Merge tag 'for-next-dma_ops' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma

Pull rdma DMA mapping updates from Doug Ledford:
 "Drop IB DMA mapping code and use core DMA code instead.

  Bart Van Assche noted that the ib DMA mapping code was significantly
  similar enough to the core DMA mapping code that with a few changes it
  was possible to remove the IB DMA mapping code entirely and switch the
  RDMA stack to use the core DMA mapping code.

  This resulted in a nice set of cleanups, but touched the entire tree
  and has been kept separate for that reason."

* tag 'for-next-dma_ops' of git://git.kernel.org/pub/scm/linux/kernel/git/dledford/rdma: (37 commits)
  IB/rxe, IB/rdmavt: Use dma_virt_ops instead of duplicating it
  IB/core: Remove ib_device.dma_device
  nvme-rdma: Switch from dma_device to dev.parent
  RDS: net: Switch from dma_device to dev.parent
  IB/srpt: Modify a debug statement
  IB/srp: Switch from dma_device to dev.parent
  IB/iser: Switch from dma_device to dev.parent
  IB/IPoIB: Switch from dma_device to dev.parent
  IB/rxe: Switch from dma_device to dev.parent
  IB/vmw_pvrdma: Switch from dma_device to dev.parent
  IB/usnic: Switch from dma_device to dev.parent
  IB/qib: Switch from dma_device to dev.parent
  IB/qedr: Switch from dma_device to dev.parent
  IB/ocrdma: Switch from dma_device to dev.parent
  IB/nes: Remove a superfluous assignment statement
  IB/mthca: Switch from dma_device to dev.parent
  IB/mlx5: Switch from dma_device to dev.parent
  IB/mlx4: Switch from dma_device to dev.parent
  IB/i40iw: Remove a superfluous assignment statement
  IB/hns: Switch from dma_device to dev.parent
  ...

108 files changed, 218 insertions, 278 deletions

diff --git a/arch/alpha/include/asm/dma-mapping.h b/arch/alpha/include/asm/dma-mapping.h
index c63b6ac19ee5..5d53666935e6 100644
--- a/arch/alpha/include/asm/dma-mapping.h
+++ b/arch/alpha/include/asm/dma-mapping.h
@@ -1,9 +1,9 @@
 #ifndef _ALPHA_DMA_MAPPING_H
 #define _ALPHA_DMA_MAPPING_H
 
-extern struct dma_map_ops *dma_ops;
+extern const struct dma_map_ops *dma_ops;
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
 	return dma_ops;
 }
diff --git a/arch/alpha/kernel/pci-noop.c b/arch/alpha/kernel/pci-noop.c
index bb152e21e5ae..ffbdb3fb672f 100644
--- a/arch/alpha/kernel/pci-noop.c
+++ b/arch/alpha/kernel/pci-noop.c
@@ -128,7 +128,7 @@ static int alpha_noop_supported(struct device *dev, u64 mask)
 	return mask < 0x00ffffffUL ? 0 : 1;
 }
 
-struct dma_map_ops alpha_noop_ops = {
+const struct dma_map_ops alpha_noop_ops = {
 	.alloc			= alpha_noop_alloc_coherent,
 	.free			= dma_noop_free_coherent,
 	.map_page		= dma_noop_map_page,
@@ -137,5 +137,5 @@ struct dma_map_ops alpha_noop_ops = {
 	.dma_supported		= alpha_noop_supported,
 };
 
-struct dma_map_ops *dma_ops = &alpha_noop_ops;
+const struct dma_map_ops *dma_ops = &alpha_noop_ops;
 EXPORT_SYMBOL(dma_ops);
diff --git a/arch/alpha/kernel/pci_iommu.c b/arch/alpha/kernel/pci_iommu.c
index 451fc9cdd323..7fd2329038a3 100644
--- a/arch/alpha/kernel/pci_iommu.c
+++ b/arch/alpha/kernel/pci_iommu.c
@@ -939,7 +939,7 @@ static int alpha_pci_mapping_error(struct device *dev, dma_addr_t dma_addr)
 	return dma_addr == 0;
 }
 
-struct dma_map_ops alpha_pci_ops = {
+const struct dma_map_ops alpha_pci_ops = {
 	.alloc			= alpha_pci_alloc_coherent,
 	.free			= alpha_pci_free_coherent,
 	.map_page		= alpha_pci_map_page,
@@ -950,5 +950,5 @@ struct dma_map_ops alpha_pci_ops = {
 	.dma_supported		= alpha_pci_supported,
 };
 
-struct dma_map_ops *dma_ops = &alpha_pci_ops;
+const struct dma_map_ops *dma_ops = &alpha_pci_ops;
 EXPORT_SYMBOL(dma_ops);
diff --git a/arch/arc/include/asm/dma-mapping.h b/arch/arc/include/asm/dma-mapping.h
index 266f11c9bd59..94285031c4fb 100644
--- a/arch/arc/include/asm/dma-mapping.h
+++ b/arch/arc/include/asm/dma-mapping.h
@@ -18,9 +18,9 @@
 #include <plat/dma.h>
 #endif
 
-extern struct dma_map_ops arc_dma_ops;
+extern const struct dma_map_ops arc_dma_ops;
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
 	return &arc_dma_ops;
 }
diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c
index 08450a1a5b5f..2a07e6ecafbd 100644
--- a/arch/arc/mm/dma.c
+++ b/arch/arc/mm/dma.c
@@ -218,7 +218,7 @@ static int arc_dma_supported(struct device *dev, u64 dma_mask)
 	return dma_mask == DMA_BIT_MASK(32);
 }
 
-struct dma_map_ops arc_dma_ops = {
+const struct dma_map_ops arc_dma_ops = {
 	.alloc			= arc_dma_alloc,
 	.free			= arc_dma_free,
 	.mmap			= arc_dma_mmap,
diff --git a/arch/arm/common/dmabounce.c b/arch/arm/common/dmabounce.c
index 75055df1cda3..9b1b7be2ec0e 100644
--- a/arch/arm/common/dmabounce.c
+++ b/arch/arm/common/dmabounce.c
@@ -452,7 +452,7 @@ static int dmabounce_set_mask(struct device *dev, u64 dma_mask)
 	return arm_dma_ops.set_dma_mask(dev, dma_mask);
 }
 
-static struct dma_map_ops dmabounce_ops = {
+static const struct dma_map_ops dmabounce_ops = {
 	.alloc			= arm_dma_alloc,
 	.free			= arm_dma_free,
 	.mmap			= arm_dma_mmap,
diff --git a/arch/arm/include/asm/device.h b/arch/arm/include/asm/device.h
index 4111592f0130..220ba207be91 100644
--- a/arch/arm/include/asm/device.h
+++ b/arch/arm/include/asm/device.h
@@ -7,7 +7,6 @@
 #define ASMARM_DEVICE_H
 
 struct dev_archdata {
-	struct dma_map_ops	*dma_ops;
 #ifdef CONFIG_DMABOUNCE
 	struct dmabounce_device_info *dmabounce;
 #endif
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index bf02dbd9ccda..716656925975 100644
--- a/arch/arm/include/asm/dma-mapping.h
+++ b/arch/arm/include/asm/dma-mapping.h
@@ -13,28 +13,22 @@
 #include <asm/xen/hypervisor.h>
 
 #define DMA_ERROR_CODE	(~(dma_addr_t)0x0)
-extern struct dma_map_ops arm_dma_ops;
-extern struct dma_map_ops arm_coherent_dma_ops;
+extern const struct dma_map_ops arm_dma_ops;
+extern const struct dma_map_ops arm_coherent_dma_ops;
 
-static inline struct dma_map_ops *__generic_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *__generic_dma_ops(struct device *dev)
 {
-	if (dev && dev->archdata.dma_ops)
-		return dev->archdata.dma_ops;
+	if (dev && dev->dma_ops)
+		return dev->dma_ops;
 	return &arm_dma_ops;
 }
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
 	if (xen_initial_domain())
 		return xen_dma_ops;
 	else
-		return __generic_dma_ops(dev);
-}
-
-static inline void set_dma_ops(struct device *dev, struct dma_map_ops *ops)
-{
-	BUG_ON(!dev);
-	dev->archdata.dma_ops = ops;
+		return __generic_dma_ops(NULL);
 }
 
 #define HAVE_ARCH_DMA_SUPPORTED 1
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 6ffdf17e0d5c..e309a5e2c935 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -180,7 +180,7 @@ static void arm_dma_sync_single_for_device(struct device *dev,
 	__dma_page_cpu_to_dev(page, offset, size, dir);
 }
 
-struct dma_map_ops arm_dma_ops = {
+const struct dma_map_ops arm_dma_ops = {
 	.alloc			= arm_dma_alloc,
 	.free			= arm_dma_free,
 	.mmap			= arm_dma_mmap,
@@ -204,7 +204,7 @@ static int arm_coherent_dma_mmap(struct device *dev, struct vm_area_struct *vma,
 		 void *cpu_addr, dma_addr_t dma_addr, size_t size,
 		 unsigned long attrs);
 
-struct dma_map_ops arm_coherent_dma_ops = {
+const struct dma_map_ops arm_coherent_dma_ops = {
 	.alloc			= arm_coherent_dma_alloc,
 	.free			= arm_coherent_dma_free,
 	.mmap			= arm_coherent_dma_mmap,
@@ -1069,7 +1069,7 @@ static void __dma_page_dev_to_cpu(struct page *page, unsigned long off,
 int arm_dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
 		enum dma_data_direction dir, unsigned long attrs)
 {
-	struct dma_map_ops *ops = get_dma_ops(dev);
+	const struct dma_map_ops *ops = get_dma_ops(dev);
 	struct scatterlist *s;
 	int i, j;
 
@@ -1103,7 +1103,7 @@ int arm_dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
 void arm_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
 		enum dma_data_direction dir, unsigned long attrs)
 {
-	struct dma_map_ops *ops = get_dma_ops(dev);
+	const struct dma_map_ops *ops = get_dma_ops(dev);
 	struct scatterlist *s;
 
 	int i;
@@ -1122,7 +1122,7 @@ void arm_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
 void arm_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
 			int nents, enum dma_data_direction dir)
 {
-	struct dma_map_ops *ops = get_dma_ops(dev);
+	const struct dma_map_ops *ops = get_dma_ops(dev);
 	struct scatterlist *s;
 	int i;
 
@@ -1141,7 +1141,7 @@ void arm_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
 void arm_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
 			int nents, enum dma_data_direction dir)
 {
-	struct dma_map_ops *ops = get_dma_ops(dev);
+	const struct dma_map_ops *ops = get_dma_ops(dev);
 	struct scatterlist *s;
 	int i;
 
@@ -2101,7 +2101,7 @@ static void arm_iommu_sync_single_for_device(struct device *dev,
 	__dma_page_cpu_to_dev(page, offset, size, dir);
 }
 
-struct dma_map_ops iommu_ops = {
+const struct dma_map_ops iommu_ops = {
 	.alloc		= arm_iommu_alloc_attrs,
 	.free		= arm_iommu_free_attrs,
 	.mmap		= arm_iommu_mmap_attrs,
@@ -2121,7 +2121,7 @@ struct dma_map_ops iommu_ops = {
 	.unmap_resource		= arm_iommu_unmap_resource,
 };
 
-struct dma_map_ops iommu_coherent_ops = {
+const struct dma_map_ops iommu_coherent_ops = {
 	.alloc		= arm_coherent_iommu_alloc_attrs,
 	.free		= arm_coherent_iommu_free_attrs,
 	.mmap		= arm_coherent_iommu_mmap_attrs,
@@ -2321,7 +2321,7 @@ void arm_iommu_detach_device(struct device *dev)
 }
 EXPORT_SYMBOL_GPL(arm_iommu_detach_device);
 
-static struct dma_map_ops *arm_get_iommu_dma_map_ops(bool coherent)
+static const struct dma_map_ops *arm_get_iommu_dma_map_ops(bool coherent)
 {
 	return coherent ? &iommu_coherent_ops : &iommu_ops;
 }
@@ -2376,7 +2376,7 @@ static void arm_teardown_iommu_dma_ops(struct device *dev) { }
 
 #endif	/* CONFIG_ARM_DMA_USE_IOMMU */
 
-static struct dma_map_ops *arm_get_dma_map_ops(bool coherent)
+static const struct dma_map_ops *arm_get_dma_map_ops(bool coherent)
 {
 	return coherent ? &arm_coherent_dma_ops : &arm_dma_ops;
 }
@@ -2384,7 +2384,7 @@ static struct dma_map_ops *arm_get_dma_map_ops(bool coherent)
 void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
 			const struct iommu_ops *iommu, bool coherent)
 {
-	struct dma_map_ops *dma_ops;
+	const struct dma_map_ops *dma_ops;
 
 	dev->archdata.dma_coherent = coherent;
 	if (arm_setup_iommu_dma_ops(dev, dma_base, size, iommu))
diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c
index bd62d94f8ac5..ce18c91b50a1 100644
--- a/arch/arm/xen/mm.c
+++ b/arch/arm/xen/mm.c
@@ -182,10 +182,10 @@ void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order)
 }
 EXPORT_SYMBOL_GPL(xen_destroy_contiguous_region);
 
-struct dma_map_ops *xen_dma_ops;
+const struct dma_map_ops *xen_dma_ops;
 EXPORT_SYMBOL(xen_dma_ops);
 
-static struct dma_map_ops xen_swiotlb_dma_ops = {
+static const struct dma_map_ops xen_swiotlb_dma_ops = {
 	.alloc = xen_swiotlb_alloc_coherent,
 	.free = xen_swiotlb_free_coherent,
 	.sync_single_for_cpu = xen_swiotlb_sync_single_for_cpu,
diff --git a/arch/arm64/include/asm/device.h b/arch/arm64/include/asm/device.h
index 243ef256b8c9..73d5bab015eb 100644
--- a/arch/arm64/include/asm/device.h
+++ b/arch/arm64/include/asm/device.h
@@ -17,7 +17,6 @@
 #define __ASM_DEVICE_H
 
 struct dev_archdata {
-	struct dma_map_ops *dma_ops;
 #ifdef CONFIG_IOMMU_API
 	void *iommu;			/* private IOMMU data */
 #endif
diff --git a/arch/arm64/include/asm/dma-mapping.h b/arch/arm64/include/asm/dma-mapping.h
index ccea82c2b089..505756cdc67a 100644
--- a/arch/arm64/include/asm/dma-mapping.h
+++ b/arch/arm64/include/asm/dma-mapping.h
@@ -25,12 +25,12 @@
 #include <asm/xen/hypervisor.h>
 
 #define DMA_ERROR_CODE	(~(dma_addr_t)0)
-extern struct dma_map_ops dummy_dma_ops;
+extern const struct dma_map_ops dummy_dma_ops;
 
-static inline struct dma_map_ops *__generic_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *__generic_dma_ops(struct device *dev)
 {
-	if (dev && dev->archdata.dma_ops)
-		return dev->archdata.dma_ops;
+	if (dev && dev->dma_ops)
+		return dev->dma_ops;
 
 	/*
 	 * We expect no ISA devices, and all other DMA masters are expected to
@@ -39,12 +39,12 @@ static inline struct dma_map_ops *__generic_dma_ops(struct device *dev)
 	return &dummy_dma_ops;
 }
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
 	if (xen_initial_domain())
 		return xen_dma_ops;
 	else
-		return __generic_dma_ops(dev);
+		return __generic_dma_ops(NULL);
 }
 
 void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index aff1d0afeb1e..81cdb2e844ed 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -363,7 +363,7 @@ static int __swiotlb_dma_mapping_error(struct device *hwdev, dma_addr_t addr)
 	return 0;
 }
 
-static struct dma_map_ops swiotlb_dma_ops = {
+static const struct dma_map_ops swiotlb_dma_ops = {
 	.alloc = __dma_alloc,
 	.free = __dma_free,
 	.mmap = __swiotlb_mmap,
@@ -516,7 +516,7 @@ static int __dummy_dma_supported(struct device *hwdev, u64 mask)
 	return 0;
 }
 
-struct dma_map_ops dummy_dma_ops = {
+const struct dma_map_ops dummy_dma_ops = {
 	.alloc                  = __dummy_alloc,
 	.free                   = __dummy_free,
 	.mmap                   = __dummy_mmap,
@@ -795,7 +795,7 @@ static void __iommu_unmap_sg_attrs(struct device *dev,
 	iommu_dma_unmap_sg(dev, sgl, nelems, dir, attrs);
 }
 
-static struct dma_map_ops iommu_dma_ops = {
+static const struct dma_map_ops iommu_dma_ops = {
 	.alloc = __iommu_alloc_attrs,
 	.free = __iommu_free_attrs,
 	.mmap = __iommu_mmap_attrs,
@@ -848,7 +848,7 @@ static bool do_iommu_attach(struct device *dev, const struct iommu_ops *ops,
 		if (iommu_dma_init_domain(domain, dma_base, size, dev))
 			goto out_err;
 
-		dev->archdata.dma_ops = &iommu_dma_ops;
+		dev->dma_ops = &iommu_dma_ops;
 	}
 
 	return true;
@@ -958,7 +958,7 @@ static void __iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
 
 void arch_teardown_dma_ops(struct device *dev)
 {
-	dev->archdata.dma_ops = NULL;
+	dev->dma_ops = NULL;
 }
 
 #else
@@ -972,8 +972,8 @@ static void __iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
 void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
 			const struct iommu_ops *iommu, bool coherent)
 {
-	if (!dev->archdata.dma_ops)
-		dev->archdata.dma_ops = &swiotlb_dma_ops;
+	if (!dev->dma_ops)
+		dev->dma_ops = &swiotlb_dma_ops;
 
 	dev->archdata.dma_coherent = coherent;
 	__iommu_setup_dma_ops(dev, dma_base, size, iommu);
diff --git a/arch/avr32/include/asm/dma-mapping.h b/arch/avr32/include/asm/dma-mapping.h
index 1115f2a645d1..7388451f9905 100644
--- a/arch/avr32/include/asm/dma-mapping.h
+++ b/arch/avr32/include/asm/dma-mapping.h
@@ -4,9 +4,9 @@
 extern void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
 	int direction);
 
-extern struct dma_map_ops avr32_dma_ops;
+extern const struct dma_map_ops avr32_dma_ops;
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
 	return &avr32_dma_ops;
 }
diff --git a/arch/avr32/mm/dma-coherent.c b/arch/avr32/mm/dma-coherent.c
index 54534e5d0781..555222d4f414 100644
--- a/arch/avr32/mm/dma-coherent.c
+++ b/arch/avr32/mm/dma-coherent.c
@@ -191,7 +191,7 @@ static void avr32_dma_sync_sg_for_device(struct device *dev,
 		dma_cache_sync(dev, sg_virt(sg), sg->length, direction);
 }
 
-struct dma_map_ops avr32_dma_ops = {
+const struct dma_map_ops avr32_dma_ops = {
 	.alloc			= avr32_dma_alloc,
 	.free			= avr32_dma_free,
 	.map_page		= avr32_dma_map_page,
diff --git a/arch/blackfin/include/asm/dma-mapping.h b/arch/blackfin/include/asm/dma-mapping.h
index 3490570aaa82..04254ac36bed 100644
--- a/arch/blackfin/include/asm/dma-mapping.h
+++ b/arch/blackfin/include/asm/dma-mapping.h
@@ -36,9 +36,9 @@ _dma_sync(dma_addr_t addr, size_t size, enum dma_data_direction dir)
 		__dma_sync(addr, size, dir);
 }
 
-extern struct dma_map_ops bfin_dma_ops;
+extern const struct dma_map_ops bfin_dma_ops;
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
 	return &bfin_dma_ops;
 }
diff --git a/arch/blackfin/kernel/dma-mapping.c b/arch/blackfin/kernel/dma-mapping.c
index a27a74a18fb0..477bb29a7987 100644
--- a/arch/blackfin/kernel/dma-mapping.c
+++ b/arch/blackfin/kernel/dma-mapping.c
@@ -159,7 +159,7 @@ static inline void bfin_dma_sync_single_for_device(struct device *dev,
 	_dma_sync(handle, size, dir);
 }
 
-struct dma_map_ops bfin_dma_ops = {
+const struct dma_map_ops bfin_dma_ops = {
 	.alloc			= bfin_dma_alloc,
 	.free			= bfin_dma_free,
 
diff --git a/arch/c6x/include/asm/dma-mapping.h b/arch/c6x/include/asm/dma-mapping.h
index 5717b1e52d96..aca9f755e4f8 100644
--- a/arch/c6x/include/asm/dma-mapping.h
+++ b/arch/c6x/include/asm/dma-mapping.h
@@ -17,9 +17,9 @@
  */
 #define DMA_ERROR_CODE ~0
 
-extern struct dma_map_ops c6x_dma_ops;
+extern const struct dma_map_ops c6x_dma_ops;
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
 	return &c6x_dma_ops;
 }
diff --git a/arch/c6x/kernel/dma.c b/arch/c6x/kernel/dma.c
index 6752df32ef06..9fff8be75f58 100644
--- a/arch/c6x/kernel/dma.c
+++ b/arch/c6x/kernel/dma.c
@@ -123,7 +123,7 @@ static void c6x_dma_sync_sg_for_device(struct device *dev,
 
 }
 
-struct dma_map_ops c6x_dma_ops = {
+const struct dma_map_ops c6x_dma_ops = {
 	.alloc			= c6x_dma_alloc,
 	.free			= c6x_dma_free,
 	.map_page		= c6x_dma_map_page,
diff --git a/arch/cris/arch-v32/drivers/pci/dma.c b/arch/cris/arch-v32/drivers/pci/dma.c
index 1f0636793f0c..7072341995ff 100644
--- a/arch/cris/arch-v32/drivers/pci/dma.c
+++ b/arch/cris/arch-v32/drivers/pci/dma.c
@@ -69,7 +69,7 @@ static inline int v32_dma_supported(struct device *dev, u64 mask)
 	return 1;
 }
 
-struct dma_map_ops v32_dma_ops = {
+const struct dma_map_ops v32_dma_ops = {
 	.alloc			= v32_dma_alloc,
 	.free			= v32_dma_free,
 	.map_page		= v32_dma_map_page,
diff --git a/arch/cris/include/asm/dma-mapping.h b/arch/cris/include/asm/dma-mapping.h
index 5a370178a0e9..256169de3743 100644
--- a/arch/cris/include/asm/dma-mapping.h
+++ b/arch/cris/include/asm/dma-mapping.h
@@ -2,14 +2,14 @@
 #define _ASM_CRIS_DMA_MAPPING_H
 
 #ifdef CONFIG_PCI
-extern struct dma_map_ops v32_dma_ops;
+extern const struct dma_map_ops v32_dma_ops;
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
 	return &v32_dma_ops;
 }
 #else
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
 	BUG();
 	return NULL;
diff --git a/arch/frv/include/asm/dma-mapping.h b/arch/frv/include/asm/dma-mapping.h
index 9a82bfa4303b..354900917585 100644
--- a/arch/frv/include/asm/dma-mapping.h
+++ b/arch/frv/include/asm/dma-mapping.h
@@ -7,9 +7,9 @@
 extern unsigned long __nongprelbss dma_coherent_mem_start;
 extern unsigned long __nongprelbss dma_coherent_mem_end;
 
-extern struct dma_map_ops frv_dma_ops;
+extern const struct dma_map_ops frv_dma_ops;
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
 	return &frv_dma_ops;
 }
diff --git a/arch/frv/mb93090-mb00/pci-dma-nommu.c b/arch/frv/mb93090-mb00/pci-dma-nommu.c
index 187688128c65..4a96de7f0af4 100644
--- a/arch/frv/mb93090-mb00/pci-dma-nommu.c
+++ b/arch/frv/mb93090-mb00/pci-dma-nommu.c
@@ -164,7 +164,7 @@ static int frv_dma_supported(struct device *dev, u64 mask)
 	return 1;
 }
 
-struct dma_map_ops frv_dma_ops = {
+const struct dma_map_ops frv_dma_ops = {
 	.alloc			= frv_dma_alloc,
 	.free			= frv_dma_free,
 	.map_page		= frv_dma_map_page,
diff --git a/arch/frv/mb93090-mb00/pci-dma.c b/arch/frv/mb93090-mb00/pci-dma.c
index dba7df918144..e7130abc0dae 100644
--- a/arch/frv/mb93090-mb00/pci-dma.c
+++ b/arch/frv/mb93090-mb00/pci-dma.c
@@ -106,7 +106,7 @@ static int frv_dma_supported(struct device *dev, u64 mask)
 	return 1;
 }
 
-struct dma_map_ops frv_dma_ops = {
+const struct dma_map_ops frv_dma_ops = {
 	.alloc			= frv_dma_alloc,
 	.free			= frv_dma_free,
 	.map_page		= frv_dma_map_page,
diff --git a/arch/h8300/include/asm/dma-mapping.h b/arch/h8300/include/asm/dma-mapping.h
index 7ac7fadffed0..847c7562e046 100644
--- a/arch/h8300/include/asm/dma-mapping.h
+++ b/arch/h8300/include/asm/dma-mapping.h
@@ -1,9 +1,9 @@
 #ifndef _H8300_DMA_MAPPING_H
 #define _H8300_DMA_MAPPING_H
 
-extern struct dma_map_ops h8300_dma_map_ops;
+extern const struct dma_map_ops h8300_dma_map_ops;
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
 	return &h8300_dma_map_ops;
 }
diff --git a/arch/h8300/kernel/dma.c b/arch/h8300/kernel/dma.c
index 3651da045806..225dd0a188dc 100644
--- a/arch/h8300/kernel/dma.c
+++ b/arch/h8300/kernel/dma.c
@@ -60,7 +60,7 @@ static int map_sg(struct device *dev, struct scatterlist *sgl,
 	return nents;
 }
 
-struct dma_map_ops h8300_dma_map_ops = {
+const struct dma_map_ops h8300_dma_map_ops = {
 	.alloc = dma_alloc,
 	.free = dma_free,
 	.map_page = map_page,
diff --git a/arch/hexagon/include/asm/dma-mapping.h b/arch/hexagon/include/asm/dma-mapping.h
index 7ef58df909fc..d3a87bd9b686 100644
--- a/arch/hexagon/include/asm/dma-mapping.h
+++ b/arch/hexagon/include/asm/dma-mapping.h
@@ -32,13 +32,10 @@ struct device;
 extern int bad_dma_address;
 #define DMA_ERROR_CODE bad_dma_address
 
-extern struct dma_map_ops *dma_ops;
+extern const struct dma_map_ops *dma_ops;
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
-	if (unlikely(dev == NULL))
-		return NULL;
-
 	return dma_ops;
 }
 
diff --git a/arch/hexagon/kernel/dma.c b/arch/hexagon/kernel/dma.c
index dbc4f1003da4..e74b65009587 100644
--- a/arch/hexagon/kernel/dma.c
+++ b/arch/hexagon/kernel/dma.c
@@ -25,7 +25,7 @@
 #include <linux/module.h>
 #include <asm/page.h>
 
-struct dma_map_ops *dma_ops;
+const struct dma_map_ops *dma_ops;
 EXPORT_SYMBOL(dma_ops);
 
 int bad_dma_address;  /*  globals are automatically initialized to zero  */
@@ -203,7 +203,7 @@ static void hexagon_sync_single_for_device(struct device *dev,
 	dma_sync(dma_addr_to_virt(dma_handle), size, dir);
 }
 
-struct dma_map_ops hexagon_dma_ops = {
+const struct dma_map_ops hexagon_dma_ops = {
 	.alloc		= hexagon_dma_alloc_coherent,
 	.free		= hexagon_free_coherent,
 	.map_sg		= hexagon_map_sg,
diff --git a/arch/ia64/hp/common/hwsw_iommu.c b/arch/ia64/hp/common/hwsw_iommu.c
index 1e4cae5ae053..0310078a95f8 100644
--- a/arch/ia64/hp/common/hwsw_iommu.c
+++ b/arch/ia64/hp/common/hwsw_iommu.c
@@ -18,7 +18,7 @@
 #include <linux/export.h>
 #include <asm/machvec.h>
 
-extern struct dma_map_ops sba_dma_ops, swiotlb_dma_ops;
+extern const struct dma_map_ops sba_dma_ops, swiotlb_dma_ops;
 
 /* swiotlb declarations & definitions: */
 extern int swiotlb_late_init_with_default_size (size_t size);
@@ -34,7 +34,7 @@ static inline int use_swiotlb(struct device *dev)
 		!sba_dma_ops.dma_supported(dev, *dev->dma_mask);
 }
 
-struct dma_map_ops *hwsw_dma_get_ops(struct device *dev)
+const struct dma_map_ops *hwsw_dma_get_ops(struct device *dev)
 {
 	if (use_swiotlb(dev))
 		return &swiotlb_dma_ops;
diff --git a/arch/ia64/hp/common/sba_iommu.c b/arch/ia64/hp/common/sba_iommu.c
index 630ee8073899..aec4a3354abe 100644
--- a/arch/ia64/hp/common/sba_iommu.c
+++ b/arch/ia64/hp/common/sba_iommu.c
@@ -2096,7 +2096,7 @@ static int __init acpi_sba_ioc_init_acpi(void)
 /* This has to run before acpi_scan_init(). */
 arch_initcall(acpi_sba_ioc_init_acpi);
 
-extern struct dma_map_ops swiotlb_dma_ops;
+extern const struct dma_map_ops swiotlb_dma_ops;
 
 static int __init
 sba_init(void)
@@ -2216,7 +2216,7 @@ sba_page_override(char *str)
 
 __setup("sbapagesize=",sba_page_override);
 
-struct dma_map_ops sba_dma_ops = {
+const struct dma_map_ops sba_dma_ops = {
 	.alloc			= sba_alloc_coherent,
 	.free			= sba_free_coherent,
 	.map_page		= sba_map_page,
diff --git a/arch/ia64/include/asm/dma-mapping.h b/arch/ia64/include/asm/dma-mapping.h
index d472805edfa9..73ec3c6f4cfe 100644
--- a/arch/ia64/include/asm/dma-mapping.h
+++ b/arch/ia64/include/asm/dma-mapping.h
@@ -14,7 +14,7 @@
 
 #define DMA_ERROR_CODE 0
 
-extern struct dma_map_ops *dma_ops;
+extern const struct dma_map_ops *dma_ops;
 extern struct ia64_machine_vector ia64_mv;
 extern void set_iommu_machvec(void);
 
@@ -23,7 +23,10 @@ extern void machvec_dma_sync_single(struct device *, dma_addr_t, size_t,
 extern void machvec_dma_sync_sg(struct device *, struct scatterlist *, int,
 				enum dma_data_direction);
 
-#define get_dma_ops(dev) platform_dma_get_ops(dev)
+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)
 {
diff --git a/arch/ia64/include/asm/machvec.h b/arch/ia64/include/asm/machvec.h
index ed7f09089f12..af285c423e1e 100644
--- a/arch/ia64/include/asm/machvec.h
+++ b/arch/ia64/include/asm/machvec.h
@@ -44,7 +44,7 @@ typedef void ia64_mv_kernel_launch_event_t(void);
 /* DMA-mapping interface: */
 typedef void ia64_mv_dma_init (void);
 typedef u64 ia64_mv_dma_get_required_mask (struct device *);
-typedef struct dma_map_ops *ia64_mv_dma_get_ops(struct device *);
+typedef const struct dma_map_ops *ia64_mv_dma_get_ops(struct device *);
 
 /*
  * WARNING: The legacy I/O space is _architected_.  Platforms are
@@ -248,7 +248,7 @@ extern void machvec_init_from_cmdline(const char *cmdline);
 # endif /* CONFIG_IA64_GENERIC */
 
 extern void swiotlb_dma_init(void);
-extern struct dma_map_ops *dma_get_ops(struct device *);
+extern const struct dma_map_ops *dma_get_ops(struct device *);
 
 /*
  * Define default versions so we can extend machvec for new platforms without having
diff --git a/arch/ia64/kernel/dma-mapping.c b/arch/ia64/kernel/dma-mapping.c
index 7f7916238208..e0dd97f4eb69 100644
--- a/arch/ia64/kernel/dma-mapping.c
+++ b/arch/ia64/kernel/dma-mapping.c
@@ -4,7 +4,7 @@
 /* Set this to 1 if there is a HW IOMMU in the system */
 int iommu_detected __read_mostly;
 
-struct dma_map_ops *dma_ops;
+const struct dma_map_ops *dma_ops;
 EXPORT_SYMBOL(dma_ops);
 
 #define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
@@ -17,7 +17,7 @@ static int __init dma_init(void)
 }
 fs_initcall(dma_init);
 
-struct dma_map_ops *dma_get_ops(struct device *dev)
+const struct dma_map_ops *dma_get_ops(struct device *dev)
 {
 	return dma_ops;
 }
diff --git a/arch/ia64/kernel/pci-dma.c b/arch/ia64/kernel/pci-dma.c
index 992c1098c522..9094a73f996f 100644
--- a/arch/ia64/kernel/pci-dma.c
+++ b/arch/ia64/kernel/pci-dma.c
@@ -90,11 +90,11 @@ void __init pci_iommu_alloc(void)
 {
 	dma_ops = &intel_dma_ops;
 
-	dma_ops->sync_single_for_cpu = machvec_dma_sync_single;
-	dma_ops->sync_sg_for_cpu = machvec_dma_sync_sg;
-	dma_ops->sync_single_for_device = machvec_dma_sync_single;
-	dma_ops->sync_sg_for_device = machvec_dma_sync_sg;
-	dma_ops->dma_supported = iommu_dma_supported;
+	intel_dma_ops.sync_single_for_cpu = machvec_dma_sync_single;
+	intel_dma_ops.sync_sg_for_cpu = machvec_dma_sync_sg;
+	intel_dma_ops.sync_single_for_device = machvec_dma_sync_single;
+	intel_dma_ops.sync_sg_for_device = machvec_dma_sync_sg;
+	intel_dma_ops.dma_supported = iommu_dma_supported;
 
 	/*
 	 * The order of these functions is important for
diff --git a/arch/ia64/kernel/pci-swiotlb.c b/arch/ia64/kernel/pci-swiotlb.c
index 2933208c0285..a14989dacded 100644
--- a/arch/ia64/kernel/pci-swiotlb.c
+++ b/arch/ia64/kernel/pci-swiotlb.c
@@ -30,7 +30,7 @@ static void ia64_swiotlb_free_coherent(struct device *dev, size_t size,
 	swiotlb_free_coherent(dev, size, vaddr, dma_addr);
 }
 
-struct dma_map_ops swiotlb_dma_ops = {
+const struct dma_map_ops swiotlb_dma_ops = {
 	.alloc = ia64_swiotlb_alloc_coherent,
 	.free = ia64_swiotlb_free_coherent,
 	.map_page = swiotlb_map_page,
diff --git a/arch/m32r/Kconfig b/arch/m32r/Kconfig
index d227a6988d6b..95474460b367 100644
--- a/arch/m32r/Kconfig
+++ b/arch/m32r/Kconfig
@@ -18,6 +18,7 @@ config M32R
 	select MODULES_USE_ELF_RELA
 	select HAVE_DEBUG_STACKOVERFLOW
 	select CPU_NO_EFFICIENT_FFS
+	select DMA_NOOP_OPS
 
 config SBUS
 	bool
diff --git a/arch/m32r/include/asm/device.h b/arch/m32r/include/asm/device.h
index 4a9f35e0973f..5203fc87f080 100644
--- a/arch/m32r/include/asm/device.h
+++ b/arch/m32r/include/asm/device.h
@@ -4,7 +4,6 @@
  * This file is released under the GPLv2
  */
 struct dev_archdata {
-	struct dma_map_ops *dma_ops;
 };
 
 struct pdev_archdata {
diff --git a/arch/m32r/include/asm/dma-mapping.h b/arch/m32r/include/asm/dma-mapping.h
index 2c43a77fe942..c01d9f52d228 100644
--- a/arch/m32r/include/asm/dma-mapping.h
+++ b/arch/m32r/include/asm/dma-mapping.h
@@ -10,10 +10,8 @@
 
 #define DMA_ERROR_CODE (~(dma_addr_t)0x0)
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
-	if (dev && dev->archdata.dma_ops)
-		return dev->archdata.dma_ops;
 	return &dma_noop_ops;
 }
 
diff --git a/arch/m68k/include/asm/dma-mapping.h b/arch/m68k/include/asm/dma-mapping.h
index 96c536194287..9210e470771b 100644
--- a/arch/m68k/include/asm/dma-mapping.h
+++ b/arch/m68k/include/asm/dma-mapping.h
@@ -1,9 +1,9 @@
 #ifndef _M68K_DMA_MAPPING_H
 #define _M68K_DMA_MAPPING_H
 
-extern struct dma_map_ops m68k_dma_ops;
+extern const struct dma_map_ops m68k_dma_ops;
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
         return &m68k_dma_ops;
 }
diff --git a/arch/m68k/kernel/dma.c b/arch/m68k/kernel/dma.c
index 1e4f386ba31e..87ef73a93856 100644
--- a/arch/m68k/kernel/dma.c
+++ b/arch/m68k/kernel/dma.c
@@ -158,7 +158,7 @@ static int m68k_dma_map_sg(struct device *dev, struct scatterlist *sglist,
 	return nents;
 }
 
-struct dma_map_ops m68k_dma_ops = {
+const struct dma_map_ops m68k_dma_ops = {
 	.alloc			= m68k_dma_alloc,
 	.free			= m68k_dma_free,
 	.map_page		= m68k_dma_map_page,
diff --git a/arch/metag/include/asm/dma-mapping.h b/arch/metag/include/asm/dma-mapping.h
index 27af5d479ce6..fad3dc3cb210 100644
--- a/arch/metag/include/asm/dma-mapping.h
+++ b/arch/metag/include/asm/dma-mapping.h
@@ -1,9 +1,9 @@
 #ifndef _ASM_METAG_DMA_MAPPING_H
 #define _ASM_METAG_DMA_MAPPING_H
 
-extern struct dma_map_ops metag_dma_ops;
+extern const struct dma_map_ops metag_dma_ops;
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
 	return &metag_dma_ops;
 }
diff --git a/arch/metag/kernel/dma.c b/arch/metag/kernel/dma.c
index 91968d92652b..f0ab3a498328 100644
--- a/arch/metag/kernel/dma.c
+++ b/arch/metag/kernel/dma.c
@@ -575,7 +575,7 @@ static void metag_dma_sync_sg_for_device(struct device *dev,
 		dma_sync_for_device(sg_virt(sg), sg->length, direction);
 }
 
-struct dma_map_ops metag_dma_ops = {
+const struct dma_map_ops metag_dma_ops = {
 	.alloc			= metag_dma_alloc,
 	.free			= metag_dma_free,
 	.map_page		= metag_dma_map_page,
diff --git a/arch/microblaze/include/asm/dma-mapping.h b/arch/microblaze/include/asm/dma-mapping.h
index 1768d4bdc8d3..3fad5e722a66 100644
--- a/arch/microblaze/include/asm/dma-mapping.h
+++ b/arch/microblaze/include/asm/dma-mapping.h
@@ -36,9 +36,9 @@
 /*
  * Available generic sets of operations
  */
-extern struct dma_map_ops dma_direct_ops;
+extern const struct dma_map_ops dma_direct_ops;
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
 	return &dma_direct_ops;
 }
diff --git a/arch/microblaze/kernel/dma.c b/arch/microblaze/kernel/dma.c
index 818daf230eb4..12e093a03e60 100644
--- a/arch/microblaze/kernel/dma.c
+++ b/arch/microblaze/kernel/dma.c
@@ -187,7 +187,7 @@ int dma_direct_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
 #endif
 }
 
-struct dma_map_ops dma_direct_ops = {
+const struct dma_map_ops dma_direct_ops = {
 	.alloc		= dma_direct_alloc_coherent,
 	.free		= dma_direct_free_coherent,
 	.mmap		= dma_direct_mmap_coherent,
diff --git a/arch/mips/cavium-octeon/dma-octeon.c b/arch/mips/cavium-octeon/dma-octeon.c
index 1226965e1e4f..c64bd87f0b6e 100644
--- a/arch/mips/cavium-octeon/dma-octeon.c
+++ b/arch/mips/cavium-octeon/dma-octeon.c
@@ -200,7 +200,7 @@ static phys_addr_t octeon_unity_dma_to_phys(struct device *dev, dma_addr_t daddr
 }
 
 struct octeon_dma_map_ops {
-	struct dma_map_ops dma_map_ops;
+	const struct dma_map_ops dma_map_ops;
 	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);
 };
@@ -328,7 +328,7 @@ static struct octeon_dma_map_ops _octeon_pci_dma_map_ops = {
 	},
 };
 
-struct dma_map_ops *octeon_pci_dma_map_ops;
+const struct dma_map_ops *octeon_pci_dma_map_ops;
 
 void __init octeon_pci_dma_init(void)
 {
diff --git a/arch/mips/include/asm/device.h b/arch/mips/include/asm/device.h
index 21c2082a0dfb..6aa796f1081a 100644
--- a/arch/mips/include/asm/device.h
+++ b/arch/mips/include/asm/device.h
@@ -6,12 +6,7 @@
 #ifndef _ASM_MIPS_DEVICE_H
 #define _ASM_MIPS_DEVICE_H
 
-struct dma_map_ops;
-
 struct dev_archdata {
-	/* DMA operations on that device */
-	struct dma_map_ops *dma_ops;
-
 #ifdef CONFIG_DMA_PERDEV_COHERENT
 	/* Non-zero if DMA is coherent with CPU caches */
 	bool dma_coherent;
diff --git a/arch/mips/include/asm/dma-mapping.h b/arch/mips/include/asm/dma-mapping.h
index 7aa71b9b0258..aba71385f9d1 100644
--- a/arch/mips/include/asm/dma-mapping.h
+++ b/arch/mips/include/asm/dma-mapping.h
@@ -9,14 +9,11 @@
 #include <dma-coherence.h>
 #endif
 
-extern struct dma_map_ops *mips_dma_map_ops;
+extern const struct dma_map_ops *mips_dma_map_ops;
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
-	if (dev && dev->archdata.dma_ops)
-		return dev->archdata.dma_ops;
-	else
-		return mips_dma_map_ops;
+	return mips_dma_map_ops;
 }
 
 static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
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 460042ee5d6f..9110988b92a1 100644
--- a/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h
+++ b/arch/mips/include/asm/mach-cavium-octeon/dma-coherence.h
@@ -65,7 +65,7 @@ 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);
 
 struct dma_map_ops;
-extern struct dma_map_ops *octeon_pci_dma_map_ops;
+extern const struct dma_map_ops *octeon_pci_dma_map_ops;
 extern char *octeon_swiotlb;
 
 #endif /* __ASM_MACH_CAVIUM_OCTEON_DMA_COHERENCE_H */
diff --git a/arch/mips/include/asm/netlogic/common.h b/arch/mips/include/asm/netlogic/common.h
index be52c2125d71..e0717d10e650 100644
--- a/arch/mips/include/asm/netlogic/common.h
+++ b/arch/mips/include/asm/netlogic/common.h
@@ -88,7 +88,7 @@ extern struct plat_smp_ops nlm_smp_ops;
 extern char nlm_reset_entry[], nlm_reset_entry_end[];
 
 /* SWIOTLB */
-extern struct dma_map_ops nlm_swiotlb_dma_ops;
+extern const struct dma_map_ops nlm_swiotlb_dma_ops;
 
 extern unsigned int nlm_threads_per_core;
 extern cpumask_t nlm_cpumask;
diff --git a/arch/mips/loongson64/common/dma-swiotlb.c b/arch/mips/loongson64/common/dma-swiotlb.c
index df7235e33499..178ca17a5667 100644
--- a/arch/mips/loongson64/common/dma-swiotlb.c
+++ b/arch/mips/loongson64/common/dma-swiotlb.c
@@ -114,7 +114,7 @@ phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
 	return daddr;
 }
 
-static struct dma_map_ops loongson_dma_map_ops = {
+static const struct dma_map_ops loongson_dma_map_ops = {
 	.alloc = loongson_dma_alloc_coherent,
 	.free = loongson_dma_free_coherent,
 	.map_page = loongson_dma_map_page,
diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c
index 1895a692efd4..fe8df14b6169 100644
--- a/arch/mips/mm/dma-default.c
+++ b/arch/mips/mm/dma-default.c
@@ -417,7 +417,7 @@ void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
 
 EXPORT_SYMBOL(dma_cache_sync);
 
-static struct dma_map_ops mips_default_dma_map_ops = {
+static const struct dma_map_ops mips_default_dma_map_ops = {
 	.alloc = mips_dma_alloc_coherent,
 	.free = mips_dma_free_coherent,
 	.mmap = mips_dma_mmap,
@@ -433,7 +433,7 @@ static struct dma_map_ops mips_default_dma_map_ops = {
 	.dma_supported = mips_dma_supported
 };
 
-struct dma_map_ops *mips_dma_map_ops = &mips_default_dma_map_ops;
+const struct dma_map_ops *mips_dma_map_ops = &mips_default_dma_map_ops;
 EXPORT_SYMBOL(mips_dma_map_ops);
 
 #define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
diff --git a/arch/mips/netlogic/common/nlm-dma.c b/arch/mips/netlogic/common/nlm-dma.c
index 0630693bec2a..0ec9d9da6d51 100644
--- a/arch/mips/netlogic/common/nlm-dma.c
+++ b/arch/mips/netlogic/common/nlm-dma.c
@@ -67,7 +67,7 @@ static void nlm_dma_free_coherent(struct device *dev, size_t size,
 	swiotlb_free_coherent(dev, size, vaddr, dma_handle);
 }
 
-struct dma_map_ops nlm_swiotlb_dma_ops = {
+const struct dma_map_ops nlm_swiotlb_dma_ops = {
 	.alloc = nlm_dma_alloc_coherent,
 	.free = nlm_dma_free_coherent,
 	.map_page = swiotlb_map_page,
diff --git a/arch/mips/pci/pci-octeon.c b/arch/mips/pci/pci-octeon.c
index 308d051fc45c..9ee01936862e 100644
--- a/arch/mips/pci/pci-octeon.c
+++ b/arch/mips/pci/pci-octeon.c
@@ -167,7 +167,7 @@ int pcibios_plat_dev_init(struct pci_dev *dev)
 		pci_write_config_dword(dev, pos + PCI_ERR_ROOT_STATUS, dconfig);
 	}
 
-	dev->dev.archdata.dma_ops = octeon_pci_dma_map_ops;
+	dev->dev.dma_ops = octeon_pci_dma_map_ops;
 
 	return 0;
 }
diff --git a/arch/mn10300/include/asm/dma-mapping.h b/arch/mn10300/include/asm/dma-mapping.h
index 1dcd44757f32..737ef574b3ea 100644
--- a/arch/mn10300/include/asm/dma-mapping.h
+++ b/arch/mn10300/include/asm/dma-mapping.h
@@ -14,9 +14,9 @@
 #include <asm/cache.h>
 #include <asm/io.h>
 
-extern struct dma_map_ops mn10300_dma_ops;
+extern const struct dma_map_ops mn10300_dma_ops;
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
 	return &mn10300_dma_ops;
 }
diff --git a/arch/mn10300/mm/dma-alloc.c b/arch/mn10300/mm/dma-alloc.c
index 4f4b9029f0ea..86108d2496b3 100644
--- a/arch/mn10300/mm/dma-alloc.c
+++ b/arch/mn10300/mm/dma-alloc.c
@@ -121,7 +121,7 @@ static int mn10300_dma_supported(struct device *dev, u64 mask)
 	return 1;
 }
 
-struct dma_map_ops mn10300_dma_ops = {
+const struct dma_map_ops mn10300_dma_ops = {
 	.alloc			= mn10300_dma_alloc,
 	.free			= mn10300_dma_free,
 	.map_page		= mn10300_dma_map_page,
diff --git a/arch/nios2/include/asm/dma-mapping.h b/arch/nios2/include/asm/dma-mapping.h
index bec8ac8e6ad2..7b3c6f280293 100644
--- a/arch/nios2/include/asm/dma-mapping.h
+++ b/arch/nios2/include/asm/dma-mapping.h
@@ -10,9 +10,9 @@
 #ifndef _ASM_NIOS2_DMA_MAPPING_H
 #define _ASM_NIOS2_DMA_MAPPING_H
 
-extern struct dma_map_ops nios2_dma_ops;
+extern const struct dma_map_ops nios2_dma_ops;
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
 	return &nios2_dma_ops;
 }
diff --git a/arch/nios2/mm/dma-mapping.c b/arch/nios2/mm/dma-mapping.c
index f6a5dcf9d682..7040c1adbb5e 100644
--- a/arch/nios2/mm/dma-mapping.c
+++ b/arch/nios2/mm/dma-mapping.c
@@ -192,7 +192,7 @@ static void nios2_dma_sync_sg_for_device(struct device *dev,
 
 }
 
-struct dma_map_ops nios2_dma_ops = {
+const struct dma_map_ops nios2_dma_ops = {
 	.alloc			= nios2_dma_alloc,
 	.free			= nios2_dma_free,
 	.map_page		= nios2_dma_map_page,
diff --git a/arch/openrisc/include/asm/dma-mapping.h b/arch/openrisc/include/asm/dma-mapping.h
index 1f260bccb368..0c0075f17145 100644
--- a/arch/openrisc/include/asm/dma-mapping.h
+++ b/arch/openrisc/include/asm/dma-mapping.h
@@ -28,9 +28,9 @@
 
 #define DMA_ERROR_CODE		(~(dma_addr_t)0x0)
 
-extern struct dma_map_ops or1k_dma_map_ops;
+extern const struct dma_map_ops or1k_dma_map_ops;
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
 	return &or1k_dma_map_ops;
 }
diff --git a/arch/openrisc/kernel/dma.c b/arch/openrisc/kernel/dma.c
index 906998bac957..b10369b7e31b 100644
--- a/arch/openrisc/kernel/dma.c
+++ b/arch/openrisc/kernel/dma.c
@@ -232,7 +232,7 @@ or1k_sync_single_for_device(struct device *dev,
 		mtspr(SPR_DCBFR, cl);
 }
 
-struct dma_map_ops or1k_dma_map_ops = {
+const struct dma_map_ops or1k_dma_map_ops = {
 	.alloc = or1k_dma_alloc,
 	.free = or1k_dma_free,
 	.map_page = or1k_map_page,
diff --git a/arch/parisc/include/asm/dma-mapping.h b/arch/parisc/include/asm/dma-mapping.h
index 16e024602737..5404c6a726b2 100644
--- a/arch/parisc/include/asm/dma-mapping.h
+++ b/arch/parisc/include/asm/dma-mapping.h
@@ -21,13 +21,13 @@
 */
 
 #ifdef CONFIG_PA11
-extern struct dma_map_ops pcxl_dma_ops;
-extern struct dma_map_ops pcx_dma_ops;
+extern const struct dma_map_ops pcxl_dma_ops;
+extern const struct dma_map_ops pcx_dma_ops;
 #endif
 
-extern struct dma_map_ops *hppa_dma_ops;
+extern const struct dma_map_ops *hppa_dma_ops;
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
 	return hppa_dma_ops;
 }
diff --git a/arch/parisc/kernel/drivers.c b/arch/parisc/kernel/drivers.c
index 700e2d2da096..fa78419100c8 100644
--- a/arch/parisc/kernel/drivers.c
+++ b/arch/parisc/kernel/drivers.c
@@ -40,7 +40,7 @@
 #include <asm/parisc-device.h>
 
 /* See comments in include/asm-parisc/pci.h */
-struct dma_map_ops *hppa_dma_ops __read_mostly;
+const struct dma_map_ops *hppa_dma_ops __read_mostly;
 EXPORT_SYMBOL(hppa_dma_ops);
 
 static struct device root = {
diff --git a/arch/parisc/kernel/pci-dma.c b/arch/parisc/kernel/pci-dma.c
index 697c53543a4d..5f0067a62738 100644
--- a/arch/parisc/kernel/pci-dma.c
+++ b/arch/parisc/kernel/pci-dma.c
@@ -572,7 +572,7 @@ static void pa11_dma_sync_sg_for_device(struct device *dev, struct scatterlist *
 		flush_kernel_vmap_range(sg_virt(sg), sg->length);
 }
 
-struct dma_map_ops pcxl_dma_ops = {
+const struct dma_map_ops pcxl_dma_ops = {
 	.dma_supported =	pa11_dma_supported,
 	.alloc =		pa11_dma_alloc,
 	.free =			pa11_dma_free,
@@ -608,7 +608,7 @@ static void pcx_dma_free(struct device *dev, size_t size, void *vaddr,
 	return;
 }
 
-struct dma_map_ops pcx_dma_ops = {
+const struct dma_map_ops pcx_dma_ops = {
 	.dma_supported =	pa11_dma_supported,
 	.alloc =		pcx_dma_alloc,
 	.free =			pcx_dma_free,
diff --git a/arch/powerpc/include/asm/device.h b/arch/powerpc/include/asm/device.h
index 406c2b1ff82d..0245bfcaac32 100644
--- a/arch/powerpc/include/asm/device.h
+++ b/arch/powerpc/include/asm/device.h
@@ -6,7 +6,6 @@
 #ifndef _ASM_POWERPC_DEVICE_H
 #define _ASM_POWERPC_DEVICE_H
 
-struct dma_map_ops;
 struct device_node;
 #ifdef CONFIG_PPC64
 struct pci_dn;
@@ -20,9 +19,6 @@ struct iommu_table;
  * drivers/macintosh/macio_asic.c
  */
 struct dev_archdata {
-	/* DMA operations on that device */
-	struct dma_map_ops	*dma_ops;
-
 	/*
 	 * These two used to be a union. However, with the hybrid ops we need
 	 * both so here we store both a DMA offset for direct mappings and
diff --git a/arch/powerpc/include/asm/dma-mapping.h b/arch/powerpc/include/asm/dma-mapping.h
index 84e3f8dd5e4f..181a095468e4 100644
--- a/arch/powerpc/include/asm/dma-mapping.h
+++ b/arch/powerpc/include/asm/dma-mapping.h
@@ -76,24 +76,16 @@ static inline unsigned long device_to_mask(struct device *dev)
 #ifdef CONFIG_PPC64
 extern struct dma_map_ops dma_iommu_ops;
 #endif
-extern struct dma_map_ops dma_direct_ops;
+extern const struct dma_map_ops dma_direct_ops;
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
 	/* We don't handle the NULL dev case for ISA for now. We could
 	 * do it via an out of line call but it is not needed for now. The
 	 * only ISA DMA device we support is the floppy and we have a hack
 	 * in the floppy driver directly to get a device for us.
 	 */
-	if (unlikely(dev == NULL))
-		return NULL;
-
-	return dev->archdata.dma_ops;
-}
-
-static inline void set_dma_ops(struct device *dev, struct dma_map_ops *ops)
-{
-	dev->archdata.dma_ops = ops;
+	return NULL;
 }
 
 /*
diff --git a/arch/powerpc/include/asm/pci.h b/arch/powerpc/include/asm/pci.h
index e9bd6cf0212f..93eded8d3843 100644
--- a/arch/powerpc/include/asm/pci.h
+++ b/arch/powerpc/include/asm/pci.h
@@ -53,8 +53,8 @@ static inline int pci_get_legacy_ide_irq(struct pci_dev *dev, int channel)
 }
 
 #ifdef CONFIG_PCI
-extern void set_pci_dma_ops(struct dma_map_ops *dma_ops);
-extern struct dma_map_ops *get_pci_dma_ops(void);
+extern void set_pci_dma_ops(const struct dma_map_ops *dma_ops);
+extern const struct dma_map_ops *get_pci_dma_ops(void);
 #else	/* CONFIG_PCI */
 #define set_pci_dma_ops(d)
 #define get_pci_dma_ops()	NULL
diff --git a/arch/powerpc/include/asm/ps3.h b/arch/powerpc/include/asm/ps3.h
index a19f831a4cc9..17ee719e799f 100644
--- a/arch/powerpc/include/asm/ps3.h
+++ b/arch/powerpc/include/asm/ps3.h
@@ -435,7 +435,7 @@ static inline void *ps3_system_bus_get_drvdata(
 	return dev_get_drvdata(&dev->core);
 }
 
-/* These two need global scope for get_dma_ops(). */
+/* These two need global scope for get_arch_dma_ops(). */
 
 extern struct bus_type ps3_system_bus_type;
 
diff --git a/arch/powerpc/include/asm/swiotlb.h b/arch/powerpc/include/asm/swiotlb.h
index de99d6e29430..01d45a5fd00b 100644
--- a/arch/powerpc/include/asm/swiotlb.h
+++ b/arch/powerpc/include/asm/swiotlb.h
@@ -13,7 +13,7 @@
 
 #include <linux/swiotlb.h>
 
-extern struct dma_map_ops swiotlb_dma_ops;
+extern const struct dma_map_ops swiotlb_dma_ops;
 
 static inline void dma_mark_clean(void *addr, size_t size) {}
 
diff --git a/arch/powerpc/kernel/dma-swiotlb.c b/arch/powerpc/kernel/dma-swiotlb.c
index c6689f658b50..d0ea7860e02b 100644
--- a/arch/powerpc/kernel/dma-swiotlb.c
+++ b/arch/powerpc/kernel/dma-swiotlb.c
@@ -46,7 +46,7 @@ static u64 swiotlb_powerpc_get_required(struct device *dev)
  * map_page, and unmap_page on highmem, use normal dma_ops
  * for everything else.
  */
-struct dma_map_ops swiotlb_dma_ops = {
+const struct dma_map_ops swiotlb_dma_ops = {
 	.alloc = __dma_direct_alloc_coherent,
 	.free = __dma_direct_free_coherent,
 	.mmap = dma_direct_mmap_coherent,
diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c
index 6877e3fa95bb..41c749586bd2 100644
--- a/arch/powerpc/kernel/dma.c
+++ b/arch/powerpc/kernel/dma.c
@@ -33,7 +33,7 @@ static u64 __maybe_unused get_pfn_limit(struct device *dev)
 	struct dev_archdata __maybe_unused *sd = &dev->archdata;
 
 #ifdef CONFIG_SWIOTLB
-	if (sd->max_direct_dma_addr && sd->dma_ops == &swiotlb_dma_ops)
+	if (sd->max_direct_dma_addr && dev->dma_ops == &swiotlb_dma_ops)
 		pfn = min_t(u64, pfn, sd->max_direct_dma_addr >> PAGE_SHIFT);
 #endif
 
@@ -274,7 +274,7 @@ static inline void dma_direct_sync_single(struct device *dev,
 }
 #endif
 
-struct dma_map_ops dma_direct_ops = {
+const struct dma_map_ops dma_direct_ops = {
 	.alloc				= dma_direct_alloc_coherent,
 	.free				= dma_direct_free_coherent,
 	.mmap				= dma_direct_mmap_coherent,
@@ -316,7 +316,7 @@ EXPORT_SYMBOL(dma_set_coherent_mask);
 
 int __dma_set_mask(struct device *dev, u64 dma_mask)
 {
-	struct dma_map_ops *dma_ops = get_dma_ops(dev);
+	const struct dma_map_ops *dma_ops = get_dma_ops(dev);
 
 	if ((dma_ops != NULL) && (dma_ops->set_dma_mask != NULL))
 		return dma_ops->set_dma_mask(dev, dma_mask);
@@ -344,7 +344,7 @@ EXPORT_SYMBOL(dma_set_mask);
 
 u64 __dma_get_required_mask(struct device *dev)
 {
-	struct dma_map_ops *dma_ops = get_dma_ops(dev);
+	const struct dma_map_ops *dma_ops = get_dma_ops(dev);
 
 	if (unlikely(dma_ops == NULL))
 		return 0;
diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index a3f5334f5d8c..8e6fde8d28f3 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -60,14 +60,14 @@ resource_size_t isa_mem_base;
 EXPORT_SYMBOL(isa_mem_base);
 
 
-static struct dma_map_ops *pci_dma_ops = &dma_direct_ops;
+static const struct dma_map_ops *pci_dma_ops = &dma_direct_ops;
 
-void set_pci_dma_ops(struct dma_map_ops *dma_ops)
+void set_pci_dma_ops(const struct dma_map_ops *dma_ops)
 {
 	pci_dma_ops = dma_ops;
 }
 
-struct dma_map_ops *get_pci_dma_ops(void)
+const struct dma_map_ops *get_pci_dma_ops(void)
 {
 	return pci_dma_ops;
 }
diff --git a/arch/powerpc/platforms/cell/iommu.c b/arch/powerpc/platforms/cell/iommu.c
index 7ff51f96a00e..71b995bbcae0 100644
--- a/arch/powerpc/platforms/cell/iommu.c
+++ b/arch/powerpc/platforms/cell/iommu.c
@@ -651,7 +651,7 @@ static int dma_fixed_dma_supported(struct device *dev, u64 mask)
 
 static int dma_set_mask_and_switch(struct device *dev, u64 dma_mask);
 
-static struct dma_map_ops dma_iommu_fixed_ops = {
+static const struct dma_map_ops dma_iommu_fixed_ops = {
 	.alloc          = dma_fixed_alloc_coherent,
 	.free           = dma_fixed_free_coherent,
 	.map_sg         = dma_fixed_map_sg,
@@ -692,7 +692,7 @@ static int cell_of_bus_notify(struct notifier_block *nb, unsigned long action,
 		return 0;
 
 	/* We use the PCI DMA ops */
-	dev->archdata.dma_ops = get_pci_dma_ops();
+	dev->dma_ops = get_pci_dma_ops();
 
 	cell_dma_dev_setup(dev);
 
@@ -1172,7 +1172,7 @@ __setup("iommu_fixed=", setup_iommu_fixed);
 
 static u64 cell_dma_get_required_mask(struct device *dev)
 {
-	struct dma_map_ops *dma_ops;
+	const struct dma_map_ops *dma_ops;
 
 	if (!dev->dma_mask)
 		return 0;
diff --git a/arch/powerpc/platforms/pasemi/iommu.c b/arch/powerpc/platforms/pasemi/iommu.c
index e74adc4e7fd8..7fec04de27fc 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.archdata.dma_ops = &dma_direct_ops;
+		dev->dev.dma_ops = &dma_direct_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 3182400cf48f..c4a3e93dc324 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->archdata.dma_ops = &dma_direct_ops;
+	dev->dma_ops = &dma_direct_ops;
 
 	return 0;
 }
diff --git a/arch/powerpc/platforms/powernv/npu-dma.c b/arch/powerpc/platforms/powernv/npu-dma.c
index 73b155fd4481..1c383f38031d 100644
--- a/arch/powerpc/platforms/powernv/npu-dma.c
+++ b/arch/powerpc/platforms/powernv/npu-dma.c
@@ -115,7 +115,7 @@ static u64 dma_npu_get_required_mask(struct device *dev)
 	return 0;
 }
 
-static struct dma_map_ops dma_npu_ops = {
+static const struct dma_map_ops dma_npu_ops = {
 	.map_page		= dma_npu_map_page,
 	.map_sg			= dma_npu_map_sg,
 	.alloc			= dma_npu_alloc,
diff --git a/arch/powerpc/platforms/ps3/system-bus.c b/arch/powerpc/platforms/ps3/system-bus.c
index 8af1c15aef85..2d2e5f80a3d3 100644
--- a/arch/powerpc/platforms/ps3/system-bus.c
+++ b/arch/powerpc/platforms/ps3/system-bus.c
@@ -701,7 +701,7 @@ static u64 ps3_dma_get_required_mask(struct device *_dev)
 	return DMA_BIT_MASK(32);
 }
 
-static struct dma_map_ops ps3_sb_dma_ops = {
+static const struct dma_map_ops ps3_sb_dma_ops = {
 	.alloc = ps3_alloc_coherent,
 	.free = ps3_free_coherent,
 	.map_sg = ps3_sb_map_sg,
@@ -712,7 +712,7 @@ static struct dma_map_ops ps3_sb_dma_ops = {
 	.unmap_page = ps3_unmap_page,
 };
 
-static struct dma_map_ops ps3_ioc0_dma_ops = {
+static const struct dma_map_ops ps3_ioc0_dma_ops = {
 	.alloc = ps3_alloc_coherent,
 	.free = ps3_free_coherent,
 	.map_sg = ps3_ioc0_map_sg,
@@ -756,11 +756,11 @@ int ps3_system_bus_device_register(struct ps3_system_bus_device *dev)
 
 	switch (dev->dev_type) {
 	case PS3_DEVICE_TYPE_IOC0:
-		dev->core.archdata.dma_ops = &ps3_ioc0_dma_ops;
+		dev->core.dma_ops = &ps3_ioc0_dma_ops;
 		dev_set_name(&dev->core, "ioc0_%02x", ++dev_ioc0_count);
 		break;
 	case PS3_DEVICE_TYPE_SB:
-		dev->core.archdata.dma_ops = &ps3_sb_dma_ops;
+		dev->core.dma_ops = &ps3_sb_dma_ops;
 		dev_set_name(&dev->core, "sb_%02x", ++dev_sb_count);
 
 		break;
diff --git a/arch/powerpc/platforms/pseries/ibmebus.c b/arch/powerpc/platforms/pseries/ibmebus.c
index 614c28537141..99a6bf7f3bcf 100644
--- a/arch/powerpc/platforms/pseries/ibmebus.c
+++ b/arch/powerpc/platforms/pseries/ibmebus.c
@@ -136,7 +136,7 @@ static u64 ibmebus_dma_get_required_mask(struct device *dev)
 	return DMA_BIT_MASK(64);
 }
 
-static struct dma_map_ops ibmebus_dma_ops = {
+static const struct dma_map_ops ibmebus_dma_ops = {
 	.alloc              = ibmebus_alloc_coherent,
 	.free               = ibmebus_free_coherent,
 	.map_sg             = ibmebus_map_sg,
@@ -169,7 +169,7 @@ static int ibmebus_create_device(struct device_node *dn)
 		return -ENOMEM;
 
 	dev->dev.bus = &ibmebus_bus_type;
-	dev->dev.archdata.dma_ops = &ibmebus_dma_ops;
+	dev->dev.dma_ops = &ibmebus_dma_ops;
 
 	ret = of_device_add(dev);
 	if (ret)
diff --git a/arch/powerpc/platforms/pseries/vio.c b/arch/powerpc/platforms/pseries/vio.c
index 2c8fb3ec989e..720493932486 100644
--- a/arch/powerpc/platforms/pseries/vio.c
+++ b/arch/powerpc/platforms/pseries/vio.c
@@ -615,7 +615,7 @@ static u64 vio_dma_get_required_mask(struct device *dev)
         return dma_iommu_ops.get_required_mask(dev);
 }
 
-static struct dma_map_ops vio_dma_mapping_ops = {
+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,
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 2ef031bee7ab..d5c1073a2584 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -137,6 +137,7 @@ config S390
 	select HAVE_DEBUG_KMEMLEAK
 	select HAVE_DMA_API_DEBUG
 	select HAVE_DMA_CONTIGUOUS
+	select DMA_NOOP_OPS
 	select HAVE_DYNAMIC_FTRACE
 	select HAVE_DYNAMIC_FTRACE_WITH_REGS
 	select HAVE_EFFICIENT_UNALIGNED_ACCESS
diff --git a/arch/s390/include/asm/device.h b/arch/s390/include/asm/device.h
index 4a9f35e0973f..5203fc87f080 100644
--- a/arch/s390/include/asm/device.h
+++ b/arch/s390/include/asm/device.h
@@ -4,7 +4,6 @@
  * This file is released under the GPLv2
  */
 struct dev_archdata {
-	struct dma_map_ops *dma_ops;
 };
 
 struct pdev_archdata {
diff --git a/arch/s390/include/asm/dma-mapping.h b/arch/s390/include/asm/dma-mapping.h
index ffaba07f50ab..3108b8dbe266 100644
--- a/arch/s390/include/asm/dma-mapping.h
+++ b/arch/s390/include/asm/dma-mapping.h
@@ -10,12 +10,10 @@
 
 #define DMA_ERROR_CODE		(~(dma_addr_t) 0x0)
 
-extern struct dma_map_ops s390_pci_dma_ops;
+extern const struct dma_map_ops s390_pci_dma_ops;
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
-	if (dev && dev->archdata.dma_ops)
-		return dev->archdata.dma_ops;
 	return &dma_noop_ops;
 }
 
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index 4c0fa9b3b2a0..364b9d824be3 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -641,7 +641,7 @@ int pcibios_add_device(struct pci_dev *pdev)
 	int i;
 
 	pdev->dev.groups = zpci_attr_groups;
-	pdev->dev.archdata.dma_ops = &s390_pci_dma_ops;
+	pdev->dev.dma_ops = &s390_pci_dma_ops;
 	zpci_map_resources(pdev);
 
 	for (i = 0; i < PCI_BAR_COUNT; i++) {
diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c
index 1d7a9c71944a..9081a57fa340 100644
--- a/arch/s390/pci/pci_dma.c
+++ b/arch/s390/pci/pci_dma.c
@@ -650,7 +650,7 @@ static int __init dma_debug_do_init(void)
 }
 fs_initcall(dma_debug_do_init);
 
-struct dma_map_ops s390_pci_dma_ops = {
+const struct dma_map_ops s390_pci_dma_ops = {
 	.alloc		= s390_dma_alloc,
 	.free		= s390_dma_free,
 	.map_sg		= s390_dma_map_sg,
diff --git a/arch/sh/include/asm/dma-mapping.h b/arch/sh/include/asm/dma-mapping.h
index 0052ad40e86d..d99008af5f73 100644
--- a/arch/sh/include/asm/dma-mapping.h
+++ b/arch/sh/include/asm/dma-mapping.h
@@ -1,10 +1,10 @@
 #ifndef __ASM_SH_DMA_MAPPING_H
 #define __ASM_SH_DMA_MAPPING_H
 
-extern struct dma_map_ops *dma_ops;
+extern const struct dma_map_ops *dma_ops;
 extern void no_iommu_init(void);
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
 	return dma_ops;
 }
diff --git a/arch/sh/kernel/dma-nommu.c b/arch/sh/kernel/dma-nommu.c
index 47fee3b6e29c..d24c707b2181 100644
--- a/arch/sh/kernel/dma-nommu.c
+++ b/arch/sh/kernel/dma-nommu.c
@@ -65,7 +65,7 @@ static void nommu_sync_sg(struct device *dev, struct scatterlist *sg,
 }
 #endif
 
-struct dma_map_ops nommu_dma_ops = {
+const struct dma_map_ops nommu_dma_ops = {
 	.alloc			= dma_generic_alloc_coherent,
 	.free			= dma_generic_free_coherent,
 	.map_page		= nommu_map_page,
diff --git a/arch/sh/mm/consistent.c b/arch/sh/mm/consistent.c
index 92b6976fde59..d1275adfa0ef 100644
--- a/arch/sh/mm/consistent.c
+++ b/arch/sh/mm/consistent.c
@@ -22,7 +22,7 @@
 
 #define PREALLOC_DMA_DEBUG_ENTRIES	4096
 
-struct dma_map_ops *dma_ops;
+const struct dma_map_ops *dma_ops;
 EXPORT_SYMBOL(dma_ops);
 
 static int __init dma_init(void)
diff --git a/arch/sparc/include/asm/dma-mapping.h b/arch/sparc/include/asm/dma-mapping.h
index 1180ae254154..69cc627779f2 100644
--- a/arch/sparc/include/asm/dma-mapping.h
+++ b/arch/sparc/include/asm/dma-mapping.h
@@ -18,20 +18,20 @@ static inline void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
 	 */
 }
 
-extern struct dma_map_ops *dma_ops;
-extern struct dma_map_ops *leon_dma_ops;
-extern struct dma_map_ops pci32_dma_ops;
+extern const struct dma_map_ops *dma_ops;
+extern const struct dma_map_ops *leon_dma_ops;
+extern const struct dma_map_ops pci32_dma_ops;
 
 extern struct bus_type pci_bus_type;
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
 #ifdef CONFIG_SPARC_LEON
 	if (sparc_cpu_model == sparc_leon)
 		return leon_dma_ops;
 #endif
 #if defined(CONFIG_SPARC32) && defined(CONFIG_PCI)
-	if (dev->bus == &pci_bus_type)
+	if (bus == &pci_bus_type)
 		return &pci32_dma_ops;
 #endif
 	return dma_ops;
diff --git a/arch/sparc/kernel/iommu.c b/arch/sparc/kernel/iommu.c
index 9df997995f6b..c63ba99ca551 100644
--- a/arch/sparc/kernel/iommu.c
+++ b/arch/sparc/kernel/iommu.c
@@ -741,7 +741,7 @@ static void dma_4u_sync_sg_for_cpu(struct device *dev,
 	spin_unlock_irqrestore(&iommu->lock, flags);
 }
 
-static struct dma_map_ops sun4u_dma_ops = {
+static const struct dma_map_ops sun4u_dma_ops = {
 	.alloc			= dma_4u_alloc_coherent,
 	.free			= dma_4u_free_coherent,
 	.map_page		= dma_4u_map_page,
@@ -752,7 +752,7 @@ static struct dma_map_ops sun4u_dma_ops = {
 	.sync_sg_for_cpu	= dma_4u_sync_sg_for_cpu,
 };
 
-struct dma_map_ops *dma_ops = &sun4u_dma_ops;
+const struct dma_map_ops *dma_ops = &sun4u_dma_ops;
 EXPORT_SYMBOL(dma_ops);
 
 int dma_supported(struct device *dev, u64 device_mask)
diff --git a/arch/sparc/kernel/ioport.c b/arch/sparc/kernel/ioport.c
index 6ffaec44931a..cf20033a1458 100644
--- a/arch/sparc/kernel/ioport.c
+++ b/arch/sparc/kernel/ioport.c
@@ -401,7 +401,7 @@ static void sbus_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
 	BUG();
 }
 
-static struct dma_map_ops sbus_dma_ops = {
+static const struct dma_map_ops sbus_dma_ops = {
 	.alloc			= sbus_alloc_coherent,
 	.free			= sbus_free_coherent,
 	.map_page		= sbus_map_page,
@@ -637,7 +637,7 @@ static void pci32_sync_sg_for_device(struct device *device, struct scatterlist *
 	}
 }
 
-struct dma_map_ops pci32_dma_ops = {
+const struct dma_map_ops pci32_dma_ops = {
 	.alloc			= pci32_alloc_coherent,
 	.free			= pci32_free_coherent,
 	.map_page		= pci32_map_page,
@@ -652,10 +652,10 @@ struct dma_map_ops pci32_dma_ops = {
 EXPORT_SYMBOL(pci32_dma_ops);
 
 /* leon re-uses pci32_dma_ops */
-struct dma_map_ops *leon_dma_ops = &pci32_dma_ops;
+const struct dma_map_ops *leon_dma_ops = &pci32_dma_ops;
 EXPORT_SYMBOL(leon_dma_ops);
 
-struct dma_map_ops *dma_ops = &sbus_dma_ops;
+const struct dma_map_ops *dma_ops = &sbus_dma_ops;
 EXPORT_SYMBOL(dma_ops);
 
 
diff --git a/arch/sparc/kernel/pci_sun4v.c b/arch/sparc/kernel/pci_sun4v.c
index f4daccd12bf5..68bec7c97cb8 100644
--- a/arch/sparc/kernel/pci_sun4v.c
+++ b/arch/sparc/kernel/pci_sun4v.c
@@ -669,7 +669,7 @@ static void dma_4v_unmap_sg(struct device *dev, struct scatterlist *sglist,
 	local_irq_restore(flags);
 }
 
-static struct dma_map_ops sun4v_dma_ops = {
+static const struct dma_map_ops sun4v_dma_ops = {
 	.alloc				= dma_4v_alloc_coherent,
 	.free				= dma_4v_free_coherent,
 	.map_page			= dma_4v_map_page,
diff --git a/arch/tile/include/asm/device.h b/arch/tile/include/asm/device.h
index 6ab8bf146d4c..1cf45422a0df 100644
--- a/arch/tile/include/asm/device.h
+++ b/arch/tile/include/asm/device.h
@@ -17,9 +17,6 @@
 #define _ASM_TILE_DEVICE_H
 
 struct dev_archdata {
-	/* DMA operations on that device */
-        struct dma_map_ops	*dma_ops;
-
 	/* Offset of the DMA address from the PA. */
 	dma_addr_t		dma_offset;
 
diff --git a/arch/tile/include/asm/dma-mapping.h b/arch/tile/include/asm/dma-mapping.h
index 01ceb4a895b0..bbc71a29b2c6 100644
--- a/arch/tile/include/asm/dma-mapping.h
+++ b/arch/tile/include/asm/dma-mapping.h
@@ -24,17 +24,14 @@
 #define ARCH_HAS_DMA_GET_REQUIRED_MASK
 #endif
 
-extern struct dma_map_ops *tile_dma_map_ops;
-extern struct dma_map_ops *gx_pci_dma_map_ops;
-extern struct dma_map_ops *gx_legacy_pci_dma_map_ops;
-extern struct dma_map_ops *gx_hybrid_pci_dma_map_ops;
+extern const struct dma_map_ops *tile_dma_map_ops;
+extern const struct dma_map_ops *gx_pci_dma_map_ops;
+extern const struct dma_map_ops *gx_legacy_pci_dma_map_ops;
+extern const struct dma_map_ops *gx_hybrid_pci_dma_map_ops;
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
-	if (dev && dev->archdata.dma_ops)
-		return dev->archdata.dma_ops;
-	else
-		return tile_dma_map_ops;
+	return tile_dma_map_ops;
 }
 
 static inline dma_addr_t get_dma_offset(struct device *dev)
@@ -59,11 +56,6 @@ static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
 
 static inline void dma_mark_clean(void *addr, size_t size) {}
 
-static inline void set_dma_ops(struct device *dev, struct dma_map_ops *ops)
-{
-	dev->archdata.dma_ops = ops;
-}
-
 static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
 {
 	if (!dev->dma_mask)
diff --git a/arch/tile/kernel/pci-dma.c b/arch/tile/kernel/pci-dma.c
index 24e0f8c21f2f..569bb6dd154a 100644
--- a/arch/tile/kernel/pci-dma.c
+++ b/arch/tile/kernel/pci-dma.c
@@ -329,7 +329,7 @@ tile_dma_supported(struct device *dev, u64 mask)
 	return 1;
 }
 
-static struct dma_map_ops tile_default_dma_map_ops = {
+static const struct dma_map_ops tile_default_dma_map_ops = {
 	.alloc = tile_dma_alloc_coherent,
 	.free = tile_dma_free_coherent,
 	.map_page = tile_dma_map_page,
@@ -344,7 +344,7 @@ static struct dma_map_ops tile_default_dma_map_ops = {
 	.dma_supported = tile_dma_supported
 };
 
-struct dma_map_ops *tile_dma_map_ops = &tile_default_dma_map_ops;
+const struct dma_map_ops *tile_dma_map_ops = &tile_default_dma_map_ops;
 EXPORT_SYMBOL(tile_dma_map_ops);
 
 /* Generic PCI DMA mapping functions */
@@ -516,7 +516,7 @@ tile_pci_dma_supported(struct device *dev, u64 mask)
 	return 1;
 }
 
-static struct dma_map_ops tile_pci_default_dma_map_ops = {
+static const struct dma_map_ops tile_pci_default_dma_map_ops = {
 	.alloc = tile_pci_dma_alloc_coherent,
 	.free = tile_pci_dma_free_coherent,
 	.map_page = tile_pci_dma_map_page,
@@ -531,7 +531,7 @@ static struct dma_map_ops tile_pci_default_dma_map_ops = {
 	.dma_supported = tile_pci_dma_supported
 };
 
-struct dma_map_ops *gx_pci_dma_map_ops = &tile_pci_default_dma_map_ops;
+const struct dma_map_ops *gx_pci_dma_map_ops = &tile_pci_default_dma_map_ops;
 EXPORT_SYMBOL(gx_pci_dma_map_ops);
 
 /* PCI DMA mapping functions for legacy PCI devices */
@@ -552,7 +552,7 @@ static void tile_swiotlb_free_coherent(struct device *dev, size_t size,
 	swiotlb_free_coherent(dev, size, vaddr, dma_addr);
 }
 
-static struct dma_map_ops pci_swiotlb_dma_ops = {
+static const struct dma_map_ops pci_swiotlb_dma_ops = {
 	.alloc = tile_swiotlb_alloc_coherent,
 	.free = tile_swiotlb_free_coherent,
 	.map_page = swiotlb_map_page,
@@ -567,7 +567,7 @@ static struct dma_map_ops pci_swiotlb_dma_ops = {
 	.mapping_error = swiotlb_dma_mapping_error,
 };
 
-static struct dma_map_ops pci_hybrid_dma_ops = {
+static const struct dma_map_ops pci_hybrid_dma_ops = {
 	.alloc = tile_swiotlb_alloc_coherent,
 	.free = tile_swiotlb_free_coherent,
 	.map_page = tile_pci_dma_map_page,
@@ -582,18 +582,18 @@ static struct dma_map_ops pci_hybrid_dma_ops = {
 	.dma_supported = tile_pci_dma_supported
 };
 
-struct dma_map_ops *gx_legacy_pci_dma_map_ops = &pci_swiotlb_dma_ops;
-struct dma_map_ops *gx_hybrid_pci_dma_map_ops = &pci_hybrid_dma_ops;
+const struct dma_map_ops *gx_legacy_pci_dma_map_ops = &pci_swiotlb_dma_ops;
+const struct dma_map_ops *gx_hybrid_pci_dma_map_ops = &pci_hybrid_dma_ops;
 #else
-struct dma_map_ops *gx_legacy_pci_dma_map_ops;
-struct dma_map_ops *gx_hybrid_pci_dma_map_ops;
+const struct dma_map_ops *gx_legacy_pci_dma_map_ops;
+const struct dma_map_ops *gx_hybrid_pci_dma_map_ops;
 #endif
 EXPORT_SYMBOL(gx_legacy_pci_dma_map_ops);
 EXPORT_SYMBOL(gx_hybrid_pci_dma_map_ops);
 
 int dma_set_mask(struct device *dev, u64 mask)
 {
-	struct dma_map_ops *dma_ops = get_dma_ops(dev);
+	const struct dma_map_ops *dma_ops = get_dma_ops(dev);
 
 	/*
 	 * For PCI devices with 64-bit DMA addressing capability, promote
@@ -623,7 +623,7 @@ EXPORT_SYMBOL(dma_set_mask);
 #ifdef CONFIG_ARCH_HAS_DMA_SET_COHERENT_MASK
 int dma_set_coherent_mask(struct device *dev, u64 mask)
 {
-	struct dma_map_ops *dma_ops = get_dma_ops(dev);
+	const struct dma_map_ops *dma_ops = get_dma_ops(dev);
 
 	/*
 	 * For PCI devices with 64-bit DMA addressing capability, promote
diff --git a/arch/unicore32/include/asm/dma-mapping.h b/arch/unicore32/include/asm/dma-mapping.h
index 4749854afd03..518ba5848dd6 100644
--- a/arch/unicore32/include/asm/dma-mapping.h
+++ b/arch/unicore32/include/asm/dma-mapping.h
@@ -21,9 +21,9 @@
 #include <asm/memory.h>
 #include <asm/cacheflush.h>
 
-extern struct dma_map_ops swiotlb_dma_map_ops;
+extern const struct dma_map_ops swiotlb_dma_map_ops;
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
 	return &swiotlb_dma_map_ops;
 }
diff --git a/arch/unicore32/mm/dma-swiotlb.c b/arch/unicore32/mm/dma-swiotlb.c
index 3e9f6489ba38..525413d6690e 100644
--- a/arch/unicore32/mm/dma-swiotlb.c
+++ b/arch/unicore32/mm/dma-swiotlb.c
@@ -31,7 +31,7 @@ static void unicore_swiotlb_free_coherent(struct device *dev, size_t size,
 	swiotlb_free_coherent(dev, size, vaddr, dma_addr);
 }
 
-struct dma_map_ops swiotlb_dma_map_ops = {
+const struct dma_map_ops swiotlb_dma_map_ops = {
 	.alloc = unicore_swiotlb_alloc_coherent,
 	.free = unicore_swiotlb_free_coherent,
 	.map_sg = swiotlb_map_sg_attrs,
diff --git a/arch/x86/include/asm/device.h b/arch/x86/include/asm/device.h
index 684ed6c3aa67..1b3ef26e77df 100644
--- a/arch/x86/include/asm/device.h
+++ b/arch/x86/include/asm/device.h
@@ -2,9 +2,6 @@
 #define _ASM_X86_DEVICE_H
 
 struct dev_archdata {
-#ifdef CONFIG_X86_DEV_DMA_OPS
-	struct dma_map_ops *dma_ops;
-#endif
 #if defined(CONFIG_INTEL_IOMMU) || defined(CONFIG_AMD_IOMMU)
 	void *iommu; /* hook for IOMMU specific extension */
 #endif
@@ -13,7 +10,7 @@ struct dev_archdata {
 #if defined(CONFIG_X86_DEV_DMA_OPS) && defined(CONFIG_PCI_DOMAINS)
 struct dma_domain {
 	struct list_head node;
-	struct dma_map_ops *dma_ops;
+	const struct dma_map_ops *dma_ops;
 	int domain_nr;
 };
 void add_dma_domain(struct dma_domain *domain);
diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
index 44461626830e..08a0838b83fb 100644
--- a/arch/x86/include/asm/dma-mapping.h
+++ b/arch/x86/include/asm/dma-mapping.h
@@ -25,18 +25,11 @@ extern int iommu_merge;
 extern struct device x86_dma_fallback_dev;
 extern int panic_on_overflow;
 
-extern struct dma_map_ops *dma_ops;
+extern const struct dma_map_ops *dma_ops;
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
-#ifndef CONFIG_X86_DEV_DMA_OPS
 	return dma_ops;
-#else
-	if (unlikely(!dev) || !dev->archdata.dma_ops)
-		return dma_ops;
-	else
-		return dev->archdata.dma_ops;
-#endif
 }
 
 bool arch_dma_alloc_attrs(struct device **dev, gfp_t *gfp);
diff --git a/arch/x86/include/asm/iommu.h b/arch/x86/include/asm/iommu.h
index 345c99cef152..793869879464 100644
--- a/arch/x86/include/asm/iommu.h
+++ b/arch/x86/include/asm/iommu.h
@@ -1,7 +1,7 @@
 #ifndef _ASM_X86_IOMMU_H
 #define _ASM_X86_IOMMU_H
 
-extern struct dma_map_ops nommu_dma_ops;
+extern const struct dma_map_ops nommu_dma_ops;
 extern int force_iommu, no_iommu;
 extern int iommu_detected;
 extern int iommu_pass_through;
diff --git a/arch/x86/kernel/amd_gart_64.c b/arch/x86/kernel/amd_gart_64.c
index 63ff468a7986..82dfe32faaf4 100644
--- a/arch/x86/kernel/amd_gart_64.c
+++ b/arch/x86/kernel/amd_gart_64.c
@@ -695,7 +695,7 @@ static __init int init_amd_gatt(struct agp_kern_info *info)
 	return -1;
 }
 
-static struct dma_map_ops gart_dma_ops = {
+static const struct dma_map_ops gart_dma_ops = {
 	.map_sg				= gart_map_sg,
 	.unmap_sg			= gart_unmap_sg,
 	.map_page			= gart_map_page,
diff --git a/arch/x86/kernel/pci-calgary_64.c b/arch/x86/kernel/pci-calgary_64.c
index d47517941bbc..0c150c06fa5a 100644
--- a/arch/x86/kernel/pci-calgary_64.c
+++ b/arch/x86/kernel/pci-calgary_64.c
@@ -478,7 +478,7 @@ static void calgary_free_coherent(struct device *dev, size_t size,
 	free_pages((unsigned long)vaddr, get_order(size));
 }
 
-static struct dma_map_ops calgary_dma_ops = {
+static const struct dma_map_ops calgary_dma_ops = {
 	.alloc = calgary_alloc_coherent,
 	.free = calgary_free_coherent,
 	.map_sg = calgary_map_sg,
@@ -1177,7 +1177,7 @@ static int __init calgary_init(void)
 		tbl = find_iommu_table(&dev->dev);
 
 		if (translation_enabled(tbl))
-			dev->dev.archdata.dma_ops = &calgary_dma_ops;
+			dev->dev.dma_ops = &calgary_dma_ops;
 	}
 
 	return ret;
@@ -1201,7 +1201,7 @@ error:
 		calgary_disable_translation(dev);
 		calgary_free_bus(dev);
 		pci_dev_put(dev); /* Undo calgary_init_one()'s pci_dev_get() */
-		dev->dev.archdata.dma_ops = NULL;
+		dev->dev.dma_ops = NULL;
 	} while (1);
 
 	return ret;
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index d5c223c9cf11..3a216ec869cd 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -17,7 +17,7 @@
 
 static int forbid_dac __read_mostly;
 
-struct dma_map_ops *dma_ops = &nommu_dma_ops;
+const struct dma_map_ops *dma_ops = &nommu_dma_ops;
 EXPORT_SYMBOL(dma_ops);
 
 static int iommu_sac_force __read_mostly;
@@ -215,7 +215,7 @@ early_param("iommu", iommu_setup);
 
 int dma_supported(struct device *dev, u64 mask)
 {
-	struct dma_map_ops *ops = get_dma_ops(dev);
+	const struct dma_map_ops *ops = get_dma_ops(dev);
 
 #ifdef CONFIG_PCI
 	if (mask > 0xffffffff && forbid_dac > 0) {
diff --git a/arch/x86/kernel/pci-nommu.c b/arch/x86/kernel/pci-nommu.c
index 00e71ce396a8..a88952ef371c 100644
--- a/arch/x86/kernel/pci-nommu.c
+++ b/arch/x86/kernel/pci-nommu.c
@@ -88,7 +88,7 @@ static void nommu_sync_sg_for_device(struct device *dev,
 	flush_write_buffers();
 }
 
-struct dma_map_ops nommu_dma_ops = {
+const struct dma_map_ops nommu_dma_ops = {
 	.alloc			= dma_generic_alloc_coherent,
 	.free			= dma_generic_free_coherent,
 	.map_sg			= nommu_map_sg,
diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c
index 410efb2c7b80..1e23577e17cf 100644
--- a/arch/x86/kernel/pci-swiotlb.c
+++ b/arch/x86/kernel/pci-swiotlb.c
@@ -45,7 +45,7 @@ void x86_swiotlb_free_coherent(struct device *dev, size_t size,
 		dma_generic_free_coherent(dev, size, vaddr, dma_addr, attrs);
 }
 
-static struct dma_map_ops swiotlb_dma_ops = {
+static const struct dma_map_ops swiotlb_dma_ops = {
 	.mapping_error = swiotlb_dma_mapping_error,
 	.alloc = x86_swiotlb_alloc_coherent,
 	.free = x86_swiotlb_free_coherent,
diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
index a4fdfa7dcc1b..0cb52ae0a8f0 100644
--- a/arch/x86/pci/common.c
+++ b/arch/x86/pci/common.c
@@ -667,7 +667,7 @@ static void set_dma_domain_ops(struct pci_dev *pdev)
 	spin_lock(&dma_domain_list_lock);
 	list_for_each_entry(domain, &dma_domain_list, node) {
 		if (pci_domain_nr(pdev->bus) == domain->domain_nr) {
-			pdev->dev.archdata.dma_ops = domain->dma_ops;
+			pdev->dev.dma_ops = domain->dma_ops;
 			break;
 		}
 	}
diff --git a/arch/x86/pci/sta2x11-fixup.c b/arch/x86/pci/sta2x11-fixup.c
index 052c1cb76305..ec008e800b45 100644
--- a/arch/x86/pci/sta2x11-fixup.c
+++ b/arch/x86/pci/sta2x11-fixup.c
@@ -179,7 +179,7 @@ static void *sta2x11_swiotlb_alloc_coherent(struct device *dev,
 }
 
 /* We have our own dma_ops: the same as swiotlb but from alloc (above) */
-static struct dma_map_ops sta2x11_dma_ops = {
+static const struct dma_map_ops sta2x11_dma_ops = {
 	.alloc = sta2x11_swiotlb_alloc_coherent,
 	.free = x86_swiotlb_free_coherent,
 	.map_page = swiotlb_map_page,
@@ -203,7 +203,7 @@ static void sta2x11_setup_pdev(struct pci_dev *pdev)
 		return;
 	pci_set_consistent_dma_mask(pdev, STA2X11_AMBA_SIZE - 1);
 	pci_set_dma_mask(pdev, STA2X11_AMBA_SIZE - 1);
-	pdev->dev.archdata.dma_ops = &sta2x11_dma_ops;
+	pdev->dev.dma_ops = &sta2x11_dma_ops;
 
 	/* We must enable all devices as master, for audio DMA to work */
 	pci_set_master(pdev);
@@ -223,7 +223,7 @@ bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
 {
 	struct sta2x11_mapping *map;
 
-	if (dev->archdata.dma_ops != &sta2x11_dma_ops) {
+	if (dev->dma_ops != &sta2x11_dma_ops) {
 		if (!dev->dma_mask)
 			return false;
 		return addr + size - 1 <= *dev->dma_mask;
@@ -247,7 +247,7 @@ 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)
 {
-	if (dev->archdata.dma_ops != &sta2x11_dma_ops)
+	if (dev->dma_ops != &sta2x11_dma_ops)
 		return paddr;
 	return p2a(paddr, to_pci_dev(dev));
 }
@@ -259,7 +259,7 @@ 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)
 {
-	if (dev->archdata.dma_ops != &sta2x11_dma_ops)
+	if (dev->dma_ops != &sta2x11_dma_ops)
 		return daddr;
 	return a2p(daddr, to_pci_dev(dev));
 }
diff --git a/arch/x86/xen/pci-swiotlb-xen.c b/arch/x86/xen/pci-swiotlb-xen.c
index a0b36a9d5df1..42b08f8fc2ca 100644
--- a/arch/x86/xen/pci-swiotlb-xen.c
+++ b/arch/x86/xen/pci-swiotlb-xen.c
@@ -18,7 +18,7 @@
 
 int xen_swiotlb __read_mostly;
 
-static struct dma_map_ops xen_swiotlb_dma_ops = {
+static const struct dma_map_ops xen_swiotlb_dma_ops = {
 	.alloc = xen_swiotlb_alloc_coherent,
 	.free = xen_swiotlb_free_coherent,
 	.sync_single_for_cpu = xen_swiotlb_sync_single_for_cpu,
diff --git a/arch/xtensa/include/asm/device.h b/arch/xtensa/include/asm/device.h
index fe1f5c878493..1deeb8ebbb1b 100644
--- a/arch/xtensa/include/asm/device.h
+++ b/arch/xtensa/include/asm/device.h
@@ -6,11 +6,7 @@
 #ifndef _ASM_XTENSA_DEVICE_H
 #define _ASM_XTENSA_DEVICE_H
 
-struct dma_map_ops;
-
 struct dev_archdata {
-	/* DMA operations on that device */
-	struct dma_map_ops *dma_ops;
 };
 
 struct pdev_archdata {
diff --git a/arch/xtensa/include/asm/dma-mapping.h b/arch/xtensa/include/asm/dma-mapping.h
index 3fc1170a6488..c6140fa8c0be 100644
--- a/arch/xtensa/include/asm/dma-mapping.h
+++ b/arch/xtensa/include/asm/dma-mapping.h
@@ -18,14 +18,11 @@
 
 #define DMA_ERROR_CODE		(~(dma_addr_t)0x0)
 
-extern struct dma_map_ops xtensa_dma_map_ops;
+extern const struct dma_map_ops xtensa_dma_map_ops;
 
-static inline struct dma_map_ops *get_dma_ops(struct device *dev)
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 {
-	if (dev && dev->archdata.dma_ops)
-		return dev->archdata.dma_ops;
-	else
-		return &xtensa_dma_map_ops;
+	return &xtensa_dma_map_ops;
 }
 
 void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
diff --git a/arch/xtensa/kernel/pci-dma.c b/arch/xtensa/kernel/pci-dma.c
index 34c1f9fa6acc..cec86a1c2acc 100644
--- a/arch/xtensa/kernel/pci-dma.c
+++ b/arch/xtensa/kernel/pci-dma.c
@@ -250,7 +250,7 @@ int xtensa_dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 	return 0;
 }
 
-struct dma_map_ops xtensa_dma_map_ops = {
+const struct dma_map_ops xtensa_dma_map_ops = {
 	.alloc = xtensa_dma_alloc,
 	.free = xtensa_dma_free,
 	.map_page = xtensa_map_page,