1/* SPDX-License-Identifier: GPL-2.0 */
  2#ifndef ASMARM_DMA_MAPPING_H
  3#define ASMARM_DMA_MAPPING_H
  4
  5#ifdef __KERNEL__
  6
  7#include <linux/mm_types.h>
  8#include <linux/scatterlist.h>
  9
 10#include <xen/xen.h>
 11#include <asm/xen/hypervisor.h>
 12
 13extern const struct dma_map_ops arm_dma_ops;
 14extern const struct dma_map_ops arm_coherent_dma_ops;
 15
 16static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 17{
 18	if (IS_ENABLED(CONFIG_MMU) && !IS_ENABLED(CONFIG_ARM_LPAE))
 19		return &arm_dma_ops;
 20	return NULL;
 21}
 22
 23/**
 24 * arm_dma_alloc - allocate consistent memory for DMA
 25 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 26 * @size: required memory size
 27 * @handle: bus-specific DMA address
 28 * @attrs: optinal attributes that specific mapping properties
 29 *
 30 * Allocate some memory for a device for performing DMA.  This function
 31 * allocates pages, and will return the CPU-viewed address, and sets @handle
 32 * to be the device-viewed address.
 33 */
 34extern void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
 35			   gfp_t gfp, unsigned long attrs);
 36
 37/**
 38 * arm_dma_free - free memory allocated by arm_dma_alloc
 39 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 40 * @size: size of memory originally requested in dma_alloc_coherent
 41 * @cpu_addr: CPU-view address returned from dma_alloc_coherent
 42 * @handle: device-view address returned from dma_alloc_coherent
 43 * @attrs: optinal attributes that specific mapping properties
 44 *
 45 * Free (and unmap) a DMA buffer previously allocated by
 46 * arm_dma_alloc().
 47 *
 48 * References to memory and mappings associated with cpu_addr/handle
 49 * during and after this call executing are illegal.
 50 */
 51extern void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
 52			 dma_addr_t handle, unsigned long attrs);
 53
 54/**
 55 * arm_dma_mmap - map a coherent DMA allocation into user space
 56 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 57 * @vma: vm_area_struct describing requested user mapping
 58 * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
 59 * @handle: device-view address returned from dma_alloc_coherent
 60 * @size: size of memory originally requested in dma_alloc_coherent
 61 * @attrs: optinal attributes that specific mapping properties
 62 *
 63 * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
 64 * into user space.  The coherent DMA buffer must not be freed by the
 65 * driver until the user space mapping has been released.
 66 */
 67extern int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
 68			void *cpu_addr, dma_addr_t dma_addr, size_t size,
 69			unsigned long attrs);
 70
 71/*
 72 * For SA-1111, IXP425, and ADI systems  the dma-mapping functions are "magic"
 73 * and utilize bounce buffers as needed to work around limited DMA windows.
 74 *
 75 * On the SA-1111, a bug limits DMA to only certain regions of RAM.
 76 * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
 77 * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
 78 *
 79 * The following are helper functions used by the dmabounce subystem
 80 *
 81 */
 82
 83/**
 84 * dmabounce_register_dev
 85 *
 86 * @dev: valid struct device pointer
 87 * @small_buf_size: size of buffers to use with small buffer pool
 88 * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
 89 * @needs_bounce_fn: called to determine whether buffer needs bouncing
 90 *
 91 * This function should be called by low-level platform code to register
 92 * a device as requireing DMA buffer bouncing. The function will allocate
 93 * appropriate DMA pools for the device.
 94 */
 95extern int dmabounce_register_dev(struct device *, unsigned long,
 96		unsigned long, int (*)(struct device *, dma_addr_t, size_t));
 97
 98/**
 99 * dmabounce_unregister_dev
100 *
101 * @dev: valid struct device pointer
102 *
103 * This function should be called by low-level platform code when device
104 * that was previously registered with dmabounce_register_dev is removed
105 * from the system.
106 *
107 */
108extern void dmabounce_unregister_dev(struct device *);
109
110
111
112/*
113 * The scatter list versions of the above methods.
114 */
115extern int arm_dma_map_sg(struct device *, struct scatterlist *, int,
116		enum dma_data_direction, unsigned long attrs);
117extern void arm_dma_unmap_sg(struct device *, struct scatterlist *, int,
118		enum dma_data_direction, unsigned long attrs);
119extern void arm_dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
120		enum dma_data_direction);
121extern void arm_dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
122		enum dma_data_direction);
123extern int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
124		void *cpu_addr, dma_addr_t dma_addr, size_t size,
125		unsigned long attrs);
126
127#endif /* __KERNEL__ */
128#endif