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