waterDataStatisticsCrossAssociation memoryCall.h 沈礼文 commit at 2020-09-24

waterDataStatisticsCrossAssociation/dataSharedMemory/memoryCall.h

@@ -130,3 +130,139 @@ dma_map_single(struct device *dev, void *cpu_addr, size_t size,
  *
  * Unmap a single streaming mode DMA translation.  The handle and size
  * must match what was provided in the previous dma_map_single() call.
+ * All other usages are undefined.
+ *
+ * After this call, reads by the CPU to the buffer are guaranteed to see
+ * whatever the device wrote there.
+ */
+static inline void
+dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
+		 enum dma_data_direction direction)
+{
+
+}
+
+/**
+ * dma_map_page - map a portion of a page for streaming DMA
+ * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
+ * @page: page that buffer resides in
+ * @offset: offset into page for start of buffer
+ * @size: size of buffer to map
+ * @dir: DMA transfer direction
+ *
+ * Ensure that any data held in the cache is appropriately discarded
+ * or written back.
+ *
+ * The device owns this memory once this call has completed.  The CPU
+ * can regain ownership by calling dma_unmap_page() or dma_sync_single().
+ */
+static inline dma_addr_t
+dma_map_page(struct device *dev, struct page *page,
+	     unsigned long offset, size_t size,
+	     enum dma_data_direction direction)
+{
+	return dma_map_single(dev, page_address(page) + offset,
+			      size, direction);
+}
+
+/**
+ * dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
+ * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
+ * @handle: DMA address of buffer
+ * @size: size of buffer to map
+ * @dir: DMA transfer direction
+ *
+ * Unmap a single streaming mode DMA translation.  The handle and size
+ * must match what was provided in the previous dma_map_single() call.
+ * All other usages are undefined.
+ *
+ * After this call, reads by the CPU to the buffer are guaranteed to see
+ * whatever the device wrote there.
+ */
+static inline void
+dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
+	       enum dma_data_direction direction)
+{
+	dma_unmap_single(dev, dma_address, size, direction);
+}
+
+/**
+ * dma_map_sg - map a set of SG buffers for streaming mode DMA
+ * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
+ * @sg: list of buffers
+ * @nents: number of buffers to map
+ * @dir: DMA transfer direction
+ *
+ * Map a set of buffers described by scatterlist in streaming
+ * mode for DMA.  This is the scatter-gather version of the
+ * above pci_map_single interface.  Here the scatter gather list
+ * elements are each tagged with the appropriate dma address
+ * and length.  They are obtained via sg_dma_{address,length}(SG).
+ *
+ * NOTE: An implementation may be able to use a smaller number of
+ *       DMA address/length pairs than there are SG table elements.
+ *       (for example via virtual mapping capabilities)
+ *       The routine returns the number of addr/length pairs actually
+ *       used, at most nents.
+ *
+ * Device ownership issues as mentioned above for pci_map_single are
+ * the same here.
+ */
+static inline int
+dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
+	   enum dma_data_direction direction)
+{
+	int i;
+
+	for (i = 0; i < nents; i++) {
+		char *virt;
+
+		sg[i].dma_address = page_to_bus(sg_page(&sg[i])) + sg[i].offset;
+		virt = sg_virt(&sg[i]);
+		dma_cache_sync(dev, virt, sg[i].length, direction);
+	}
+
+	return nents;
+}
+
+/**
+ * dma_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
+ * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
+ * @sg: list of buffers
+ * @nents: number of buffers to map
+ * @dir: DMA transfer direction
+ *
+ * Unmap a set of streaming mode DMA translations.
+ * Again, CPU read rules concerning calls here are the same as for
+ * pci_unmap_single() above.
+ */
+static inline void
+dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nhwentries,
+	     enum dma_data_direction direction)
+{
+
+}
+
+/**
+ * dma_sync_single_for_cpu
+ * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
+ * @handle: DMA address of buffer
+ * @size: size of buffer to map
+ * @dir: DMA transfer direction
+ *
+ * Make physical memory consistent for a single streaming mode DMA
+ * translation after a transfer.
+ *
+ * If you perform a dma_map_single() but wish to interrogate the
+ * buffer using the cpu, yet do not wish to teardown the DMA mapping,
+ * you must call this function before doing so.  At the next point you
+ * give the DMA address back to the card, you must first perform a
+ * dma_sync_single_for_device, and then the device again owns the
+ * buffer.
+ */
+static inline void
+dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
+			size_t size, enum dma_data_direction direction)
+{
+	/*
+	 * No need to do anything since the CPU isn't supposed to