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#include <linux/dma-debug.h>
 10
 11#include <asm/memory.h>
 12
 13#include <xen/xen.h>
 14#include <asm/xen/hypervisor.h>
 15
 16extern const struct dma_map_ops arm_dma_ops;
 17extern const struct dma_map_ops arm_coherent_dma_ops;
 18
 19static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus)
 20{
 21	if (IS_ENABLED(CONFIG_MMU) && !IS_ENABLED(CONFIG_ARM_LPAE))
 22		return &arm_dma_ops;
 23	return NULL;
 24}
 25
 26#ifdef __arch_page_to_dma
 27#error Please update to __arch_pfn_to_dma
 28#endif
 29
 30/*
 31 * dma_to_pfn/pfn_to_dma/dma_to_virt/virt_to_dma are architecture private
 32 * functions used internally by the DMA-mapping API to provide DMA
 33 * addresses. They must not be used by drivers.
 34 */
 35#ifndef __arch_pfn_to_dma
 36static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
 37{
 38	if (dev)
 39		pfn -= dev->dma_pfn_offset;
 40	return (dma_addr_t)__pfn_to_bus(pfn);
 41}
 42
 43static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
 44{
 45	unsigned long pfn = __bus_to_pfn(addr);
 46
 47	if (dev)
 48		pfn += dev->dma_pfn_offset;
 49
 50	return pfn;
 51}
 52
 53static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
 54{
 55	if (dev) {
 56		unsigned long pfn = dma_to_pfn(dev, addr);
 57
 58		return phys_to_virt(__pfn_to_phys(pfn));
 59	}
 60
 61	return (void *)__bus_to_virt((unsigned long)addr);
 62}
 63
 64static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
 65{
 66	if (dev)
 67		return pfn_to_dma(dev, virt_to_pfn(addr));
 68
 69	return (dma_addr_t)__virt_to_bus((unsigned long)(addr));
 70}
 71
 72#else
 73static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
 74{
 75	return __arch_pfn_to_dma(dev, pfn);
 76}
 77
 78static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
 79{
 80	return __arch_dma_to_pfn(dev, addr);
 81}
 82
 83static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
 84{
 85	return __arch_dma_to_virt(dev, addr);
 86}
 87
 88static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
 89{
 90	return __arch_virt_to_dma(dev, addr);
 91}
 92#endif
 93
 94/**
 95 * arm_dma_alloc - allocate consistent memory for DMA
 96 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
 97 * @size: required memory size
 98 * @handle: bus-specific DMA address
 99 * @attrs: optinal attributes that specific mapping properties
100 *
101 * Allocate some memory for a device for performing DMA.  This function
102 * allocates pages, and will return the CPU-viewed address, and sets @handle
103 * to be the device-viewed address.
104 */
105extern void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
106			   gfp_t gfp, unsigned long attrs);
107
108/**
109 * arm_dma_free - free memory allocated by arm_dma_alloc
110 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
111 * @size: size of memory originally requested in dma_alloc_coherent
112 * @cpu_addr: CPU-view address returned from dma_alloc_coherent
113 * @handle: device-view address returned from dma_alloc_coherent
114 * @attrs: optinal attributes that specific mapping properties
115 *
116 * Free (and unmap) a DMA buffer previously allocated by
117 * arm_dma_alloc().
118 *
119 * References to memory and mappings associated with cpu_addr/handle
120 * during and after this call executing are illegal.
121 */
122extern void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
123			 dma_addr_t handle, unsigned long attrs);
124
125/**
126 * arm_dma_mmap - map a coherent DMA allocation into user space
127 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
128 * @vma: vm_area_struct describing requested user mapping
129 * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
130 * @handle: device-view address returned from dma_alloc_coherent
131 * @size: size of memory originally requested in dma_alloc_coherent
132 * @attrs: optinal attributes that specific mapping properties
133 *
134 * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
135 * into user space.  The coherent DMA buffer must not be freed by the
136 * driver until the user space mapping has been released.
137 */
138extern int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
139			void *cpu_addr, dma_addr_t dma_addr, size_t size,
140			unsigned long attrs);
141
142/*
143 * For SA-1111, IXP425, and ADI systems  the dma-mapping functions are "magic"
144 * and utilize bounce buffers as needed to work around limited DMA windows.
145 *
146 * On the SA-1111, a bug limits DMA to only certain regions of RAM.
147 * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
148 * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
149 *
150 * The following are helper functions used by the dmabounce subystem
151 *
152 */
153
154/**
155 * dmabounce_register_dev
156 *
157 * @dev: valid struct device pointer
158 * @small_buf_size: size of buffers to use with small buffer pool
159 * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
160 * @needs_bounce_fn: called to determine whether buffer needs bouncing
161 *
162 * This function should be called by low-level platform code to register
163 * a device as requireing DMA buffer bouncing. The function will allocate
164 * appropriate DMA pools for the device.
165 */
166extern int dmabounce_register_dev(struct device *, unsigned long,
167		unsigned long, int (*)(struct device *, dma_addr_t, size_t));
168
169/**
170 * dmabounce_unregister_dev
171 *
172 * @dev: valid struct device pointer
173 *
174 * This function should be called by low-level platform code when device
175 * that was previously registered with dmabounce_register_dev is removed
176 * from the system.
177 *
178 */
179extern void dmabounce_unregister_dev(struct device *);
180
181
182
183/*
184 * The scatter list versions of the above methods.
185 */
186extern int arm_dma_map_sg(struct device *, struct scatterlist *, int,
187		enum dma_data_direction, unsigned long attrs);
188extern void arm_dma_unmap_sg(struct device *, struct scatterlist *, int,
189		enum dma_data_direction, unsigned long attrs);
190extern void arm_dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
191		enum dma_data_direction);
192extern void arm_dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
193		enum dma_data_direction);
194extern int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
195		void *cpu_addr, dma_addr_t dma_addr, size_t size,
196		unsigned long attrs);
197
198#endif /* __KERNEL__ */
199#endif