Merge tag 'dma-mapping-4.15' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping updates from Christoph Hellwig:

 - turn dma_cache_sync into a dma_map_ops instance and remove
   implementation that purely are dead because the architecture doesn't
   support noncoherent allocations

 - add a flag for busses that need DMA configuration (Robin Murphy)

* tag 'dma-mapping-4.15' of git://git.infradead.org/users/hch/dma-mapping:
  dma-mapping: turn dma_cache_sync into a dma_map_ops method
  sh: make dma_cache_sync a no-op
  xtensa: make dma_cache_sync a no-op
  unicore32: make dma_cache_sync a no-op
  powerpc: make dma_cache_sync a no-op
  mn10300: make dma_cache_sync a no-op
  microblaze: make dma_cache_sync a no-op
  ia64: make dma_cache_sync a no-op
  frv: make dma_cache_sync a no-op
  x86: make dma_cache_sync a no-op
  floppy: consolidate the dummy fd_cacheflush definition
  drivers: flag buses which demand DMA configuration

2 files changed, 17 insertions, 0 deletions

diff --git a/include/linux/device.h b/include/linux/device.h
index fb9451599aca..9d32000725da 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -97,6 +97,8 @@ extern void bus_remove_file(struct bus_type *, struct bus_attribute *);
  * @p:		The private data of the driver core, only the driver core can
  *		touch this.
  * @lock_key:	Lock class key for use by the lock validator
+ * @force_dma:	Assume devices on this bus should be set up by dma_configure()
+ * 		even if DMA capability is not explicitly described by firmware.
  *
  * A bus is a channel between the processor and one or more devices. For the
  * purposes of the device model, all devices are connected via a bus, even if
@@ -135,6 +137,8 @@ struct bus_type {
 
 	struct subsys_private *p;
 	struct lock_class_key lock_key;
+
+	bool force_dma;
 };
 
 extern int __must_check bus_register(struct bus_type *bus);
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 7653ea66874d..eee1499db396 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -127,6 +127,8 @@ struct dma_map_ops {
 	void (*sync_sg_for_device)(struct device *dev,
 				   struct scatterlist *sg, int nents,
 				   enum dma_data_direction dir);
+	void (*cache_sync)(struct device *dev, void *vaddr, size_t size,
+			enum dma_data_direction direction);
 	int (*mapping_error)(struct device *dev, dma_addr_t dma_addr);
 	int (*dma_supported)(struct device *dev, u64 mask);
 #ifdef ARCH_HAS_DMA_GET_REQUIRED_MASK
@@ -437,6 +439,17 @@ dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
 #define dma_map_page(d, p, o, s, r) dma_map_page_attrs(d, p, o, s, r, 0)
 #define dma_unmap_page(d, a, s, r) dma_unmap_page_attrs(d, a, s, r, 0)
 
+static inline void
+dma_cache_sync(struct device *dev, void *vaddr, size_t size,
+		enum dma_data_direction dir)
+{
+	const struct dma_map_ops *ops = get_dma_ops(dev);
+
+	BUG_ON(!valid_dma_direction(dir));
+	if (ops->cache_sync)
+		ops->cache_sync(dev, vaddr, size, dir);
+}
+
 extern int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
 			   void *cpu_addr, dma_addr_t dma_addr, size_t size);