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drm/i915: Rephrase pwrite bounds checking to avoid any potential overflow
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / arch / sh / mm / pmb.c
blobaade311021124ece9c161278a2b145df8c39782a
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 void __pmb_unmap(struct pmb_entry *);
37
38 static struct kmem_cache *pmb_cache;
39 static unsigned long pmb_map;
40
41 static struct pmb_entry pmb_init_map[] = {
42 /* vpn ppn flags (ub/sz/c/wt) */
43
44 /* P1 Section Mappings */
45 { 0x80000000, 0x00000000, PMB_SZ_64M | PMB_C, },
46 { 0x84000000, 0x04000000, PMB_SZ_64M | PMB_C, },
47 { 0x88000000, 0x08000000, PMB_SZ_128M | PMB_C, },
48 { 0x90000000, 0x10000000, PMB_SZ_64M | PMB_C, },
49 { 0x94000000, 0x14000000, PMB_SZ_64M | PMB_C, },
50 { 0x98000000, 0x18000000, PMB_SZ_64M | PMB_C, },
51
52 /* P2 Section Mappings */
53 { 0xa0000000, 0x00000000, PMB_UB | PMB_SZ_64M | PMB_WT, },
54 { 0xa4000000, 0x04000000, PMB_UB | PMB_SZ_64M | PMB_WT, },
55 { 0xa8000000, 0x08000000, PMB_UB | PMB_SZ_128M | PMB_WT, },
56 { 0xb0000000, 0x10000000, PMB_UB | PMB_SZ_64M | PMB_WT, },
57 { 0xb4000000, 0x14000000, PMB_UB | PMB_SZ_64M | PMB_WT, },
58 { 0xb8000000, 0x18000000, PMB_UB | PMB_SZ_64M | PMB_WT, },
59 };
60
61 static inline unsigned long mk_pmb_entry(unsigned int entry)
62 {
63 return (entry & PMB_E_MASK) << PMB_E_SHIFT;
64 }
65
66 static inline unsigned long mk_pmb_addr(unsigned int entry)
67 {
68 return mk_pmb_entry(entry) | PMB_ADDR;
69 }
70
71 static inline unsigned long mk_pmb_data(unsigned int entry)
72 {
73 return mk_pmb_entry(entry) | PMB_DATA;
74 }
75
76 static DEFINE_SPINLOCK(pmb_list_lock);
77 static struct pmb_entry *pmb_list;
78
79 static inline void pmb_list_add(struct pmb_entry *pmbe)
80 {
81 struct pmb_entry **p, *tmp;
82
83 p = &pmb_list;
84 while ((tmp = *p) != NULL)
85 p = &tmp->next;
86
87 pmbe->next = tmp;
88 *p = pmbe;
89 }
90
91 static inline void pmb_list_del(struct pmb_entry *pmbe)
92 {
93 struct pmb_entry **p, *tmp;
94
95 for (p = &pmb_list; (tmp = *p); p = &tmp->next)
96 if (tmp == pmbe) {
97 *p = tmp->next;
98 return;
99 }
100 }
101
102 struct pmb_entry *pmb_alloc(unsigned long vpn, unsigned long ppn,
103 unsigned long flags)
104 {
105 struct pmb_entry *pmbe;
106
107 pmbe = kmem_cache_alloc(pmb_cache, GFP_KERNEL);
108 if (!pmbe)
109 return ERR_PTR(-ENOMEM);
110
111 pmbe->vpn = vpn;
112 pmbe->ppn = ppn;
113 pmbe->flags = flags;
114
115 spin_lock_irq(&pmb_list_lock);
116 pmb_list_add(pmbe);
117 spin_unlock_irq(&pmb_list_lock);
118
119 return pmbe;
120 }
121
122 void pmb_free(struct pmb_entry *pmbe)
123 {
124 spin_lock_irq(&pmb_list_lock);
125 pmb_list_del(pmbe);
126 spin_unlock_irq(&pmb_list_lock);
127
128 kmem_cache_free(pmb_cache, pmbe);
129 }
130
131 /*
132 * Must be in P2 for __set_pmb_entry()
133 */
134 int __set_pmb_entry(unsigned long vpn, unsigned long ppn,
135 unsigned long flags, int *entry)
136 {
137 unsigned int pos = *entry;
138
139 if (unlikely(pos == PMB_NO_ENTRY))
140 pos = find_first_zero_bit(&pmb_map, NR_PMB_ENTRIES);
141
142 repeat:
143 if (unlikely(pos > NR_PMB_ENTRIES))
144 return -ENOSPC;
145
146 if (test_and_set_bit(pos, &pmb_map)) {
147 pos = find_first_zero_bit(&pmb_map, NR_PMB_ENTRIES);
148 goto repeat;
149 }
150
151 ctrl_outl(vpn | PMB_V, mk_pmb_addr(pos));
152
153 #ifdef CONFIG_CACHE_WRITETHROUGH
154 /*
155 * When we are in 32-bit address extended mode, CCR.CB becomes
156 * invalid, so care must be taken to manually adjust cacheable
157 * translations.
158 */
159 if (likely(flags & PMB_C))
160 flags |= PMB_WT;
161 #endif
162
163 ctrl_outl(ppn | flags | PMB_V, mk_pmb_data(pos));
164
165 *entry = pos;
166
167 return 0;
168 }
169
170 int __uses_jump_to_uncached set_pmb_entry(struct pmb_entry *pmbe)
171 {
172 int ret;
173
174 jump_to_uncached();
175 ret = __set_pmb_entry(pmbe->vpn, pmbe->ppn, pmbe->flags, &pmbe->entry);
176 back_to_cached();
177
178 return ret;
179 }
180
181 void __uses_jump_to_uncached clear_pmb_entry(struct pmb_entry *pmbe)
182 {
183 unsigned int entry = pmbe->entry;
184 unsigned long addr;
185
186 /*
187 * Don't allow clearing of wired init entries, P1 or P2 access
188 * without a corresponding mapping in the PMB will lead to reset
189 * by the TLB.
190 */
191 if (unlikely(entry < ARRAY_SIZE(pmb_init_map) ||
192 entry >= NR_PMB_ENTRIES))
193 return;
194
195 jump_to_uncached();
196
197 /* Clear V-bit */
198 addr = mk_pmb_addr(entry);
199 ctrl_outl(ctrl_inl(addr) & ~PMB_V, addr);
200
201 addr = mk_pmb_data(entry);
202 ctrl_outl(ctrl_inl(addr) & ~PMB_V, addr);
203
204 back_to_cached();
205
206 clear_bit(entry, &pmb_map);
207 }
208
209
210 static struct {
211 unsigned long size;
212 int flag;
213 } pmb_sizes[] = {
214 { .size = 0x20000000, .flag = PMB_SZ_512M, },
215 { .size = 0x08000000, .flag = PMB_SZ_128M, },
216 { .size = 0x04000000, .flag = PMB_SZ_64M, },
217 { .size = 0x01000000, .flag = PMB_SZ_16M, },
218 };
219
220 long pmb_remap(unsigned long vaddr, unsigned long phys,
221 unsigned long size, unsigned long flags)
222 {
223 struct pmb_entry *pmbp, *pmbe;
224 unsigned long wanted;
225 int pmb_flags, i;
226 long err;
227
228 /* Convert typical pgprot value to the PMB equivalent */
229 if (flags & _PAGE_CACHABLE) {
230 if (flags & _PAGE_WT)
231 pmb_flags = PMB_WT;
232 else
233 pmb_flags = PMB_C;
234 } else
235 pmb_flags = PMB_WT | PMB_UB;
236
237 pmbp = NULL;
238 wanted = size;
239
240 again:
241 for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++) {
242 int ret;
243
244 if (size < pmb_sizes[i].size)
245 continue;
246
247 pmbe = pmb_alloc(vaddr, phys, pmb_flags | pmb_sizes[i].flag);
248 if (IS_ERR(pmbe)) {
249 err = PTR_ERR(pmbe);
250 goto out;
251 }
252
253 ret = set_pmb_entry(pmbe);
254 if (ret != 0) {
255 pmb_free(pmbe);
256 err = -EBUSY;
257 goto out;
258 }
259
260 phys += pmb_sizes[i].size;
261 vaddr += pmb_sizes[i].size;
262 size -= pmb_sizes[i].size;
263
264 /*
265 * Link adjacent entries that span multiple PMB entries
266 * for easier tear-down.
267 */
268 if (likely(pmbp))
269 pmbp->link = pmbe;
270
271 pmbp = pmbe;
272
273 /*
274 * Instead of trying smaller sizes on every iteration
275 * (even if we succeed in allocating space), try using
276 * pmb_sizes[i].size again.
277 */
278 i--;
279 }
280
281 if (size >= 0x1000000)
282 goto again;
283
284 return wanted - size;
285
286 out:
287 if (pmbp)
288 __pmb_unmap(pmbp);
289
290 return err;
291 }
292
293 void pmb_unmap(unsigned long addr)
294 {
295 struct pmb_entry **p, *pmbe;
296
297 for (p = &pmb_list; (pmbe = *p); p = &pmbe->next)
298 if (pmbe->vpn == addr)
299 break;
300
301 if (unlikely(!pmbe))
302 return;
303
304 __pmb_unmap(pmbe);
305 }
306
307 static void __pmb_unmap(struct pmb_entry *pmbe)
308 {
309 WARN_ON(!test_bit(pmbe->entry, &pmb_map));
310
311 do {
312 struct pmb_entry *pmblink = pmbe;
313
314 if (pmbe->entry != PMB_NO_ENTRY)
315 clear_pmb_entry(pmbe);
316
317 pmbe = pmblink->link;
318
319 pmb_free(pmblink);
320 } while (pmbe);
321 }
322
323 static void pmb_cache_ctor(void *pmb)
324 {
325 struct pmb_entry *pmbe = pmb;
326
327 memset(pmb, 0, sizeof(struct pmb_entry));
328
329 pmbe->entry = PMB_NO_ENTRY;
330 }
331
332 static int __uses_jump_to_uncached pmb_init(void)
333 {
334 unsigned int nr_entries = ARRAY_SIZE(pmb_init_map);
335 unsigned int entry, i;
336
337 BUG_ON(unlikely(nr_entries >= NR_PMB_ENTRIES));
338
339 pmb_cache = kmem_cache_create("pmb", sizeof(struct pmb_entry), 0,
340 SLAB_PANIC, pmb_cache_ctor);
341
342 jump_to_uncached();
343
344 /*
345 * Ordering is important, P2 must be mapped in the PMB before we
346 * can set PMB.SE, and P1 must be mapped before we jump back to
347 * P1 space.
348 */
349 for (entry = 0; entry < nr_entries; entry++) {
350 struct pmb_entry *pmbe = pmb_init_map + entry;
351
352 __set_pmb_entry(pmbe->vpn, pmbe->ppn, pmbe->flags, &entry);
353 }
354
355 ctrl_outl(0, PMB_IRMCR);
356
357 /* PMB.SE and UB[7] */
358 ctrl_outl((1 << 31) | (1 << 7), PMB_PASCR);
359
360 /* Flush out the TLB */
361 i = ctrl_inl(MMUCR);
362 i |= MMUCR_TI;
363 ctrl_outl(i, MMUCR);
364
365 back_to_cached();
366
367 return 0;
368 }
369 arch_initcall(pmb_init);
370
371 static int pmb_seq_show(struct seq_file *file, void *iter)
372 {
373 int i;
374
375 seq_printf(file, "V: Valid, C: Cacheable, WT: Write-Through\n"
376 "CB: Copy-Back, B: Buffered, UB: Unbuffered\n");
377 seq_printf(file, "ety vpn ppn size flags\n");
378
379 for (i = 0; i < NR_PMB_ENTRIES; i++) {
380 unsigned long addr, data;
381 unsigned int size;
382 char *sz_str = NULL;
383
384 addr = ctrl_inl(mk_pmb_addr(i));
385 data = ctrl_inl(mk_pmb_data(i));
386
387 size = data & PMB_SZ_MASK;
388 sz_str = (size == PMB_SZ_16M) ? " 16MB":
389 (size == PMB_SZ_64M) ? " 64MB":
390 (size == PMB_SZ_128M) ? "128MB":
391 "512MB";
392
393 /* 02: V 0x88 0x08 128MB C CB B */
394 seq_printf(file, "%02d: %c 0x%02lx 0x%02lx %s %c %s %s\n",
395 i, ((addr & PMB_V) && (data & PMB_V)) ? 'V' : ' ',
396 (addr >> 24) & 0xff, (data >> 24) & 0xff,
397 sz_str, (data & PMB_C) ? 'C' : ' ',
398 (data & PMB_WT) ? "WT" : "CB",
399 (data & PMB_UB) ? "UB" : " B");
400 }
401
402 return 0;
403 }
404
405 static int pmb_debugfs_open(struct inode *inode, struct file *file)
406 {
407 return single_open(file, pmb_seq_show, NULL);
408 }
409
410 static const struct file_operations pmb_debugfs_fops = {
411 .owner = THIS_MODULE,
412 .open = pmb_debugfs_open,
413 .read = seq_read,
414 .llseek = seq_lseek,
415 .release = single_release,
416 };
417
418 static int __init pmb_debugfs_init(void)
419 {
420 struct dentry *dentry;
421
422 dentry = debugfs_create_file("pmb", S_IFREG | S_IRUGO,
423 sh_debugfs_root, NULL, &pmb_debugfs_fops);
424 if (!dentry)
425 return -ENOMEM;
426 if (IS_ERR(dentry))
427 return PTR_ERR(dentry);
428
429 return 0;
430 }
431 postcore_initcall(pmb_debugfs_init);
432
433 #ifdef CONFIG_PM
434 static int pmb_sysdev_suspend(struct sys_device *dev, pm_message_t state)
435 {
436 static pm_message_t prev_state;
437
438 /* Restore the PMB after a resume from hibernation */
439 if (state.event == PM_EVENT_ON &&
440 prev_state.event == PM_EVENT_FREEZE) {
441 struct pmb_entry *pmbe;
442 spin_lock_irq(&pmb_list_lock);
443 for (pmbe = pmb_list; pmbe; pmbe = pmbe->next)
444 set_pmb_entry(pmbe);
445 spin_unlock_irq(&pmb_list_lock);
446 }
447 prev_state = state;
448 return 0;
449 }
450
451 static int pmb_sysdev_resume(struct sys_device *dev)
452 {
453 return pmb_sysdev_suspend(dev, PMSG_ON);
454 }
455
456 static struct sysdev_driver pmb_sysdev_driver = {
457 .suspend = pmb_sysdev_suspend,
458 .resume = pmb_sysdev_resume,
459 };
460
461 static int __init pmb_sysdev_init(void)
462 {
463 return sysdev_driver_register(&cpu_sysdev_class, &pmb_sysdev_driver);
464 }
465
466 subsys_initcall(pmb_sysdev_init);
467 #endif
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