Merge tag 'dma-mapping-4.18' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping updates from Christoph Hellwig:

 - replace the force_dma flag with a dma_configure bus method. (Nipun
   Gupta, although one patch is іncorrectly attributed to me due to a
   git rebase bug)

 - use GFP_DMA32 more agressively in dma-direct. (Takashi Iwai)

 - remove PCI_DMA_BUS_IS_PHYS and rely on the dma-mapping API to do the
   right thing for bounce buffering.

 - move dma-debug initialization to common code, and apply a few
   cleanups to the dma-debug code.

 - cleanup the Kconfig mess around swiotlb selection

 - swiotlb comment fixup (Yisheng Xie)

 - a trivial swiotlb fix. (Dan Carpenter)

 - support swiotlb on RISC-V. (based on a patch from Palmer Dabbelt)

 - add a new generic dma-noncoherent dma_map_ops implementation and use
   it for arc, c6x and nds32.

 - improve scatterlist validity checking in dma-debug. (Robin Murphy)

 - add a struct device quirk to limit the dma-mask to 32-bit due to
   bridge/system issues, and switch x86 to use it instead of a local
   hack for VIA bridges.

 - handle devices without a dma_mask more gracefully in the dma-direct
   code.

* tag 'dma-mapping-4.18' of git://git.infradead.org/users/hch/dma-mapping: (48 commits)
  dma-direct: don't crash on device without dma_mask
  nds32: use generic dma_noncoherent_ops
  nds32: implement the unmap_sg DMA operation
  nds32: consolidate DMA cache maintainance routines
  x86/pci-dma: switch the VIA 32-bit DMA quirk to use the struct device flag
  x86/pci-dma: remove the explicit nodac and allowdac option
  x86/pci-dma: remove the experimental forcesac boot option
  Documentation/x86: remove a stray reference to pci-nommu.c
  core, dma-direct: add a flag 32-bit dma limits
  dma-mapping: remove unused gfp_t parameter to arch_dma_alloc_attrs
  dma-debug: check scatterlist segments
  c6x: use generic dma_noncoherent_ops
  arc: use generic dma_noncoherent_ops
  arc: fix arc_dma_{map,unmap}_page
  arc: fix arc_dma_sync_sg_for_{cpu,device}
  arc: simplify arc_dma_sync_single_for_{cpu,device}
  dma-mapping: provide a generic dma-noncoherent implementation
  dma-mapping: simplify Kconfig dependencies
  riscv: add swiotlb support
  riscv: only enable ZONE_DMA32 for 64-bit
  ...

4 files changed, 21 insertions, 81 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index c07f492b871a..f2ee6a8ffe65 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -28,6 +28,8 @@ config X86_64
 	select ARCH_USE_CMPXCHG_LOCKREF
 	select HAVE_ARCH_SOFT_DIRTY
 	select MODULES_USE_ELF_RELA
+	select NEED_DMA_MAP_STATE
+	select SWIOTLB
 	select X86_DEV_DMA_OPS
 	select ARCH_HAS_SYSCALL_WRAPPER
 
@@ -134,7 +136,6 @@ config X86
 	select HAVE_C_RECORDMCOUNT
 	select HAVE_DEBUG_KMEMLEAK
 	select HAVE_DEBUG_STACKOVERFLOW
-	select HAVE_DMA_API_DEBUG
 	select HAVE_DMA_CONTIGUOUS
 	select HAVE_DYNAMIC_FTRACE
 	select HAVE_DYNAMIC_FTRACE_WITH_REGS
@@ -184,6 +185,7 @@ config X86
 	select HAVE_UNSTABLE_SCHED_CLOCK
 	select HAVE_USER_RETURN_NOTIFIER
 	select IRQ_FORCED_THREADING
+	select NEED_SG_DMA_LENGTH
 	select PCI_LOCKLESS_CONFIG
 	select PERF_EVENTS
 	select RTC_LIB
@@ -236,13 +238,6 @@ config ARCH_MMAP_RND_COMPAT_BITS_MAX
 config SBUS
 	bool
 
-config NEED_DMA_MAP_STATE
-	def_bool y
-	depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
-
-config NEED_SG_DMA_LENGTH
-	def_bool y
-
 config GENERIC_ISA_DMA
 	def_bool y
 	depends on ISA_DMA_API
@@ -875,6 +870,7 @@ config DMI
 
 config GART_IOMMU
 	bool "Old AMD GART IOMMU support"
+	select IOMMU_HELPER
 	select SWIOTLB
 	depends on X86_64 && PCI && AMD_NB
 	---help---
@@ -896,6 +892,7 @@ config GART_IOMMU
 
 config CALGARY_IOMMU
 	bool "IBM Calgary IOMMU support"
+	select IOMMU_HELPER
 	select SWIOTLB
 	depends on X86_64 && PCI
 	---help---
@@ -923,20 +920,6 @@ config CALGARY_IOMMU_ENABLED_BY_DEFAULT
 	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
 	  If unsure, say Y.
 
-# need this always selected by IOMMU for the VIA workaround
-config SWIOTLB
-	def_bool y if X86_64
-	---help---
-	  Support for software bounce buffers used on x86-64 systems
-	  which don't have a hardware IOMMU. Using this PCI devices
-	  which can only access 32-bits of memory can be used on systems
-	  with more than 3 GB of memory.
-	  If unsure, say Y.
-
-config IOMMU_HELPER
-	def_bool y
-	depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
-
 config MAXSMP
 	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
 	depends on X86_64 && SMP && DEBUG_KERNEL
@@ -1458,6 +1441,7 @@ config HIGHMEM
 config X86_PAE
 	bool "PAE (Physical Address Extension) Support"
 	depends on X86_32 && !HIGHMEM4G
+	select PHYS_ADDR_T_64BIT
 	select SWIOTLB
 	---help---
 	  PAE is required for NX support, and furthermore enables
@@ -1485,14 +1469,6 @@ config X86_5LEVEL
 
 	  Say N if unsure.
 
-config ARCH_PHYS_ADDR_T_64BIT
-	def_bool y
-	depends on X86_64 || X86_PAE
-
-config ARCH_DMA_ADDR_T_64BIT
-	def_bool y
-	depends on X86_64 || HIGHMEM64G
-
 config X86_DIRECT_GBPAGES
 	def_bool y
 	depends on X86_64 && !DEBUG_PAGEALLOC
diff --git a/arch/x86/include/asm/dma-mapping.h b/arch/x86/include/asm/dma-mapping.h
index 89ce4bfd241f..ce4d176b3d13 100644
--- a/arch/x86/include/asm/dma-mapping.h
+++ b/arch/x86/include/asm/dma-mapping.h
@@ -30,10 +30,7 @@ static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 	return dma_ops;
 }
 
-int arch_dma_supported(struct device *dev, u64 mask);
-#define arch_dma_supported arch_dma_supported
-
-bool arch_dma_alloc_attrs(struct device **dev, gfp_t *gfp);
+bool arch_dma_alloc_attrs(struct device **dev);
 #define arch_dma_alloc_attrs arch_dma_alloc_attrs
 
 #endif
diff --git a/arch/x86/include/asm/pci.h b/arch/x86/include/asm/pci.h
index d32175e30259..662963681ea6 100644
--- a/arch/x86/include/asm/pci.h
+++ b/arch/x86/include/asm/pci.h
@@ -117,9 +117,6 @@ void native_restore_msi_irqs(struct pci_dev *dev);
 #define native_setup_msi_irqs		NULL
 #define native_teardown_msi_irq		NULL
 #endif
-
-#define PCI_DMA_BUS_IS_PHYS (dma_ops->is_phys)
-
 #endif  /* __KERNEL__ */
 
 #ifdef CONFIG_X86_64
diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index 77625b60a510..ab5d9dd668d2 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -15,13 +15,11 @@
 #include <asm/x86_init.h>
 #include <asm/iommu_table.h>
 
-static int forbid_dac __read_mostly;
+static bool disable_dac_quirk __read_mostly;
 
 const struct dma_map_ops *dma_ops = &dma_direct_ops;
 EXPORT_SYMBOL(dma_ops);
 
-static int iommu_sac_force __read_mostly;
-
 #ifdef CONFIG_IOMMU_DEBUG
 int panic_on_overflow __read_mostly = 1;
 int force_iommu __read_mostly = 1;
@@ -55,9 +53,6 @@ struct device x86_dma_fallback_dev = {
 };
 EXPORT_SYMBOL(x86_dma_fallback_dev);
 
-/* Number of entries preallocated for DMA-API debugging */
-#define PREALLOC_DMA_DEBUG_ENTRIES       65536
-
 void __init pci_iommu_alloc(void)
 {
 	struct iommu_table_entry *p;
@@ -76,7 +71,7 @@ void __init pci_iommu_alloc(void)
 	}
 }
 
-bool arch_dma_alloc_attrs(struct device **dev, gfp_t *gfp)
+bool arch_dma_alloc_attrs(struct device **dev)
 {
 	if (!*dev)
 		*dev = &x86_dma_fallback_dev;
@@ -125,13 +120,13 @@ static __init int iommu_setup(char *p)
 		if (!strncmp(p, "nomerge", 7))
 			iommu_merge = 0;
 		if (!strncmp(p, "forcesac", 8))
-			iommu_sac_force = 1;
+			pr_warn("forcesac option ignored.\n");
 		if (!strncmp(p, "allowdac", 8))
-			forbid_dac = 0;
+			pr_warn("allowdac option ignored.\n");
 		if (!strncmp(p, "nodac", 5))
-			forbid_dac = 1;
+			pr_warn("nodac option ignored.\n");
 		if (!strncmp(p, "usedac", 6)) {
-			forbid_dac = -1;
+			disable_dac_quirk = true;
 			return 1;
 		}
 #ifdef CONFIG_SWIOTLB
@@ -156,40 +151,9 @@ static __init int iommu_setup(char *p)
 }
 early_param("iommu", iommu_setup);
 
-int arch_dma_supported(struct device *dev, u64 mask)
-{
-#ifdef CONFIG_PCI
-	if (mask > 0xffffffff && forbid_dac > 0) {
-		dev_info(dev, "PCI: Disallowing DAC for device\n");
-		return 0;
-	}
-#endif
-
-	/* Tell the device to use SAC when IOMMU force is on.  This
-	   allows the driver to use cheaper accesses in some cases.
-
-	   Problem with this is that if we overflow the IOMMU area and
-	   return DAC as fallback address the device may not handle it
-	   correctly.
-
-	   As a special case some controllers have a 39bit address
-	   mode that is as efficient as 32bit (aic79xx). Don't force
-	   SAC for these.  Assume all masks <= 40 bits are of this
-	   type. Normally this doesn't make any difference, but gives
-	   more gentle handling of IOMMU overflow. */
-	if (iommu_sac_force && (mask >= DMA_BIT_MASK(40))) {
-		dev_info(dev, "Force SAC with mask %Lx\n", mask);
-		return 0;
-	}
-
-	return 1;
-}
-EXPORT_SYMBOL(arch_dma_supported);
-
 static int __init pci_iommu_init(void)
 {
 	struct iommu_table_entry *p;
-	dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
 
 #ifdef CONFIG_PCI
 	dma_debug_add_bus(&pci_bus_type);
@@ -209,11 +173,17 @@ rootfs_initcall(pci_iommu_init);
 #ifdef CONFIG_PCI
 /* Many VIA bridges seem to corrupt data for DAC. Disable it here */
 
+static int via_no_dac_cb(struct pci_dev *pdev, void *data)
+{
+	pdev->dev.dma_32bit_limit = true;
+	return 0;
+}
+
 static void via_no_dac(struct pci_dev *dev)
 {
-	if (forbid_dac == 0) {
+	if (!disable_dac_quirk) {
 		dev_info(&dev->dev, "disabling DAC on VIA PCI bridge\n");
-		forbid_dac = 1;
+		pci_walk_bus(dev->subordinate, via_no_dac_cb, NULL);
 	}
 }
 DECLARE_PCI_FIXUP_CLASS_FINAL(PCI_VENDOR_ID_VIA, PCI_ANY_ID,