1 files changed, 128 insertions, 0 deletions
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
new file mode 100644
index 000000000..77082246a
--- /dev/null
+++ b/arch/arm/include/asm/dma-mapping.h
@@ -0,0 +1,128 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef ASMARM_DMA_MAPPING_H
+#define ASMARM_DMA_MAPPING_H
+
+#ifdef __KERNEL__
+
+#include <linux/mm_types.h>
+#include <linux/scatterlist.h>
+
+#include <xen/xen.h>
+#include <asm/xen/hypervisor.h>
+
+extern const struct dma_map_ops arm_dma_ops;
+extern const struct dma_map_ops arm_coherent_dma_ops;
+
+static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
+{
+	if (IS_ENABLED(CONFIG_MMU) && !IS_ENABLED(CONFIG_ARM_LPAE))
+		return &arm_dma_ops;
+	return NULL;
+}
+
+/**
+ * arm_dma_alloc - allocate consistent memory for DMA
+ * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
+ * @size: required memory size
+ * @handle: bus-specific DMA address
+ * @attrs: optinal attributes that specific mapping properties
+ *
+ * Allocate some memory for a device for performing DMA.  This function
+ * allocates pages, and will return the CPU-viewed address, and sets @handle
+ * to be the device-viewed address.
+ */
+extern void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
+			   gfp_t gfp, unsigned long attrs);
+
+/**
+ * arm_dma_free - free memory allocated by arm_dma_alloc
+ * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
+ * @size: size of memory originally requested in dma_alloc_coherent
+ * @cpu_addr: CPU-view address returned from dma_alloc_coherent
+ * @handle: device-view address returned from dma_alloc_coherent
+ * @attrs: optinal attributes that specific mapping properties
+ *
+ * Free (and unmap) a DMA buffer previously allocated by
+ * arm_dma_alloc().
+ *
+ * References to memory and mappings associated with cpu_addr/handle
+ * during and after this call executing are illegal.
+ */
+extern void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
+			 dma_addr_t handle, unsigned long attrs);
+
+/**
+ * arm_dma_mmap - map a coherent DMA allocation into user space
+ * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
+ * @vma: vm_area_struct describing requested user mapping
+ * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
+ * @handle: device-view address returned from dma_alloc_coherent
+ * @size: size of memory originally requested in dma_alloc_coherent
+ * @attrs: optinal attributes that specific mapping properties
+ *
+ * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
+ * into user space.  The coherent DMA buffer must not be freed by the
+ * driver until the user space mapping has been released.
+ */
+extern int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
+			void *cpu_addr, dma_addr_t dma_addr, size_t size,
+			unsigned long attrs);
+
+/*
+ * For SA-1111, IXP425, and ADI systems  the dma-mapping functions are "magic"
+ * and utilize bounce buffers as needed to work around limited DMA windows.
+ *
+ * On the SA-1111, a bug limits DMA to only certain regions of RAM.
+ * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
+ * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
+ *
+ * The following are helper functions used by the dmabounce subystem
+ *
+ */
+
+/**
+ * dmabounce_register_dev
+ *
+ * @dev: valid struct device pointer
+ * @small_buf_size: size of buffers to use with small buffer pool
+ * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
+ * @needs_bounce_fn: called to determine whether buffer needs bouncing
+ *
+ * This function should be called by low-level platform code to register
+ * a device as requireing DMA buffer bouncing. The function will allocate
+ * appropriate DMA pools for the device.
+ */
+extern int dmabounce_register_dev(struct device *, unsigned long,
+		unsigned long, int (*)(struct device *, dma_addr_t, size_t));
+
+/**
+ * dmabounce_unregister_dev
+ *
+ * @dev: valid struct device pointer
+ *
+ * This function should be called by low-level platform code when device
+ * that was previously registered with dmabounce_register_dev is removed
+ * from the system.
+ *
+ */
+extern void dmabounce_unregister_dev(struct device *);
+
+
+
+/*
+ * The scatter list versions of the above methods.
+ */
+extern int arm_dma_map_sg(struct device *, struct scatterlist *, int,
+		enum dma_data_direction, unsigned long attrs);
+extern void arm_dma_unmap_sg(struct device *, struct scatterlist *, int,
+		enum dma_data_direction, unsigned long attrs);
+extern void arm_dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
+		enum dma_data_direction);
+extern void arm_dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
+		enum dma_data_direction);
+extern int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
+		void *cpu_addr, dma_addr_t dma_addr, size_t size,
+		unsigned long attrs);
+
+#endif /* __KERNEL__ */
+#endif