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	return IS_ENABLED(CONFIG_MMU) ? &arm_dma_ops : &dma_direct_ops;
 22}
 23
 24#ifdef __arch_page_to_dma
 25#error Please update to __arch_pfn_to_dma
 26#endif
 27
 28/*
 29 * dma_to_pfn/pfn_to_dma/dma_to_virt/virt_to_dma are architecture private
 30 * functions used internally by the DMA-mapping API to provide DMA
 31 * addresses. They must not be used by drivers.
 32 */
 33#ifndef __arch_pfn_to_dma
 34static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
 35{
 36	if (dev)
 37		pfn -= dev->dma_pfn_offset;
 38	return (dma_addr_t)__pfn_to_bus(pfn);
 39}
 40
 41static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
 42{
 43	unsigned long pfn = __bus_to_pfn(addr);
 44
 45	if (dev)
 46		pfn += dev->dma_pfn_offset;
 47
 48	return pfn;
 49}
 50
 51static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
 52{
 53	if (dev) {
 54		unsigned long pfn = dma_to_pfn(dev, addr);
 55
 56		return phys_to_virt(__pfn_to_phys(pfn));
 57	}
 58
 59	return (void *)__bus_to_virt((unsigned long)addr);
 60}
 61
 62static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
 63{
 64	if (dev)
 65		return pfn_to_dma(dev, virt_to_pfn(addr));
 66
 67	return (dma_addr_t)__virt_to_bus((unsigned long)(addr));
 68}
 69
 70#else
 71static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn)
 72{
 73	return __arch_pfn_to_dma(dev, pfn);
 74}
 75
 76static inline unsigned long dma_to_pfn(struct device *dev, dma_addr_t addr)
 77{
 78	return __arch_dma_to_pfn(dev, addr);
 79}
 80
 81static inline void *dma_to_virt(struct device *dev, dma_addr_t addr)
 82{
 83	return __arch_dma_to_virt(dev, addr);
 84}
 85
 86static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
 87{
 88	return __arch_virt_to_dma(dev, addr);
 89}
 90#endif
 91
 92/* The ARM override for dma_max_pfn() */
 93static inline unsigned long dma_max_pfn(struct device *dev)
 94{
 95	return dma_to_pfn(dev, *dev->dma_mask);
 96}
 97#define dma_max_pfn(dev) dma_max_pfn(dev)
 98
 99#define arch_setup_dma_ops arch_setup_dma_ops
100extern void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
101			       const struct iommu_ops *iommu, bool coherent);
102
103#define arch_teardown_dma_ops arch_teardown_dma_ops
104extern void arch_teardown_dma_ops(struct device *dev);
105
106/* do not use this function in a driver */
107static inline bool is_device_dma_coherent(struct device *dev)
108{
109	return dev->archdata.dma_coherent;
110}
111
112/**
113 * arm_dma_alloc - allocate consistent memory for DMA
114 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
115 * @size: required memory size
116 * @handle: bus-specific DMA address
117 * @attrs: optinal attributes that specific mapping properties
118 *
119 * Allocate some memory for a device for performing DMA.  This function
120 * allocates pages, and will return the CPU-viewed address, and sets @handle
121 * to be the device-viewed address.
122 */
123extern void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
124			   gfp_t gfp, unsigned long attrs);
125
126/**
127 * arm_dma_free - free memory allocated by arm_dma_alloc
128 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
129 * @size: size of memory originally requested in dma_alloc_coherent
130 * @cpu_addr: CPU-view address returned from dma_alloc_coherent
131 * @handle: device-view address returned from dma_alloc_coherent
132 * @attrs: optinal attributes that specific mapping properties
133 *
134 * Free (and unmap) a DMA buffer previously allocated by
135 * arm_dma_alloc().
136 *
137 * References to memory and mappings associated with cpu_addr/handle
138 * during and after this call executing are illegal.
139 */
140extern void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
141			 dma_addr_t handle, unsigned long attrs);
142
143/**
144 * arm_dma_mmap - map a coherent DMA allocation into user space
145 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
146 * @vma: vm_area_struct describing requested user mapping
147 * @cpu_addr: kernel CPU-view address returned from dma_alloc_coherent
148 * @handle: device-view address returned from dma_alloc_coherent
149 * @size: size of memory originally requested in dma_alloc_coherent
150 * @attrs: optinal attributes that specific mapping properties
151 *
152 * Map a coherent DMA buffer previously allocated by dma_alloc_coherent
153 * into user space.  The coherent DMA buffer must not be freed by the
154 * driver until the user space mapping has been released.
155 */
156extern int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
157			void *cpu_addr, dma_addr_t dma_addr, size_t size,
158			unsigned long attrs);
159
160/*
161 * For SA-1111, IXP425, and ADI systems  the dma-mapping functions are "magic"
162 * and utilize bounce buffers as needed to work around limited DMA windows.
163 *
164 * On the SA-1111, a bug limits DMA to only certain regions of RAM.
165 * On the IXP425, the PCI inbound window is 64MB (256MB total RAM)
166 * On some ADI engineering systems, PCI inbound window is 32MB (12MB total RAM)
167 *
168 * The following are helper functions used by the dmabounce subystem
169 *
170 */
171
172/**
173 * dmabounce_register_dev
174 *
175 * @dev: valid struct device pointer
176 * @small_buf_size: size of buffers to use with small buffer pool
177 * @large_buf_size: size of buffers to use with large buffer pool (can be 0)
178 * @needs_bounce_fn: called to determine whether buffer needs bouncing
179 *
180 * This function should be called by low-level platform code to register
181 * a device as requireing DMA buffer bouncing. The function will allocate
182 * appropriate DMA pools for the device.
183 */
184extern int dmabounce_register_dev(struct device *, unsigned long,
185		unsigned long, int (*)(struct device *, dma_addr_t, size_t));
186
187/**
188 * dmabounce_unregister_dev
189 *
190 * @dev: valid struct device pointer
191 *
192 * This function should be called by low-level platform code when device
193 * that was previously registered with dmabounce_register_dev is removed
194 * from the system.
195 *
196 */
197extern void dmabounce_unregister_dev(struct device *);
198
199
200
201/*
202 * The scatter list versions of the above methods.
203 */
204extern int arm_dma_map_sg(struct device *, struct scatterlist *, int,
205		enum dma_data_direction, unsigned long attrs);
206extern void arm_dma_unmap_sg(struct device *, struct scatterlist *, int,
207		enum dma_data_direction, unsigned long attrs);
208extern void arm_dma_sync_sg_for_cpu(struct device *, struct scatterlist *, int,
209		enum dma_data_direction);
210extern void arm_dma_sync_sg_for_device(struct device *, struct scatterlist *, int,
211		enum dma_data_direction);
212extern int arm_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
213		void *cpu_addr, dma_addr_t dma_addr, size_t size,
214		unsigned long attrs);
215
216#endif /* __KERNEL__ */
217#endif