Merge tag 'dma-mapping-5.1' of git://git.infradead.org/users/hch/dma-mapping

Pull DMA mapping updates from Christoph Hellwig:

 - add debugfs support for dumping dma-debug information (Corentin
   Labbe)

 - Kconfig cleanups (Andy Shevchenko and me)

 - debugfs cleanups (Greg Kroah-Hartman)

 - improve dma_map_resource and use it in the media code

 - arch_setup_dma_ops / arch_teardown_dma_ops cleanups

 - various small cleanups and improvements for the per-device coherent
   allocator

 - make the DMA mask an upper bound and don't fail "too large" dma mask
   in the remaning two architectures - this will allow big driver
   cleanups in the following merge windows

* tag 'dma-mapping-5.1' of git://git.infradead.org/users/hch/dma-mapping: (21 commits)
  Documentation/DMA-API-HOWTO: update dma_mask sections
  sparc64/pci_sun4v: allow large DMA masks
  sparc64/iommu: allow large DMA masks
  sparc64: refactor the ali DMA quirk
  ccio: allow large DMA masks
  dma-mapping: remove the DMA_MEMORY_EXCLUSIVE flag
  dma-mapping: remove dma_mark_declared_memory_occupied
  dma-mapping: move CONFIG_DMA_CMA to kernel/dma/Kconfig
  dma-mapping: improve selection of dma_declare_coherent availability
  dma-mapping: remove an incorrect __iommem annotation
  of: select OF_RESERVED_MEM automatically
  device.h: dma_mem is only needed for HAVE_GENERIC_DMA_COHERENT
  mfd/sm501: depend on HAS_DMA
  dma-mapping: add a kconfig symbol for arch_teardown_dma_ops availability
  dma-mapping: add a kconfig symbol for arch_setup_dma_ops availability
  dma-mapping: move debug configuration options to kernel/dma
  dma-debug: add dumping facility via debugfs
  dma: debug: no need to check return value of debugfs_create functions
  videobuf2: replace a layering violation with dma_map_resource
  dma-mapping: don't BUG when calling dma_map_resource on RAM
  ...

Documentation/DMA-API-HOWTO.txt

@@ -146,114 +146,75 @@ What about block I/O and networking buffers?  The block I/O and
 networking subsystems make sure that the buffers they use are valid
 for you to DMA from/to.
 
-DMA addressing limitations
+DMA addressing capabilities
 ==========================
 
-Does your device have any DMA addressing limitations?  For example, is
-your device only capable of driving the low order 24-bits of address?
-If so, you need to inform the kernel of this fact.
+By default, the kernel assumes that your device can address 32-bits of DMA
+addressing.  For a 64-bit capable device, this needs to be increased, and for
+a device with limitations, it needs to be decreased.
 
-By default, the kernel assumes that your device can address the full
-32-bits.  For a 64-bit capable device, this needs to be increased.
-And for a device with limitations, as discussed in the previous
-paragraph, it needs to be decreased.
+Special note about PCI: PCI-X specification requires PCI-X devices to support
+64-bit addressing (DAC) for all transactions.  And at least one platform (SGI
+SN2) requires 64-bit consistent allocations to operate correctly when the IO
+bus is in PCI-X mode.
 
-Special note about PCI: PCI-X specification requires PCI-X devices to
-support 64-bit addressing (DAC) for all transactions.  And at least
-one platform (SGI SN2) requires 64-bit consistent allocations to
-operate correctly when the IO bus is in PCI-X mode.
+For correct operation, you must set the DMA mask to inform the kernel about
+your devices DMA addressing capabilities.
 
-For correct operation, you must interrogate the kernel in your device
-probe routine to see if the DMA controller on the machine can properly
-support the DMA addressing limitation your device has.  It is good
-style to do this even if your device holds the default setting,
-because this shows that you did think about these issues wrt. your
-device.
-
-The query is performed via a call to dma_set_mask_and_coherent()::
+This is performed via a call to dma_set_mask_and_coherent()::
 
 	int dma_set_mask_and_coherent(struct device *dev, u64 mask);
 
-which will query the mask for both streaming and coherent APIs together.
-If you have some special requirements, then the following two separate
-queries can be used instead:
+which will set the mask for both streaming and coherent APIs together.  If you
+have some special requirements, then the following two separate calls can be
+used instead:
 
-	The query for streaming mappings is performed via a call to
+	The setup for streaming mappings is performed via a call to
 	dma_set_mask()::
 
 		int dma_set_mask(struct device *dev, u64 mask);
 
-	The query for consistent allocations is performed via a call
+	The setup for consistent allocations is performed via a call
 	to dma_set_coherent_mask()::
 
 		int dma_set_coherent_mask(struct device *dev, u64 mask);
 
-Here, dev is a pointer to the device struct of your device, and mask
-is a bit mask describing which bits of an address your device
-supports.  It returns zero if your card can perform DMA properly on
-the machine given the address mask you provided.  In general, the
-device struct of your device is embedded in the bus-specific device
-struct of your device.  For example, &pdev->dev is a pointer to the
-device struct of a PCI device (pdev is a pointer to the PCI device
-struct of your device).
+Here, dev is a pointer to the device struct of your device, and mask is a bit
+mask describing which bits of an address your device supports.  Often the
+device struct of your device is embedded in the bus-specific device struct of
+your device.  For example, &pdev->dev is a pointer to the device struct of a
+PCI device (pdev is a pointer to the PCI device struct of your device).
 
-If it returns non-zero, your device cannot perform DMA properly on
-this platform, and attempting to do so will result in undefined
-behavior.  You must either use a different mask, or not use DMA.
+These calls usually return zero to indicated your device can perform DMA
+properly on the machine given the address mask you provided, but they might
+return an error if the mask is too small to be supportable on the given
+system.  If it returns non-zero, your device cannot perform DMA properly on
+this platform, and attempting to do so will result in undefined behavior.
+You must not use DMA on this device unless the dma_set_mask family of
+functions has returned success.
 
-This means that in the failure case, you have three options:
+This means that in the failure case, you have two options:
 
-1) Use another DMA mask, if possible (see below).
-2) Use some non-DMA mode for data transfer, if possible.
-3) Ignore this device and do not initialize it.
+1) Use some non-DMA mode for data transfer, if possible.
+2) Ignore this device and do not initialize it.
 
-It is recommended that your driver print a kernel KERN_WARNING message
-when you end up performing either #2 or #3.  In this manner, if a user
-of your driver reports that performance is bad or that the device is not
-even detected, you can ask them for the kernel messages to find out
-exactly why.
+It is recommended that your driver print a kernel KERN_WARNING message when
+setting the DMA mask fails.  In this manner, if a user of your driver reports
+that performance is bad or that the device is not even detected, you can ask
+them for the kernel messages to find out exactly why.
 
-The standard 32-bit addressing device would do something like this::
+The standard 64-bit addressing device would do something like this::
 
-	if (dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32))) {
+	if (dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64))) {
 		dev_warn(dev, "mydev: No suitable DMA available\n");
 		goto ignore_this_device;
 	}
 
-Another common scenario is a 64-bit capable device.  The approach here
-is to try for 64-bit addressing, but back down to a 32-bit mask that
-should not fail.  The kernel may fail the 64-bit mask not because the
-platform is not capable of 64-bit addressing.  Rather, it may fail in
-this case simply because 32-bit addressing is done more efficiently
-than 64-bit addressing.  For example, Sparc64 PCI SAC addressing is
-more efficient than DAC addressing.
-
-Here is how you would handle a 64-bit capable device which can drive
-all 64-bits when accessing streaming DMA::
-
-	int using_dac;
+If the device only supports 32-bit addressing for descriptors in the
+coherent allocations, but supports full 64-bits for streaming mappings
+it would look like this:
 
-	if (!dma_set_mask(dev, DMA_BIT_MASK(64))) {
-		using_dac = 1;
-	} else if (!dma_set_mask(dev, DMA_BIT_MASK(32))) {
-		using_dac = 0;
-	} else {
-		dev_warn(dev, "mydev: No suitable DMA available\n");
-		goto ignore_this_device;
-	}
-
-If a card is capable of using 64-bit consistent allocations as well,
-the case would look like this::
-
-	int using_dac, consistent_using_dac;
-
-	if (!dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64))) {
-		using_dac = 1;
-		consistent_using_dac = 1;
-	} else if (!dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32))) {
-		using_dac = 0;
-		consistent_using_dac = 0;
-	} else {
+	if (dma_set_mask(dev, DMA_BIT_MASK(64))) {
 		dev_warn(dev, "mydev: No suitable DMA available\n");
 		goto ignore_this_device;
 	}

Documentation/DMA-API.txt

@@ -566,8 +566,7 @@ boundaries when doing this.
 
 	int
 	dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
-				    dma_addr_t device_addr, size_t size, int
-				    flags)
+				    dma_addr_t device_addr, size_t size);
 
 Declare region of memory to be handed out by dma_alloc_coherent() when
 it's asked for coherent memory for this device.
@@ -581,12 +580,6 @@ dma_addr_t in dma_alloc_coherent()).
 
 size is the size of the area (must be multiples of PAGE_SIZE).
 
-flags can be ORed together and are:
-
-- DMA_MEMORY_EXCLUSIVE - only allocate memory from the declared regions.
-  Do not allow dma_alloc_coherent() to fall back to system memory when
-  it's out of memory in the declared region.
-
 As a simplification for the platforms, only *one* such region of
 memory may be declared per device.
 
@@ -605,23 +598,6 @@ unconditionally having removed all the required structures.  It is the
 driver's job to ensure that no parts of this memory region are
 currently in use.
 
-::
-
-	void *
-	dma_mark_declared_memory_occupied(struct device *dev,
-					  dma_addr_t device_addr, size_t size)
-
-This is used to occupy specific regions of the declared space
-(dma_alloc_coherent() will hand out the first free region it finds).
-
-device_addr is the *device* address of the region requested.
-
-size is the size (and should be a page-sized multiple).
-
-The return value will be either a pointer to the processor virtual
-address of the memory, or an error (via PTR_ERR()) if any part of the
-region is occupied.
-
 Part III - Debug drivers use of the DMA-API
 -------------------------------------------
 
@@ -696,6 +672,9 @@ dma-api/disabled		This read-only file contains the character 'Y'
 				happen when it runs out of memory or if it was
 				disabled at boot time
 
+dma-api/dump			This read-only file contains current DMA
+				mappings.
+
 dma-api/error_count		This file is read-only and shows the total
 				numbers of errors found.
 

arch/arc/Kconfig

@@ -11,6 +11,7 @@ config ARC
 	select ARC_TIMERS
 	select ARCH_HAS_DMA_COHERENT_TO_PFN
 	select ARCH_HAS_PTE_SPECIAL
+	select ARCH_HAS_SETUP_DMA_OPS
 	select ARCH_HAS_SYNC_DMA_FOR_CPU
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
 	select ARCH_SUPPORTS_ATOMIC_RMW if ARC_HAS_LLSC
@@ -31,7 +32,6 @@ config ARC
 	select HAVE_ARCH_TRACEHOOK
 	select HAVE_DEBUG_STACKOVERFLOW
 	select HAVE_FUTEX_CMPXCHG if FUTEX
-	select HAVE_GENERIC_DMA_COHERENT
 	select HAVE_IOREMAP_PROT
 	select HAVE_KERNEL_GZIP
 	select HAVE_KERNEL_LZMA
@@ -45,7 +45,6 @@ config ARC
 	select MODULES_USE_ELF_RELA
 	select OF
 	select OF_EARLY_FLATTREE
-	select OF_RESERVED_MEM
 	select PCI_SYSCALL if PCI
 	select PERF_USE_VMALLOC if ARC_CACHE_VIPT_ALIASING
 

arch/arc/include/asm/Kbuild

@@ -3,6 +3,7 @@ generic-y += bugs.h
 generic-y += compat.h
 generic-y += device.h
 generic-y += div64.h
+generic-y += dma-mapping.h
 generic-y += emergency-restart.h
 generic-y += extable.h
 generic-y += ftrace.h

arch/arc/include/asm/dma-mapping.h

-// SPDX-License-Identifier:  GPL-2.0
-// (C) 2018 Synopsys, Inc. (www.synopsys.com)
-
-#ifndef ASM_ARC_DMA_MAPPING_H
-#define ASM_ARC_DMA_MAPPING_H
-
-#include <asm-generic/dma-mapping.h>
-
-void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
-			const struct iommu_ops *iommu, bool coherent);
-#define arch_setup_dma_ops arch_setup_dma_ops
-
-#endif

arch/arm/Kconfig

@@ -13,9 +13,11 @@ config ARM
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
 	select ARCH_HAS_PTE_SPECIAL if ARM_LPAE
 	select ARCH_HAS_PHYS_TO_DMA
+	select ARCH_HAS_SETUP_DMA_OPS
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_STRICT_KERNEL_RWX if MMU && !XIP_KERNEL
 	select ARCH_HAS_STRICT_MODULE_RWX if MMU
+	select ARCH_HAS_TEARDOWN_DMA_OPS if MMU
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_HAVE_CUSTOM_GPIO_H
 	select ARCH_HAS_GCOV_PROFILE_ALL
@@ -31,6 +33,7 @@ config ARM
 	select CLONE_BACKWARDS
 	select CPU_PM if SUSPEND || CPU_IDLE
 	select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS
+	select DMA_DECLARE_COHERENT
 	select DMA_REMAP if MMU
 	select EDAC_SUPPORT
 	select EDAC_ATOMIC_SCRUB
@@ -73,7 +76,6 @@ config ARM
 	select HAVE_FUNCTION_GRAPH_TRACER if !THUMB2_KERNEL
 	select HAVE_FUNCTION_TRACER if !XIP_KERNEL
 	select HAVE_GCC_PLUGINS
-	select HAVE_GENERIC_DMA_COHERENT
 	select HAVE_HW_BREAKPOINT if PERF_EVENTS && (CPU_V6 || CPU_V6K || CPU_V7)
 	select HAVE_IDE if PCI || ISA || PCMCIA
 	select HAVE_IRQ_TIME_ACCOUNTING
@@ -102,7 +104,6 @@ config ARM
 	select MODULES_USE_ELF_REL
 	select NEED_DMA_MAP_STATE
 	select OF_EARLY_FLATTREE if OF
-	select OF_RESERVED_MEM if OF
 	select OLD_SIGACTION
 	select OLD_SIGSUSPEND3
 	select PCI_SYSCALL if PCI

arch/arm/include/asm/dma-mapping.h

@@ -96,15 +96,6 @@ static inline unsigned long dma_max_pfn(struct device *dev)
 }
 #define dma_max_pfn(dev) dma_max_pfn(dev)
 
-#define arch_setup_dma_ops arch_setup_dma_ops
-extern void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
-			       const struct iommu_ops *iommu, bool coherent);
-
-#ifdef CONFIG_MMU
-#define arch_teardown_dma_ops arch_teardown_dma_ops
-extern void arch_teardown_dma_ops(struct device *dev);
-#endif
-
 /* do not use this function in a driver */
 static inline bool is_device_dma_coherent(struct device *dev)
 {

arch/arm/mach-imx/mach-imx27_visstrim_m10.c

@@ -258,8 +258,7 @@ static void __init visstrim_analog_camera_init(void)
 		return;
 
 	dma_declare_coherent_memory(&pdev->dev, mx2_camera_base,
-				    mx2_camera_base, MX2_CAMERA_BUF_SIZE,
-				    DMA_MEMORY_EXCLUSIVE);
+				    mx2_camera_base, MX2_CAMERA_BUF_SIZE);
 }
 
 static void __init visstrim_reserve(void)
@@ -445,8 +444,7 @@ static void __init visstrim_coda_init(void)
 	dma_declare_coherent_memory(&pdev->dev,
 				    mx2_camera_base + MX2_CAMERA_BUF_SIZE,
 				    mx2_camera_base + MX2_CAMERA_BUF_SIZE,
-				    MX2_CAMERA_BUF_SIZE,
-				    DMA_MEMORY_EXCLUSIVE);
+				    MX2_CAMERA_BUF_SIZE);
 }
 
 /* DMA deinterlace */
@@ -465,8 +463,7 @@ static void __init visstrim_deinterlace_init(void)
 	dma_declare_coherent_memory(&pdev->dev,
 				    mx2_camera_base + 2 * MX2_CAMERA_BUF_SIZE,
 				    mx2_camera_base + 2 * MX2_CAMERA_BUF_SIZE,
-				    MX2_CAMERA_BUF_SIZE,
-				    DMA_MEMORY_EXCLUSIVE);
+				    MX2_CAMERA_BUF_SIZE);
 }
 
 /* Emma-PrP for format conversion */
@@ -485,8 +482,7 @@ static void __init visstrim_emmaprp_init(void)
 	 */
 	ret = dma_declare_coherent_memory(&pdev->dev,
 				mx2_camera_base, mx2_camera_base,
-				MX2_CAMERA_BUF_SIZE,
-				DMA_MEMORY_EXCLUSIVE);
+				MX2_CAMERA_BUF_SIZE);
 	if (ret)
 		pr_err("Failed to declare memory for emmaprp\n");
 }

arch/arm/mach-imx/mach-mx31moboard.c

@@ -475,8 +475,7 @@ static int __init mx31moboard_init_cam(void)
 
 	ret = dma_declare_coherent_memory(&pdev->dev,
 					  mx3_camera_base, mx3_camera_base,
-					  MX3_CAMERA_BUF_SIZE,
-					  DMA_MEMORY_EXCLUSIVE);
+					  MX3_CAMERA_BUF_SIZE);
 	if (ret)
 		goto err;
 

arch/arm/mm/dma-mapping.c

@@ -188,6 +188,7 @@ const struct dma_map_ops arm_dma_ops = {
 	.unmap_page		= arm_dma_unmap_page,
 	.map_sg			= arm_dma_map_sg,
 	.unmap_sg		= arm_dma_unmap_sg,
+	.map_resource		= dma_direct_map_resource,
 	.sync_single_for_cpu	= arm_dma_sync_single_for_cpu,
 	.sync_single_for_device	= arm_dma_sync_single_for_device,
 	.sync_sg_for_cpu	= arm_dma_sync_sg_for_cpu,
@@ -211,6 +212,7 @@ const struct dma_map_ops arm_coherent_dma_ops = {
 	.get_sgtable		= arm_dma_get_sgtable,
 	.map_page		= arm_coherent_dma_map_page,
 	.map_sg			= arm_dma_map_sg,
+	.map_resource		= dma_direct_map_resource,
 	.dma_supported		= arm_dma_supported,
 };
 EXPORT_SYMBOL(arm_coherent_dma_ops);

arch/arm64/Kconfig

@@ -22,12 +22,14 @@ config ARM64
 	select ARCH_HAS_KCOV
 	select ARCH_HAS_MEMBARRIER_SYNC_CORE
 	select ARCH_HAS_PTE_SPECIAL
+	select ARCH_HAS_SETUP_DMA_OPS
 	select ARCH_HAS_SET_MEMORY
 	select ARCH_HAS_STRICT_KERNEL_RWX
 	select ARCH_HAS_STRICT_MODULE_RWX
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
 	select ARCH_HAS_SYNC_DMA_FOR_CPU
 	select ARCH_HAS_SYSCALL_WRAPPER
+	select ARCH_HAS_TEARDOWN_DMA_OPS if IOMMU_SUPPORT
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select ARCH_INLINE_READ_LOCK if !PREEMPT
@@ -137,7 +139,6 @@ config ARM64
 	select HAVE_FUNCTION_TRACER
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_GCC_PLUGINS
-	select HAVE_GENERIC_DMA_COHERENT
 	select HAVE_HW_BREAKPOINT if PERF_EVENTS
 	select HAVE_IRQ_TIME_ACCOUNTING
 	select HAVE_MEMBLOCK_NODE_MAP if NUMA
@@ -163,7 +164,6 @@ config ARM64
 	select NEED_SG_DMA_LENGTH
 	select OF
 	select OF_EARLY_FLATTREE
-	select OF_RESERVED_MEM
 	select PCI_DOMAINS_GENERIC if PCI
 	select PCI_ECAM if (ACPI && PCI)
 	select PCI_SYSCALL if PCI

arch/arm64/include/asm/dma-mapping.h

@@ -29,15 +29,6 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 	return NULL;
 }
 
-void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
-			const struct iommu_ops *iommu, bool coherent);
-#define arch_setup_dma_ops	arch_setup_dma_ops
-
-#ifdef CONFIG_IOMMU_DMA
-void arch_teardown_dma_ops(struct device *dev);
-#define arch_teardown_dma_ops	arch_teardown_dma_ops
-#endif
-
 /*
  * Do not use this function in a driver, it is only provided for
  * arch/arm/mm/xen.c, which is used by arm64 as well.

arch/csky/Kconfig

@@ -31,7 +31,6 @@ config CSKY
 	select HAVE_ARCH_TRACEHOOK
 	select HAVE_FUNCTION_TRACER
 	select HAVE_FUNCTION_GRAPH_TRACER
-	select HAVE_GENERIC_DMA_COHERENT
 	select HAVE_KERNEL_GZIP
 	select HAVE_KERNEL_LZO
 	select HAVE_KERNEL_LZMA
@@ -43,7 +42,6 @@ config CSKY
 	select MODULES_USE_ELF_RELA if MODULES
 	select OF
 	select OF_EARLY_FLATTREE
-	select OF_RESERVED_MEM
 	select PERF_USE_VMALLOC if CPU_CK610
 	select RTC_LIB
 	select TIMER_OF

arch/mips/Kconfig

@@ -57,7 +57,6 @@ config MIPS
 	select HAVE_FTRACE_MCOUNT_RECORD
 	select HAVE_FUNCTION_GRAPH_TRACER
 	select HAVE_FUNCTION_TRACER
-	select HAVE_GENERIC_DMA_COHERENT
 	select HAVE_IDE
 	select HAVE_IOREMAP_PROT
 	select HAVE_IRQ_EXIT_ON_IRQ_STACK
@@ -1119,6 +1118,7 @@ config DMA_MAYBE_COHERENT
 
 config DMA_PERDEV_COHERENT
 	bool
+	select ARCH_HAS_SETUP_DMA_OPS
 	select DMA_NONCOHERENT
 
 config DMA_NONCOHERENT

arch/mips/include/asm/dma-mapping.h

@@ -15,14 +15,4 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 #endif
 }
 
-#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,
-				      bool coherent)
-{
-#ifdef CONFIG_DMA_PERDEV_COHERENT
-	dev->dma_coherent = coherent;
-#endif
-}
-
 #endif /* _ASM_DMA_MAPPING_H */

arch/mips/mm/dma-noncoherent.c

@@ -156,3 +156,11 @@ void arch_dma_cache_sync(struct device *dev, void *vaddr, size_t size,
 
 	dma_sync_virt(vaddr, size, direction);
 }
+
+#ifdef CONFIG_DMA_PERDEV_COHERENT
+void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
+		const struct iommu_ops *iommu, bool coherent)
+{
+	dev->dma_coherent = coherent;
+}
+#endif

arch/powerpc/Kconfig

@@ -232,7 +232,6 @@ config PPC
 	select NEED_SG_DMA_LENGTH
 	select OF
 	select OF_EARLY_FLATTREE
-	select OF_RESERVED_MEM
 	select OLD_SIGACTION			if PPC32
 	select OLD_SIGSUSPEND
 	select PCI_DOMAINS			if PCI

arch/riscv/Kconfig

@@ -32,7 +32,6 @@ config RISCV
 	select HAVE_MEMBLOCK_NODE_MAP
 	select HAVE_DMA_CONTIGUOUS
 	select HAVE_FUTEX_CMPXCHG if FUTEX
-	select HAVE_GENERIC_DMA_COHERENT
 	select HAVE_PERF_EVENTS
 	select HAVE_SYSCALL_TRACEPOINTS
 	select IRQ_DOMAIN

arch/sh/Kconfig

@@ -7,11 +7,11 @@ config SUPERH
 	select ARCH_NO_COHERENT_DMA_MMAP if !MMU
 	select HAVE_PATA_PLATFORM
 	select CLKDEV_LOOKUP
+	select DMA_DECLARE_COHERENT
 	select HAVE_IDE if HAS_IOPORT_MAP
 	select HAVE_MEMBLOCK_NODE_MAP
 	select ARCH_DISCARD_MEMBLOCK
 	select HAVE_OPROFILE
-	select HAVE_GENERIC_DMA_COHERENT
 	select HAVE_ARCH_TRACEHOOK
 	select HAVE_PERF_EVENTS
 	select HAVE_DEBUG_BUGVERBOSE

arch/sh/boards/mach-ap325rxa/setup.c

@@ -529,9 +529,8 @@ static int __init ap325rxa_devices_setup(void)
 	device_initialize(&ap325rxa_ceu_device.dev);
 	arch_setup_pdev_archdata(&ap325rxa_ceu_device);
 	dma_declare_coherent_memory(&ap325rxa_ceu_device.dev,
-				    ceu_dma_membase, ceu_dma_membase,
-				    ceu_dma_membase + CEU_BUFFER_MEMORY_SIZE - 1,
-				    DMA_MEMORY_EXCLUSIVE);
+			ceu_dma_membase, ceu_dma_membase,
+			ceu_dma_membase + CEU_BUFFER_MEMORY_SIZE - 1);
 
 	platform_device_add(&ap325rxa_ceu_device);
 

arch/sh/boards/mach-ecovec24/setup.c

@@ -1438,8 +1438,7 @@ static int __init arch_setup(void)
 	dma_declare_coherent_memory(&ecovec_ceu_devices[0]->dev,
 				    ceu0_dma_membase, ceu0_dma_membase,
 				    ceu0_dma_membase +
-				    CEU_BUFFER_MEMORY_SIZE - 1,
-				    DMA_MEMORY_EXCLUSIVE);
+				    CEU_BUFFER_MEMORY_SIZE - 1);
 	platform_device_add(ecovec_ceu_devices[0]);
 
 	device_initialize(&ecovec_ceu_devices[1]->dev);
@@ -1447,8 +1446,7 @@ static int __init arch_setup(void)
 	dma_declare_coherent_memory(&ecovec_ceu_devices[1]->dev,
 				    ceu1_dma_membase, ceu1_dma_membase,
 				    ceu1_dma_membase +
-				    CEU_BUFFER_MEMORY_SIZE - 1,
-				    DMA_MEMORY_EXCLUSIVE);
+				    CEU_BUFFER_MEMORY_SIZE - 1);
 	platform_device_add(ecovec_ceu_devices[1]);
 
 	gpiod_add_lookup_table(&cn12_power_gpiod_table);

arch/sh/boards/mach-kfr2r09/setup.c

@@ -603,9 +603,8 @@ static int __init kfr2r09_devices_setup(void)
 	device_initialize(&kfr2r09_ceu_device.dev);
 	arch_setup_pdev_archdata(&kfr2r09_ceu_device);
 	dma_declare_coherent_memory(&kfr2r09_ceu_device.dev,
-				    ceu_dma_membase, ceu_dma_membase,
-				    ceu_dma_membase + CEU_BUFFER_MEMORY_SIZE - 1,
-				    DMA_MEMORY_EXCLUSIVE);
+			ceu_dma_membase, ceu_dma_membase,
+			ceu_dma_membase + CEU_BUFFER_MEMORY_SIZE - 1);
 
 	platform_device_add(&kfr2r09_ceu_device);
 

arch/sh/boards/mach-migor/setup.c

@@ -604,9 +604,8 @@ static int __init migor_devices_setup(void)
 	device_initialize(&migor_ceu_device.dev);
 	arch_setup_pdev_archdata(&migor_ceu_device);
 	dma_declare_coherent_memory(&migor_ceu_device.dev,
-				    ceu_dma_membase, ceu_dma_membase,
-				    ceu_dma_membase + CEU_BUFFER_MEMORY_SIZE - 1,
-				    DMA_MEMORY_EXCLUSIVE);
+			ceu_dma_membase, ceu_dma_membase,
+			ceu_dma_membase + CEU_BUFFER_MEMORY_SIZE - 1);
 
 	platform_device_add(&migor_ceu_device);
 

arch/sh/boards/mach-se/7724/setup.c

@@ -941,8 +941,7 @@ static int __init devices_setup(void)
 	dma_declare_coherent_memory(&ms7724se_ceu_devices[0]->dev,
 				    ceu0_dma_membase, ceu0_dma_membase,
 				    ceu0_dma_membase +
-				    CEU_BUFFER_MEMORY_SIZE - 1,
-				    DMA_MEMORY_EXCLUSIVE);
+				    CEU_BUFFER_MEMORY_SIZE - 1);
 	platform_device_add(ms7724se_ceu_devices[0]);
 
 	device_initialize(&ms7724se_ceu_devices[1]->dev);
@@ -950,8 +949,7 @@ static int __init devices_setup(void)
 	dma_declare_coherent_memory(&ms7724se_ceu_devices[1]->dev,
 				    ceu1_dma_membase, ceu1_dma_membase,
 				    ceu1_dma_membase +
-				    CEU_BUFFER_MEMORY_SIZE - 1,
-				    DMA_MEMORY_EXCLUSIVE);
+				    CEU_BUFFER_MEMORY_SIZE - 1);
 	platform_device_add(ms7724se_ceu_devices[1]);
 
 	return platform_add_devices(ms7724se_devices,

arch/sh/drivers/pci/fixups-dreamcast.c

@@ -63,8 +63,7 @@ static void gapspci_fixup_resources(struct pci_dev *dev)
 		BUG_ON(dma_declare_coherent_memory(&dev->dev,
 						res.start,
 						region.start,
-						resource_size(&res),
-						DMA_MEMORY_EXCLUSIVE));
+						resource_size(&res)));
 		break;
 	default:
 		printk("PCI: Failed resource fixup\n");

arch/sparc/kernel/iommu.c

@@ -745,15 +745,12 @@ static int dma_4u_supported(struct device *dev, u64 device_mask)
 {
 	struct iommu *iommu = dev->archdata.iommu;
 
-	if (device_mask > DMA_BIT_MASK(32))
-		return 0;
-	if ((device_mask & iommu->dma_addr_mask) == iommu->dma_addr_mask)
+	if (ali_sound_dma_hack(dev, device_mask))
 		return 1;
-#ifdef CONFIG_PCI
-	if (dev_is_pci(dev))
-		return pci64_dma_supported(to_pci_dev(dev), device_mask);
-#endif
-	return 0;
+
+	if (device_mask < iommu->dma_addr_mask)
+		return 0;
+	return 1;
 }
 
 static const struct dma_map_ops sun4u_dma_ops = {

arch/sparc/kernel/kernel.h

@@ -45,7 +45,11 @@ void __irq_entry smp_receive_signal_client(int irq, struct pt_regs *regs);
 void __irq_entry smp_kgdb_capture_client(int irq, struct pt_regs *regs);
 
 /* pci.c */
-int pci64_dma_supported(struct pci_dev *pdev, u64 device_mask);
+#ifdef CONFIG_PCI
+int ali_sound_dma_hack(struct device *dev, u64 device_mask);
+#else
+#define ali_sound_dma_hack(dev, mask)	(0)
+#endif
 
 /* signal32.c */
 void do_sigreturn32(struct pt_regs *regs);

arch/sparc/kernel/pci.c

@@ -956,51 +956,35 @@ void arch_teardown_msi_irq(unsigned int irq)
 }
 #endif /* !(CONFIG_PCI_MSI) */
 
-static void ali_sound_dma_hack(struct pci_dev *pdev, int set_bit)
+/* ALI sound chips generate 31-bits of DMA, a special register
+ * determines what bit 31 is emitted as.
+ */
+int ali_sound_dma_hack(struct device *dev, u64 device_mask)
 {
+	struct iommu *iommu = dev->archdata.iommu;
 	struct pci_dev *ali_isa_bridge;
 	u8 val;
 
-	/* ALI sound chips generate 31-bits of DMA, a special register
-	 * determines what bit 31 is emitted as.
-	 */
+	if (!dev_is_pci(dev))
+		return 0;
+
+	if (to_pci_dev(dev)->vendor != PCI_VENDOR_ID_AL ||
+	    to_pci_dev(dev)->device != PCI_DEVICE_ID_AL_M5451 ||
+	    device_mask != 0x7fffffff)
+		return 0;
+
 	ali_isa_bridge = pci_get_device(PCI_VENDOR_ID_AL,
 					 PCI_DEVICE_ID_AL_M1533,
 					 NULL);
 
 	pci_read_config_byte(ali_isa_bridge, 0x7e, &val);
-	if (set_bit)
+	if (iommu->dma_addr_mask & 0x80000000)
 		val |= 0x01;
 	else
 		val &= ~0x01;
 	pci_write_config_byte(ali_isa_bridge, 0x7e, val);
 	pci_dev_put(ali_isa_bridge);
-}
-
-int pci64_dma_supported(struct pci_dev *pdev, u64 device_mask)
-{
-	u64 dma_addr_mask;
-
-	if (pdev == NULL) {
-		dma_addr_mask = 0xffffffff;
-	} else {
-		struct iommu *iommu = pdev->dev.archdata.iommu;
-
-		dma_addr_mask = iommu->dma_addr_mask;
-
-		if (pdev->vendor == PCI_VENDOR_ID_AL &&
-		    pdev->device == PCI_DEVICE_ID_AL_M5451 &&
-		    device_mask == 0x7fffffff) {
-			ali_sound_dma_hack(pdev,
-					   (dma_addr_mask & 0x80000000) != 0);
-			return 1;
-		}
-	}
-
-	if (device_mask >= (1UL << 32UL))
-		return 0;
-
-	return (device_mask & dma_addr_mask) == dma_addr_mask;
+	return 1;
 }
 
 void pci_resource_to_user(const struct pci_dev *pdev, int bar,

arch/sparc/kernel/pci_sun4v.c

@@ -92,7 +92,7 @@ static long iommu_batch_flush(struct iommu_batch *p, u64 mask)
 		prot &= (HV_PCI_MAP_ATTR_READ | HV_PCI_MAP_ATTR_WRITE);
 
 	while (npages != 0) {
-		if (mask <= DMA_BIT_MASK(32)) {
+		if (mask <= DMA_BIT_MASK(32) || !pbm->iommu->atu) {
 			num = pci_sun4v_iommu_map(devhandle,
 						  HV_PCI_TSBID(0, entry),
 						  npages,
@@ -208,7 +208,7 @@ static void *dma_4v_alloc_coherent(struct device *dev, size_t size,
 	atu = iommu->atu;
 
 	mask = dev->coherent_dma_mask;
-	if (mask <= DMA_BIT_MASK(32))
+	if (mask <= DMA_BIT_MASK(32) || !atu)
 		tbl = &iommu->tbl;
 	else
 		tbl = &atu->tbl;
@@ -674,18 +674,12 @@ static void dma_4v_unmap_sg(struct device *dev, struct scatterlist *sglist,
 static int dma_4v_supported(struct device *dev, u64 device_mask)
 {
 	struct iommu *iommu = dev->archdata.iommu;
-	u64 dma_addr_mask = iommu->dma_addr_mask;
-
-	if (device_mask > DMA_BIT_MASK(32)) {
-		if (iommu->atu)
-			dma_addr_mask = iommu->atu->dma_addr_mask;
-		else
-			return 0;
-	}
 
-	if ((device_mask & dma_addr_mask) == dma_addr_mask)
+	if (ali_sound_dma_hack(dev, device_mask))
 		return 1;
-	return pci64_dma_supported(to_pci_dev(dev), device_mask);
+	if (device_mask < iommu->dma_addr_mask)
+		return 0;
+	return 1;
 }
 
 static const struct dma_map_ops sun4v_dma_ops = {

arch/unicore32/Kconfig

@@ -5,7 +5,6 @@ config UNICORE32
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_MIGHT_HAVE_PC_PARPORT
 	select ARCH_MIGHT_HAVE_PC_SERIO
-	select HAVE_GENERIC_DMA_COHERENT
 	select HAVE_KERNEL_GZIP
 	select HAVE_KERNEL_BZIP2
 	select GENERIC_ATOMIC64

arch/x86/Kconfig

@@ -14,7 +14,6 @@ config X86_32
 	select ARCH_WANT_IPC_PARSE_VERSION
 	select CLKSRC_I8253
 	select CLONE_BACKWARDS
-	select HAVE_GENERIC_DMA_COHERENT
 	select MODULES_USE_ELF_REL
 	select OLD_SIGACTION
 

arch/xtensa/Kconfig

@@ -450,7 +450,6 @@ config USE_OF
 	bool "Flattened Device Tree support"
 	select OF
 	select OF_EARLY_FLATTREE
-	select OF_RESERVED_MEM
 	help
 	  Include support for flattened device tree machine descriptions.
 

drivers/base/Kconfig

@@ -191,83 +191,6 @@ config DMA_FENCE_TRACE
 	  lockup related problems for dma-buffers shared across multiple
 	  devices.
 
-config DMA_CMA
-	bool "DMA Contiguous Memory Allocator"
-	depends on HAVE_DMA_CONTIGUOUS && CMA
-	help
-	  This enables the Contiguous Memory Allocator which allows drivers
-	  to allocate big physically-contiguous blocks of memory for use with
-	  hardware components that do not support I/O map nor scatter-gather.
-
-	  You can disable CMA by specifying "cma=0" on the kernel's command
-	  line.
-
-	  For more information see <include/linux/dma-contiguous.h>.
-	  If unsure, say "n".
-
-if  DMA_CMA
-comment "Default contiguous memory area size:"
-
-config CMA_SIZE_MBYTES
-	int "Size in Mega Bytes"
-	depends on !CMA_SIZE_SEL_PERCENTAGE
-	default 0 if X86
-	default 16
-	help
-	  Defines the size (in MiB) of the default memory area for Contiguous
-	  Memory Allocator.  If the size of 0 is selected, CMA is disabled by
-	  default, but it can be enabled by passing cma=size[MG] to the kernel.
-
-
-config CMA_SIZE_PERCENTAGE
-	int "Percentage of total memory"
-	depends on !CMA_SIZE_SEL_MBYTES
-	default 0 if X86
-	default 10
-	help
-	  Defines the size of the default memory area for Contiguous Memory
-	  Allocator as a percentage of the total memory in the system.
-	  If 0 percent is selected, CMA is disabled by default, but it can be
-	  enabled by passing cma=size[MG] to the kernel.
-
-choice
-	prompt "Selected region size"
-	default CMA_SIZE_SEL_MBYTES
-
-config CMA_SIZE_SEL_MBYTES
-	bool "Use mega bytes value only"
-
-config CMA_SIZE_SEL_PERCENTAGE
-	bool "Use percentage value only"
-
-config CMA_SIZE_SEL_MIN
-	bool "Use lower value (minimum)"
-
-config CMA_SIZE_SEL_MAX
-	bool "Use higher value (maximum)"
-
-endchoice
-
-config CMA_ALIGNMENT
-	int "Maximum PAGE_SIZE order of alignment for contiguous buffers"
-	range 4 12
-	default 8
-	help
-	  DMA mapping framework by default aligns all buffers to the smallest
-	  PAGE_SIZE order which is greater than or equal to the requested buffer
-	  size. This works well for buffers up to a few hundreds kilobytes, but
-	  for larger buffers it just a memory waste. With this parameter you can
-	  specify the maximum PAGE_SIZE order for contiguous buffers. Larger
-	  buffers will be aligned only to this specified order. The order is
-	  expressed as a power of two multiplied by the PAGE_SIZE.
-
-	  For example, if your system defaults to 4KiB pages, the order value
-	  of 8 means that the buffers will be aligned up to 1MiB only.
-
-	  If unsure, leave the default value "8".
-
-endif
-
 config GENERIC_ARCH_TOPOLOGY
 	bool
 	help

drivers/media/common/videobuf2/videobuf2-dma-contig.c

@@ -439,42 +439,14 @@ static void vb2_dc_put_userptr(void *buf_priv)
 				set_page_dirty_lock(pages[i]);
 		sg_free_table(sgt);
 		kfree(sgt);
+	} else {
+		dma_unmap_resource(buf->dev, buf->dma_addr, buf->size,
+				   buf->dma_dir, 0);
 	}
 	vb2_destroy_framevec(buf->vec);
 	kfree(buf);
 }
 
-/*
- * For some kind of reserved memory there might be no struct page available,
- * so all that can be done to support such 'pages' is to try to convert
- * pfn to dma address or at the last resort just assume that
- * dma address == physical address (like it has been assumed in earlier version
- * of videobuf2-dma-contig
- */
-
-#ifdef __arch_pfn_to_dma
-static inline dma_addr_t vb2_dc_pfn_to_dma(struct device *dev, unsigned long pfn)
-{
-	return (dma_addr_t)__arch_pfn_to_dma(dev, pfn);
-}
-#elif defined(__pfn_to_bus)
-static inline dma_addr_t vb2_dc_pfn_to_dma(struct device *dev, unsigned long pfn)
-{
-	return (dma_addr_t)__pfn_to_bus(pfn);
-}
-#elif defined(__pfn_to_phys)
-static inline dma_addr_t vb2_dc_pfn_to_dma(struct device *dev, unsigned long pfn)
-{
-	return (dma_addr_t)__pfn_to_phys(pfn);
-}
-#else
-static inline dma_addr_t vb2_dc_pfn_to_dma(struct device *dev, unsigned long pfn)
-{
-	/* really, we cannot do anything better at this point */
-	return (dma_addr_t)(pfn) << PAGE_SHIFT;
-}
-#endif
-
 static void *vb2_dc_get_userptr(struct device *dev, unsigned long vaddr,
 	unsigned long size, enum dma_data_direction dma_dir)
 {
@@ -528,7 +500,12 @@ static void *vb2_dc_get_userptr(struct device *dev, unsigned long vaddr,
 		for (i = 1; i < n_pages; i++)
 			if (nums[i-1] + 1 != nums[i])
 				goto fail_pfnvec;
-		buf->dma_addr = vb2_dc_pfn_to_dma(buf->dev, nums[0]);
+		buf->dma_addr = dma_map_resource(buf->dev,
+				__pfn_to_phys(nums[0]), size, buf->dma_dir, 0);
+		if (dma_mapping_error(buf->dev, buf->dma_addr)) {
+			ret = -ENOMEM;
+			goto fail_pfnvec;
+		}
 		goto out;
 	}
 

drivers/mfd/Kconfig

@@ -1065,6 +1065,8 @@ config MFD_SI476X_CORE
 
 config MFD_SM501
 	tristate "Silicon Motion SM501"
+	depends on HAS_DMA
+	select DMA_DECLARE_COHERENT
 	 ---help---
 	  This is the core driver for the Silicon Motion SM501 multimedia
 	  companion chip. This device is a multifunction device which may
@@ -1674,6 +1676,7 @@ config MFD_TC6393XB
 	select GPIOLIB
 	select MFD_CORE
 	select MFD_TMIO
+	select DMA_DECLARE_COHERENT
 	help
 	  Support for Toshiba Mobile IO Controller TC6393XB
 

drivers/of/Kconfig

@@ -43,6 +43,7 @@ config OF_FLATTREE
 
 config OF_EARLY_FLATTREE
 	bool
+	select DMA_DECLARE_COHERENT if HAS_DMA
 	select OF_FLATTREE
 
 config OF_PROMTREE
@@ -81,10 +82,9 @@ config OF_MDIO
 	  OpenFirmware MDIO bus (Ethernet PHY) accessors
 
 config OF_RESERVED_MEM
-	depends on OF_EARLY_FLATTREE
 	bool
-	help
-	  Helpers to allow for reservation of memory regions
+	depends on OF_EARLY_FLATTREE
+	default y if DMA_DECLARE_COHERENT || DMA_CMA
 
 config OF_RESOLVE
 	bool

drivers/parisc/ccio-dma.c

@@ -712,8 +712,8 @@ ccio_dma_supported(struct device *dev, u64 mask)
 		return 0;
 	}
 
-	/* only support 32-bit devices (ie PCI/GSC) */
-	return (int)(mask == 0xffffffffUL);
+	/* only support 32-bit or better devices (ie PCI/GSC) */
+	return (int)(mask >= 0xffffffffUL);
 }
 
 /**

drivers/usb/host/ohci-sm501.c

@@ -126,8 +126,7 @@ static int ohci_hcd_sm501_drv_probe(struct platform_device *pdev)
 
 	retval = dma_declare_coherent_memory(dev, mem->start,
 					 mem->start - mem->parent->start,
-					 resource_size(mem),
-					 DMA_MEMORY_EXCLUSIVE);
+					 resource_size(mem));
 	if (retval) {
 		dev_err(dev, "cannot declare coherent memory\n");
 		goto err1;

drivers/usb/host/ohci-tmio.c

@@ -225,7 +225,7 @@ static int ohci_hcd_tmio_drv_probe(struct platform_device *dev)
 	}
 
 	ret = dma_declare_coherent_memory(&dev->dev, sram->start, sram->start,
-				resource_size(sram), DMA_MEMORY_EXCLUSIVE);
+				resource_size(sram));
 	if (ret)
 		goto err_dma_declare;
 

include/linux/device.h

@@ -1028,8 +1028,10 @@ struct device {
 
 	struct list_head	dma_pools;	/* dma pools (if dma'ble) */
 
+#ifdef CONFIG_DMA_DECLARE_COHERENT
 	struct dma_coherent_mem	*dma_mem; /* internal for coherent mem
 					     override */
+#endif
 #ifdef CONFIG_DMA_CMA
 	struct cma *cma_area;		/* contiguous memory area for dma
 					   allocations */

include/linux/dma-mapping.h

@@ -153,7 +153,7 @@ static inline int is_device_dma_capable(struct device *dev)
 	return dev->dma_mask != NULL && *dev->dma_mask != DMA_MASK_NONE;
 }
 
-#ifdef CONFIG_HAVE_GENERIC_DMA_COHERENT
+#ifdef CONFIG_DMA_DECLARE_COHERENT
 /*
  * These three functions are only for dma allocator.
  * Don't use them in device drivers.
@@ -192,7 +192,7 @@ static inline int dma_mmap_from_global_coherent(struct vm_area_struct *vma,
 {
 	return 0;
 }
-#endif /* CONFIG_HAVE_GENERIC_DMA_COHERENT */
+#endif /* CONFIG_DMA_DECLARE_COHERENT */
 
 static inline bool dma_is_direct(const struct dma_map_ops *ops)
 {
@@ -208,6 +208,8 @@ dma_addr_t dma_direct_map_page(struct device *dev, struct page *page,
 		unsigned long attrs);
 int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
 		enum dma_data_direction dir, unsigned long attrs);
+dma_addr_t dma_direct_map_resource(struct device *dev, phys_addr_t paddr,
+		size_t size, enum dma_data_direction dir, unsigned long attrs);
 
 #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
     defined(CONFIG_SWIOTLB)
@@ -346,19 +348,20 @@ static inline dma_addr_t dma_map_resource(struct device *dev,
 					  unsigned long attrs)
 {
 	const struct dma_map_ops *ops = get_dma_ops(dev);
-	dma_addr_t addr;
+	dma_addr_t addr = DMA_MAPPING_ERROR;
 
 	BUG_ON(!valid_dma_direction(dir));
 
 	/* Don't allow RAM to be mapped */
-	BUG_ON(pfn_valid(PHYS_PFN(phys_addr)));
+	if (WARN_ON_ONCE(pfn_valid(PHYS_PFN(phys_addr))))
+		return DMA_MAPPING_ERROR;
 
-	addr = phys_addr;
-	if (ops && ops->map_resource)
+	if (dma_is_direct(ops))
+		addr = dma_direct_map_resource(dev, phys_addr, size, dir, attrs);
+	else if (ops->map_resource)
 		addr = ops->map_resource(dev, phys_addr, size, dir, attrs);
 
 	debug_dma_map_resource(dev, phys_addr, size, dir, addr);
-
 	return addr;
 }
 
@@ -369,7 +372,7 @@ static inline void dma_unmap_resource(struct device *dev, dma_addr_t addr,
 	const struct dma_map_ops *ops = get_dma_ops(dev);
 
 	BUG_ON(!valid_dma_direction(dir));
-	if (ops && ops->unmap_resource)
+	if (!dma_is_direct(ops) && ops->unmap_resource)
 		ops->unmap_resource(dev, addr, size, dir, attrs);
 	debug_dma_unmap_resource(dev, addr, size, dir);
 }
@@ -668,15 +671,23 @@ static inline int dma_coerce_mask_and_coherent(struct device *dev, u64 mask)
 	return dma_set_mask_and_coherent(dev, mask);
 }
 
-#ifndef arch_setup_dma_ops
+#ifdef CONFIG_ARCH_HAS_SETUP_DMA_OPS
+void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
+		const struct iommu_ops *iommu, bool coherent);
+#else
 static inline void arch_setup_dma_ops(struct device *dev, u64 dma_base,
-				      u64 size, const struct iommu_ops *iommu,
-				      bool coherent) { }
-#endif
+		u64 size, const struct iommu_ops *iommu, bool coherent)
+{
+}
+#endif /* CONFIG_ARCH_HAS_SETUP_DMA_OPS */
 
-#ifndef arch_teardown_dma_ops
-static inline void arch_teardown_dma_ops(struct device *dev) { }
-#endif
+#ifdef CONFIG_ARCH_HAS_TEARDOWN_DMA_OPS
+void arch_teardown_dma_ops(struct device *dev);
+#else
+static inline void arch_teardown_dma_ops(struct device *dev)
+{
+}
+#endif /* CONFIG_ARCH_HAS_TEARDOWN_DMA_OPS */
 
 static inline unsigned int dma_get_max_seg_size(struct device *dev)
 {
@@ -725,19 +736,14 @@ static inline int dma_get_cache_alignment(void)
 	return 1;
 }
 
-/* flags for the coherent memory api */
-#define DMA_MEMORY_EXCLUSIVE		0x01
-
-#ifdef CONFIG_HAVE_GENERIC_DMA_COHERENT
+#ifdef CONFIG_DMA_DECLARE_COHERENT
 int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
-				dma_addr_t device_addr, size_t size, int flags);
+				dma_addr_t device_addr, size_t size);
 void dma_release_declared_memory(struct device *dev);
-void *dma_mark_declared_memory_occupied(struct device *dev,
-					dma_addr_t device_addr, size_t size);
 #else
 static inline int
 dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
-			    dma_addr_t device_addr, size_t size, int flags)
+			    dma_addr_t device_addr, size_t size)
 {
 	return -ENOSYS;
 }
@@ -746,14 +752,7 @@ static inline void
 dma_release_declared_memory(struct device *dev)
 {
 }
-
-static inline void *
-dma_mark_declared_memory_occupied(struct device *dev,
-				  dma_addr_t device_addr, size_t size)
-{
-	return ERR_PTR(-EBUSY);
-}
-#endif /* CONFIG_HAVE_GENERIC_DMA_COHERENT */
+#endif /* CONFIG_DMA_DECLARE_COHERENT */
 
 static inline void *dmam_alloc_coherent(struct device *dev, size_t size,
 		dma_addr_t *dma_handle, gfp_t gfp)

kernel/dma/Kconfig

@@ -19,7 +19,13 @@ config ARCH_HAS_DMA_COHERENCE_H
 config ARCH_HAS_DMA_SET_MASK
 	bool
 
-config HAVE_GENERIC_DMA_COHERENT
+config DMA_DECLARE_COHERENT
+	bool
+
+config ARCH_HAS_SETUP_DMA_OPS
+	bool
+
+config ARCH_HAS_TEARDOWN_DMA_OPS
 	bool
 
 config ARCH_HAS_SYNC_DMA_FOR_DEVICE
@@ -56,3 +62,116 @@ config DMA_REMAP
 config DMA_DIRECT_REMAP
 	bool
 	select DMA_REMAP
+
+config DMA_CMA
+	bool "DMA Contiguous Memory Allocator"
+	depends on HAVE_DMA_CONTIGUOUS && CMA
+	help
+	  This enables the Contiguous Memory Allocator which allows drivers
+	  to allocate big physically-contiguous blocks of memory for use with
+	  hardware components that do not support I/O map nor scatter-gather.
+
+	  You can disable CMA by specifying "cma=0" on the kernel's command
+	  line.
+
+	  For more information see <include/linux/dma-contiguous.h>.
+	  If unsure, say "n".
+
+if  DMA_CMA
+comment "Default contiguous memory area size:"
+
+config CMA_SIZE_MBYTES
+	int "Size in Mega Bytes"
+	depends on !CMA_SIZE_SEL_PERCENTAGE
+	default 0 if X86
+	default 16
+	help
+	  Defines the size (in MiB) of the default memory area for Contiguous
+	  Memory Allocator.  If the size of 0 is selected, CMA is disabled by
+	  default, but it can be enabled by passing cma=size[MG] to the kernel.
+
+
+config CMA_SIZE_PERCENTAGE
+	int "Percentage of total memory"
+	depends on !CMA_SIZE_SEL_MBYTES
+	default 0 if X86
+	default 10
+	help
+	  Defines the size of the default memory area for Contiguous Memory
+	  Allocator as a percentage of the total memory in the system.
+	  If 0 percent is selected, CMA is disabled by default, but it can be
+	  enabled by passing cma=size[MG] to the kernel.
+
+choice
+	prompt "Selected region size"
+	default CMA_SIZE_SEL_MBYTES
+
+config CMA_SIZE_SEL_MBYTES
+	bool "Use mega bytes value only"
+
+config CMA_SIZE_SEL_PERCENTAGE
+	bool "Use percentage value only"
+
+config CMA_SIZE_SEL_MIN
+	bool "Use lower value (minimum)"
+
+config CMA_SIZE_SEL_MAX
+	bool "Use higher value (maximum)"
+
+endchoice
+
+config CMA_ALIGNMENT
+	int "Maximum PAGE_SIZE order of alignment for contiguous buffers"
+	range 4 12
+	default 8
+	help
+	  DMA mapping framework by default aligns all buffers to the smallest
+	  PAGE_SIZE order which is greater than or equal to the requested buffer
+	  size. This works well for buffers up to a few hundreds kilobytes, but
+	  for larger buffers it just a memory waste. With this parameter you can
+	  specify the maximum PAGE_SIZE order for contiguous buffers. Larger
+	  buffers will be aligned only to this specified order. The order is
+	  expressed as a power of two multiplied by the PAGE_SIZE.
+
+	  For example, if your system defaults to 4KiB pages, the order value
+	  of 8 means that the buffers will be aligned up to 1MiB only.
+
+	  If unsure, leave the default value "8".
+
+endif
+
+config DMA_API_DEBUG
+	bool "Enable debugging of DMA-API usage"
+	select NEED_DMA_MAP_STATE
+	help
+	  Enable this option to debug the use of the DMA API by device drivers.
+	  With this option you will be able to detect common bugs in device
+	  drivers like double-freeing of DMA mappings or freeing mappings that
+	  were never allocated.
+
+	  This also attempts to catch cases where a page owned by DMA is
+	  accessed by the cpu in a way that could cause data corruption.  For
+	  example, this enables cow_user_page() to check that the source page is
+	  not undergoing DMA.
+
+	  This option causes a performance degradation.  Use only if you want to
+	  debug device drivers and dma interactions.
+
+	  If unsure, say N.
+
+config DMA_API_DEBUG_SG
+	bool "Debug DMA scatter-gather usage"
+	default y
+	depends on DMA_API_DEBUG
+	help
+	  Perform extra checking that callers of dma_map_sg() have respected the
+	  appropriate segment length/boundary limits for the given device when
+	  preparing DMA scatterlists.
+
+	  This is particularly likely to have been overlooked in cases where the
+	  dma_map_sg() API is used for general bulk mapping of pages rather than
+	  preparing literal scatter-gather descriptors, where there is a risk of
+	  unexpected behaviour from DMA API implementations if the scatterlist
+	  is technically out-of-spec.
+
+	  If unsure, say N.

kernel/dma/Makefile

@@ -2,7 +2,7 @@
 
 obj-$(CONFIG_HAS_DMA)			+= mapping.o direct.o dummy.o
 obj-$(CONFIG_DMA_CMA)			+= contiguous.o
-obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += coherent.o
+obj-$(CONFIG_DMA_DECLARE_COHERENT)	+= coherent.o
 obj-$(CONFIG_DMA_VIRT_OPS)		+= virt.o
 obj-$(CONFIG_DMA_API_DEBUG)		+= debug.o
 obj-$(CONFIG_SWIOTLB)			+= swiotlb.o

kernel/dma/coherent.c

@@ -14,7 +14,6 @@ struct dma_coherent_mem {
 	dma_addr_t	device_base;
 	unsigned long	pfn_base;
 	int		size;
-	int		flags;
 	unsigned long	*bitmap;
 	spinlock_t	spinlock;
 	bool		use_dev_dma_pfn_offset;
@@ -38,12 +37,12 @@ static inline dma_addr_t dma_get_device_base(struct device *dev,
 		return mem->device_base;
 }
 
-static int dma_init_coherent_memory(
-	phys_addr_t phys_addr, dma_addr_t device_addr, size_t size, int flags,
-	struct dma_coherent_mem **mem)
+static int dma_init_coherent_memory(phys_addr_t phys_addr,
+		dma_addr_t device_addr, size_t size,
+		struct dma_coherent_mem **mem)
 {
 	struct dma_coherent_mem *dma_mem = NULL;
-	void __iomem *mem_base = NULL;
+	void *mem_base = NULL;
 	int pages = size >> PAGE_SHIFT;
 	int bitmap_size = BITS_TO_LONGS(pages) * sizeof(long);
 	int ret;
@@ -73,7 +72,6 @@ static int dma_init_coherent_memory(
 	dma_mem->device_base = device_addr;
 	dma_mem->pfn_base = PFN_DOWN(phys_addr);
 	dma_mem->size = pages;
-	dma_mem->flags = flags;
 	spin_lock_init(&dma_mem->spinlock);
 
 	*mem = dma_mem;
@@ -110,12 +108,12 @@ static int dma_assign_coherent_memory(struct device *dev,
 }
 
 int dma_declare_coherent_memory(struct device *dev, phys_addr_t phys_addr,
-				dma_addr_t device_addr, size_t size, int flags)
+				dma_addr_t device_addr, size_t size)
 {
 	struct dma_coherent_mem *mem;
 	int ret;
 
-	ret = dma_init_coherent_memory(phys_addr, device_addr, size, flags, &mem);
+	ret = dma_init_coherent_memory(phys_addr, device_addr, size, &mem);
 	if (ret)
 		return ret;
 
@@ -137,29 +135,6 @@ void dma_release_declared_memory(struct device *dev)
 }
 EXPORT_SYMBOL(dma_release_declared_memory);
 
-void *dma_mark_declared_memory_occupied(struct device *dev,
-					dma_addr_t device_addr, size_t size)
-{
-	struct dma_coherent_mem *mem = dev->dma_mem;
-	unsigned long flags;
-	int pos, err;
-
-	size += device_addr & ~PAGE_MASK;
-
-	if (!mem)
-		return ERR_PTR(-EINVAL);
-
-	spin_lock_irqsave(&mem->spinlock, flags);
-	pos = PFN_DOWN(device_addr - dma_get_device_base(dev, mem));
-	err = bitmap_allocate_region(mem->bitmap, pos, get_order(size));
-	spin_unlock_irqrestore(&mem->spinlock, flags);
-
-	if (err != 0)
-		return ERR_PTR(err);
-	return mem->virt_base + (pos << PAGE_SHIFT);
-}
-EXPORT_SYMBOL(dma_mark_declared_memory_occupied);
-
 static void *__dma_alloc_from_coherent(struct dma_coherent_mem *mem,
 		ssize_t size, dma_addr_t *dma_handle)
 {
@@ -213,15 +188,7 @@ int dma_alloc_from_dev_coherent(struct device *dev, ssize_t size,
 		return 0;
 
 	*ret = __dma_alloc_from_coherent(mem, size, dma_handle);
-	if (*ret)
-		return 1;
-
-	/*
-	 * In the case where the allocation can not be satisfied from the
-	 * per-device area, try to fall back to generic memory if the
-	 * constraints allow it.
-	 */
-	return mem->flags & DMA_MEMORY_EXCLUSIVE;
+	return 1;
 }
 
 void *dma_alloc_from_global_coherent(ssize_t size, dma_addr_t *dma_handle)
@@ -350,8 +317,7 @@ static int rmem_dma_device_init(struct reserved_mem *rmem, struct device *dev)
 
 	if (!mem) {
 		ret = dma_init_coherent_memory(rmem->base, rmem->base,
-					       rmem->size,
-					       DMA_MEMORY_EXCLUSIVE, &mem);
+					       rmem->size, &mem);
 		if (ret) {
 			pr_err("Reserved memory: failed to init DMA memory pool at %pa, size %ld MiB\n",
 				&rmem->base, (unsigned long)rmem->size / SZ_1M);

kernel/dma/debug.c

@@ -134,17 +134,6 @@ static u32 nr_total_entries;
 /* number of preallocated entries requested by kernel cmdline */
 static u32 nr_prealloc_entries = PREALLOC_DMA_DEBUG_ENTRIES;
 
-/* debugfs dentry's for the stuff above */
-static struct dentry *dma_debug_dent        __read_mostly;
-static struct dentry *global_disable_dent   __read_mostly;
-static struct dentry *error_count_dent      __read_mostly;
-static struct dentry *show_all_errors_dent  __read_mostly;
-static struct dentry *show_num_errors_dent  __read_mostly;
-static struct dentry *num_free_entries_dent __read_mostly;
-static struct dentry *min_free_entries_dent __read_mostly;
-static struct dentry *nr_total_entries_dent __read_mostly;
-static struct dentry *filter_dent           __read_mostly;
-
 /* per-driver filter related state */
 
 #define NAME_MAX_LEN	64
@@ -840,66 +829,46 @@ static const struct file_operations filter_fops = {
 	.llseek = default_llseek,
 };
 
-static int dma_debug_fs_init(void)
+static int dump_show(struct seq_file *seq, void *v)
 {
-	dma_debug_dent = debugfs_create_dir("dma-api", NULL);
-	if (!dma_debug_dent) {
-		pr_err("can not create debugfs directory\n");
-		return -ENOMEM;
-	}
+	int idx;
 
-	global_disable_dent = debugfs_create_bool("disabled", 0444,
-			dma_debug_dent,
-			&global_disable);
-	if (!global_disable_dent)
-		goto out_err;
-
-	error_count_dent = debugfs_create_u32("error_count", 0444,
-			dma_debug_dent, &error_count);
-	if (!error_count_dent)
-		goto out_err;
-
-	show_all_errors_dent = debugfs_create_u32("all_errors", 0644,
-			dma_debug_dent,
-			&show_all_errors);
-	if (!show_all_errors_dent)
-		goto out_err;
-
-	show_num_errors_dent = debugfs_create_u32("num_errors", 0644,
-			dma_debug_dent,
-			&show_num_errors);
-	if (!show_num_errors_dent)
-		goto out_err;
-
-	num_free_entries_dent = debugfs_create_u32("num_free_entries", 0444,
-			dma_debug_dent,
-			&num_free_entries);
-	if (!num_free_entries_dent)
-		goto out_err;
-
-	min_free_entries_dent = debugfs_create_u32("min_free_entries", 0444,
-			dma_debug_dent,
-			&min_free_entries);
-	if (!min_free_entries_dent)
-		goto out_err;
-
-	nr_total_entries_dent = debugfs_create_u32("nr_total_entries", 0444,
-			dma_debug_dent,
-			&nr_total_entries);
-	if (!nr_total_entries_dent)
-		goto out_err;
-
-	filter_dent = debugfs_create_file("driver_filter", 0644,
-					  dma_debug_dent, NULL, &filter_fops);
-	if (!filter_dent)
-		goto out_err;
+	for (idx = 0; idx < HASH_SIZE; idx++) {
+		struct hash_bucket *bucket = &dma_entry_hash[idx];
+		struct dma_debug_entry *entry;
+		unsigned long flags;
 
+		spin_lock_irqsave(&bucket->lock, flags);
+		list_for_each_entry(entry, &bucket->list, list) {
+			seq_printf(seq,
+				   "%s %s %s idx %d P=%llx N=%lx D=%llx L=%llx %s %s\n",
+				   dev_name(entry->dev),
+				   dev_driver_string(entry->dev),
+				   type2name[entry->type], idx,
+				   phys_addr(entry), entry->pfn,
+				   entry->dev_addr, entry->size,
+				   dir2name[entry->direction],
+				   maperr2str[entry->map_err_type]);
+		}
+		spin_unlock_irqrestore(&bucket->lock, flags);
+	}
 	return 0;
+}
+DEFINE_SHOW_ATTRIBUTE(dump);
 
-out_err:
-	debugfs_remove_recursive(dma_debug_dent);
-
-	return -ENOMEM;
+static void dma_debug_fs_init(void)
+{
+	struct dentry *dentry = debugfs_create_dir("dma-api", NULL);
+
+	debugfs_create_bool("disabled", 0444, dentry, &global_disable);
+	debugfs_create_u32("error_count", 0444, dentry, &error_count);
+	debugfs_create_u32("all_errors", 0644, dentry, &show_all_errors);
+	debugfs_create_u32("num_errors", 0644, dentry, &show_num_errors);
+	debugfs_create_u32("num_free_entries", 0444, dentry, &num_free_entries);
+	debugfs_create_u32("min_free_entries", 0444, dentry, &min_free_entries);
+	debugfs_create_u32("nr_total_entries", 0444, dentry, &nr_total_entries);
+	debugfs_create_file("driver_filter", 0644, dentry, NULL, &filter_fops);
+	debugfs_create_file("dump", 0444, dentry, NULL, &dump_fops);
 }
 
 static int device_dma_allocations(struct device *dev, struct dma_debug_entry **out_entry)
@@ -985,12 +954,7 @@ static int dma_debug_init(void)
 		spin_lock_init(&dma_entry_hash[i].lock);
 	}
 
-	if (dma_debug_fs_init() != 0) {
-		pr_err("error creating debugfs entries - disabling\n");
-		global_disable = true;
-
-		return 0;
-	}
+	dma_debug_fs_init();
 
 	nr_pages = DIV_ROUND_UP(nr_prealloc_entries, DMA_DEBUG_DYNAMIC_ENTRIES);
 	for (i = 0; i < nr_pages; ++i)

kernel/dma/direct.c

@@ -355,6 +355,20 @@ int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl, int nents,
 }
 EXPORT_SYMBOL(dma_direct_map_sg);
 
+dma_addr_t dma_direct_map_resource(struct device *dev, phys_addr_t paddr,
+		size_t size, enum dma_data_direction dir, unsigned long attrs)
+{
+	dma_addr_t dma_addr = paddr;
+
+	if (unlikely(!dma_direct_possible(dev, dma_addr, size))) {
+		report_addr(dev, dma_addr, size);
+		return DMA_MAPPING_ERROR;
+	}
+
+	return dma_addr;
+}
+EXPORT_SYMBOL(dma_direct_map_resource);
+
 /*
  * 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

lib/Kconfig.debug

@@ -1654,42 +1654,6 @@ config PROVIDE_OHCI1394_DMA_INIT
 
 	  See Documentation/debugging-via-ohci1394.txt for more information.
 
-config DMA_API_DEBUG
-	bool "Enable debugging of DMA-API usage"
-	select NEED_DMA_MAP_STATE
-	help
-	  Enable this option to debug the use of the DMA API by device drivers.
-	  With this option you will be able to detect common bugs in device
-	  drivers like double-freeing of DMA mappings or freeing mappings that
-	  were never allocated.
-
-	  This also attempts to catch cases where a page owned by DMA is
-	  accessed by the cpu in a way that could cause data corruption.  For
-	  example, this enables cow_user_page() to check that the source page is
-	  not undergoing DMA.
-
-	  This option causes a performance degradation.  Use only if you want to
-	  debug device drivers and dma interactions.
-
-	  If unsure, say N.
-
-config DMA_API_DEBUG_SG
-	bool "Debug DMA scatter-gather usage"
-	default y
-	depends on DMA_API_DEBUG
-	help
-	  Perform extra checking that callers of dma_map_sg() have respected the
-	  appropriate segment length/boundary limits for the given device when
-	  preparing DMA scatterlists.
-
-	  This is particularly likely to have been overlooked in cases where the
-	  dma_map_sg() API is used for general bulk mapping of pages rather than
-	  preparing literal scatter-gather descriptors, where there is a risk of
-	  unexpected behaviour from DMA API implementations if the scatterlist
-	  is technically out-of-spec.
-
-	  If unsure, say N.
-
 menuconfig RUNTIME_TESTING_MENU
 	bool "Runtime Testing"
 	def_bool y