1 | /* SPDX-License-Identifier: GPL-2.0-only */ |
2 | /* |
3 | * Copyright © 2008 Keith Packard <keithp@keithp.com> |
4 | */ |
5 | |
6 | #ifndef _LINUX_IO_MAPPING_H |
7 | #define _LINUX_IO_MAPPING_H |
8 | |
9 | #include <linux/types.h> |
10 | #include <linux/slab.h> |
11 | #include <linux/bug.h> |
12 | #include <linux/io.h> |
13 | #include <linux/pgtable.h> |
14 | #include <asm/page.h> |
15 | |
16 | /* |
17 | * The io_mapping mechanism provides an abstraction for mapping |
18 | * individual pages from an io device to the CPU in an efficient fashion. |
19 | * |
20 | * See Documentation/driver-api/io-mapping.rst |
21 | */ |
22 | |
23 | struct io_mapping { |
24 | resource_size_t base; |
25 | unsigned long size; |
26 | pgprot_t prot; |
27 | void __iomem *iomem; |
28 | }; |
29 | |
30 | #ifdef CONFIG_HAVE_ATOMIC_IOMAP |
31 | |
32 | #include <linux/pfn.h> |
33 | #include <asm/iomap.h> |
34 | /* |
35 | * For small address space machines, mapping large objects |
36 | * into the kernel virtual space isn't practical. Where |
37 | * available, use fixmap support to dynamically map pages |
38 | * of the object at run time. |
39 | */ |
40 | |
41 | static inline struct io_mapping * |
42 | io_mapping_init_wc(struct io_mapping *iomap, |
43 | resource_size_t base, |
44 | unsigned long size) |
45 | { |
46 | pgprot_t prot; |
47 | |
48 | if (iomap_create_wc(base, size, &prot)) |
49 | return NULL; |
50 | |
51 | iomap->base = base; |
52 | iomap->size = size; |
53 | iomap->prot = prot; |
54 | return iomap; |
55 | } |
56 | |
57 | static inline void |
58 | io_mapping_fini(struct io_mapping *mapping) |
59 | { |
60 | iomap_free(mapping->base, mapping->size); |
61 | } |
62 | |
63 | /* Atomic map/unmap */ |
64 | static inline void __iomem * |
65 | io_mapping_map_atomic_wc(struct io_mapping *mapping, |
66 | unsigned long offset) |
67 | { |
68 | resource_size_t phys_addr; |
69 | |
70 | BUG_ON(offset >= mapping->size); |
71 | phys_addr = mapping->base + offset; |
72 | if (!IS_ENABLED(CONFIG_PREEMPT_RT)) |
73 | preempt_disable(); |
74 | else |
75 | migrate_disable(); |
76 | pagefault_disable(); |
77 | return __iomap_local_pfn_prot(PHYS_PFN(phys_addr), mapping->prot); |
78 | } |
79 | |
80 | static inline void |
81 | io_mapping_unmap_atomic(void __iomem *vaddr) |
82 | { |
83 | kunmap_local_indexed((void __force *)vaddr); |
84 | pagefault_enable(); |
85 | if (!IS_ENABLED(CONFIG_PREEMPT_RT)) |
86 | preempt_enable(); |
87 | else |
88 | migrate_enable(); |
89 | } |
90 | |
91 | static inline void __iomem * |
92 | io_mapping_map_local_wc(struct io_mapping *mapping, unsigned long offset) |
93 | { |
94 | resource_size_t phys_addr; |
95 | |
96 | BUG_ON(offset >= mapping->size); |
97 | phys_addr = mapping->base + offset; |
98 | return __iomap_local_pfn_prot(PHYS_PFN(phys_addr), mapping->prot); |
99 | } |
100 | |
101 | static inline void io_mapping_unmap_local(void __iomem *vaddr) |
102 | { |
103 | kunmap_local_indexed((void __force *)vaddr); |
104 | } |
105 | |
106 | static inline void __iomem * |
107 | io_mapping_map_wc(struct io_mapping *mapping, |
108 | unsigned long offset, |
109 | unsigned long size) |
110 | { |
111 | resource_size_t phys_addr; |
112 | |
113 | BUG_ON(offset >= mapping->size); |
114 | phys_addr = mapping->base + offset; |
115 | |
116 | return ioremap_wc(phys_addr, size); |
117 | } |
118 | |
119 | static inline void |
120 | io_mapping_unmap(void __iomem *vaddr) |
121 | { |
122 | iounmap(vaddr); |
123 | } |
124 | |
125 | #else /* HAVE_ATOMIC_IOMAP */ |
126 | |
127 | #include <linux/uaccess.h> |
128 | |
129 | /* Create the io_mapping object*/ |
130 | static inline struct io_mapping * |
131 | io_mapping_init_wc(struct io_mapping *iomap, |
132 | resource_size_t base, |
133 | unsigned long size) |
134 | { |
135 | iomap->iomem = ioremap_wc(offset: base, size); |
136 | if (!iomap->iomem) |
137 | return NULL; |
138 | |
139 | iomap->base = base; |
140 | iomap->size = size; |
141 | iomap->prot = pgprot_writecombine(PAGE_KERNEL); |
142 | |
143 | return iomap; |
144 | } |
145 | |
146 | static inline void |
147 | io_mapping_fini(struct io_mapping *mapping) |
148 | { |
149 | iounmap(addr: mapping->iomem); |
150 | } |
151 | |
152 | /* Non-atomic map/unmap */ |
153 | static inline void __iomem * |
154 | io_mapping_map_wc(struct io_mapping *mapping, |
155 | unsigned long offset, |
156 | unsigned long size) |
157 | { |
158 | return mapping->iomem + offset; |
159 | } |
160 | |
161 | static inline void |
162 | io_mapping_unmap(void __iomem *vaddr) |
163 | { |
164 | } |
165 | |
166 | /* Atomic map/unmap */ |
167 | static inline void __iomem * |
168 | io_mapping_map_atomic_wc(struct io_mapping *mapping, |
169 | unsigned long offset) |
170 | { |
171 | if (!IS_ENABLED(CONFIG_PREEMPT_RT)) |
172 | preempt_disable(); |
173 | else |
174 | migrate_disable(); |
175 | pagefault_disable(); |
176 | return io_mapping_map_wc(mapping, offset, PAGE_SIZE); |
177 | } |
178 | |
179 | static inline void |
180 | io_mapping_unmap_atomic(void __iomem *vaddr) |
181 | { |
182 | io_mapping_unmap(vaddr); |
183 | pagefault_enable(); |
184 | if (!IS_ENABLED(CONFIG_PREEMPT_RT)) |
185 | preempt_enable(); |
186 | else |
187 | migrate_enable(); |
188 | } |
189 | |
190 | static inline void __iomem * |
191 | io_mapping_map_local_wc(struct io_mapping *mapping, unsigned long offset) |
192 | { |
193 | return io_mapping_map_wc(mapping, offset, PAGE_SIZE); |
194 | } |
195 | |
196 | static inline void io_mapping_unmap_local(void __iomem *vaddr) |
197 | { |
198 | io_mapping_unmap(vaddr); |
199 | } |
200 | |
201 | #endif /* !HAVE_ATOMIC_IOMAP */ |
202 | |
203 | static inline struct io_mapping * |
204 | io_mapping_create_wc(resource_size_t base, |
205 | unsigned long size) |
206 | { |
207 | struct io_mapping *iomap; |
208 | |
209 | iomap = kmalloc(size: sizeof(*iomap), GFP_KERNEL); |
210 | if (!iomap) |
211 | return NULL; |
212 | |
213 | if (!io_mapping_init_wc(iomap, base, size)) { |
214 | kfree(objp: iomap); |
215 | return NULL; |
216 | } |
217 | |
218 | return iomap; |
219 | } |
220 | |
221 | static inline void |
222 | io_mapping_free(struct io_mapping *iomap) |
223 | { |
224 | io_mapping_fini(mapping: iomap); |
225 | kfree(objp: iomap); |
226 | } |
227 | |
228 | int io_mapping_map_user(struct io_mapping *iomap, struct vm_area_struct *vma, |
229 | unsigned long addr, unsigned long pfn, unsigned long size); |
230 | |
231 | #endif /* _LINUX_IO_MAPPING_H */ |
232 | |