tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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