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nilfs2: fix oopses with doubly mounted snapshots
[linux-2.6/mini2440.git] / arch / sh / mm / pmb.c
blobb1a714a92b14fe4fcb8d029d6100456b3cc46d5b
1 /*
2 * arch/sh/mm/pmb.c
3 *
4 * Privileged Space Mapping Buffer (PMB) Support.
5 *
6 * Copyright (C) 2005, 2006, 2007 Paul Mundt
7 *
8 * P1/P2 Section mapping definitions from map32.h, which was:
9 *
10 * Copyright 2003 (c) Lineo Solutions,Inc.
11 *
12 * This file is subject to the terms and conditions of the GNU General Public
13 * License. See the file "COPYING" in the main directory of this archive
14 * for more details.
15 */
16 #include <linux/init.h>
17 #include <linux/kernel.h>
18 #include <linux/sysdev.h>
19 #include <linux/cpu.h>
20 #include <linux/module.h>
21 #include <linux/slab.h>
22 #include <linux/bitops.h>
23 #include <linux/debugfs.h>
24 #include <linux/fs.h>
25 #include <linux/seq_file.h>
26 #include <linux/err.h>
27 #include <asm/system.h>
28 #include <asm/uaccess.h>
29 #include <asm/pgtable.h>
30 #include <asm/mmu.h>
31 #include <asm/io.h>
32 #include <asm/mmu_context.h>
33
34 #define NR_PMB_ENTRIES 16
35
36 static struct kmem_cache *pmb_cache;
37 static unsigned long pmb_map;
38
39 static struct pmb_entry pmb_init_map[] = {
40 /* vpn ppn flags (ub/sz/c/wt) */
41
42 /* P1 Section Mappings */
43 { 0x80000000, 0x00000000, PMB_SZ_64M | PMB_C, },
44 { 0x84000000, 0x04000000, PMB_SZ_64M | PMB_C, },
45 { 0x88000000, 0x08000000, PMB_SZ_128M | PMB_C, },
46 { 0x90000000, 0x10000000, PMB_SZ_64M | PMB_C, },
47 { 0x94000000, 0x14000000, PMB_SZ_64M | PMB_C, },
48 { 0x98000000, 0x18000000, PMB_SZ_64M | PMB_C, },
49
50 /* P2 Section Mappings */
51 { 0xa0000000, 0x00000000, PMB_UB | PMB_SZ_64M | PMB_WT, },
52 { 0xa4000000, 0x04000000, PMB_UB | PMB_SZ_64M | PMB_WT, },
53 { 0xa8000000, 0x08000000, PMB_UB | PMB_SZ_128M | PMB_WT, },
54 { 0xb0000000, 0x10000000, PMB_UB | PMB_SZ_64M | PMB_WT, },
55 { 0xb4000000, 0x14000000, PMB_UB | PMB_SZ_64M | PMB_WT, },
56 { 0xb8000000, 0x18000000, PMB_UB | PMB_SZ_64M | PMB_WT, },
57 };
58
59 static inline unsigned long mk_pmb_entry(unsigned int entry)
60 {
61 return (entry & PMB_E_MASK) << PMB_E_SHIFT;
62 }
63
64 static inline unsigned long mk_pmb_addr(unsigned int entry)
65 {
66 return mk_pmb_entry(entry) | PMB_ADDR;
67 }
68
69 static inline unsigned long mk_pmb_data(unsigned int entry)
70 {
71 return mk_pmb_entry(entry) | PMB_DATA;
72 }
73
74 static DEFINE_SPINLOCK(pmb_list_lock);
75 static struct pmb_entry *pmb_list;
76
77 static inline void pmb_list_add(struct pmb_entry *pmbe)
78 {
79 struct pmb_entry **p, *tmp;
80
81 p = &pmb_list;
82 while ((tmp = *p) != NULL)
83 p = &tmp->next;
84
85 pmbe->next = tmp;
86 *p = pmbe;
87 }
88
89 static inline void pmb_list_del(struct pmb_entry *pmbe)
90 {
91 struct pmb_entry **p, *tmp;
92
93 for (p = &pmb_list; (tmp = *p); p = &tmp->next)
94 if (tmp == pmbe) {
95 *p = tmp->next;
96 return;
97 }
98 }
99
100 struct pmb_entry *pmb_alloc(unsigned long vpn, unsigned long ppn,
101 unsigned long flags)
102 {
103 struct pmb_entry *pmbe;
104
105 pmbe = kmem_cache_alloc(pmb_cache, GFP_KERNEL);
106 if (!pmbe)
107 return ERR_PTR(-ENOMEM);
108
109 pmbe->vpn = vpn;
110 pmbe->ppn = ppn;
111 pmbe->flags = flags;
112
113 spin_lock_irq(&pmb_list_lock);
114 pmb_list_add(pmbe);
115 spin_unlock_irq(&pmb_list_lock);
116
117 return pmbe;
118 }
119
120 void pmb_free(struct pmb_entry *pmbe)
121 {
122 spin_lock_irq(&pmb_list_lock);
123 pmb_list_del(pmbe);
124 spin_unlock_irq(&pmb_list_lock);
125
126 kmem_cache_free(pmb_cache, pmbe);
127 }
128
129 /*
130 * Must be in P2 for __set_pmb_entry()
131 */
132 int __set_pmb_entry(unsigned long vpn, unsigned long ppn,
133 unsigned long flags, int *entry)
134 {
135 unsigned int pos = *entry;
136
137 if (unlikely(pos == PMB_NO_ENTRY))
138 pos = find_first_zero_bit(&pmb_map, NR_PMB_ENTRIES);
139
140 repeat:
141 if (unlikely(pos > NR_PMB_ENTRIES))
142 return -ENOSPC;
143
144 if (test_and_set_bit(pos, &pmb_map)) {
145 pos = find_first_zero_bit(&pmb_map, NR_PMB_ENTRIES);
146 goto repeat;
147 }
148
149 ctrl_outl(vpn | PMB_V, mk_pmb_addr(pos));
150
151 #ifdef CONFIG_CACHE_WRITETHROUGH
152 /*
153 * When we are in 32-bit address extended mode, CCR.CB becomes
154 * invalid, so care must be taken to manually adjust cacheable
155 * translations.
156 */
157 if (likely(flags & PMB_C))
158 flags |= PMB_WT;
159 #endif
160
161 ctrl_outl(ppn | flags | PMB_V, mk_pmb_data(pos));
162
163 *entry = pos;
164
165 return 0;
166 }
167
168 int __uses_jump_to_uncached set_pmb_entry(struct pmb_entry *pmbe)
169 {
170 int ret;
171
172 jump_to_uncached();
173 ret = __set_pmb_entry(pmbe->vpn, pmbe->ppn, pmbe->flags, &pmbe->entry);
174 back_to_cached();
175
176 return ret;
177 }
178
179 void __uses_jump_to_uncached clear_pmb_entry(struct pmb_entry *pmbe)
180 {
181 unsigned int entry = pmbe->entry;
182 unsigned long addr;
183
184 /*
185 * Don't allow clearing of wired init entries, P1 or P2 access
186 * without a corresponding mapping in the PMB will lead to reset
187 * by the TLB.
188 */
189 if (unlikely(entry < ARRAY_SIZE(pmb_init_map) ||
190 entry >= NR_PMB_ENTRIES))
191 return;
192
193 jump_to_uncached();
194
195 /* Clear V-bit */
196 addr = mk_pmb_addr(entry);
197 ctrl_outl(ctrl_inl(addr) & ~PMB_V, addr);
198
199 addr = mk_pmb_data(entry);
200 ctrl_outl(ctrl_inl(addr) & ~PMB_V, addr);
201
202 back_to_cached();
203
204 clear_bit(entry, &pmb_map);
205 }
206
207
208 static struct {
209 unsigned long size;
210 int flag;
211 } pmb_sizes[] = {
212 { .size = 0x20000000, .flag = PMB_SZ_512M, },
213 { .size = 0x08000000, .flag = PMB_SZ_128M, },
214 { .size = 0x04000000, .flag = PMB_SZ_64M, },
215 { .size = 0x01000000, .flag = PMB_SZ_16M, },
216 };
217
218 long pmb_remap(unsigned long vaddr, unsigned long phys,
219 unsigned long size, unsigned long flags)
220 {
221 struct pmb_entry *pmbp;
222 unsigned long wanted;
223 int pmb_flags, i;
224
225 /* Convert typical pgprot value to the PMB equivalent */
226 if (flags & _PAGE_CACHABLE) {
227 if (flags & _PAGE_WT)
228 pmb_flags = PMB_WT;
229 else
230 pmb_flags = PMB_C;
231 } else
232 pmb_flags = PMB_WT | PMB_UB;
233
234 pmbp = NULL;
235 wanted = size;
236
237 again:
238 for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++) {
239 struct pmb_entry *pmbe;
240 int ret;
241
242 if (size < pmb_sizes[i].size)
243 continue;
244
245 pmbe = pmb_alloc(vaddr, phys, pmb_flags | pmb_sizes[i].flag);
246 if (IS_ERR(pmbe))
247 return PTR_ERR(pmbe);
248
249 ret = set_pmb_entry(pmbe);
250 if (ret != 0) {
251 pmb_free(pmbe);
252 return -EBUSY;
253 }
254
255 phys += pmb_sizes[i].size;
256 vaddr += pmb_sizes[i].size;
257 size -= pmb_sizes[i].size;
258
259 /*
260 * Link adjacent entries that span multiple PMB entries
261 * for easier tear-down.
262 */
263 if (likely(pmbp))
264 pmbp->link = pmbe;
265
266 pmbp = pmbe;
267 }
268
269 if (size >= 0x1000000)
270 goto again;
271
272 return wanted - size;
273 }
274
275 void pmb_unmap(unsigned long addr)
276 {
277 struct pmb_entry **p, *pmbe;
278
279 for (p = &pmb_list; (pmbe = *p); p = &pmbe->next)
280 if (pmbe->vpn == addr)
281 break;
282
283 if (unlikely(!pmbe))
284 return;
285
286 WARN_ON(!test_bit(pmbe->entry, &pmb_map));
287
288 do {
289 struct pmb_entry *pmblink = pmbe;
290
291 clear_pmb_entry(pmbe);
292 pmbe = pmblink->link;
293
294 pmb_free(pmblink);
295 } while (pmbe);
296 }
297
298 static void pmb_cache_ctor(void *pmb)
299 {
300 struct pmb_entry *pmbe = pmb;
301
302 memset(pmb, 0, sizeof(struct pmb_entry));
303
304 pmbe->entry = PMB_NO_ENTRY;
305 }
306
307 static int __uses_jump_to_uncached pmb_init(void)
308 {
309 unsigned int nr_entries = ARRAY_SIZE(pmb_init_map);
310 unsigned int entry, i;
311
312 BUG_ON(unlikely(nr_entries >= NR_PMB_ENTRIES));
313
314 pmb_cache = kmem_cache_create("pmb", sizeof(struct pmb_entry), 0,
315 SLAB_PANIC, pmb_cache_ctor);
316
317 jump_to_uncached();
318
319 /*
320 * Ordering is important, P2 must be mapped in the PMB before we
321 * can set PMB.SE, and P1 must be mapped before we jump back to
322 * P1 space.
323 */
324 for (entry = 0; entry < nr_entries; entry++) {
325 struct pmb_entry *pmbe = pmb_init_map + entry;
326
327 __set_pmb_entry(pmbe->vpn, pmbe->ppn, pmbe->flags, &entry);
328 }
329
330 ctrl_outl(0, PMB_IRMCR);
331
332 /* PMB.SE and UB[7] */
333 ctrl_outl((1 << 31) | (1 << 7), PMB_PASCR);
334
335 /* Flush out the TLB */
336 i = ctrl_inl(MMUCR);
337 i |= MMUCR_TI;
338 ctrl_outl(i, MMUCR);
339
340 back_to_cached();
341
342 return 0;
343 }
344 arch_initcall(pmb_init);
345
346 static int pmb_seq_show(struct seq_file *file, void *iter)
347 {
348 int i;
349
350 seq_printf(file, "V: Valid, C: Cacheable, WT: Write-Through\n"
351 "CB: Copy-Back, B: Buffered, UB: Unbuffered\n");
352 seq_printf(file, "ety vpn ppn size flags\n");
353
354 for (i = 0; i < NR_PMB_ENTRIES; i++) {
355 unsigned long addr, data;
356 unsigned int size;
357 char *sz_str = NULL;
358
359 addr = ctrl_inl(mk_pmb_addr(i));
360 data = ctrl_inl(mk_pmb_data(i));
361
362 size = data & PMB_SZ_MASK;
363 sz_str = (size == PMB_SZ_16M) ? " 16MB":
364 (size == PMB_SZ_64M) ? " 64MB":
365 (size == PMB_SZ_128M) ? "128MB":
366 "512MB";
367
368 /* 02: V 0x88 0x08 128MB C CB B */
369 seq_printf(file, "%02d: %c 0x%02lx 0x%02lx %s %c %s %s\n",
370 i, ((addr & PMB_V) && (data & PMB_V)) ? 'V' : ' ',
371 (addr >> 24) & 0xff, (data >> 24) & 0xff,
372 sz_str, (data & PMB_C) ? 'C' : ' ',
373 (data & PMB_WT) ? "WT" : "CB",
374 (data & PMB_UB) ? "UB" : " B");
375 }
376
377 return 0;
378 }
379
380 static int pmb_debugfs_open(struct inode *inode, struct file *file)
381 {
382 return single_open(file, pmb_seq_show, NULL);
383 }
384
385 static const struct file_operations pmb_debugfs_fops = {
386 .owner = THIS_MODULE,
387 .open = pmb_debugfs_open,
388 .read = seq_read,
389 .llseek = seq_lseek,
390 .release = single_release,
391 };
392
393 static int __init pmb_debugfs_init(void)
394 {
395 struct dentry *dentry;
396
397 dentry = debugfs_create_file("pmb", S_IFREG | S_IRUGO,
398 sh_debugfs_root, NULL, &pmb_debugfs_fops);
399 if (!dentry)
400 return -ENOMEM;
401 if (IS_ERR(dentry))
402 return PTR_ERR(dentry);
403
404 return 0;
405 }
406 postcore_initcall(pmb_debugfs_init);
407
408 #ifdef CONFIG_PM
409 static int pmb_sysdev_suspend(struct sys_device *dev, pm_message_t state)
410 {
411 static pm_message_t prev_state;
412
413 /* Restore the PMB after a resume from hibernation */
414 if (state.event == PM_EVENT_ON &&
415 prev_state.event == PM_EVENT_FREEZE) {
416 struct pmb_entry *pmbe;
417 spin_lock_irq(&pmb_list_lock);
418 for (pmbe = pmb_list; pmbe; pmbe = pmbe->next)
419 set_pmb_entry(pmbe);
420 spin_unlock_irq(&pmb_list_lock);
421 }
422 prev_state = state;
423 return 0;
424 }
425
426 static int pmb_sysdev_resume(struct sys_device *dev)
427 {
428 return pmb_sysdev_suspend(dev, PMSG_ON);
429 }
430
431 static struct sysdev_driver pmb_sysdev_driver = {
432 .suspend = pmb_sysdev_suspend,
433 .resume = pmb_sysdev_resume,
434 };
435
436 static int __init pmb_sysdev_init(void)
437 {
438 return sysdev_driver_register(&cpu_sysdev_class, &pmb_sysdev_driver);
439 }
440
441 subsys_initcall(pmb_sysdev_init);
442 #endif
Support for the Chinese Samsung S3C2440 based development boards