Merge tag 'dma-mapping-4.16' of git://git.infradead.org/users/hch/dma-mapping

Pull dma mapping updates from Christoph Hellwig:
 "Except for a runtime warning fix from Christian this is all about
  consolidation of the generic no-IOMMU code, a well as the glue code
  for swiotlb.

  All the code is based on the x86 implementation with hooks to allow
  all architectures that aren't cache coherent to use it.

  The x86 conversion itself has been deferred because the x86
  maintainers were a little busy in the last months"

* tag 'dma-mapping-4.16' of git://git.infradead.org/users/hch/dma-mapping: (57 commits)
  MAINTAINERS: add the iommu list for swiotlb and xen-swiotlb
  arm64: use swiotlb_alloc and swiotlb_free
  arm64: replace ZONE_DMA with ZONE_DMA32
  mips: use swiotlb_{alloc,free}
  mips/netlogic: remove swiotlb support
  tile: use generic swiotlb_ops
  tile: replace ZONE_DMA with ZONE_DMA32
  unicore32: use generic swiotlb_ops
  ia64: remove an ifdef around the content of pci-dma.c
  ia64: clean up swiotlb support
  ia64: use generic swiotlb_ops
  ia64: replace ZONE_DMA with ZONE_DMA32
  swiotlb: remove various exports
  swiotlb: refactor coherent buffer allocation
  swiotlb: refactor coherent buffer freeing
  swiotlb: wire up ->dma_supported in swiotlb_dma_ops
  swiotlb: add common swiotlb_map_ops
  swiotlb: rename swiotlb_free to swiotlb_exit
  x86: rename swiotlb_dma_ops
  powerpc: rename swiotlb_dma_ops
  ...

4 files changed, 88 insertions, 4 deletions

diff --git a/include/asm-generic/dma-mapping.h b/include/asm-generic/dma-mapping.h
new file mode 100644
index 000000000000..880a292d792f
--- /dev/null
+++ b/include/asm-generic/dma-mapping.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_GENERIC_DMA_MAPPING_H
+#define _ASM_GENERIC_DMA_MAPPING_H
+
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
+{
+	return &dma_direct_ops;
+}
+
+#endif /* _ASM_GENERIC_DMA_MAPPING_H */
diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h
new file mode 100644
index 000000000000..bcdb1a3e4b1f
--- /dev/null
+++ b/include/linux/dma-direct.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_DMA_DIRECT_H
+#define _LINUX_DMA_DIRECT_H 1
+
+#include <linux/dma-mapping.h>
+
+#ifdef CONFIG_ARCH_HAS_PHYS_TO_DMA
+#include <asm/dma-direct.h>
+#else
+static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
+{
+	dma_addr_t dev_addr = (dma_addr_t)paddr;
+
+	return dev_addr - ((dma_addr_t)dev->dma_pfn_offset << PAGE_SHIFT);
+}
+
+static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dev_addr)
+{
+	phys_addr_t paddr = (phys_addr_t)dev_addr;
+
+	return paddr + ((phys_addr_t)dev->dma_pfn_offset << PAGE_SHIFT);
+}
+
+static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
+{
+	if (!dev->dma_mask)
+		return false;
+
+	return addr + size - 1 <= *dev->dma_mask;
+}
+#endif /* !CONFIG_ARCH_HAS_PHYS_TO_DMA */
+
+#ifdef CONFIG_ARCH_HAS_DMA_MARK_CLEAN
+void dma_mark_clean(void *addr, size_t size);
+#else
+static inline void dma_mark_clean(void *addr, size_t size)
+{
+}
+#endif /* CONFIG_ARCH_HAS_DMA_MARK_CLEAN */
+
+void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
+		gfp_t gfp, unsigned long attrs);
+void dma_direct_free(struct device *dev, size_t size, void *cpu_addr,
+		dma_addr_t dma_addr, unsigned long attrs);
+int dma_direct_supported(struct device *dev, u64 mask);
+
+#endif /* _LINUX_DMA_DIRECT_H */
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 81ed9b2d84dc..34fe8463d10e 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -136,7 +136,7 @@ struct dma_map_ops {
 	int is_phys;
 };
 
-extern const struct dma_map_ops dma_noop_ops;
+extern const struct dma_map_ops dma_direct_ops;
 extern const struct dma_map_ops dma_virt_ops;
 
 #define DMA_BIT_MASK(n)	(((n) == 64) ? ~0ULL : ((1ULL<<(n))-1))
@@ -513,10 +513,18 @@ static inline void *dma_alloc_attrs(struct device *dev, size_t size,
 	void *cpu_addr;
 
 	BUG_ON(!ops);
+	WARN_ON_ONCE(dev && !dev->coherent_dma_mask);
 
 	if (dma_alloc_from_dev_coherent(dev, size, dma_handle, &cpu_addr))
 		return cpu_addr;
 
+	/*
+	 * Let the implementation decide on the zone to allocate from, and
+	 * decide on the way of zeroing the memory given that the memory
+	 * returned should always be zeroed.
+	 */
+	flag &= ~(__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM | __GFP_ZERO);
+
 	if (!arch_dma_alloc_attrs(&dev, &flag))
 		return NULL;
 	if (!ops->alloc)
@@ -568,6 +576,14 @@ static inline int dma_mapping_error(struct device *dev, dma_addr_t dma_addr)
 	return 0;
 }
 
+/*
+ * This is a hack for the legacy x86 forbid_dac and iommu_sac_force. Please
+ * don't use this is new code.
+ */
+#ifndef arch_dma_supported
+#define arch_dma_supported(dev, mask)	(1)
+#endif
+
 static inline void dma_check_mask(struct device *dev, u64 mask)
 {
 	if (sme_active() && (mask < (((u64)sme_get_me_mask() << 1) - 1)))
@@ -580,6 +596,9 @@ static inline int dma_supported(struct device *dev, u64 mask)
 
 	if (!ops)
 		return 0;
+	if (!arch_dma_supported(dev, mask))
+		return 0;
+
 	if (!ops->dma_supported)
 		return 1;
 	return ops->dma_supported(dev, mask);
@@ -692,7 +711,7 @@ static inline int dma_set_seg_boundary(struct device *dev, unsigned long mask)
 #ifndef dma_max_pfn
 static inline unsigned long dma_max_pfn(struct device *dev)
 {
-	return *dev->dma_mask >> PAGE_SHIFT;
+	return (*dev->dma_mask >> PAGE_SHIFT) + dev->dma_pfn_offset;
 }
 #endif
 
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 24ed817082ee..5b1f2a00491c 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -66,6 +66,12 @@ extern void swiotlb_tbl_sync_single(struct device *hwdev,
 				    enum dma_sync_target target);
 
 /* Accessory functions. */
+
+void *swiotlb_alloc(struct device *hwdev, size_t size, dma_addr_t *dma_handle,
+		gfp_t flags, unsigned long attrs);
+void swiotlb_free(struct device *dev, size_t size, void *vaddr,
+		dma_addr_t dma_addr, unsigned long attrs);
+
 extern void
 *swiotlb_alloc_coherent(struct device *hwdev, size_t size,
 			dma_addr_t *dma_handle, gfp_t flags);
@@ -115,10 +121,10 @@ extern int
 swiotlb_dma_supported(struct device *hwdev, u64 mask);
 
 #ifdef CONFIG_SWIOTLB
-extern void __init swiotlb_free(void);
+extern void __init swiotlb_exit(void);
 unsigned int swiotlb_max_segment(void);
 #else
-static inline void swiotlb_free(void) { }
+static inline void swiotlb_exit(void) { }
 static inline unsigned int swiotlb_max_segment(void) { return 0; }
 #endif
 
@@ -126,4 +132,6 @@ extern void swiotlb_print_info(void);
 extern int is_swiotlb_buffer(phys_addr_t paddr);
 extern void swiotlb_set_max_segment(unsigned int);
 
+extern const struct dma_map_ops swiotlb_dma_ops;
+
 #endif /* __LINUX_SWIOTLB_H */