_alloc_coherent() */
+	if (dma_nommu_dma_supported(dev, dev->coherent_dma_mask))
+		return __dma_nommu_free_coherent(dev, size, vaddr, dma_handle,
 						  attrs);
 	/* Maybe we used an iommu ... */
 	iommu = get_iommu_table_base(dev);
@@ -175,7 +175,7 @@ static void dma_direct_free_coherent(struct device *dev, size_t size,
 	iommu_free_coherent(iommu, size, vaddr, dma_handle);
 }
 
-int dma_direct_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
+int dma_nommu_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
 			     void *cpu_addr, dma_addr_t handle, size_t size,
 			     unsigned long attrs)
 {
@@ -193,7 +193,7 @@ int dma_direct_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
 			       vma->vm_page_prot);
 }
 
-static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
+static int dma_nommu_map_sg(struct device *dev, struct scatterlist *sgl,
 			     int nents, enum dma_data_direction direction,
 			     unsigned long attrs)
 {
@@ -213,13 +213,13 @@ static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
 	return nents;
 }
 
-static void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sg,
+static void dma_nommu_unmap_sg(struct device *dev, struct scatterlist *sg,
 				int nents, enum dma_data_direction direction,
 				unsigned long attrs)
 {
 }
 
-static u64 dma_direct_get_required_mask(struct device *dev)
+static u64 dma_nommu_get_required_mask(struct device *dev)
 {
 	u64 end, mask;
 
@@ -231,7 +231,7 @@ static u64 dma_direct_get_required_mask(struct device *dev)
 	return mask;
 }
 
-static inline dma_addr_t dma_direct_map_page(struct device *dev,
+static inline dma_addr_t dma_nommu_map_page(struct device *dev,
 					     struct page *page,
 					     unsigned long offset,
 					     size_t size,
@@ -246,7 +246,7 @@ static inline dma_addr_t dma_direct_map_page(struct device *dev,
 	return page_to_phys(page) + offset + get_dma_offset(dev);
 }
 
-static inline void dma_direct_unmap_page(struct device *dev,
+static inline void dma_nommu_unmap_page(struct device *dev,
 					 dma_addr_t dma_address,
 					 size_t size,
 					 enum dma_data_direction direction,
@@ -255,7 +255,7 @@ static inline void dma_direct_unmap_page(struct device *dev,
 }
 
 #ifdef CONFIG_NOT_COHERENT_CACHE
-static inline void dma_direct_sync_sg(struct device *dev,
+static inline void dma_nommu_sync_sg(struct device *dev,
 		struct scatterlist *sgl, int nents,
 		enum dma_data_direction direction)
 {
@@ -266,7 +266,7 @@ static inline void dma_direct_sync_sg(struct device *dev,
 		__dma_sync_page(sg_page(sg), sg->offset, sg->length, direction);
 }
 
-static inline void dma_direct_sync_single(struct device *dev,
+static inline void dma_nommu_sync_single(struct device *dev,
 					  dma_addr_t dma_handle, size_t size,
 					  enum dma_data_direction direction)
 {
@@ -274,24 +274,24 @@ static inline void dma_direct_sync_single(struct device *dev,
 }
 #endif
 
-const struct dma_map_ops dma_direct_ops = {
-	.alloc				= dma_direct_alloc_coherent,
-	.free				= dma_direct_free_coherent,
-	.mmap				= dma_direct_mmap_coherent,
-	.map_sg				= dma_direct_map_sg,
-	.unmap_sg			= dma_direct_unmap_sg,
-	.dma_supported			= dma_direct_dma_supported,
-	.map_page			= dma_direct_map_page,
-	.unmap_page			= dma_direct_unmap_page,
-	.get_required_mask		= dma_direct_get_required_mask,
+const struct dma_map_ops dma_nommu_ops = {
+	.alloc				= dma_nommu_alloc_coherent,
+	.free				= dma_nommu_free_coherent,
+	.mmap				= dma_nommu_mmap_coherent,
+	.map_sg				= dma_nommu_map_sg,
+	.unmap_sg			= dma_nommu_unmap_sg,
+	.dma_supported			= dma_nommu_dma_supported,
+	.map_page			= dma_nommu_map_page,
+	.unmap_page			= dma_nommu_unmap_page,
+	.get_required_mask		= dma_nommu_get_required_mask,
 #ifdef CONFIG_NOT_COHERENT_CACHE
-	.sync_single_for_cpu 		= dma_direct_sync_single,
-	.sync_single_for_device 	= dma_direct_sync_single,
-	.sync_sg_for_cpu 		= dma_direct_sync_sg,
-	.sync_sg_for_device 		= dma_direct_sync_sg,
+	.sync_single_for_cpu 		= dma_nommu_sync_single,
+	.sync_single_for_device 	= dma_nommu_sync_single,
+	.sync_sg_for_cpu 		= dma_nommu_sync_sg,
+	.sync_sg_for_device 		= dma_nommu_sync_sg,
 #endif
 };
-EXPORT_SYMBOL(dma_direct_ops);
+EXPORT_SYMBOL(dma_nommu_ops);
 
 int dma_set_coherent_mask(struct device *dev, u64 mask)
 {
@@ -302,7 +302,7 @@ int dma_set_coherent_mask(struct device *dev, u64 mask)
 		 * is no dma_op->set_coherent_mask() so we have to do
 		 * things the hard way:
 		 */
-		if (get_dma_ops(dev) != &dma_direct_ops ||
+		if (get_dma_ops(dev) != &dma_nommu_ops ||
 		    get_iommu_table_base(dev) == NULL ||
 		    !dma_iommu_dma_supported(dev, mask))
 			return -EIO;
diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index 0ac7aa346c69..590f4d0a6cb1 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -60,7 +60,7 @@ resource_size_t isa_mem_base;
 EXPORT_SYMBOL(isa_mem_base);
 
 
-static const struct dma_map_ops *pci_dma_ops = &dma_direct_ops;
+static const struct dma_map_ops *pci_dma_ops = &dma_nommu_ops;
 
 void set_pci_dma_ops(const struct dma_map_ops *dma_ops)
 {
diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
index 9d213542a48b..9b89df1e71ab 100644
--- a/arch/powerpc/kernel/setup-common.c
+++ b/arch/powerpc/kernel/setup-common.c
@@ -791,7 +791,7 @@ void arch_setup_pdev_archdata(struct platform_device *pdev)
 {
 	pdev->archdata.dma_mask = DMA_BIT_MASK(32);
 	pdev->dev.dma_mask = &pdev->archdata.dma_mask;
- 	set_dma_ops(&pdev->dev, &dma_direct_ops);
+ 	set_dma_ops(&pdev->dev, &dma_nommu_ops);
 }
 
 static __init void print_system_info(void)
diff --git a/arch/powerpc/platforms/cell/iommu.c b/arch/powerpc/platforms/cell/iommu.c
index 4b91ad08eefd..12352a58072a 100644
--- a/arch/powerpc/platforms/cell/iommu.c
+++ b/arch/powerpc/platforms/cell/iommu.c
@@ -541,7 +541,7 @@ static struct cbe_iommu *cell_iommu_for_node(int nid)
 	return NULL;
 }
 
-static unsigned long cell_dma_direct_offset;
+static unsigned long cell_dma_nommu_offset;
 
 static unsigned long dma_iommu_fixed_base;
 
@@ -580,7 +580,7 @@ static void *dma_fixed_alloc_coherent(struct device *dev, size_t size,
 					    device_to_mask(dev), flag,
 					    dev_to_node(dev));
 	else
-		return dma_direct_ops.alloc(dev, size, dma_handle, flag,
+		return dma_nommu_ops.alloc(dev, size, dma_handle, flag,
 					    attrs);
 }
 
@@ -592,7 +592,7 @@ static void dma_fixed_free_coherent(struct device *dev, size_t size,
 		iommu_free_coherent(cell_get_iommu_table(dev), size, vaddr,
 				    dma_handle);
 	else
-		dma_direct_ops.free(dev, size, vaddr, dma_handle, attrs);
+		dma_nommu_ops.free(dev, size, vaddr, dma_handle, attrs);
 }
 
 static dma_addr_t dma_fixed_map_page(struct device *dev, struct page *page,
@@ -601,7 +601,7 @@ static dma_addr_t dma_fixed_map_page(struct device *dev, struct page *page,
 				     unsigned long attrs)
 {
 	if (iommu_fixed_is_weak == (attrs & DMA_ATTR_WEAK_ORDERING))
-		return dma_direct_ops.map_page(dev, page, offset, size,
+		return dma_nommu_ops.map_page(dev, page, offset, size,
 					       direction, attrs);
 	else
 		return iommu_map_page(dev, cell_get_iommu_table(dev), page,
@@ -614,7 +614,7 @@ static void dma_fixed_unmap_page(struct device *dev, dma_addr_t dma_addr,
 				 unsigned long attrs)
 {
 	if (iommu_fixed_is_weak == (attrs & DMA_ATTR_WEAK_ORDERING))
-		dma_direct_ops.unmap_page(dev, dma_addr, size, direction,
+		dma_nommu_ops.unmap_page(dev, dma_addr, size, direction,
 					  attrs);
 	else
 		iommu_unmap_page(cell_get_iommu_table(dev), dma_addr, size,
@@ -626,7 +626,7 @@ static int dma_fixed_map_sg(struct device *dev, struct scatterlist *sg,
 			   unsigned long attrs)
 {
 	if (iommu_fixed_is_weak == (attrs & DMA_ATTR_WEAK_ORDERING))
-		return dma_direct_ops.map_sg(dev, sg, nents, direction, attrs);
+		return dma_nommu_ops.map_sg(dev, sg, nents, direction, attrs);
 	else
 		return ppc_iommu_map_sg(dev, cell_get_iommu_table(dev), sg,
 					nents, device_to_mask(dev),
@@ -638,7 +638,7 @@ static void dma_fixed_unmap_sg(struct device *dev, struct scatterlist *sg,
 			       unsigned long attrs)
 {
 	if (iommu_fixed_is_weak == (attrs & DMA_ATTR_WEAK_ORDERING))
-		dma_direct_ops.unmap_sg(dev, sg, nents, direction, attrs);
+		dma_nommu_ops.unmap_sg(dev, sg, nents, direction, attrs);
 	else
 		ppc_iommu_unmap_sg(cell_get_iommu_table(dev), sg, nents,
 				   direction, attrs);
@@ -661,8 +661,8 @@ static void cell_dma_dev_setup(struct device *dev)
 {
 	if (get_pci_dma_ops() == &dma_iommu_ops)
 		set_iommu_table_base(dev, cell_get_iommu_table(dev));
-	else if (get_pci_dma_ops() == &dma_direct_ops)
-		set_dma_offset(dev, cell_dma_direct_offset);
+	else if (get_pci_dma_ops() == &dma_nommu_ops)
+		set_dma_offset(dev, cell_dma_nommu_offset);
 	else
 		BUG();
 }
@@ -810,14 +810,14 @@ static int __init cell_iommu_init_disabled(void)
 	unsigned long base = 0, size;
 
 	/* When no iommu is present, we use direct DMA ops */
-	set_pci_dma_ops(&dma_direct_ops);
+	set_pci_dma_ops(&dma_nommu_ops);
 
 	/* First make sure all IOC translation is turned off */
 	cell_disable_iommus();
 
 	/* If we have no Axon, we set up the spider DMA magic offset */
 	if (of_find_node_by_name(NULL, "axon") == NULL)
-		cell_dma_direct_offset = SPIDER_DMA_OFFSET;
+		cell_dma_nommu_offset = SPIDER_DMA_OFFSET;
 
 	/* Now we need to check to see where the memory is mapped
 	 * in PCI space. We assume that all busses use the same dma
@@ -851,13 +851,13 @@ static int __init cell_iommu_init_disabled(void)
 		return -ENODEV;
 	}
 
-	cell_dma_direct_offset += base;
+	cell_dma_nommu_offset += base;
 
-	if (cell_dma_direct_offset != 0)
+	if (cell_dma_nommu_offset != 0)
 		cell_pci_controller_ops.dma_dev_setup = cell_pci_dma_dev_setup;
 
 	printk("iommu: disabled, direct DMA offset is 0x%lx\n",
-	       cell_dma_direct_offset);
+	       cell_dma_nommu_offset);
 
 	return 0;
 }
diff --git a/arch/powerpc/platforms/pasemi/iommu.c b/arch/powerpc/platforms/pasemi/iommu.c
index 7fec04de27fc..78b80cbd9768 100644
--- a/arch/powerpc/platforms/pasemi/iommu.c
+++ b/arch/powerpc/platforms/pasemi/iommu.c
@@ -186,7 +186,7 @@ static void pci_dma_dev_setup_pasemi(struct pci_dev *dev)
 	 */
 	if (dev->vendor == 0x1959 && dev->device == 0xa007 &&
 	    !firmware_has_feature(FW_FEATURE_LPAR)) {
-		dev->dev.dma_ops = &dma_direct_ops;
+		dev->dev.dma_ops = &dma_nommu_ops;
 		/*
 		 * Set the coherent DMA mask to prevent the iommu
 		 * being used unnecessarily
diff --git a/arch/powerpc/platforms/pasemi/setup.c b/arch/powerpc/platforms/pasemi/setup.c
index c4a3e93dc324..d0b8ae53660d 100644
--- a/arch/powerpc/platforms/pasemi/setup.c
+++ b/arch/powerpc/platforms/pasemi/setup.c
@@ -363,7 +363,7 @@ static int pcmcia_notify(struct notifier_block *nb, unsigned long action,
 		return 0;
 
 	/* We use the direct ops for localbus */
-	dev->dma_ops = &dma_direct_ops;
+	dev->dma_ops = &dma_nommu_ops;
 
 	return 0;
 }
diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
index 749055553064..9582aeb1fe4c 100644
--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -1850,7 +1850,7 @@ static int pnv_pci_ioda_dma_set_mask(struct pci_dev *pdev, u64 dma_mask)
 
 	if (bypass) {
 		dev_info(&pdev->dev, "Using 64-bit DMA iommu bypass\n");
-		set_dma_ops(&pdev->dev, &dma_direct_ops);
+		set_dma_ops(&pdev->dev, &dma_nommu_ops);
 	} else {
 		/*
 		 * If the device can't set the TCE bypass bit but still wants
@@ -1868,7 +1868,7 @@ static int pnv_pci_ioda_dma_set_mask(struct pci_dev *pdev, u64 dma_mask)
 				return rc;
 			/* 4GB offset bypasses 32-bit space */
 			set_dma_offset(&pdev->dev, (1ULL << 32));
-			set_dma_ops(&pdev->dev, &dma_direct_ops);
+			set_dma_ops(&pdev->dev, &dma_nommu_ops);
 		} else if (dma_mask >> 32 && dma_mask != DMA_BIT_MASK(64)) {
 			/*
 			 * Fail the request if a DMA mask between 32 and 64 bits
diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 69921f72e2da..eaa11334fc8c 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -1231,7 +1231,7 @@ static int dma_set_mask_pSeriesLP(struct device *dev, u64 dma_mask)
 			if (dma_offset != 0) {
 				dev_info(dev, "Using 64-bit direct DMA at offset %llx\n", dma_offset);
 				set_dma_offset(dev, dma_offset);
-				set_dma_ops(dev, &dma_direct_ops);
+				set_dma_ops(dev, &dma_nommu_ops);
 				ddw_enabled = true;
 			}
 		}
diff --git a/arch/powerpc/platforms/pseries/vio.c b/arch/powerpc/platforms/pseries/vio.c
index d86938260a86..49e04ec19238 100644
--- a/arch/powerpc/platforms/pseries/vio.c
+++ b/arch/powerpc/platforms/pseries/vio.c
@@ -618,7 +618,7 @@ static u64 vio_dma_get_required_mask(struct device *dev)
 static const struct dma_map_ops vio_dma_mapping_ops = {
 	.alloc             = vio_dma_iommu_alloc_coherent,
 	.free              = vio_dma_iommu_free_coherent,
-	.mmap		   = dma_direct_mmap_coherent,
+	.mmap		   = dma_nommu_mmap_coherent,
 	.map_sg            = vio_dma_iommu_map_sg,
 	.unmap_sg          = vio_dma_iommu_unmap_sg,
 	.map_page          = vio_dma_iommu_map_page,
diff --git a/arch/powerpc/sysdev/dart_iommu.c b/arch/powerpc/sysdev/dart_iommu.c
index 3573d54b2770..a6198d4f0f03 100644
--- a/arch/powerpc/sysdev/dart_iommu.c
+++ b/arch/powerpc/sysdev/dart_iommu.c
@@ -402,7 +402,7 @@ static int dart_dma_set_mask(struct device *dev, u64 dma_mask)
 	 */
 	if (dart_device_on_pcie(dev) && dma_mask >= DMA_BIT_MASK(40)) {
 		dev_info(dev, "Using 64-bit DMA iommu bypass\n");
-		set_dma_ops(dev, &dma_direct_ops);
+		set_dma_ops(dev, &dma_nommu_ops);
 	} else {
 		dev_info(dev, "Using 32-bit DMA via iommu\n");
 		set_dma_ops(dev, &dma_iommu_ops);
@@ -446,7 +446,7 @@ void __init iommu_init_early_dart(struct pci_controller_ops *controller_ops)
 	controller_ops->dma_bus_setup = NULL;
 
 	/* Setup pci_dma ops */
-	set_pci_dma_ops(&dma_direct_ops);
+	set_pci_dma_ops(&dma_nommu_ops);
 }
 
 #ifdef CONFIG_PM
diff --git a/arch/powerpc/sysdev/fsl_pci.c b/arch/powerpc/sysdev/fsl_pci.c
index 22d98057f773..e4d0133bbeeb 100644
--- a/arch/powerpc/sysdev/fsl_pci.c
+++ b/arch/powerpc/sysdev/fsl_pci.c
@@ -135,7 +135,7 @@ static int fsl_pci_dma_set_mask(struct device *dev, u64 dma_mask)
 	 * mapping that allows addressing any RAM address from across PCI.
 	 */
 	if (dev_is_pci(dev) && dma_mask >= pci64_dma_offset * 2 - 1) {
-		set_dma_ops(dev, &dma_direct_ops);
+		set_dma_ops(dev, &dma_nommu_ops);
 		set_dma_offset(dev, pci64_dma_offset);
 	}
 
diff --git a/drivers/misc/cxl/vphb.c b/drivers/misc/cxl/vphb.c
index 512a4897dbf6..7fd0bdc1436a 100644
--- a/drivers/misc/cxl/vphb.c
+++ b/drivers/misc/cxl/vphb.c
@@ -54,7 +54,7 @@ static bool cxl_pci_enable_device_hook(struct pci_dev *dev)
 		return false;
 	}
 
-	set_dma_ops(&dev->dev, &dma_direct_ops);
+	set_dma_ops(&dev->dev, &dma_nommu_ops);
 	set_dma_offset(&dev->dev, PAGE_OFFSET);
 
 	return _cxl_pci_associate_default_context(dev, afu);
-- 
2.14.2

[PATCH 16/34] microblaze: rename dma_direct to dma_nommu

[Christoph Hellwig]

This frees the dma_direct_* namespace for a generic implementation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/microblaze/include/asm/dma-mapping.h |  4 +--
 arch/microblaze/kernel/dma.c              | 48 +++++++++++++++----------------
 2 files changed, 26 insertions(+), 26 deletions(-)

diff --git a/arch/microblaze/include/asm/dma-mapping.h b/arch/microblaze/include/asm/dma-mapping.h
index 6b9ea39405b8..add50c1373bf 100644
--- a/arch/microblaze/include/asm/dma-mapping.h
+++ b/arch/microblaze/include/asm/dma-mapping.h
@@ -18,11 +18,11 @@
 /*
  * Available generic sets of operations
  */
-extern const struct dma_map_ops dma_direct_ops;
+extern const struct dma_map_ops dma_nommu_ops;
 
 static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
-	return &dma_direct_ops;
+	return &dma_nommu_ops;
 }
 
 #endif	/* _ASM_MICROBLAZE_DMA_MAPPING_H */
diff --git a/arch/microblaze/kernel/dma.c b/arch/microblaze/kernel/dma.c
index 990bf9ea0ec6..450803e5731a 100644
--- a/arch/microblaze/kernel/dma.c
+++ b/arch/microblaze/kernel/dma.c
@@ -17,7 +17,7 @@
 
 #define NOT_COHERENT_CACHE
 
-static void *dma_direct_alloc_coherent(struct device *dev, size_t size,
+static void *dma_nommu_alloc_coherent(struct device *dev, size_t size,
 				       dma_addr_t *dma_handle, gfp_t flag,
 				       unsigned long attrs)
 {
@@ -42,7 +42,7 @@ static void *dma_direct_alloc_coherent(struct device *dev, size_t size,
 #endif
 }
 
-static void dma_direct_free_coherent(struct device *dev, size_t size,
+static void dma_nommu_free_coherent(struct device *dev, size_t size,
 				     void *vaddr, dma_addr_t dma_handle,
 				     unsigned long attrs)
 {
@@ -69,7 +69,7 @@ static inline void __dma_sync(unsigned long paddr,
 	}
 }
 
-static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
+static int dma_nommu_map_sg(struct device *dev, struct scatterlist *sgl,
 			     int nents, enum dma_data_direction direction,
 			     unsigned long attrs)
 {
@@ -89,12 +89,12 @@ static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
 	return nents;
 }
 
-static int dma_direct_dma_supported(struct device *dev, u64 mask)
+static int dma_nommu_dma_supported(struct device *dev, u64 mask)
 {
 	return 1;
 }
 
-static inline dma_addr_t dma_direct_map_page(struct device *dev,
+static inline dma_addr_t dma_nommu_map_page(struct device *dev,
 					     struct page *page,
 					     unsigned long offset,
 					     size_t size,
@@ -106,7 +106,7 @@ static inline dma_addr_t dma_direct_map_page(struct device *dev,
 	return page_to_phys(page) + offset;
 }
 
-static inline void dma_direct_unmap_page(struct device *dev,
+static inline void dma_nommu_unmap_page(struct device *dev,
 					 dma_addr_t dma_address,
 					 size_t size,
 					 enum dma_data_direction direction,
@@ -122,7 +122,7 @@ static inline void dma_direct_unmap_page(struct device *dev,
 }
 
 static inline void
-dma_direct_sync_single_for_cpu(struct device *dev,
+dma_nommu_sync_single_for_cpu(struct device *dev,
 			       dma_addr_t dma_handle, size_t size,
 			       enum dma_data_direction direction)
 {
@@ -136,7 +136,7 @@ dma_direct_sync_single_for_cpu(struct device *dev,
 }
 
 static inline void
-dma_direct_sync_single_for_device(struct device *dev,
+dma_nommu_sync_single_for_device(struct device *dev,
 				  dma_addr_t dma_handle, size_t size,
 				  enum dma_data_direction direction)
 {
@@ -150,7 +150,7 @@ dma_direct_sync_single_for_device(struct device *dev,
 }
 
 static inline void
-dma_direct_sync_sg_for_cpu(struct device *dev,
+dma_nommu_sync_sg_for_cpu(struct device *dev,
 			   struct scatterlist *sgl, int nents,
 			   enum dma_data_direction direction)
 {
@@ -164,7 +164,7 @@ dma_direct_sync_sg_for_cpu(struct device *dev,
 }
 
 static inline void
-dma_direct_sync_sg_for_device(struct device *dev,
+dma_nommu_sync_sg_for_device(struct device *dev,
 			      struct scatterlist *sgl, int nents,
 			      enum dma_data_direction direction)
 {
@@ -178,7 +178,7 @@ dma_direct_sync_sg_for_device(struct device *dev,
 }
 
 static
-int dma_direct_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
+int dma_nommu_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
 			     void *cpu_addr, dma_addr_t handle, size_t size,
 			     unsigned long attrs)
 {
@@ -204,20 +204,20 @@ int dma_direct_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
 #endif
 }
 
-const struct dma_map_ops dma_direct_ops = {
-	.alloc		= dma_direct_alloc_coherent,
-	.free		= dma_direct_free_coherent,
-	.mmap		= dma_direct_mmap_coherent,
-	.map_sg		= dma_direct_map_sg,
-	.dma_supported	= dma_direct_dma_supported,
-	.map_page	= dma_direct_map_page,
-	.unmap_page	= dma_direct_unmap_page,
-	.sync_single_for_cpu		= dma_direct_sync_single_for_cpu,
-	.sync_single_for_device		= dma_direct_sync_single_for_device,
-	.sync_sg_for_cpu		= dma_direct_sync_sg_for_cpu,
-	.sync_sg_for_device		= dma_direct_sync_sg_for_device,
+const struct dma_map_ops dma_nommu_ops = {
+	.alloc			= dma_nommu_alloc_coherent,
+	.free			= dma_nommu_free_coherent,
+	.mmap			= dma_nommu_mmap_coherent,
+	.map_sg			= dma_nommu_map_sg,
+	.dma_supported		= dma_nommu_dma_supported,
+	.map_page		= dma_nommu_map_page,
+	.unmap_page		= dma_nommu_unmap_page,
+	.sync_single_for_cpu	= dma_nommu_sync_single_for_cpu,
+	.sync_single_for_device	= dma_nommu_sync_single_for_device,
+	.sync_sg_for_cpu	= dma_nommu_sync_sg_for_cpu,
+	.sync_sg_for_device	= dma_nommu_sync_sg_for_device,
 };
-EXPORT_SYMBOL(dma_direct_ops);
+EXPORT_SYMBOL(dma_nommu_ops);
 
 /* Number of entries preallocated for DMA-API debugging */
 #define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
-- 
2.14.2

[PATCH 17/34] microblaze: remove dma_nommu_dma_supported

[Christoph Hellwig]

Always returning 1 is the same behavior as not supplying a method at all.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/microblaze/kernel/dma.c | 6 ------
 arch/parisc/kernel/pci-dma.c | 7 -------
 2 files changed, 13 deletions(-)

diff --git a/arch/microblaze/kernel/dma.c b/arch/microblaze/kernel/dma.c
index 450803e5731a..b45d8f8967af 100644
--- a/arch/microblaze/kernel/dma.c
+++ b/arch/microblaze/kernel/dma.c
@@ -89,11 +89,6 @@ static int dma_nommu_map_sg(struct device *dev, struct scatterlist *sgl,
 	return nents;
 }
 
-static int dma_nommu_dma_supported(struct device *dev, u64 mask)
-{
-	return 1;
-}
-
 static inline dma_addr_t dma_nommu_map_page(struct device *dev,
 					     struct page *page,
 					     unsigned long offset,
@@ -209,7 +204,6 @@ const struct dma_map_ops dma_nommu_ops = {
 	.free			= dma_nommu_free_coherent,
 	.mmap			= dma_nommu_mmap_coherent,
 	.map_sg			= dma_nommu_map_sg,
-	.dma_supported		= dma_nommu_dma_supported,
 	.map_page		= dma_nommu_map_page,
 	.unmap_page		= dma_nommu_unmap_page,
 	.sync_single_for_cpu	= dma_nommu_sync_single_for_cpu,
diff --git a/arch/parisc/kernel/pci-dma.c b/arch/parisc/kernel/pci-dma.c
index c0dfd892f70c..91bc0cac03a1 100644
--- a/arch/parisc/kernel/pci-dma.c
+++ b/arch/parisc/kernel/pci-dma.c
@@ -75,11 +75,6 @@ void dump_resmap(void)
 static inline void dump_resmap(void) {;}
 #endif
 
-static int pa11_dma_supported( struct device *dev, u64 mask)
-{
-	return 1;
-}
-
 static inline int map_pte_uncached(pte_t * pte,
 		unsigned long vaddr,
 		unsigned long size, unsigned long *paddr_ptr)
@@ -579,7 +574,6 @@ static void pa11_dma_cache_sync(struct device *dev, void *vaddr, size_t size,
 }
 
 const struct dma_map_ops pcxl_dma_ops = {
-	.dma_supported =	pa11_dma_supported,
 	.alloc =		pa11_dma_alloc,
 	.free =			pa11_dma_free,
 	.map_page =		pa11_dma_map_page,
@@ -616,7 +610,6 @@ static void pcx_dma_free(struct device *dev, size_t size, void *vaddr,
 }
 
 const struct dma_map_ops pcx_dma_ops = {
-	.dma_supported =	pa11_dma_supported,
 	.alloc =		pcx_dma_alloc,
 	.free =			pcx_dma_free,
 	.map_page =		pa11_dma_map_page,
-- 
2.14.2

[PATCH 18/34] microblaze: remove the dead !NOT_COHERENT_CACHE dma code

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/microblaze/kernel/dma.c | 28 ----------------------------
 1 file changed, 28 deletions(-)

diff --git a/arch/microblaze/kernel/dma.c b/arch/microblaze/kernel/dma.c
index b45d8f8967af..c91e8cef98dd 100644
--- a/arch/microblaze/kernel/dma.c
+++ b/arch/microblaze/kernel/dma.c
@@ -15,42 +15,18 @@
 #include <linux/bug.h>
 #include <asm/cacheflush.h>
 
-#define NOT_COHERENT_CACHE
-
 static void *dma_nommu_alloc_coherent(struct device *dev, size_t size,
 				       dma_addr_t *dma_handle, gfp_t flag,
 				       unsigned long attrs)
 {
-#ifdef NOT_COHERENT_CACHE
 	return consistent_alloc(flag, size, dma_handle);
-#else
-	void *ret;
-	struct page *page;
-	int node = dev_to_node(dev);
-
-	/* ignore region specifiers */
-	flag  &= ~(__GFP_HIGHMEM);
-
-	page = alloc_pages_node(node, flag, get_order(size));
-	if (page == NULL)
-		return NULL;
-	ret = page_address(page);
-	memset(ret, 0, size);
-	*dma_handle = virt_to_phys(ret);
-
-	return ret;
-#endif
 }
 
 static void dma_nommu_free_coherent(struct device *dev, size_t size,
 				     void *vaddr, dma_addr_t dma_handle,
 				     unsigned long attrs)
 {
-#ifdef NOT_COHERENT_CACHE
 	consistent_free(size, vaddr);
-#else
-	free_pages((unsigned long)vaddr, get_order(size));
-#endif
 }
 
 static inline void __dma_sync(unsigned long paddr,
@@ -186,12 +162,8 @@ int dma_nommu_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
 	if (off >= count || user_count > (count - off))
 		return -ENXIO;
 
-#ifdef NOT_COHERENT_CACHE
 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 	pfn = consistent_virt_to_pfn(cpu_addr);
-#else
-	pfn = virt_to_pfn(cpu_addr);
-#endif
 	return remap_pfn_range(vma, vma->vm_start, pfn + off,
 			       vma->vm_end - vma->vm_start, vma->vm_page_prot);
 #else
-- 
2.14.2

[PATCH 19/34] s390: move s390_pci_dma_ops to asm/pci_dma.h

[Christoph Hellwig]

This is not needed in drivers, so move it to a private header.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/s390/include/asm/dma-mapping.h | 2 --
 arch/s390/include/asm/pci_dma.h     | 3 +++
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/s390/include/asm/dma-mapping.h b/arch/s390/include/asm/dma-mapping.h
index 2ec7240c1ada..bdc2455483f6 100644
--- a/arch/s390/include/asm/dma-mapping.h
+++ b/arch/s390/include/asm/dma-mapping.h
@@ -9,8 +9,6 @@
 #include <linux/dma-debug.h>
 #include <linux/io.h>
 
-extern const struct dma_map_ops s390_pci_dma_ops;
-
 static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
 	return &dma_noop_ops;
diff --git a/arch/s390/include/asm/pci_dma.h b/arch/s390/include/asm/pci_dma.h
index e8d9161fa17a..419fac7a62c0 100644
--- a/arch/s390/include/asm/pci_dma.h
+++ b/arch/s390/include/asm/pci_dma.h
@@ -201,4 +201,7 @@ void dma_cleanup_tables(unsigned long *);
 unsigned long *dma_walk_cpu_trans(unsigned long *rto, dma_addr_t dma_addr);
 void dma_update_cpu_trans(unsigned long *entry, void *page_addr, int flags);
 
+extern const struct dma_map_ops s390_pci_dma_ops;
+
+
 #endif
-- 
2.14.2

[PATCH 20/34] dma-mapping: warn when there is no coherent_dma_mask

[Christoph Hellwig]

These days all devices should have a DMA coherent mask, and most dma_ops
implementations rely on that fact.  But just to be sure add an assert to
ring the warning bell if that is not the case.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
---
 include/linux/dma-mapping.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index d84951865be7..9f28b2fa329e 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -513,6 +513,7 @@ static inline void *dma_alloc_attrs(struct device *dev, size_t size,
 	void *cpu_addr;
 
 	BUG_ON(!ops);
+	WARN_ON_ONCE(!dev->coherent_dma_mask);
 
 	if (dma_alloc_from_dev_coherent(dev, size, dma_handle, &cpu_addr))
 		return cpu_addr;
-- 
2.14.2

[PATCH 21/34] dma-mapping: clear harmful GFP_* flags in common code

[Christoph Hellwig]

Lift the code from x86 so that we behave consistently.  In the future we
should probably warn if any of these is set.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k]
---
 arch/cris/arch-v32/drivers/pci/dma.c      | 3 ---
 arch/h8300/kernel/dma.c                   | 3 ---
 arch/m68k/kernel/dma.c                    | 2 --
 arch/mips/cavium-octeon/dma-octeon.c      | 3 ---
 arch/mips/loongson64/common/dma-swiotlb.c | 3 ---
 arch/mips/mm/dma-default.c                | 3 ---
 arch/mips/netlogic/common/nlm-dma.c       | 3 ---
 arch/mn10300/mm/dma-alloc.c               | 3 ---
 arch/nios2/mm/dma-mapping.c               | 3 ---
 arch/powerpc/kernel/dma.c                 | 3 ---
 arch/x86/kernel/pci-dma.c                 | 2 --
 include/linux/dma-mapping.h               | 7 +++++++
 12 files changed, 7 insertions(+), 31 deletions(-)

diff --git a/arch/cris/arch-v32/drivers/pci/dma.c b/arch/cris/arch-v32/drivers/pci/dma.c
index dbbd3816cc0b..8c3802244ef3 100644
--- a/arch/cris/arch-v32/drivers/pci/dma.c
+++ b/arch/cris/arch-v32/drivers/pci/dma.c
@@ -22,9 +22,6 @@ static void *v32_dma_alloc(struct device *dev, size_t size,
 {
 	void *ret;
 
-	/* ignore region specifiers */
-	gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
-
 	if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
 		gfp |= GFP_DMA;
 
diff --git a/arch/h8300/kernel/dma.c b/arch/h8300/kernel/dma.c
index 225dd0a188dc..d44ba5db4ac3 100644
--- a/arch/h8300/kernel/dma.c
+++ b/arch/h8300/kernel/dma.c
@@ -16,9 +16,6 @@ static void *dma_alloc(struct device *dev, size_t size,
 {
 	void *ret;
 
-	/* ignore region specifiers */
-	gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
-
 	if (dev == NULL || (*dev->dma_mask < 0xffffffff))
 		gfp |= GFP_DMA;
 	ret = (void *)__get_free_pages(gfp, get_order(size));
diff --git a/arch/m68k/kernel/dma.c b/arch/m68k/kernel/dma.c
index 87ef73a93856..c01b9b8f97bf 100644
--- a/arch/m68k/kernel/dma.c
+++ b/arch/m68k/kernel/dma.c
@@ -76,8 +76,6 @@ static void *m68k_dma_alloc(struct device *dev, size_t size,
 		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
 {
 	void *ret;
-	/* ignore region specifiers */
-	gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
 
 	if (dev == NULL || (*dev->dma_mask < 0xffffffff))
 		gfp |= GFP_DMA;
diff --git a/arch/mips/cavium-octeon/dma-octeon.c b/arch/mips/cavium-octeon/dma-octeon.c
index c64bd87f0b6e..5baf79fce643 100644
--- a/arch/mips/cavium-octeon/dma-octeon.c
+++ b/arch/mips/cavium-octeon/dma-octeon.c
@@ -161,9 +161,6 @@ static void *octeon_dma_alloc_coherent(struct device *dev, size_t size,
 {
 	void *ret;
 
-	/* ignore region specifiers */
-	gfp &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM);
-
 	if (IS_ENABLED(CONFIG_ZONE_DMA) && dev == NULL)
 		gfp |= __GFP_DMA;
 	else if (IS_ENABLED(CONFIG_ZONE_DMA) &&
diff --git a/arch/mips/loongson64/common/dma-swiotlb.c b/arch/mips/loongson64/common/dma-swiotlb.c
index ef07740cee61..15388c24a504 100644
--- a/arch/mips/loongson64/common/dma-swiotlb.c
+++ b/arch/mips/loongson64/common/dma-swiotlb.c
@@ -15,9 +15,6 @@ static void *loongson_dma_alloc_coherent(struct device *dev, size_t size,
 {
 	void *ret;
 
-	/* ignore region specifiers */
-	gfp &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM);
-
 	if ((IS_ENABLED(CONFIG_ISA) && dev == NULL) ||
 	    (IS_ENABLED(CONFIG_ZONE_DMA) &&
 	     dev->coherent_dma_mask < DMA_BIT_MASK(32)))
diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c
index e3e94d05f0fd..237532e89919 100644
--- a/arch/mips/mm/dma-default.c
+++ b/arch/mips/mm/dma-default.c
@@ -93,9 +93,6 @@ static gfp_t massage_gfp_flags(const struct device *dev, gfp_t gfp)
 {
 	gfp_t dma_flag;
 
-	/* ignore region specifiers */
-	gfp &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM);
-
 #ifdef CONFIG_ISA
 	if (dev == NULL)
 		dma_flag = __GFP_DMA;
diff --git a/arch/mips/netlogic/common/nlm-dma.c b/arch/mips/netlogic/common/nlm-dma.c
index 0ec9d9da6d51..49c975b6aa28 100644
--- a/arch/mips/netlogic/common/nlm-dma.c
+++ b/arch/mips/netlogic/common/nlm-dma.c
@@ -47,9 +47,6 @@ static char *nlm_swiotlb;
 static void *nlm_dma_alloc_coherent(struct device *dev, size_t size,
 	dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
 {
-	/* ignore region specifiers */
-	gfp &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM);
-
 #ifdef CONFIG_ZONE_DMA32
 	if (dev->coherent_dma_mask <= DMA_BIT_MASK(32))
 		gfp |= __GFP_DMA32;
diff --git a/arch/mn10300/mm/dma-alloc.c b/arch/mn10300/mm/dma-alloc.c
index 86108d2496b3..e3910d4db102 100644
--- a/arch/mn10300/mm/dma-alloc.c
+++ b/arch/mn10300/mm/dma-alloc.c
@@ -37,9 +37,6 @@ static void *mn10300_dma_alloc(struct device *dev, size_t size,
 		goto done;
 	}
 
-	/* ignore region specifiers */
-	gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
-
 	if (dev == NULL || dev->coherent_dma_mask < 0xffffffff)
 		gfp |= GFP_DMA;
 
diff --git a/arch/nios2/mm/dma-mapping.c b/arch/nios2/mm/dma-mapping.c
index 7040c1adbb5e..4be815519dd4 100644
--- a/arch/nios2/mm/dma-mapping.c
+++ b/arch/nios2/mm/dma-mapping.c
@@ -63,9 +63,6 @@ static void *nios2_dma_alloc(struct device *dev, size_t size,
 {
 	void *ret;
 
-	/* ignore region specifiers */
-	gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
-
 	/* optimized page clearing */
 	gfp |= __GFP_ZERO;
 
diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c
index 6d5d04ccf3b4..76079841d3d0 100644
--- a/arch/powerpc/kernel/dma.c
+++ b/arch/powerpc/kernel/dma.c
@@ -105,9 +105,6 @@ void *__dma_nommu_alloc_coherent(struct device *dev, size_t size,
 	};
 #endif /* CONFIG_FSL_SOC */
 
-	/* ignore region specifiers */
-	flag  &= ~(__GFP_HIGHMEM);
-
 	page = alloc_pages_node(node, flag, get_order(size));
 	if (page == NULL)
 		return NULL;
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index 8439e6de6156..61a8f1cb3829 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -87,7 +87,6 @@ void *dma_generic_alloc_coherent(struct device *dev, size_t size,
 
 	dma_mask = dma_alloc_coherent_mask(dev, flag);
 
-	flag &= ~__GFP_ZERO;
 again:
 	page = NULL;
 	/* CMA can be used only in the context which permits sleeping */
@@ -139,7 +138,6 @@ bool arch_dma_alloc_attrs(struct device **dev, gfp_t *gfp)
 	if (!*dev)
 		*dev = &x86_dma_fallback_dev;
 
-	*gfp &= ~(__GFP_DMA | __GFP_HIGHMEM | __GFP_DMA32);
 	*gfp = dma_alloc_coherent_gfp_flags(*dev, *gfp);
 
 	if (!is_device_dma_capable(*dev))
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 9f28b2fa329e..88bcb1a8211d 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -518,6 +518,13 @@ static inline void *dma_alloc_attrs(struct device *dev, size_t size,
 	if (dma_alloc_from_dev_coherent(dev, size, dma_handle, &cpu_addr))
 		return cpu_addr;
 
+	/*
+	 * Let the implementation decide on the zone to allocate from, and
+	 * decide on the way of zeroing the memory given that the memory
+	 * returned should always be zeroed.
+	 */
+	flag &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM | __GFP_ZERO);
+
 	if (!arch_dma_alloc_attrs(&dev, &flag))
 		return NULL;
 	if (!ops->alloc)
-- 
2.14.2

[PATCH 22/34] dma-mapping: add an arch_dma_supported hook

[Christoph Hellwig]

To implement the x86 forbid_dac and iommu_sac_force we want an arch hook
so that it can apply the global options across all dma_map_ops
implementations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/x86/include/asm/dma-mapping.h |  3 +++
 arch/x86/kernel/pci-dma.c          | 19 ++++++++++++-------
 include/linux/dma-mapping.h        | 11 +++++++++++
 3 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
index dfdc9357a349..6277c83c0eb1 100644
--- a/arch/x86/include/asm/dma-mapping.h
+++ b/arch/x86/include/asm/dma-mapping.h
@@ -30,6 +30,9 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 	return dma_ops;
 }
 
+int arch_dma_supported(struct device *dev, u64 mask);
+#define arch_dma_supported arch_dma_supported
+
 bool arch_dma_alloc_attrs(struct device **dev, gfp_t *gfp);
 #define arch_dma_alloc_attrs arch_dma_alloc_attrs
 
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index 61a8f1cb3829..df7ab02f959f 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -215,7 +215,7 @@ static __init int iommu_setup(char *p)
 }
 early_param("iommu", iommu_setup);
 
-int x86_dma_supported(struct device *dev, u64 mask)
+int arch_dma_supported(struct device *dev, u64 mask)
 {
 #ifdef CONFIG_PCI
 	if (mask > 0xffffffff && forbid_dac > 0) {
@@ -224,12 +224,6 @@ int x86_dma_supported(struct device *dev, u64 mask)
 	}
 #endif
 
-	/* Copied from i386. Doesn't make much sense, because it will
-	   only work for pci_alloc_coherent.
-	   The caller just has to use GFP_DMA in this case. */
-	if (mask < DMA_BIT_MASK(24))
-		return 0;
-
 	/* Tell the device to use SAC when IOMMU force is on.  This
 	   allows the driver to use cheaper accesses in some cases.
 
@@ -249,6 +243,17 @@ int x86_dma_supported(struct device *dev, u64 mask)
 
 	return 1;
 }
+EXPORT_SYMBOL(arch_dma_supported);
+
+int x86_dma_supported(struct device *dev, u64 mask)
+{
+	/* Copied from i386. Doesn't make much sense, because it will
+	   only work for pci_alloc_coherent.
+	   The caller just has to use GFP_DMA in this case. */
+	if (mask < DMA_BIT_MASK(24))
+		return 0;
+	return 1;
+}
 
 static int __init pci_iommu_init(void)
 {
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 88bcb1a8211d..d67742dad904 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -576,6 +576,14 @@ static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 	return 0;
 }
 
+/*
+ * This is a hack for the legacy x86 forbid_dac and iommu_sac_force. Please
+ * don't use this is new code.
+ */
+#ifndef arch_dma_supported
+#define arch_dma_supported(dev, mask)	(1)
+#endif
+
 static inline void dma_check_mask(struct device *dev, u64 mask)
 {
 	if (sme_active() && (mask < (((u64)sme_get_me_mask() << 1) - 1)))
@@ -588,6 +596,9 @@ static inline int dma_supported(struct device *dev, u64 mask)
 
 	if (!ops)
 		return 0;
+	if (!arch_dma_supported(dev, mask))
+		return 0;
+
 	if (!ops->dma_supported)
 		return 1;
 	return ops->dma_supported(dev, mask);
-- 
2.14.2

[PATCH 23/34] dma-mapping: provide a generic asm/dma-mapping.h

[Christoph Hellwig]

For architectures that just use the generic dma_noop_ops we can provide
a generic version of dma-mapping.h.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 MAINTAINERS                          |  1 +
 arch/m32r/include/asm/Kbuild         |  1 +
 arch/m32r/include/asm/dma-mapping.h  | 17 -----------------
 arch/riscv/include/asm/Kbuild        |  1 +
 arch/riscv/include/asm/dma-mapping.h | 30 ------------------------------
 arch/s390/include/asm/Kbuild         |  1 +
 arch/s390/include/asm/dma-mapping.h  | 17 -----------------
 include/asm-generic/dma-mapping.h    | 10 ++++++++++
 8 files changed, 14 insertions(+), 64 deletions(-)
 delete mode 100644 arch/m32r/include/asm/dma-mapping.h
 delete mode 100644 arch/riscv/include/asm/dma-mapping.h
 delete mode 100644 arch/s390/include/asm/dma-mapping.h
 create mode 100644 include/asm-generic/dma-mapping.h

diff --git a/MAINTAINERS b/MAINTAINERS
index d2cfdcce1db5..234e642e7149 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4338,6 +4338,7 @@ F:	lib/dma-noop.c
 F:	lib/dma-virt.c
 F:	drivers/base/dma-mapping.c
 F:	drivers/base/dma-coherent.c
+F:	include/asm-generic/dma-mapping.h
 F:	include/linux/dma-direct.h
 F:	include/linux/dma-mapping.h
 
diff --git a/arch/m32r/include/asm/Kbuild b/arch/m32r/include/asm/Kbuild
index 7e11b125c35e..ca83fda8177b 100644
--- a/arch/m32r/include/asm/Kbuild
+++ b/arch/m32r/include/asm/Kbuild
@@ -1,5 +1,6 @@
 generic-y += clkdev.h
 generic-y += current.h
+generic-y += dma-mapping.h
 generic-y += exec.h
 generic-y += extable.h
 generic-y += irq_work.h
diff --git a/arch/m32r/include/asm/dma-mapping.h b/arch/m32r/include/asm/dma-mapping.h
deleted file mode 100644
index 8967fb659691..000000000000
--- a/arch/m32r/include/asm/dma-mapping.h
+++ /dev/null
@@ -1,17 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_M32R_DMA_MAPPING_H
-#define _ASM_M32R_DMA_MAPPING_H
-
-#include <linux/kernel.h>
-#include <linux/types.h>
-#include <linux/mm.h>
-#include <linux/scatterlist.h>
-#include <linux/dma-debug.h>
-#include <linux/io.h>
-
-static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
-{
-	return &dma_noop_ops;
-}
-
-#endif /* _ASM_M32R_DMA_MAPPING_H */
diff --git a/arch/riscv/include/asm/Kbuild b/arch/riscv/include/asm/Kbuild
index 970460a0b492..197460ccbf21 100644
--- a/arch/riscv/include/asm/Kbuild
+++ b/arch/riscv/include/asm/Kbuild
@@ -7,6 +7,7 @@ generic-y += device.h
 generic-y += div64.h
 generic-y += dma.h
 generic-y += dma-contiguous.h
+generic-y += dma-mapping.h
 generic-y += emergency-restart.h
 generic-y += errno.h
 generic-y += exec.h
diff --git a/arch/riscv/include/asm/dma-mapping.h b/arch/riscv/include/asm/dma-mapping.h
deleted file mode 100644
index 73849e2cc761..000000000000
--- a/arch/riscv/include/asm/dma-mapping.h
+++ /dev/null
@@ -1,30 +0,0 @@
-/*
- * Copyright (C) 2003-2004 Hewlett-Packard Co
- *	David Mosberger-Tang <davidm@hpl.hp.com>
- * Copyright (C) 2012 ARM Ltd.
- * Copyright (C) 2016 SiFive, Inc.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-#ifndef __ASM_RISCV_DMA_MAPPING_H
-#define __ASM_RISCV_DMA_MAPPING_H
-
-/* Use ops->dma_mapping_error (if it exists) or assume success */
-// #undef DMA_ERROR_CODE
-
-static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
-{
-	return &dma_noop_ops;
-}
-
-#endif	/* __ASM_RISCV_DMA_MAPPING_H */
diff --git a/arch/s390/include/asm/Kbuild b/arch/s390/include/asm/Kbuild
index 048450869328..dade72be127b 100644
--- a/arch/s390/include/asm/Kbuild
+++ b/arch/s390/include/asm/Kbuild
@@ -4,6 +4,7 @@ generic-y += cacheflush.h
 generic-y += clkdev.h
 generic-y += device.h
 generic-y += dma-contiguous.h
+generic-y += dma-mapping.h
 generic-y += div64.h
 generic-y += emergency-restart.h
 generic-y += export.h
diff --git a/arch/s390/include/asm/dma-mapping.h b/arch/s390/include/asm/dma-mapping.h
deleted file mode 100644
index bdc2455483f6..000000000000
--- a/arch/s390/include/asm/dma-mapping.h
+++ /dev/null
@@ -1,17 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_S390_DMA_MAPPING_H
-#define _ASM_S390_DMA_MAPPING_H
-
-#include <linux/kernel.h>
-#include <linux/types.h>
-#include <linux/mm.h>
-#include <linux/scatterlist.h>
-#include <linux/dma-debug.h>
-#include <linux/io.h>
-
-static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
-{
-	return &dma_noop_ops;
-}
-
-#endif /* _ASM_S390_DMA_MAPPING_H */
diff --git a/include/asm-generic/dma-mapping.h b/include/asm-generic/dma-mapping.h
new file mode 100644
index 000000000000..164031531d85
--- /dev/null
+++ b/include/asm-generic/dma-mapping.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_GENERIC_DMA_MAPPING_H
+#define _ASM_GENERIC_DMA_MAPPING_H
+
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
+{
+	return &dma_noop_ops;
+}
+
+#endif /* _ASM_GENERIC_DMA_MAPPING_H */
-- 
2.14.2

[PATCH 24/34] dma-direct: rename dma_noop to dma_direct

[Christoph Hellwig]

The trivial direct mapping implementation already does a virtual to
physical translation which isn't strictly a noop, and will soon learn
to do non-direct but linear physical to dma translations through the
device offset and a few small tricks.  Rename it to a better fitting
name.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
---
 MAINTAINERS                        |  2 +-
 arch/arm/Kconfig                   |  2 +-
 arch/arm/include/asm/dma-mapping.h |  2 +-
 arch/arm/mm/dma-mapping-nommu.c    |  8 ++++----
 arch/m32r/Kconfig                  |  2 +-
 arch/riscv/Kconfig                 |  2 +-
 arch/s390/Kconfig                  |  2 +-
 include/asm-generic/dma-mapping.h  |  2 +-
 include/linux/dma-mapping.h        |  2 +-
 lib/Kconfig                        |  2 +-
 lib/Makefile                       |  2 +-
 lib/{dma-noop.c => dma-direct.c}   | 35 +++++++++++++++--------------------
 12 files changed, 29 insertions(+), 34 deletions(-)
 rename lib/{dma-noop.c => dma-direct.c} (52%)

diff --git a/MAINTAINERS b/MAINTAINERS
index 234e642e7149..2d54e636d625 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4334,7 +4334,7 @@ T:	git git://git.infradead.org/users/hch/dma-mapping.git
 W:	http://git.infradead.org/users/hch/dma-mapping.git
 S:	Supported
 F:	lib/dma-debug.c
-F:	lib/dma-noop.c
+F:	lib/dma-direct.c
 F:	lib/dma-virt.c
 F:	drivers/base/dma-mapping.c
 F:	drivers/base/dma-coherent.c
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 00d889a37965..430a0aa710d6 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -25,7 +25,7 @@ config ARM
 	select CLONE_BACKWARDS
 	select CPU_PM if (SUSPEND || CPU_IDLE)
 	select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS
-	select DMA_NOOP_OPS if !MMU
+	select DMA_DIRECT_OPS if !MMU
 	select EDAC_SUPPORT
 	select EDAC_ATOMIC_SCRUB
 	select GENERIC_ALLOCATOR
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index e5d9020c9ee1..8436f6ade57d 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_noop_ops;
+	return IS_ENABLED(CONFIG_MMU) ? &arm_dma_ops : &dma_direct_ops;
 }
 
 #ifdef __arch_page_to_dma
diff --git a/arch/arm/mm/dma-mapping-nommu.c b/arch/arm/mm/dma-mapping-nommu.c
index 6db5fc26d154..4d8042521e89 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_noop_ops is used if
+ *  dma_direct_ops is used if
  *   - MMU/MPU is off
  *   - cpu is v7m w/o cache support
  *   - device is coherent
@@ -39,7 +39,7 @@ static void *arm_nommu_dma_alloc(struct device *dev, size_t size,
 				 unsigned long attrs)
 
 {
-	const struct dma_map_ops *ops = &dma_noop_ops;
+	const struct dma_map_ops *ops = &dma_direct_ops;
 	void *ret;
 
 	/*
@@ -70,7 +70,7 @@ static void arm_nommu_dma_free(struct device *dev, size_t size,
 			       void *cpu_addr, dma_addr_t dma_addr,
 			       unsigned long attrs)
 {
-	const struct dma_map_ops *ops = &dma_noop_ops;
+	const struct dma_map_ops *ops = &dma_direct_ops;
 
 	if (attrs & DMA_ATTR_NON_CONSISTENT) {
 		ops->free(dev, size, cpu_addr, dma_addr, attrs);
@@ -213,7 +213,7 @@ EXPORT_SYMBOL(arm_nommu_dma_ops);
 
 static const struct dma_map_ops *arm_nommu_get_dma_map_ops(bool coherent)
 {
-	return coherent ? &dma_noop_ops : &arm_nommu_dma_ops;
+	return coherent ? &dma_direct_ops : &arm_nommu_dma_ops;
 }
 
 void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
diff --git a/arch/m32r/Kconfig b/arch/m32r/Kconfig
index 498398d915c1..dd84ee194579 100644
--- a/arch/m32r/Kconfig
+++ b/arch/m32r/Kconfig
@@ -19,7 +19,7 @@ config M32R
 	select MODULES_USE_ELF_RELA
 	select HAVE_DEBUG_STACKOVERFLOW
 	select CPU_NO_EFFICIENT_FFS
-	select DMA_NOOP_OPS
+	select DMA_DIRECT_OPS
 	select ARCH_NO_COHERENT_DMA_MMAP if !MMU
 
 config SBUS
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 2c6adf12713a..865e14f50c14 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -83,7 +83,7 @@ config PGTABLE_LEVELS
 config HAVE_KPROBES
 	def_bool n
 
-config DMA_NOOP_OPS
+config DMA_DIRECT_OPS
 	def_bool y
 
 menu "Platform type"
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 829c67986db7..9376637229c9 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -140,7 +140,7 @@ config S390
 	select HAVE_DEBUG_KMEMLEAK
 	select HAVE_DMA_API_DEBUG
 	select HAVE_DMA_CONTIGUOUS
-	select DMA_NOOP_OPS
+	select DMA_DIRECT_OPS
 	select HAVE_DYNAMIC_FTRACE
 	select HAVE_DYNAMIC_FTRACE_WITH_REGS
 	select HAVE_EFFICIENT_UNALIGNED_ACCESS
diff --git a/include/asm-generic/dma-mapping.h b/include/asm-generic/dma-mapping.h
index 164031531d85..880a292d792f 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_noop_ops;
+	return &dma_direct_ops;
 }
 
 #endif /* _ASM_GENERIC_DMA_MAPPING_H */
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index d67742dad904..b626028a3e47 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -136,7 +136,7 @@ struct dma_map_ops {
 	int is_phys;
 };
 
-extern const struct dma_map_ops dma_noop_ops;
+extern const struct dma_map_ops dma_direct_ops;
 extern const struct dma_map_ops dma_virt_ops;
 
 #define DMA_BIT_MASK(n)	(((n) == 64) ? ~0ULL : ((1ULL<<(n))-1))
diff --git a/lib/Kconfig b/lib/Kconfig
index c5e84fbcb30b..9d3d649c9dc9 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -409,7 +409,7 @@ config HAS_DMA
 	depends on !NO_DMA
 	default y
 
-config DMA_NOOP_OPS
+config DMA_DIRECT_OPS
 	bool
 	depends on HAS_DMA && (!64BIT || ARCH_DMA_ADDR_T_64BIT)
 	default n
diff --git a/lib/Makefile b/lib/Makefile
index d11c48ec8ffd..749851abe85a 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -28,7 +28,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \
 
 lib-$(CONFIG_MMU) += ioremap.o
 lib-$(CONFIG_SMP) += cpumask.o
-lib-$(CONFIG_DMA_NOOP_OPS) += dma-noop.o
+lib-$(CONFIG_DMA_DIRECT_OPS) += dma-direct.o
 lib-$(CONFIG_DMA_VIRT_OPS) += dma-virt.o
 
 lib-y	+= kobject.o klist.o
diff --git a/lib/dma-noop.c b/lib/dma-direct.c
similarity index 52%
rename from lib/dma-noop.c
rename to lib/dma-direct.c
index a10185b0c2d4..0ec3262a3148 100644
--- a/lib/dma-noop.c
+++ b/lib/dma-direct.c
@@ -10,9 +10,8 @@
 #include <linux/scatterlist.h>
 #include <linux/pfn.h>
 
-static void *dma_noop_alloc(struct device *dev, size_t size,
-			    dma_addr_t *dma_handle, gfp_t gfp,
-			    unsigned long attrs)
+static void *dma_direct_alloc(struct device *dev, size_t size,
+		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
 {
 	void *ret;
 
@@ -23,24 +22,21 @@ static void *dma_noop_alloc(struct device *dev, size_t size,
 	return ret;
 }
 
-static void dma_noop_free(struct device *dev, size_t size,
-			  void *cpu_addr, dma_addr_t dma_addr,
-			  unsigned long attrs)
+static void dma_direct_free(struct device *dev, size_t size, void *cpu_addr,
+		dma_addr_t dma_addr, unsigned long attrs)
 {
 	free_pages((unsigned long)cpu_addr, get_order(size));
 }
 
-static dma_addr_t dma_noop_map_page(struct device *dev, struct page *page,
-				      unsigned long offset, size_t size,
-				      enum dma_data_direction dir,
-				      unsigned long attrs)
+static 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)
 {
 	return page_to_phys(page) + offset - PFN_PHYS(dev->dma_pfn_offset);
 }
 
-static int dma_noop_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
-			     enum dma_data_direction dir,
-			     unsigned long attrs)
+static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
+		int nents, enum dma_data_direction dir, unsigned long attrs)
 {
 	int i;
 	struct scatterlist *sg;
@@ -58,11 +54,10 @@ static int dma_noop_map_sg(struct device *dev, struct scatterlist *sgl, int nent
 	return nents;
 }
 
-const struct dma_map_ops dma_noop_ops = {
-	.alloc			= dma_noop_alloc,
-	.free			= dma_noop_free,
-	.map_page		= dma_noop_map_page,
-	.map_sg			= dma_noop_map_sg,
+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,
 };
-
-EXPORT_SYMBOL(dma_noop_ops);
+EXPORT_SYMBOL(dma_direct_ops);
-- 
2.14.2

[PATCH 25/34] dma-direct: use phys_to_dma

[Christoph Hellwig]

This means it uses whatever linear remapping scheme that the architecture
provides is used in the generic dma_direct ops.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
---
 lib/dma-direct.c | 18 +++++++-----------
 1 file changed, 7 insertions(+), 11 deletions(-)

diff --git a/lib/dma-direct.c b/lib/dma-direct.c
index 0ec3262a3148..12ea9653781b 100644
--- a/lib/dma-direct.c
+++ b/lib/dma-direct.c
@@ -1,12 +1,11 @@
 // SPDX-License-Identifier: GPL-2.0
 /*
- *	lib/dma-noop.c
- *
- * DMA operations that map to physical addresses without flushing memory.
+ * DMA operations that map physical memory directly without using an IOMMU or
+ * flushing caches.
  */
 #include <linux/export.h>
 #include <linux/mm.h>
-#include <linux/dma-mapping.h>
+#include <linux/dma-direct.h>
 #include <linux/scatterlist.h>
 #include <linux/pfn.h>
 
@@ -17,7 +16,7 @@ static void *dma_direct_alloc(struct device *dev, size_t size,
 
 	ret = (void *)__get_free_pages(gfp, get_order(size));
 	if (ret)
-		*dma_handle = virt_to_phys(ret) - PFN_PHYS(dev->dma_pfn_offset);
+		*dma_handle = phys_to_dma(dev, virt_to_phys(ret));
 
 	return ret;
 }
@@ -32,7 +31,7 @@ static 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)
 {
-	return page_to_phys(page) + offset - PFN_PHYS(dev->dma_pfn_offset);
+	return phys_to_dma(dev, page_to_phys(page)) + offset;
 }
 
 static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
@@ -42,12 +41,9 @@ static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
 	struct scatterlist *sg;
 
 	for_each_sg(sgl, sg, nents, i) {
-		dma_addr_t offset = PFN_PHYS(dev->dma_pfn_offset);
-		void *va;
-
 		BUG_ON(!sg_page(sg));
-		va = sg_virt(sg);
-		sg_dma_address(sg) = (dma_addr_t)virt_to_phys(va) - offset;
+
+		sg_dma_address(sg) = phys_to_dma(dev, sg_phys(sg));
 		sg_dma_len(sg) = sg->length;
 	}
 
-- 
2.14.2

[PATCH 26/34] dma-direct: add dma address sanity checks

[Christoph Hellwig]

Roughly based on the x86 pci-nommu implementation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 lib/dma-direct.c | 31 ++++++++++++++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

diff --git a/lib/dma-direct.c b/lib/dma-direct.c
index 12ea9653781b..32fd4d9e4c47 100644
--- a/lib/dma-direct.c
+++ b/lib/dma-direct.c
@@ -9,6 +9,23 @@
 #include <linux/scatterlist.h>
 #include <linux/pfn.h>
 
+#define DIRECT_MAPPING_ERROR		0
+
+static bool
+check_addr(struct device *dev, dma_addr_t dma_addr, size_t size,
+		const char *caller)
+{
+	if (unlikely(dev && !dma_capable(dev, dma_addr, size))) {
+		if (*dev->dma_mask >= DMA_BIT_MASK(32)) {
+			dev_err(dev,
+				"%s: overflow %pad+%zu of device mask %llx\n",
+				caller, &dma_addr, size, *dev->dma_mask);
+		}
+		return false;
+	}
+	return true;
+}
+
 static void *dma_direct_alloc(struct device *dev, size_t size,
 		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
 {
@@ -31,7 +48,11 @@ static 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)
 {
-	return phys_to_dma(dev, page_to_phys(page)) + offset;
+	dma_addr_t dma_addr = phys_to_dma(dev, page_to_phys(page)) + offset;
+
+	if (!check_addr(dev, dma_addr, size, __func__))
+		return DIRECT_MAPPING_ERROR;
+	return dma_addr;
 }
 
 static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
@@ -44,16 +65,24 @@ static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
 		BUG_ON(!sg_page(sg));
 
 		sg_dma_address(sg) = phys_to_dma(dev, sg_phys(sg));
+		if (!check_addr(dev, sg_dma_address(sg), sg->length, __func__))
+			return 0;
 		sg_dma_len(sg) = sg->length;
 	}
 
 	return nents;
 }
 
+static int dma_direct_mapping_error(struct device *dev, dma_addr_t dma_addr)
+{
+	return dma_addr == DIRECT_MAPPING_ERROR;
+}
+
 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,
+	.mapping_error		= dma_direct_mapping_error,
 };
 EXPORT_SYMBOL(dma_direct_ops);
-- 
2.14.2

[PATCH 27/34] dma-direct: add support for CMA allocation

[Christoph Hellwig]

Try the CMA allocator for coherent allocations if supported.

Roughly modelled after the x86 code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 lib/dma-direct.c | 24 ++++++++++++++++++------
 1 file changed, 18 insertions(+), 6 deletions(-)

diff --git a/lib/dma-direct.c b/lib/dma-direct.c
index 32fd4d9e4c47..a9ae98be7af3 100644
--- a/lib/dma-direct.c
+++ b/lib/dma-direct.c
@@ -7,6 +7,7 @@
 #include <linux/mm.h>
 #include <linux/dma-direct.h>
 #include <linux/scatterlist.h>
+#include <linux/dma-contiguous.h>
 #include <linux/pfn.h>
 
 #define DIRECT_MAPPING_ERROR		0
@@ -29,19 +30,30 @@ check_addr(struct device *dev, dma_addr_t dma_addr, size_t size,
 static void *dma_direct_alloc(struct device *dev, size_t size,
 		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
 {
-	void *ret;
+	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+	int page_order = get_order(size);
+	struct page *page = NULL;
 
-	ret = (void *)__get_free_pages(gfp, get_order(size));
-	if (ret)
-		*dma_handle = phys_to_dma(dev, virt_to_phys(ret));
+	/* CMA can be used only in the context which permits sleeping */
+	if (gfpflags_allow_blocking(gfp))
+		page = dma_alloc_from_contiguous(dev, count, page_order, gfp);
+	if (!page)
+		page = alloc_pages(gfp, page_order);
+	if (!page)
+		return NULL;
 
-	return ret;
+	*dma_handle = phys_to_dma(dev, page_to_phys(page));
+	memset(page_address(page), 0, size);
+	return page_address(page);
 }
 
 static void dma_direct_free(struct device *dev, size_t size, void *cpu_addr,
 		dma_addr_t dma_addr, unsigned long attrs)
 {
-	free_pages((unsigned long)cpu_addr, get_order(size));
+	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+
+	if (!dma_release_from_contiguous(dev, virt_to_page(cpu_addr), count))
+		free_pages((unsigned long)cpu_addr, get_order(size));
 }
 
 static dma_addr_t dma_direct_map_page(struct device *dev, struct page *page,
-- 
2.14.2

[PATCH 28/34] dma-direct: use node local allocations for coherent memory

[Christoph Hellwig]

To preserve the x86 behavior.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
---
 lib/dma-direct.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/dma-direct.c b/lib/dma-direct.c
index a9ae98be7af3..f04a424f91fa 100644
--- a/lib/dma-direct.c
+++ b/lib/dma-direct.c
@@ -38,7 +38,7 @@ static void *dma_direct_alloc(struct device *dev, size_t size,
 	if (gfpflags_allow_blocking(gfp))
 		page = dma_alloc_from_contiguous(dev, count, page_order, gfp);
 	if (!page)
-		page = alloc_pages(gfp, page_order);
+		page = alloc_pages_node(dev_to_node(dev), gfp, page_order);
 	if (!page)
 		return NULL;
 
-- 
2.14.2

[PATCH 29/34] dma-direct: add support for allocation from ZONE_DMA and ZONE_DMA32

[Christoph Hellwig]

This allows to dip into zones for lower memory if they are available.
If one of the zones is not available the corresponding GFP_* flag
will evaluate to 0 so they won't change anything.  We provide an
arch tunable for those architectures that do not use GFP_DMA for
the lowest 24-bits, given that there are a few.

Roughly based on the x86 code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 lib/dma-direct.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/lib/dma-direct.c b/lib/dma-direct.c
index f04a424f91fa..8f76032ebc3c 100644
--- a/lib/dma-direct.c
+++ b/lib/dma-direct.c
@@ -12,6 +12,14 @@
 
 #define DIRECT_MAPPING_ERROR		0
 
+/*
+ * Most architectures use ZONE_DMA for the first 16 Megabytes, but
+ * some use it for entirely different regions:
+ */
+#ifndef ARCH_ZONE_DMA_BITS
+#define ARCH_ZONE_DMA_BITS 24
+#endif
+
 static bool
 check_addr(struct device *dev, dma_addr_t dma_addr, size_t size,
 		const char *caller)
@@ -34,6 +42,12 @@ static void *dma_direct_alloc(struct device *dev, size_t size,
 	int page_order = get_order(size);
 	struct page *page = NULL;
 
+	/* GFP_DMA32 and GFP_DMA are no ops without the corresponding zones: */
+	if (dev->coherent_dma_mask <= DMA_BIT_MASK(ARCH_ZONE_DMA_BITS))
+		gfp |= GFP_DMA;
+	if (dev->coherent_dma_mask <= DMA_BIT_MASK(32) && !(gfp & GFP_DMA))
+		gfp |= GFP_DMA32;
+
 	/* CMA can be used only in the context which permits sleeping */
 	if (gfpflags_allow_blocking(gfp))
 		page = dma_alloc_from_contiguous(dev, count, page_order, gfp);
-- 
2.14.2

[PATCH 30/34] dma-direct: retry allocations using GFP_DMA for small masks

[Christoph Hellwig]

If an attempt to allocate memory succeeded, but isn't inside the
supported DMA mask, retry the allocation with GFP_DMA set as a
last resort.

Based on the x86 code, but an off by one error in what is now
dma_coherent_ok has been fixed vs the x86 code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 lib/dma-direct.c | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/lib/dma-direct.c b/lib/dma-direct.c
index 8f76032ebc3c..4e43c2bb7f5f 100644
--- a/lib/dma-direct.c
+++ b/lib/dma-direct.c
@@ -35,6 +35,11 @@ check_addr(struct device *dev, dma_addr_t dma_addr, size_t size,
 	return true;
 }
 
+static bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size)
+{
+	return phys_to_dma(dev, phys) + size - 1 <= dev->coherent_dma_mask;
+}
+
 static void *dma_direct_alloc(struct device *dev, size_t size,
 		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
 {
@@ -48,11 +53,29 @@ static void *dma_direct_alloc(struct device *dev, size_t size,
 	if (dev->coherent_dma_mask <= DMA_BIT_MASK(32) && !(gfp & GFP_DMA))
 		gfp |= GFP_DMA32;
 
+again:
 	/* CMA can be used only in the context which permits sleeping */
-	if (gfpflags_allow_blocking(gfp))
+	if (gfpflags_allow_blocking(gfp)) {
 		page = dma_alloc_from_contiguous(dev, count, page_order, gfp);
+		if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) {
+			dma_release_from_contiguous(dev, page, count);
+			page = NULL;
+		}
+	}
 	if (!page)
 		page = alloc_pages_node(dev_to_node(dev), gfp, page_order);
+
+	if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) {
+		__free_pages(page, page_order);
+		page = NULL;
+
+		if (dev->coherent_dma_mask < DMA_BIT_MASK(32) &&
+		    !(gfp & GFP_DMA)) {
+			gfp = (gfp & ~GFP_DMA32) | GFP_DMA;
+			goto again;
+		}
+	}
+
 	if (!page)
 		return NULL;
 
-- 
2.14.2

[PATCH 31/34] dma-direct: make dma_direct_{alloc,free} available to other implementations

[Christoph Hellwig]

So that they don't need to indirect through the operation vector.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
---
 arch/arm/mm/dma-mapping-nommu.c | 9 +++------
 include/linux/dma-direct.h      | 5 +++++
 lib/dma-direct.c                | 6 +++---
 3 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/arch/arm/mm/dma-mapping-nommu.c b/arch/arm/mm/dma-mapping-nommu.c
index 4d8042521e89..619f24a42d09 100644
--- a/arch/arm/mm/dma-mapping-nommu.c
+++ b/arch/arm/mm/dma-mapping-nommu.c
@@ -11,7 +11,7 @@
 
 #include <linux/export.h>
 #include <linux/mm.h>
-#include <linux/dma-mapping.h>
+#include <linux/dma-direct.h>
 #include <linux/scatterlist.h>
 
 #include <asm/cachetype.h>
@@ -39,7 +39,6 @@ static void *arm_nommu_dma_alloc(struct device *dev, size_t size,
 				 unsigned long attrs)
 
 {
-	const struct dma_map_ops *ops = &dma_direct_ops;
 	void *ret;
 
 	/*
@@ -48,7 +47,7 @@ static void *arm_nommu_dma_alloc(struct device *dev, size_t size,
 	 */
 
 	if (attrs & DMA_ATTR_NON_CONSISTENT)
-		return ops->alloc(dev, size, dma_handle, gfp, attrs);
+		return dma_direct_alloc(dev, size, dma_handle, gfp, attrs);
 
 	ret = dma_alloc_from_global_coherent(size, dma_handle);
 
@@ -70,10 +69,8 @@ static void arm_nommu_dma_free(struct device *dev, size_t size,
 			       void *cpu_addr, dma_addr_t dma_addr,
 			       unsigned long attrs)
 {
-	const struct dma_map_ops *ops = &dma_direct_ops;
-
 	if (attrs & DMA_ATTR_NON_CONSISTENT) {
-		ops->free(dev, size, cpu_addr, dma_addr, attrs);
+		dma_direct_free(dev, size, cpu_addr, dma_addr, attrs);
 	} else {
 		int ret = dma_release_from_global_coherent(get_order(size),
 							   cpu_addr);
diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h
index 10e924b7cba7..4788bf0bf683 100644
--- a/include/linux/dma-direct.h
+++ b/include/linux/dma-direct.h
@@ -38,4 +38,9 @@ static inline void dma_mark_clean(void *addr, size_t size)
 }
 #endif /* CONFIG_ARCH_HAS_DMA_MARK_CLEAN */
 
+void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
+		gfp_t gfp, unsigned long attrs);
+void dma_direct_free(struct device *dev, size_t size, void *cpu_addr,
+		dma_addr_t dma_addr, unsigned long attrs);
+
 #endif /* _LINUX_DMA_DIRECT_H */
diff --git a/lib/dma-direct.c b/lib/dma-direct.c
index 4e43c2bb7f5f..784a68dfdbe3 100644
--- a/lib/dma-direct.c
+++ b/lib/dma-direct.c
@@ -40,8 +40,8 @@ static bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size)
 	return phys_to_dma(dev, phys) + size - 1 <= dev->coherent_dma_mask;
 }
 
-static void *dma_direct_alloc(struct device *dev, size_t size,
-		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
+void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
+		gfp_t gfp, unsigned long attrs)
 {
 	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
 	int page_order = get_order(size);
@@ -84,7 +84,7 @@ static void *dma_direct_alloc(struct device *dev, size_t size,
 	return page_address(page);
 }
 
-static void dma_direct_free(struct device *dev, size_t size, void *cpu_addr,
+void dma_direct_free(struct device *dev, size_t size, void *cpu_addr,
 		dma_addr_t dma_addr, unsigned long attrs)
 {
 	unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
-- 
2.14.2

[PATCH 32/34] dma-direct: reject too small dma masks

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
---
 include/linux/dma-direct.h |  1 +
 lib/dma-direct.c           | 19 +++++++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h
index 4788bf0bf683..bcdb1a3e4b1f 100644
--- a/include/linux/dma-direct.h
+++ b/include/linux/dma-direct.h
@@ -42,5 +42,6 @@ void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
 		gfp_t gfp, unsigned long attrs);
 void dma_direct_free(struct device *dev, size_t size, void *cpu_addr,
 		dma_addr_t dma_addr, unsigned long attrs);
+int dma_direct_supported(struct device *dev, u64 mask);
 
 #endif /* _LINUX_DMA_DIRECT_H */
diff --git a/lib/dma-direct.c b/lib/dma-direct.c
index 784a68dfdbe3..40b1f92f2214 100644
--- a/lib/dma-direct.c
+++ b/lib/dma-direct.c
@@ -122,6 +122,24 @@ static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
 	return nents;
 }
 
+int dma_direct_supported(struct device *dev, u64 mask)
+{
+#ifdef CONFIG_ZONE_DMA
+	if (mask < DMA_BIT_MASK(ARCH_ZONE_DMA_BITS))
+		return 0;
+#else
+	/*
+	 * Because 32-bit DMA masks are so common we expect every architecture
+	 * to be able to satisfy them - either by not supporting more physical
+	 * memory, or by providing a ZONE_DMA32.  If neither is the case, the
+	 * architecture needs to use an IOMMU instead of the direct mapping.
+	 */
+	if (mask < DMA_BIT_MASK(32))
+		return 0;
+#endif
+	return 1;
+}
+
 static int dma_direct_mapping_error(struct device *dev, dma_addr_t dma_addr)
 {
 	return dma_addr == DIRECT_MAPPING_ERROR;
@@ -132,6 +150,7 @@ const struct dma_map_ops dma_direct_ops = {
 	.free			= dma_direct_free,
 	.map_page		= dma_direct_map_page,
 	.map_sg			= dma_direct_map_sg,
+	.dma_supported		= dma_direct_supported,
 	.mapping_error		= dma_direct_mapping_error,
 };
 EXPORT_SYMBOL(dma_direct_ops);
-- 
2.14.2

[PATCH 33/34] cris: use dma-direct

[Christoph Hellwig]

cris currently has an incomplete direct mapping dma_map_ops implementation
if PCI support is enabled.  Replace it with the fully feature generic
dma-direct implementation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Jesper Nilsson <jesper.nilsson@axis.com>
---
 arch/cris/Kconfig                       |  4 ++
 arch/cris/arch-v32/drivers/pci/Makefile |  2 +-
 arch/cris/arch-v32/drivers/pci/dma.c    | 77 ---------------------------------
 arch/cris/include/asm/Kbuild            |  1 +
 arch/cris/include/asm/dma-mapping.h     | 20 ---------
 5 files changed, 6 insertions(+), 98 deletions(-)
 delete mode 100644 arch/cris/arch-v32/drivers/pci/dma.c
 delete mode 100644 arch/cris/include/asm/dma-mapping.h

diff --git a/arch/cris/Kconfig b/arch/cris/Kconfig
index 54d3f426763b..cd5a0865c97f 100644
--- a/arch/cris/Kconfig
+++ b/arch/cris/Kconfig
@@ -33,6 +33,9 @@ config GENERIC_CALIBRATE_DELAY
 config NO_IOPORT_MAP
 	def_bool y if !PCI
 
+config NO_DMA
+	def_bool y if !PCI
+
 config FORCE_MAX_ZONEORDER
 	int
 	default 6
@@ -72,6 +75,7 @@ config CRIS
 	select GENERIC_SCHED_CLOCK if ETRAX_ARCH_V32
 	select HAVE_DEBUG_BUGVERBOSE if ETRAX_ARCH_V32
 	select HAVE_NMI
+	select DMA_DIRECT_OPS if PCI
 
 config HZ
 	int
diff --git a/arch/cris/arch-v32/drivers/pci/Makefile b/arch/cris/arch-v32/drivers/pci/Makefile
index bff7482f2444..93c8be6170b1 100644
--- a/arch/cris/arch-v32/drivers/pci/Makefile
+++ b/arch/cris/arch-v32/drivers/pci/Makefile
@@ -2,4 +2,4 @@
 # Makefile for Etrax cardbus driver
 #
 
-obj-$(CONFIG_ETRAX_CARDBUS)        += bios.o dma.o
+obj-$(CONFIG_ETRAX_CARDBUS)        += bios.o
diff --git a/arch/cris/arch-v32/drivers/pci/dma.c b/arch/cris/arch-v32/drivers/pci/dma.c
deleted file mode 100644
index 8c3802244ef3..000000000000
--- a/arch/cris/arch-v32/drivers/pci/dma.c
+++ /dev/null
@@ -1,77 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * Dynamic DMA mapping support.
- *
- * On cris there is no hardware dynamic DMA address translation,
- * so consistent alloc/free are merely page allocation/freeing.
- * The rest of the dynamic DMA mapping interface is implemented
- * in asm/pci.h.
- *
- * Borrowed from i386.
- */
-
-#include <linux/types.h>
-#include <linux/mm.h>
-#include <linux/string.h>
-#include <linux/pci.h>
-#include <linux/gfp.h>
-#include <asm/io.h>
-
-static void *v32_dma_alloc(struct device *dev, size_t size,
-		dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
-{
-	void *ret;
-
-	if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
-		gfp |= GFP_DMA;
-
-	ret = (void *)__get_free_pages(gfp,  get_order(size));
-
-	if (ret != NULL) {
-		memset(ret, 0, size);
-		*dma_handle = virt_to_phys(ret);
-	}
-	return ret;
-}
-
-static void v32_dma_free(struct device *dev, size_t size, void *vaddr,
-		dma_addr_t dma_handle, unsigned long attrs)
-{
-	free_pages((unsigned long)vaddr, get_order(size));
-}
-
-static inline dma_addr_t v32_dma_map_page(struct device *dev,
-		struct page *page, unsigned long offset, size_t size,
-		enum dma_data_direction direction, unsigned long attrs)
-{
-	return page_to_phys(page) + offset;
-}
-
-static inline int v32_dma_map_sg(struct device *dev, struct scatterlist *sg,
-		int nents, enum dma_data_direction direction,
-		unsigned long attrs)
-{
-	printk("Map sg\n");
-	return nents;
-}
-
-static inline int v32_dma_supported(struct device *dev, u64 mask)
-{
-        /*
-         * we fall back to GFP_DMA when the mask isn't all 1s,
-         * so we can't guarantee allocations that must be
-         * within a tighter range than GFP_DMA..
-         */
-        if (mask < 0x00ffffff)
-                return 0;
-	return 1;
-}
-
-const struct dma_map_ops v32_dma_ops = {
-	.alloc			= v32_dma_alloc,
-	.free			= v32_dma_free,
-	.map_page		= v32_dma_map_page,
-	.map_sg                 = v32_dma_map_sg,
-	.dma_supported		= v32_dma_supported,
-};
-EXPORT_SYMBOL(v32_dma_ops);
diff --git a/arch/cris/include/asm/Kbuild b/arch/cris/include/asm/Kbuild
index 460349cb147f..8cf45ac30c1b 100644
--- a/arch/cris/include/asm/Kbuild
+++ b/arch/cris/include/asm/Kbuild
@@ -5,6 +5,7 @@ generic-y += cmpxchg.h
 generic-y += current.h
 generic-y += device.h
 generic-y += div64.h
+generic-y += dma-mapping.h
 generic-y += emergency-restart.h
 generic-y += exec.h
 generic-y += extable.h
diff --git a/arch/cris/include/asm/dma-mapping.h b/arch/cris/include/asm/dma-mapping.h
deleted file mode 100644
index 1553bdb30a0c..000000000000
--- a/arch/cris/include/asm/dma-mapping.h
+++ /dev/null
@@ -1,20 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_CRIS_DMA_MAPPING_H
-#define _ASM_CRIS_DMA_MAPPING_H
-
-#ifdef CONFIG_PCI
-extern const struct dma_map_ops v32_dma_ops;
-
-static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
-{
-	return &v32_dma_ops;
-}
-#else
-static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
-{
-	BUG();
-	return NULL;
-}
-#endif
-
-#endif
-- 
2.14.2

[PATCH 34/34] h8300: use dma-direct

[Christoph Hellwig]

Replace the bare-bones h8300 direct dma mapping implementation with
the fully featured generic dma-direct one.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 arch/h8300/Kconfig                   |  1 +
 arch/h8300/include/asm/Kbuild        |  1 +
 arch/h8300/include/asm/dma-mapping.h | 12 -------
 arch/h8300/kernel/Makefile           |  2 +-
 arch/h8300/kernel/dma.c              | 66 ------------------------------------
 5 files changed, 3 insertions(+), 79 deletions(-)
 delete mode 100644 arch/h8300/include/asm/dma-mapping.h
 delete mode 100644 arch/h8300/kernel/dma.c

diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
index f8d3fde08190..091d6d04b5e5 100644
--- a/arch/h8300/Kconfig
+++ b/arch/h8300/Kconfig
@@ -23,6 +23,7 @@ config H8300
 	select HAVE_ARCH_KGDB
 	select HAVE_ARCH_HASH
 	select CPU_NO_EFFICIENT_FFS
+	select DMA_DIRECT_OPS
 
 config CPU_BIG_ENDIAN
 	def_bool y
diff --git a/arch/h8300/include/asm/Kbuild b/arch/h8300/include/asm/Kbuild
index bc077491d299..642752c94306 100644
--- a/arch/h8300/include/asm/Kbuild
+++ b/arch/h8300/include/asm/Kbuild
@@ -9,6 +9,7 @@ generic-y += delay.h
 generic-y += device.h
 generic-y += div64.h
 generic-y += dma.h
+generic-y += dma-mapping.h
 generic-y += emergency-restart.h
 generic-y += exec.h
 generic-y += extable.h
diff --git a/arch/h8300/include/asm/dma-mapping.h b/arch/h8300/include/asm/dma-mapping.h
deleted file mode 100644
index 21bb1fc3a6f1..000000000000
--- a/arch/h8300/include/asm/dma-mapping.h
+++ /dev/null
@@ -1,12 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _H8300_DMA_MAPPING_H
-#define _H8300_DMA_MAPPING_H
-
-extern const struct dma_map_ops h8300_dma_map_ops;
-
-static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
-{
-	return &h8300_dma_map_ops;
-}
-
-#endif
diff --git a/arch/h8300/kernel/Makefile b/arch/h8300/kernel/Makefile
index b62e830525c6..307aa51576dd 100644
--- a/arch/h8300/kernel/Makefile
+++ b/arch/h8300/kernel/Makefile
@@ -7,7 +7,7 @@ extra-y := vmlinux.lds
 
 obj-y := process.o traps.o ptrace.o \
 	 signal.o setup.o syscalls.o \
-	 irq.o entry.o dma.o
+	 irq.o entry.o
 
 obj-$(CONFIG_ROMKERNEL) += head_rom.o
 obj-$(CONFIG_RAMKERNEL) += head_ram.o
diff --git a/arch/h8300/kernel/dma.c b/arch/h8300/kernel/dma.c
deleted file mode 100644
index d44ba5db4ac3..000000000000
--- a/arch/h8300/kernel/dma.c
+++ /dev/null
@@ -1,66 +0,0 @@
-/*
- * This file is subject to the terms and conditions of the GNU General Public
- * License.  See the file COPYING in the main directory of this archive
- * for more details.
- */
-
-#include <linux/dma-mapping.h>
-#include <linux/kernel.h>
-#include <linux/scatterlist.h>
-#include <linux/module.h>
-#include <asm/pgalloc.h>
-
-static void *dma_alloc(struct device *dev, size_t size,
-		       dma_addr_t *dma_handle, gfp_t gfp,
-		       unsigned long attrs)
-{
-	void *ret;
-
-	if (dev == NULL || (*dev->dma_mask < 0xffffffff))
-		gfp |= GFP_DMA;
-	ret = (void *)__get_free_pages(gfp, get_order(size));
-
-	if (ret != NULL) {
-		memset(ret, 0, size);
-		*dma_handle = virt_to_phys(ret);
-	}
-	return ret;
-}
-
-static void dma_free(struct device *dev, size_t size,
-		     void *vaddr, dma_addr_t dma_handle,
-		     unsigned long attrs)
-
-{
-	free_pages((unsigned long)vaddr, get_order(size));
-}
-
-static dma_addr_t map_page(struct device *dev, struct page *page,
-				  unsigned long offset, size_t size,
-				  enum dma_data_direction direction,
-				  unsigned long attrs)
-{
-	return page_to_phys(page) + offset;
-}
-
-static int map_sg(struct device *dev, struct scatterlist *sgl,
-		  int nents, enum dma_data_direction direction,
-		  unsigned long attrs)
-{
-	struct scatterlist *sg;
-	int i;
-
-	for_each_sg(sgl, sg, nents, i) {
-		sg->dma_address = sg_phys(sg);
-	}
-
-	return nents;
-}
-
-const struct dma_map_ops h8300_dma_map_ops = {
-	.alloc = dma_alloc,
-	.free = dma_free,
-	.map_page = map_page,
-	.map_sg = map_sg,
-};
-EXPORT_SYMBOL(h8300_dma_map_ops);
-- 
2.14.2

Re: consolidate direct dma mapping V4

[Christoph Hellwig]

I've pulled this into the dma-mapping for-next branch so that we get
a few days exposure before then end of the merge window.  If there is
anything important (e.g. the powerpc naming issue) please send
incremental patches.

Re: [PATCH 22/34] dma-mapping: add an arch_dma_supported hook

[Randy Dunlap]

On 01/12/2018 12:42 AM, Christoph Hellwig wrote:
> To implement the x86 forbid_dac and iommu_sac_force we want an arch hook
> so that it can apply the global options across all dma_map_ops
> implementations.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  arch/x86/include/asm/dma-mapping.h |  3 +++
>  arch/x86/kernel/pci-dma.c          | 19 ++++++++++++-------
>  include/linux/dma-mapping.h        | 11 +++++++++++
>  3 files changed, 26 insertions(+), 7 deletions(-)

> diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
> index 88bcb1a8211d..d67742dad904 100644
> --- a/include/linux/dma-mapping.h
> +++ b/include/linux/dma-mapping.h
> @@ -576,6 +576,14 @@ static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
>  	return 0;
>  }
>  
> +/*
> + * This is a hack for the legacy x86 forbid_dac and iommu_sac_force. Please
> + * don't use this is new code.

                     in new code.

> + */
> +#ifndef arch_dma_supported
> +#define arch_dma_supported(dev, mask)	(1)
> +#endif


-- 
~Randy