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added 2.6.29.6 aldebaran kernel
[nao-ulib.git] / kernel / 2.6.29.6-aldebaran-rt / arch / sh / mm / pmb.c
blob84241676265e61455f4e9579f7cf41810601f1e9
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/module.h>
19 #include <linux/slab.h>
20 #include <linux/bitops.h>
21 #include <linux/debugfs.h>
22 #include <linux/fs.h>
23 #include <linux/seq_file.h>
24 #include <linux/err.h>
25 #include <asm/system.h>
26 #include <asm/uaccess.h>
27 #include <asm/pgtable.h>
28 #include <asm/mmu.h>
29 #include <asm/io.h>
30 #include <asm/mmu_context.h>
31
32 #define NR_PMB_ENTRIES 16
33
34 static struct kmem_cache *pmb_cache;
35 static unsigned long pmb_map;
36
37 static struct pmb_entry pmb_init_map[] = {
38 /* vpn ppn flags (ub/sz/c/wt) */
39
40 /* P1 Section Mappings */
41 { 0x80000000, 0x00000000, PMB_SZ_64M | PMB_C, },
42 { 0x84000000, 0x04000000, PMB_SZ_64M | PMB_C, },
43 { 0x88000000, 0x08000000, PMB_SZ_128M | PMB_C, },
44 { 0x90000000, 0x10000000, PMB_SZ_64M | PMB_C, },
45 { 0x94000000, 0x14000000, PMB_SZ_64M | PMB_C, },
46 { 0x98000000, 0x18000000, PMB_SZ_64M | PMB_C, },
47
48 /* P2 Section Mappings */
49 { 0xa0000000, 0x00000000, PMB_UB | PMB_SZ_64M | PMB_WT, },
50 { 0xa4000000, 0x04000000, PMB_UB | PMB_SZ_64M | PMB_WT, },
51 { 0xa8000000, 0x08000000, PMB_UB | PMB_SZ_128M | PMB_WT, },
52 { 0xb0000000, 0x10000000, PMB_UB | PMB_SZ_64M | PMB_WT, },
53 { 0xb4000000, 0x14000000, PMB_UB | PMB_SZ_64M | PMB_WT, },
54 { 0xb8000000, 0x18000000, PMB_UB | PMB_SZ_64M | PMB_WT, },
55 };
56
57 static inline unsigned long mk_pmb_entry(unsigned int entry)
58 {
59 return (entry & PMB_E_MASK) << PMB_E_SHIFT;
60 }
61
62 static inline unsigned long mk_pmb_addr(unsigned int entry)
63 {
64 return mk_pmb_entry(entry) | PMB_ADDR;
65 }
66
67 static inline unsigned long mk_pmb_data(unsigned int entry)
68 {
69 return mk_pmb_entry(entry) | PMB_DATA;
70 }
71
72 static DEFINE_SPINLOCK(pmb_list_lock);
73 static struct pmb_entry *pmb_list;
74
75 static inline void pmb_list_add(struct pmb_entry *pmbe)
76 {
77 struct pmb_entry **p, *tmp;
78
79 p = &pmb_list;
80 while ((tmp = *p) != NULL)
81 p = &tmp->next;
82
83 pmbe->next = tmp;
84 *p = pmbe;
85 }
86
87 static inline void pmb_list_del(struct pmb_entry *pmbe)
88 {
89 struct pmb_entry **p, *tmp;
90
91 for (p = &pmb_list; (tmp = *p); p = &tmp->next)
92 if (tmp == pmbe) {
93 *p = tmp->next;
94 return;
95 }
96 }
97
98 struct pmb_entry *pmb_alloc(unsigned long vpn, unsigned long ppn,
99 unsigned long flags)
100 {
101 struct pmb_entry *pmbe;
102
103 pmbe = kmem_cache_alloc(pmb_cache, GFP_KERNEL);
104 if (!pmbe)
105 return ERR_PTR(-ENOMEM);
106
107 pmbe->vpn = vpn;
108 pmbe->ppn = ppn;
109 pmbe->flags = flags;
110
111 spin_lock_irq(&pmb_list_lock);
112 pmb_list_add(pmbe);
113 spin_unlock_irq(&pmb_list_lock);
114
115 return pmbe;
116 }
117
118 void pmb_free(struct pmb_entry *pmbe)
119 {
120 spin_lock_irq(&pmb_list_lock);
121 pmb_list_del(pmbe);
122 spin_unlock_irq(&pmb_list_lock);
123
124 kmem_cache_free(pmb_cache, pmbe);
125 }
126
127 /*
128 * Must be in P2 for __set_pmb_entry()
129 */
130 int __set_pmb_entry(unsigned long vpn, unsigned long ppn,
131 unsigned long flags, int *entry)
132 {
133 unsigned int pos = *entry;
134
135 if (unlikely(pos == PMB_NO_ENTRY))
136 pos = find_first_zero_bit(&pmb_map, NR_PMB_ENTRIES);
137
138 repeat:
139 if (unlikely(pos > NR_PMB_ENTRIES))
140 return -ENOSPC;
141
142 if (test_and_set_bit(pos, &pmb_map)) {
143 pos = find_first_zero_bit(&pmb_map, NR_PMB_ENTRIES);
144 goto repeat;
145 }
146
147 ctrl_outl(vpn | PMB_V, mk_pmb_addr(pos));
148
149 #ifdef CONFIG_CACHE_WRITETHROUGH
150 /*
151 * When we are in 32-bit address extended mode, CCR.CB becomes
152 * invalid, so care must be taken to manually adjust cacheable
153 * translations.
154 */
155 if (likely(flags & PMB_C))
156 flags |= PMB_WT;
157 #endif
158
159 ctrl_outl(ppn | flags | PMB_V, mk_pmb_data(pos));
160
161 *entry = pos;
162
163 return 0;
164 }
165
166 int __uses_jump_to_uncached set_pmb_entry(struct pmb_entry *pmbe)
167 {
168 int ret;
169
170 jump_to_uncached();
171 ret = __set_pmb_entry(pmbe->vpn, pmbe->ppn, pmbe->flags, &pmbe->entry);
172 back_to_cached();
173
174 return ret;
175 }
176
177 void __uses_jump_to_uncached clear_pmb_entry(struct pmb_entry *pmbe)
178 {
179 unsigned int entry = pmbe->entry;
180 unsigned long addr;
181
182 /*
183 * Don't allow clearing of wired init entries, P1 or P2 access
184 * without a corresponding mapping in the PMB will lead to reset
185 * by the TLB.
186 */
187 if (unlikely(entry < ARRAY_SIZE(pmb_init_map) ||
188 entry >= NR_PMB_ENTRIES))
189 return;
190
191 jump_to_uncached();
192
193 /* Clear V-bit */
194 addr = mk_pmb_addr(entry);
195 ctrl_outl(ctrl_inl(addr) & ~PMB_V, addr);
196
197 addr = mk_pmb_data(entry);
198 ctrl_outl(ctrl_inl(addr) & ~PMB_V, addr);
199
200 back_to_cached();
201
202 clear_bit(entry, &pmb_map);
203 }
204
205
206 static struct {
207 unsigned long size;
208 int flag;
209 } pmb_sizes[] = {
210 { .size = 0x20000000, .flag = PMB_SZ_512M, },
211 { .size = 0x08000000, .flag = PMB_SZ_128M, },
212 { .size = 0x04000000, .flag = PMB_SZ_64M, },
213 { .size = 0x01000000, .flag = PMB_SZ_16M, },
214 };
215
216 long pmb_remap(unsigned long vaddr, unsigned long phys,
217 unsigned long size, unsigned long flags)
218 {
219 struct pmb_entry *pmbp;
220 unsigned long wanted;
221 int pmb_flags, i;
222
223 /* Convert typical pgprot value to the PMB equivalent */
224 if (flags & _PAGE_CACHABLE) {
225 if (flags & _PAGE_WT)
226 pmb_flags = PMB_WT;
227 else
228 pmb_flags = PMB_C;
229 } else
230 pmb_flags = PMB_WT | PMB_UB;
231
232 pmbp = NULL;
233 wanted = size;
234
235 again:
236 for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++) {
237 struct pmb_entry *pmbe;
238 int ret;
239
240 if (size < pmb_sizes[i].size)
241 continue;
242
243 pmbe = pmb_alloc(vaddr, phys, pmb_flags | pmb_sizes[i].flag);
244 if (IS_ERR(pmbe))
245 return PTR_ERR(pmbe);
246
247 ret = set_pmb_entry(pmbe);
248 if (ret != 0) {
249 pmb_free(pmbe);
250 return -EBUSY;
251 }
252
253 phys += pmb_sizes[i].size;
254 vaddr += pmb_sizes[i].size;
255 size -= pmb_sizes[i].size;
256
257 /*
258 * Link adjacent entries that span multiple PMB entries
259 * for easier tear-down.
260 */
261 if (likely(pmbp))
262 pmbp->link = pmbe;
263
264 pmbp = pmbe;
265 }
266
267 if (size >= 0x1000000)
268 goto again;
269
270 return wanted - size;
271 }
272
273 void pmb_unmap(unsigned long addr)
274 {
275 struct pmb_entry **p, *pmbe;
276
277 for (p = &pmb_list; (pmbe = *p); p = &pmbe->next)
278 if (pmbe->vpn == addr)
279 break;
280
281 if (unlikely(!pmbe))
282 return;
283
284 WARN_ON(!test_bit(pmbe->entry, &pmb_map));
285
286 do {
287 struct pmb_entry *pmblink = pmbe;
288
289 clear_pmb_entry(pmbe);
290 pmbe = pmblink->link;
291
292 pmb_free(pmblink);
293 } while (pmbe);
294 }
295
296 static void pmb_cache_ctor(void *pmb)
297 {
298 struct pmb_entry *pmbe = pmb;
299
300 memset(pmb, 0, sizeof(struct pmb_entry));
301
302 pmbe->entry = PMB_NO_ENTRY;
303 }
304
305 static int __uses_jump_to_uncached pmb_init(void)
306 {
307 unsigned int nr_entries = ARRAY_SIZE(pmb_init_map);
308 unsigned int entry, i;
309
310 BUG_ON(unlikely(nr_entries >= NR_PMB_ENTRIES));
311
312 pmb_cache = kmem_cache_create("pmb", sizeof(struct pmb_entry), 0,
313 SLAB_PANIC, pmb_cache_ctor);
314
315 jump_to_uncached();
316
317 /*
318 * Ordering is important, P2 must be mapped in the PMB before we
319 * can set PMB.SE, and P1 must be mapped before we jump back to
320 * P1 space.
321 */
322 for (entry = 0; entry < nr_entries; entry++) {
323 struct pmb_entry *pmbe = pmb_init_map + entry;
324
325 __set_pmb_entry(pmbe->vpn, pmbe->ppn, pmbe->flags, &entry);
326 }
327
328 ctrl_outl(0, PMB_IRMCR);
329
330 /* PMB.SE and UB[7] */
331 ctrl_outl((1 << 31) | (1 << 7), PMB_PASCR);
332
333 /* Flush out the TLB */
334 i = ctrl_inl(MMUCR);
335 i |= MMUCR_TI;
336 ctrl_outl(i, MMUCR);
337
338 back_to_cached();
339
340 return 0;
341 }
342 arch_initcall(pmb_init);
343
344 static int pmb_seq_show(struct seq_file *file, void *iter)
345 {
346 int i;
347
348 seq_printf(file, "V: Valid, C: Cacheable, WT: Write-Through\n"
349 "CB: Copy-Back, B: Buffered, UB: Unbuffered\n");
350 seq_printf(file, "ety vpn ppn size flags\n");
351
352 for (i = 0; i < NR_PMB_ENTRIES; i++) {
353 unsigned long addr, data;
354 unsigned int size;
355 char *sz_str = NULL;
356
357 addr = ctrl_inl(mk_pmb_addr(i));
358 data = ctrl_inl(mk_pmb_data(i));
359
360 size = data & PMB_SZ_MASK;
361 sz_str = (size == PMB_SZ_16M) ? " 16MB":
362 (size == PMB_SZ_64M) ? " 64MB":
363 (size == PMB_SZ_128M) ? "128MB":
364 "512MB";
365
366 /* 02: V 0x88 0x08 128MB C CB B */
367 seq_printf(file, "%02d: %c 0x%02lx 0x%02lx %s %c %s %s\n",
368 i, ((addr & PMB_V) && (data & PMB_V)) ? 'V' : ' ',
369 (addr >> 24) & 0xff, (data >> 24) & 0xff,
370 sz_str, (data & PMB_C) ? 'C' : ' ',
371 (data & PMB_WT) ? "WT" : "CB",
372 (data & PMB_UB) ? "UB" : " B");
373 }
374
375 return 0;
376 }
377
378 static int pmb_debugfs_open(struct inode *inode, struct file *file)
379 {
380 return single_open(file, pmb_seq_show, NULL);
381 }
382
383 static const struct file_operations pmb_debugfs_fops = {
384 .owner = THIS_MODULE,
385 .open = pmb_debugfs_open,
386 .read = seq_read,
387 .llseek = seq_lseek,
388 .release = single_release,
389 };
390
391 static int __init pmb_debugfs_init(void)
392 {
393 struct dentry *dentry;
394
395 dentry = debugfs_create_file("pmb", S_IFREG | S_IRUGO,
396 sh_debugfs_root, NULL, &pmb_debugfs_fops);
397 if (!dentry)
398 return -ENOMEM;
399 if (IS_ERR(dentry))
400 return PTR_ERR(dentry);
401
402 return 0;
403 }
404 postcore_initcall(pmb_debugfs_init);
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