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 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