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
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
|
/*
* atomicio.c - ACPI IO memory pre-mapping/post-unmapping, then
* accessing in atomic context.
*
* This is used for NMI handler to access IO memory area, because
* ioremap/iounmap can not be used in NMI handler. The IO memory area
* is pre-mapped in process context and accessed in NMI handler.
*
* Copyright (C) 2009-2010, Intel Corp.
* Author: Huang Ying <ying.huang@intel.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version
* 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/init.h>
#include <linux/acpi.h>
#include <linux/io.h>
#include <linux/kref.h>
#include <linux/rculist.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/highmem.h>
#include <acpi/atomicio.h>
#define ACPI_PFX "ACPI: "
static LIST_HEAD(acpi_iomaps);
/*
* Used for mutual exclusion between writers of acpi_iomaps list, for
* synchronization between readers and writer, RCU is used.
*/
static DEFINE_SPINLOCK(acpi_iomaps_lock);
struct acpi_iomap {
struct list_head list;
void __iomem *vaddr;
unsigned long size;
phys_addr_t paddr;
struct kref ref;
};
/* acpi_iomaps_lock or RCU read lock must be held before calling */
static struct acpi_iomap *__acpi_find_iomap(phys_addr_t paddr,
unsigned long size)
{
struct acpi_iomap *map;
list_for_each_entry_rcu(map, &acpi_iomaps, list) {
if (map->paddr + map->size >= paddr + size &&
map->paddr <= paddr)
return map;
}
return NULL;
}
/*
* Atomic "ioremap" used by NMI handler, if the specified IO memory
* area is not pre-mapped, NULL will be returned.
*
* acpi_iomaps_lock or RCU read lock must be held before calling
*/
static void __iomem *__acpi_ioremap_fast(phys_addr_t paddr,
unsigned long size)
{
struct acpi_iomap *map;
map = __acpi_find_iomap(paddr, size/8);
if (map)
return map->vaddr + (paddr - map->paddr);
else
return NULL;
}
/* acpi_iomaps_lock must be held before calling */
static void __iomem *__acpi_try_ioremap(phys_addr_t paddr,
unsigned long size)
{
struct acpi_iomap *map;
map = __acpi_find_iomap(paddr, size);
if (map) {
kref_get(&map->ref);
return map->vaddr + (paddr - map->paddr);
} else
return NULL;
}
#ifndef CONFIG_IA64
#define should_use_kmap(pfn) page_is_ram(pfn)
#else
/* ioremap will take care of cache attributes */
#define should_use_kmap(pfn) 0
#endif
static void __iomem *acpi_map(phys_addr_t pg_off, unsigned long pg_sz)
{
unsigned long pfn;
pfn = pg_off >> PAGE_SHIFT;
if (should_use_kmap(pfn)) {
if (pg_sz > PAGE_SIZE)
return NULL;
return (void __iomem __force *)kmap(pfn_to_page(pfn));
} else
return ioremap(pg_off, pg_sz);
}
static void acpi_unmap(phys_addr_t pg_off, void __iomem *vaddr)
{
unsigned long pfn;
pfn = pg_off >> PAGE_SHIFT;
if (page_is_ram(pfn))
kunmap(pfn_to_page(pfn));
else
iounmap(vaddr);
}
/*
* Used to pre-map the specified IO memory area. First try to find
* whether the area is already pre-mapped, if it is, increase the
* reference count (in __acpi_try_ioremap) and return; otherwise, do
* the real ioremap, and add the mapping into acpi_iomaps list.
*/
static void __iomem *acpi_pre_map(phys_addr_t paddr,
unsigned long size)
{
void __iomem *vaddr;
struct acpi_iomap *map;
unsigned long pg_sz, flags;
phys_addr_t pg_off;
spin_lock_irqsave(&acpi_iomaps_lock, flags);
vaddr = __acpi_try_ioremap(paddr, size);
spin_unlock_irqrestore(&acpi_iomaps_lock, flags);
if (vaddr)
return vaddr;
pg_off = paddr & PAGE_MASK;
pg_sz = ((paddr + size + PAGE_SIZE - 1) & PAGE_MASK) - pg_off;
vaddr = acpi_map(pg_off, pg_sz);
if (!vaddr)
return NULL;
map = kmalloc(sizeof(*map), GFP_KERNEL);
if (!map)
goto err_unmap;
INIT_LIST_HEAD(&map->list);
map->paddr = pg_off;
map->size = pg_sz;
map->vaddr = vaddr;
kref_init(&map->ref);
spin_lock_irqsave(&acpi_iomaps_lock, flags);
vaddr = __acpi_try_ioremap(paddr, size);
if (vaddr) {
spin_unlock_irqrestore(&acpi_iomaps_lock, flags);
acpi_unmap(pg_off, map->vaddr);
kfree(map);
return vaddr;
}
list_add_tail_rcu(&map->list, &acpi_iomaps);
spin_unlock_irqrestore(&acpi_iomaps_lock, flags);
return map->vaddr + (paddr - map->paddr);
err_unmap:
acpi_unmap(pg_off, vaddr);
return NULL;
}
/* acpi_iomaps_lock must be held before calling */
static void __acpi_kref_del_iomap(struct kref *ref)
{
struct acpi_iomap *map;
map = container_of(ref, struct acpi_iomap, ref);
list_del_rcu(&map->list);
}
/*
* Used to post-unmap the specified IO memory area. The iounmap is
* done only if the reference count goes zero.
*/
static void acpi_post_unmap(phys_addr_t paddr, unsigned long size)
{
struct acpi_iomap *map;
unsigned long flags;
int del;
spin_lock_irqsave(&acpi_iomaps_lock, flags);
map = __acpi_find_iomap(paddr, size);
BUG_ON(!map);
del = kref_put(&map->ref, __acpi_kref_del_iomap);
spin_unlock_irqrestore(&acpi_iomaps_lock, flags);
if (!del)
return;
synchronize_rcu();
acpi_unmap(map->paddr, map->vaddr);
kfree(map);
}
/* In NMI handler, should set silent = 1 */
static int acpi_check_gar(struct acpi_generic_address *reg,
u64 *paddr, int silent)
{
u32 width, space_id;
width = reg->bit_width;
space_id = reg->space_id;
/* Handle possible alignment issues */
memcpy(paddr, ®->address, sizeof(*paddr));
if (!*paddr) {
if (!silent)
pr_warning(FW_BUG ACPI_PFX
"Invalid physical address in GAR [0x%llx/%u/%u]\n",
*paddr, width, space_id);
return -EINVAL;
}
if ((width != 8) && (width != 16) && (width != 32) && (width != 64)) {
if (!silent)
pr_warning(FW_BUG ACPI_PFX
"Invalid bit width in GAR [0x%llx/%u/%u]\n",
*paddr, width, space_id);
return -EINVAL;
}
if (space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY &&
space_id != ACPI_ADR_SPACE_SYSTEM_IO) {
if (!silent)
pr_warning(FW_BUG ACPI_PFX
"Invalid address space type in GAR [0x%llx/%u/%u]\n",
*paddr, width, space_id);
return -EINVAL;
}
return 0;
}
/* Pre-map, working on GAR */
int acpi_pre_map_gar(struct acpi_generic_address *reg)
{
u64 paddr;
void __iomem *vaddr;
int rc;
if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY)
return 0;
rc = acpi_check_gar(reg, &paddr, 0);
if (rc)
return rc;
vaddr = acpi_pre_map(paddr, reg->bit_width / 8);
if (!vaddr)
return -EIO;
return 0;
}
EXPORT_SYMBOL_GPL(acpi_pre_map_gar);
/* Post-unmap, working on GAR */
int acpi_post_unmap_gar(struct acpi_generic_address *reg)
{
u64 paddr;
int rc;
if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY)
return 0;
rc = acpi_check_gar(reg, &paddr, 0);
if (rc)
return rc;
acpi_post_unmap(paddr, reg->bit_width / 8);
return 0;
}
EXPORT_SYMBOL_GPL(
|