dma-mapping: make support for dma ops optional

Avoid the overhead of the dma ops support for tiny builds that only
use the direct mapping.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Alexey Kardashevskiy <aik@ozlabs.ru>

arch/alpha/Kconfig

@@ -7,6 +7,7 @@ config ALPHA
 	select ARCH_NO_PREEMPT
 	select ARCH_NO_SG_CHAIN
 	select ARCH_USE_CMPXCHG_LOCKREF
+	select DMA_OPS if PCI
 	select FORCE_PCI if !ALPHA_JENSEN
 	select PCI_DOMAINS if PCI
 	select PCI_SYSCALL if PCI

arch/arm/Kconfig

@@ -41,6 +41,7 @@ config ARM
 	select CPU_PM if SUSPEND || CPU_IDLE
 	select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS
 	select DMA_DECLARE_COHERENT
+	select DMA_OPS
 	select DMA_REMAP if MMU
 	select EDAC_SUPPORT
 	select EDAC_ATOMIC_SCRUB

arch/ia64/Kconfig

@@ -192,6 +192,7 @@ config IA64_SGI_UV
 
 config IA64_HP_SBA_IOMMU
 	bool "HP SBA IOMMU support"
+	select DMA_OPS
 	default y
 	help
 	  Say Y here to add support for the SBA IOMMU found on HP zx1 and

arch/mips/Kconfig

@@ -367,6 +367,7 @@ config MACH_JAZZ
 	select ARC_PROMLIB
 	select ARCH_MIGHT_HAVE_PC_PARPORT
 	select ARCH_MIGHT_HAVE_PC_SERIO
+	select DMA_OPS
 	select FW_ARC
 	select FW_ARC32
 	select ARCH_MAY_HAVE_PC_FDC

arch/parisc/Kconfig

@@ -14,6 +14,7 @@ config PARISC
 	select ARCH_HAS_UBSAN_SANITIZE_ALL
 	select ARCH_NO_SG_CHAIN
 	select ARCH_SUPPORTS_MEMORY_FAILURE
+	select DMA_OPS
 	select RTC_CLASS
 	select RTC_DRV_GENERIC
 	select INIT_ALL_POSSIBLE

arch/powerpc/Kconfig

@@ -151,6 +151,7 @@ config PPC
 	select BUILDTIME_TABLE_SORT
 	select CLONE_BACKWARDS
 	select DCACHE_WORD_ACCESS		if PPC64 && CPU_LITTLE_ENDIAN
+	select DMA_OPS				if PPC64
 	select DYNAMIC_FTRACE			if FUNCTION_TRACER
 	select EDAC_ATOMIC_SCRUB
 	select EDAC_SUPPORT

arch/s390/Kconfig

@@ -113,6 +113,7 @@ config S390
 	select ARCH_WANT_IPC_PARSE_VERSION
 	select BUILDTIME_TABLE_SORT
 	select CLONE_BACKWARDS2
+	select DMA_OPS if PCI
 	select DYNAMIC_FTRACE if FUNCTION_TRACER
 	select GENERIC_CLOCKEVENTS
 	select GENERIC_CPU_AUTOPROBE

arch/sparc/Kconfig

@@ -15,6 +15,7 @@ config SPARC
 	default y
 	select ARCH_MIGHT_HAVE_PC_PARPORT if SPARC64 && PCI
 	select ARCH_MIGHT_HAVE_PC_SERIO
+	select DMA_OPS
 	select OF
 	select OF_PROMTREE
 	select HAVE_ASM_MODVERSIONS

arch/x86/Kconfig

@@ -909,6 +909,7 @@ config DMI
 
 config GART_IOMMU
 	bool "Old AMD GART IOMMU support"
+	select DMA_OPS
 	select IOMMU_HELPER
 	select SWIOTLB
 	depends on X86_64 && PCI && AMD_NB

drivers/infiniband/core/device.c

@@ -1183,6 +1183,8 @@ static void setup_dma_device(struct ib_device *device)
 	struct device *parent = device->dev.parent;
 
 	WARN_ON_ONCE(device->dma_device);
+
+#ifdef CONFIG_DMA_OPS
 	if (device->dev.dma_ops) {
 		/*
 		 * The caller provided custom DMA operations. Copy the
@@ -1203,7 +1205,9 @@ static void setup_dma_device(struct ib_device *device)
 			else
 				WARN_ON_ONCE(true);
 		}
-	} else {
+	} else
+#endif /* CONFIG_DMA_OPS */
+	{
 		/*
 		 * The caller did not provide custom DMA operations. Use the
 		 * DMA mapping operations of the parent device.

drivers/iommu/Kconfig

@@ -97,6 +97,7 @@ config OF_IOMMU
 # IOMMU-agnostic DMA-mapping layer
 config IOMMU_DMA
 	bool
+	select DMA_OPS
 	select IOMMU_API
 	select IOMMU_IOVA
 	select IRQ_MSI_IOMMU
@@ -183,6 +184,7 @@ config DMAR_TABLE
 config INTEL_IOMMU
 	bool "Support for Intel IOMMU using DMA Remapping Devices"
 	depends on PCI_MSI && ACPI && (X86 || IA64)
+	select DMA_OPS
 	select IOMMU_API
 	select IOMMU_IOVA
 	select NEED_DMA_MAP_STATE

drivers/macintosh/macio_asic.c

@@ -382,7 +382,7 @@ static struct macio_dev * macio_add_one_device(struct macio_chip *chip,
 	dma_set_max_seg_size(&dev->ofdev.dev, 65536);
 	dma_set_seg_boundary(&dev->ofdev.dev, 0xffffffff);
 
-#ifdef CONFIG_PCI
+#if defined(CONFIG_PCI) && defined(CONFIG_DMA_OPS)
 	/* Set the DMA ops to the ones from the PCI device, this could be
 	 * fishy if we didn't know that on PowerMac it's always direct ops
 	 * or iommu ops that will work fine
@@ -391,7 +391,7 @@ static struct macio_dev * macio_add_one_device(struct macio_chip *chip,
 	 */
 	dev->ofdev.dev.archdata = chip->lbus.pdev->dev.archdata;
 	dev->ofdev.dev.dma_ops = chip->lbus.pdev->dev.dma_ops;
-#endif /* CONFIG_PCI */
+#endif /* CONFIG_PCI && CONFIG_DMA_OPS */
 
 #ifdef DEBUG
 	printk("preparing mdev @%p, ofdev @%p, dev @%p, kobj @%p\n",

drivers/misc/mic/Kconfig

@@ -4,6 +4,7 @@ menu "Intel MIC & related support"
 config INTEL_MIC_BUS
 	tristate "Intel MIC Bus Driver"
 	depends on 64BIT && PCI && X86
+	select DMA_OPS
 	help
 	  This option is selected by any driver which registers a
 	  device or driver on the MIC Bus, such as CONFIG_INTEL_MIC_HOST,
@@ -19,6 +20,7 @@ config INTEL_MIC_BUS
 config SCIF_BUS
 	tristate "SCIF Bus Driver"
 	depends on 64BIT && PCI && X86
+	select DMA_OPS
 	help
 	  This option is selected by any driver which registers a
 	  device or driver on the SCIF Bus, such as CONFIG_INTEL_MIC_HOST
@@ -33,6 +35,7 @@ config SCIF_BUS
 
 config VOP_BUS
 	tristate "VOP Bus Driver"
+	select DMA_OPS
 	help
 	  This option is selected by any driver which registers a
 	  device or driver on the VOP Bus, such as CONFIG_INTEL_MIC_HOST
@@ -49,6 +52,7 @@ config INTEL_MIC_HOST
 	tristate "Intel MIC Host Driver"
 	depends on 64BIT && PCI && X86
 	depends on INTEL_MIC_BUS && SCIF_BUS && MIC_COSM && VOP_BUS
+	select DMA_OPS
 	help
 	  This enables Host Driver support for the Intel Many Integrated
 	  Core (MIC) family of PCIe form factor coprocessor devices that

drivers/vdpa/Kconfig

@@ -11,6 +11,7 @@ if VDPA
 config VDPA_SIM
 	tristate "vDPA device simulator"
 	depends on RUNTIME_TESTING_MENU && HAS_DMA
+	select DMA_OPS
 	select VHOST_RING
 	default n
 	help

drivers/xen/Kconfig

@@ -179,6 +179,7 @@ config XEN_GRANT_DMA_ALLOC
 
 config SWIOTLB_XEN
 	def_bool y
+	select DMA_OPS
 	select SWIOTLB
 
 config XEN_PCIDEV_BACKEND

include/linux/device.h

@@ -568,8 +568,9 @@ struct device {
 #ifdef CONFIG_GENERIC_MSI_IRQ
 	struct list_head	msi_list;
 #endif
-
+#ifdef CONFIG_DMA_OPS
 	const struct dma_map_ops *dma_ops;
+#endif
 	u64		*dma_mask;	/* dma mask (if dma'able device) */
 	u64		coherent_dma_mask;/* Like dma_mask, but for
 					     alloc_coherent mappings as

include/linux/dma-mapping.h

@@ -191,6 +191,7 @@ static inline int dma_mmap_from_global_coherent(struct vm_area_struct *vma,
 #ifdef CONFIG_HAS_DMA
 #include <asm/dma-mapping.h>
 
+#ifdef CONFIG_DMA_OPS
 static inline const struct dma_map_ops *get_dma_ops(struct device *dev)
 {
 	if (dev->dma_ops)
@@ -203,7 +204,16 @@ static inline void set_dma_ops(struct device *dev,
 {
 	dev->dma_ops = dma_ops;
 }
-
+#else /* CONFIG_DMA_OPS */
+static inline const struct dma_map_ops *get_dma_ops(struct device *dev)
+{
+	return NULL;
+}
+static inline void set_dma_ops(struct device *dev,
+			       const struct dma_map_ops *dma_ops)
+{
+}
+#endif /* CONFIG_DMA_OPS */
 
 static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 {

kernel/dma/Kconfig

@@ -5,6 +5,9 @@ config HAS_DMA
 	depends on !NO_DMA
 	default y
 
+config DMA_OPS
+	bool
+
 config NEED_SG_DMA_LENGTH
 	bool
 
@@ -60,6 +63,7 @@ config DMA_NONCOHERENT_CACHE_SYNC
 config DMA_VIRT_OPS
 	bool
 	depends on HAS_DMA
+	select DMA_OPS
 
 config SWIOTLB
 	bool

kernel/dma/Makefile

@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 
-obj-$(CONFIG_HAS_DMA)			+= mapping.o direct.o dummy.o
+obj-$(CONFIG_HAS_DMA)			+= mapping.o direct.o
+obj-$(CONFIG_DMA_OPS)			+= dummy.o
 obj-$(CONFIG_DMA_CMA)			+= contiguous.o
 obj-$(CONFIG_DMA_DECLARE_COHERENT)	+= coherent.o
 obj-$(CONFIG_DMA_VIRT_OPS)		+= virt.o