consolidate direct dma mapping V4

consolidate direct dma mapping V4

[Christoph Hellwig]

Almost every architecture supports a direct dma mapping implementation,
where no iommu is used and the device dma address is a 1:1 mapping to
the physical address or has a simple linear offset.  Currently the
code for this implementation is most duplicated over the architectures,
and the duplicated again in the swiotlb code, and then duplicated again
for special cases like the x86 memory encryption DMA ops.

This series takes the existing very simple dma-noop dma mapping
implementation, enhances it with all the x86 features and quirks, and
creates a common set of architecture hooks for it and the swiotlb code.

It then switches a number of architectures to this generic
direct map implemention.

Note that for now this only handles architectures that do cache coherent
DMA, but a similar consolidation for non-coherent architectures is in the
work for later merge windows.

A git tree is also available:

   git://git.infradead.org/users/hch/misc.git dma-direct.3

Gitweb:

   http://git.infradead.org/users/hch/misc.git/shortlog/refs/heads/dma-direct.3

Changes since V3
 - new patch to fix an off-by-one in mips dma_capable
Changes since V2:
 - fixed a few patch description typos
 - fixed a few printk formats
 - fixed an off by one in dma_coherent_ok
 - add a few Reviewed-by/Acked-by tags.
 - moved the swiotlb consolidation to a new series
 - dropped a few patches for now to not overwhelem the x86
   maintainers.  They will be resubmitted in the next merge window

[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

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

[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.