dma-mapping: move all DMA mapping code to kernel/dma

Currently the code is split over various files with dma- prefixes in the
lib/ and drives/base directories, and the number of files keeps growing.
Move them into a single directory to keep the code together and remove
the file name prefixes. To match the irq infrastructure this directory
is placed under the kernel/ directory.

Signed-off-by: Christoph Hellwig <[e-mail]>

Documentation/driver-api/infrastructure.rst

···
 Device Drivers DMA Management
 -----------------------------
 
-.. kernel-doc:: drivers/base/dma-coherent.c
+.. kernel-doc:: kernel/dma/coherent.c
    :export:
 
-.. kernel-doc:: drivers/base/dma-mapping.c
+.. kernel-doc:: kernel/dma/mapping.c
    :export:
 
 Device drivers PnP support

MAINTAINERS

···
 T:	git git://git.infradead.org/users/hch/dma-mapping.git
 W:	http://git.infradead.org/users/hch/dma-mapping.git
 S:	Supported
-F:	lib/dma-debug.c
-F:	lib/dma-direct.c
-F:	lib/dma-noncoherent.c
-F:	lib/dma-virt.c
-F:	drivers/base/dma-mapping.c
-F:	drivers/base/dma-coherent.c
+F:	kernel/dma/
 F:	include/asm-generic/dma-mapping.h
 F:	include/linux/dma-direct.h
 F:	include/linux/dma-mapping.h
···
 L:	[e-mail]
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb.git
 S:	Supported
-F:	lib/swiotlb.c
+F:	kernel/dma/swiotlb.c
 F:	arch/*/kernel/pci-swiotlb.c
 F:	include/linux/swiotlb.h
 

drivers/base/Makefile

···
 			   topology.o container.o property.o cacheinfo.o \
 			   devcon.o
 obj-$(CONFIG_DEVTMPFS)	+= devtmpfs.o
-obj-$(CONFIG_DMA_CMA) += dma-contiguous.o
 obj-y			+= power/
-obj-$(CONFIG_HAS_DMA)	+= dma-mapping.o
-obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += dma-coherent.o
 obj-$(CONFIG_ISA_BUS_API)	+= isa.o
 obj-y				+= firmware_loader/
 obj-$(CONFIG_NUMA)	+= node.o

drivers/base/dma-mapping.c kernel/dma/mapping.c

···
 // SPDX-License-Identifier: GPL-2.0
 /*
- * drivers/base/dma-mapping.c - arch-independent dma-mapping routines
+ * arch-independent dma-mapping routines
  *
  * Copyright (c) 2006  SUSE Linux Products GmbH
  * Copyright (c) 2006  Tejun Heo <[e-mail]>

include/linux/dma-contiguous.h

···
  *   CMA should not be used by the device drivers directly. It is
  *   only a helper framework for dma-mapping subsystem.
  *
- *   For more information, see kernel-docs in drivers/base/dma-contiguous.c
+ *   For more information, see kernel-docs in kernel/dma/contiguous.c
  */
 
 #ifdef __KERNEL__

init/Kconfig

···
 
 endmenu		# General setup
 
-config HAVE_GENERIC_DMA_COHERENT
-	bool
-	default n
-
 config RT_MUTEXES
 	bool
 

kernel/Makefile

···
 obj-y += irq/
 obj-y += rcu/
 obj-y += livepatch/
+obj-y += dma/
 
 obj-$(CONFIG_CHECKPOINT_RESTORE) += kcmp.o
 obj-$(CONFIG_FREEZER) += freezer.o

kernel/dma/Kconfig

···
+
+config HAS_DMA
+	bool
+	depends on !NO_DMA
+	default y
+
+config NEED_SG_DMA_LENGTH
+	bool
+
+config NEED_DMA_MAP_STATE
+	bool
+
+config ARCH_DMA_ADDR_T_64BIT
+	def_bool 64BIT || PHYS_ADDR_T_64BIT
+
+config HAVE_GENERIC_DMA_COHERENT
+	bool
+
+config ARCH_HAS_SYNC_DMA_FOR_DEVICE
+	bool
+
+config ARCH_HAS_SYNC_DMA_FOR_CPU
+	bool
+	select NEED_DMA_MAP_STATE
+
+config DMA_DIRECT_OPS
+	bool
+	depends on HAS_DMA
+
+config DMA_NONCOHERENT_OPS
+	bool
+	depends on HAS_DMA
+	select DMA_DIRECT_OPS
+
+config DMA_NONCOHERENT_MMAP
+	bool
+	depends on DMA_NONCOHERENT_OPS
+
+config DMA_NONCOHERENT_CACHE_SYNC
+	bool
+	depends on DMA_NONCOHERENT_OPS
+
+config DMA_VIRT_OPS
+	bool
+	depends on HAS_DMA
+
+config SWIOTLB
+	bool
+	select DMA_DIRECT_OPS
+	select NEED_DMA_MAP_STATE

kernel/dma/Makefile

···
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_HAS_DMA)			+= mapping.o
+obj-$(CONFIG_DMA_CMA)			+= contiguous.o
+obj-$(CONFIG_HAVE_GENERIC_DMA_COHERENT) += coherent.o
+obj-$(CONFIG_DMA_DIRECT_OPS)		+= direct.o
+obj-$(CONFIG_DMA_NONCOHERENT_OPS)	+= noncoherent.o
+obj-$(CONFIG_DMA_VIRT_OPS)		+= virt.o
+obj-$(CONFIG_DMA_API_DEBUG)		+= debug.o
+obj-$(CONFIG_SWIOTLB)			+= swiotlb.o
+

lib/Kconfig

···
 	depends on HAS_IOMEM && !NO_IOPORT_MAP
 	default y
 
-config HAS_DMA
-	bool
-	depends on !NO_DMA
-	default y
+source "kernel/dma/Kconfig"
 
 config SGL_ALLOC
 	bool
 	default n
 
-config NEED_SG_DMA_LENGTH
-	bool
-
-config NEED_DMA_MAP_STATE
-	bool
-
-config ARCH_DMA_ADDR_T_64BIT
-	def_bool 64BIT || PHYS_ADDR_T_64BIT
-
 config IOMMU_HELPER
 	bool
-
-config ARCH_HAS_SYNC_DMA_FOR_DEVICE
-	bool
-
-config ARCH_HAS_SYNC_DMA_FOR_CPU
-	bool
-	select NEED_DMA_MAP_STATE
-
-config DMA_DIRECT_OPS
-	bool
-	depends on HAS_DMA
-
-config DMA_NONCOHERENT_OPS
-	bool
-	depends on HAS_DMA
-	select DMA_DIRECT_OPS
-
-config DMA_NONCOHERENT_MMAP
-	bool
-	depends on DMA_NONCOHERENT_OPS
-
-config DMA_NONCOHERENT_CACHE_SYNC
-	bool
-	depends on DMA_NONCOHERENT_OPS
-
-config DMA_VIRT_OPS
-	bool
-	depends on HAS_DMA
-
-config SWIOTLB
-	bool
-	select DMA_DIRECT_OPS
-	select NEED_DMA_MAP_STATE
 
 config CHECK_SIGNATURE
 	bool

lib/Makefile

···
 lib-$(CONFIG_PRINTK) += dump_stack.o
 lib-$(CONFIG_MMU) += ioremap.o
 lib-$(CONFIG_SMP) += cpumask.o
-obj-$(CONFIG_DMA_DIRECT_OPS) += dma-direct.o
-obj-$(CONFIG_DMA_NONCOHERENT_OPS) += dma-noncoherent.o
-obj-$(CONFIG_DMA_VIRT_OPS) += dma-virt.o
 
 lib-y	+= kobject.o klist.o
 obj-y	+= lockref.o
···
 obj-$(CONFIG_AUDIT_GENERIC) += audit.o
 obj-$(CONFIG_AUDIT_COMPAT_GENERIC) += compat_audit.o
 
-obj-$(CONFIG_SWIOTLB) += swiotlb.o
 obj-$(CONFIG_IOMMU_HELPER) += iommu-helper.o
 obj-$(CONFIG_FAULT_INJECTION) += fault-inject.o
 obj-$(CONFIG_NOTIFIER_ERROR_INJECTION) += notifier-error-inject.o
···
 obj-$(CONFIG_NLATTR) += nlattr.o
 
 obj-$(CONFIG_LRU_CACHE) += lru_cache.o
-
-obj-$(CONFIG_DMA_API_DEBUG) += dma-debug.o
 
 obj-$(CONFIG_GENERIC_CSUM) += checksum.o
 

lib/dma-virt.c kernel/dma/virt.c

···
 // SPDX-License-Identifier: GPL-2.0
 /*
- *	lib/dma-virt.c
- *
  * DMA operations that map to virtual addresses without flushing memory.
  */
 #include <linux/export.h>