1 /* 2 * arch/sh/mm/pmb.c 3 * 4 * Privileged Space Mapping Buffer (PMB) Support. 5 * 6 * Copyright (C) 2005 - 2010 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 pmb_entry pmb_entry_list[NR_PMB_ENTRIES]; 39 static unsigned long pmb_map; 40 41 static inline unsigned long mk_pmb_entry(unsigned int entry) 42 { 43 return (entry & PMB_E_MASK) << PMB_E_SHIFT; 44 } 45 46 static inline unsigned long mk_pmb_addr(unsigned int entry) 47 { 48 return mk_pmb_entry(entry) | PMB_ADDR; 49 } 50 51 static inline unsigned long mk_pmb_data(unsigned int entry) 52 { 53 return mk_pmb_entry(entry) | PMB_DATA; 54 } 55 56 static int pmb_alloc_entry(void) 57 { 58 unsigned int pos; 59 60 repeat: 61 pos = find_first_zero_bit(&pmb_map, NR_PMB_ENTRIES); 62 63 if (unlikely(pos > NR_PMB_ENTRIES)) 64 return -ENOSPC; 65 66 if (test_and_set_bit(pos, &pmb_map)) 67 goto repeat; 68 69 return pos; 70 } 71 72 static struct pmb_entry *pmb_alloc(unsigned long vpn, unsigned long ppn, 73 unsigned long flags, int entry) 74 { 75 struct pmb_entry *pmbe; 76 int pos; 77 78 if (entry == PMB_NO_ENTRY) { 79 pos = pmb_alloc_entry(); 80 if (pos < 0) 81 return ERR_PTR(pos); 82 } else { 83 if (test_bit(entry, &pmb_map)) 84 return ERR_PTR(-ENOSPC); 85 pos = entry; 86 } 87 88 pmbe = &pmb_entry_list[pos]; 89 if (!pmbe) 90 return ERR_PTR(-ENOMEM); 91 92 pmbe->vpn = vpn; 93 pmbe->ppn = ppn; 94 pmbe->flags = flags; 95 pmbe->entry = pos; 96 97 return pmbe; 98 } 99 100 static void pmb_free(struct pmb_entry *pmbe) 101 { 102 int pos = pmbe->entry; 103 104 pmbe->vpn = 0; 105 pmbe->ppn = 0; 106 pmbe->flags = 0; 107 pmbe->entry = 0; 108 109 clear_bit(pos, &pmb_map); 110 } 111 112 /* 113 * Must be in P2 for __set_pmb_entry() 114 */ 115 static void __set_pmb_entry(unsigned long vpn, unsigned long ppn, 116 unsigned long flags, int pos) 117 { 118 ctrl_outl(vpn | PMB_V, mk_pmb_addr(pos)); 119 120 #ifdef CONFIG_CACHE_WRITETHROUGH 121 /* 122 * When we are in 32-bit address extended mode, CCR.CB becomes 123 * invalid, so care must be taken to manually adjust cacheable 124 * translations. 125 */ 126 if (likely(flags & PMB_C)) 127 flags |= PMB_WT; 128 #endif 129 130 ctrl_outl(ppn | flags | PMB_V, mk_pmb_data(pos)); 131 } 132 133 static void __uses_jump_to_uncached set_pmb_entry(struct pmb_entry *pmbe) 134 { 135 jump_to_uncached(); 136 __set_pmb_entry(pmbe->vpn, pmbe->ppn, pmbe->flags, pmbe->entry); 137 back_to_cached(); 138 } 139 140 static void __uses_jump_to_uncached clear_pmb_entry(struct pmb_entry *pmbe) 141 { 142 unsigned int entry = pmbe->entry; 143 unsigned long addr; 144 145 if (unlikely(entry >= NR_PMB_ENTRIES)) 146 return; 147 148 jump_to_uncached(); 149 150 /* Clear V-bit */ 151 addr = mk_pmb_addr(entry); 152 ctrl_outl(ctrl_inl(addr) & ~PMB_V, addr); 153 154 addr = mk_pmb_data(entry); 155 ctrl_outl(ctrl_inl(addr) & ~PMB_V, addr); 156 157 back_to_cached(); 158 } 159 160 161 static struct { 162 unsigned long size; 163 int flag; 164 } pmb_sizes[] = { 165 { .size = 0x20000000, .flag = PMB_SZ_512M, }, 166 { .size = 0x08000000, .flag = PMB_SZ_128M, }, 167 { .size = 0x04000000, .flag = PMB_SZ_64M, }, 168 { .size = 0x01000000, .flag = PMB_SZ_16M, }, 169 }; 170 171 long pmb_remap(unsigned long vaddr, unsigned long phys, 172 unsigned long size, unsigned long flags) 173 { 174 struct pmb_entry *pmbp, *pmbe; 175 unsigned long wanted; 176 int pmb_flags, i; 177 long err; 178 179 /* Convert typical pgprot value to the PMB equivalent */ 180 if (flags & _PAGE_CACHABLE) { 181 if (flags & _PAGE_WT) 182 pmb_flags = PMB_WT; 183 else 184 pmb_flags = PMB_C; 185 } else 186 pmb_flags = PMB_WT | PMB_UB; 187 188 pmbp = NULL; 189 wanted = size; 190 191 again: 192 for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++) { 193 if (size < pmb_sizes[i].size) 194 continue; 195 196 pmbe = pmb_alloc(vaddr, phys, pmb_flags | pmb_sizes[i].flag, 197 PMB_NO_ENTRY); 198 if (IS_ERR(pmbe)) { 199 err = PTR_ERR(pmbe); 200 goto out; 201 } 202 203 set_pmb_entry(pmbe); 204 205 phys += pmb_sizes[i].size; 206 vaddr += pmb_sizes[i].size; 207 size -= pmb_sizes[i].size; 208 209 /* 210 * Link adjacent entries that span multiple PMB entries 211 * for easier tear-down. 212 */ 213 if (likely(pmbp)) 214 pmbp->link = pmbe; 215 216 pmbp = pmbe; 217 218 /* 219 * Instead of trying smaller sizes on every iteration 220 * (even if we succeed in allocating space), try using 221 * pmb_sizes[i].size again. 222 */ 223 i--; 224 } 225 226 if (size >= 0x1000000) 227 goto again; 228 229 return wanted - size; 230 231 out: 232 if (pmbp) 233 __pmb_unmap(pmbp); 234 235 return err; 236 } 237 238 void pmb_unmap(unsigned long addr) 239 { 240 struct pmb_entry *pmbe = NULL; 241 int i; 242 243 for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) { 244 if (test_bit(i, &pmb_map)) { 245 pmbe = &pmb_entry_list[i]; 246 if (pmbe->vpn == addr) 247 break; 248 } 249 } 250 251 if (unlikely(!pmbe)) 252 return; 253 254 __pmb_unmap(pmbe); 255 } 256 257 static void __pmb_unmap(struct pmb_entry *pmbe) 258 { 259 BUG_ON(!test_bit(pmbe->entry, &pmb_map)); 260 261 do { 262 struct pmb_entry *pmblink = pmbe; 263 264 /* 265 * We may be called before this pmb_entry has been 266 * entered into the PMB table via set_pmb_entry(), but 267 * that's OK because we've allocated a unique slot for 268 * this entry in pmb_alloc() (even if we haven't filled 269 * it yet). 270 * 271 * Therefore, calling clear_pmb_entry() is safe as no 272 * other mapping can be using that slot. 273 */ 274 clear_pmb_entry(pmbe); 275 276 pmbe = pmblink->link; 277 278 pmb_free(pmblink); 279 } while (pmbe); 280 } 281 282 #ifdef CONFIG_PMB_LEGACY 283 static int pmb_apply_legacy_mappings(void) 284 { 285 int i; 286 unsigned long addr, data; 287 unsigned int applied = 0; 288 289 for (i = 0; i < PMB_ENTRY_MAX; i++) { 290 struct pmb_entry *pmbe; 291 unsigned long vpn, ppn, flags; 292 293 addr = PMB_DATA + (i << PMB_E_SHIFT); 294 data = ctrl_inl(addr); 295 if (!(data & PMB_V)) 296 continue; 297 298 if (data & PMB_C) { 299 #if defined(CONFIG_CACHE_WRITETHROUGH) 300 data |= PMB_WT; 301 #elif defined(CONFIG_CACHE_WRITEBACK) 302 data &= ~PMB_WT; 303 #else 304 data &= ~(PMB_C | PMB_WT); 305 #endif 306 } 307 ctrl_outl(data, addr); 308 309 ppn = data & PMB_PFN_MASK; 310 311 flags = data & (PMB_C | PMB_WT | PMB_UB); 312 flags |= data & PMB_SZ_MASK; 313 314 addr = PMB_ADDR + (i << PMB_E_SHIFT); 315 data = ctrl_inl(addr); 316 317 vpn = data & PMB_PFN_MASK; 318 319 pmbe = pmb_alloc(vpn, ppn, flags, i); 320 WARN_ON(IS_ERR(pmbe)); 321 322 applied++; 323 } 324 325 return (applied == 0); 326 } 327 #else 328 static inline int pmb_apply_legacy_mappings(void) 329 { 330 return 1; 331 } 332 #endif 333 334 int __uses_jump_to_uncached pmb_init(void) 335 { 336 unsigned int i; 337 unsigned long size, ret; 338 339 jump_to_uncached(); 340 341 /* 342 * Attempt to apply the legacy boot mappings if configured. If 343 * this is successful then we simply carry on with those and 344 * don't bother establishing additional memory mappings. Dynamic 345 * device mappings through pmb_remap() can still be bolted on 346 * after this. 347 */ 348 ret = pmb_apply_legacy_mappings(); 349 if (ret == 0) { 350 back_to_cached(); 351 return 0; 352 } 353 354 /* 355 * Insert PMB entries for the P1 and P2 areas so that, after 356 * we've switched the MMU to 32-bit mode, the semantics of P1 357 * and P2 are the same as in 29-bit mode, e.g. 358 * 359 * P1 - provides a cached window onto physical memory 360 * P2 - provides an uncached window onto physical memory 361 */ 362 size = (unsigned long)__MEMORY_START + __MEMORY_SIZE; 363 364 ret = pmb_remap(P1SEG, 0x00000000, size, PMB_C); 365 BUG_ON(ret != size); 366 367 ret = pmb_remap(P2SEG, 0x00000000, size, PMB_WT | PMB_UB); 368 BUG_ON(ret != size); 369 370 ctrl_outl(0, PMB_IRMCR); 371 372 /* PMB.SE and UB[7] */ 373 ctrl_outl(PASCR_SE | (1 << 7), PMB_PASCR); 374 375 /* Flush out the TLB */ 376 i = ctrl_inl(MMUCR); 377 i |= MMUCR_TI; 378 ctrl_outl(i, MMUCR); 379 380 back_to_cached(); 381 382 return 0; 383 } 384 385 static int pmb_seq_show(struct seq_file *file, void *iter) 386 { 387 int i; 388 389 seq_printf(file, "V: Valid, C: Cacheable, WT: Write-Through\n" 390 "CB: Copy-Back, B: Buffered, UB: Unbuffered\n"); 391 seq_printf(file, "ety vpn ppn size flags\n"); 392 393 for (i = 0; i < NR_PMB_ENTRIES; i++) { 394 unsigned long addr, data; 395 unsigned int size; 396 char *sz_str = NULL; 397 398 addr = ctrl_inl(mk_pmb_addr(i)); 399 data = ctrl_inl(mk_pmb_data(i)); 400 401 size = data & PMB_SZ_MASK; 402 sz_str = (size == PMB_SZ_16M) ? " 16MB": 403 (size == PMB_SZ_64M) ? " 64MB": 404 (size == PMB_SZ_128M) ? "128MB": 405 "512MB"; 406 407 /* 02: V 0x88 0x08 128MB C CB B */ 408 seq_printf(file, "%02d: %c 0x%02lx 0x%02lx %s %c %s %s\n", 409 i, ((addr & PMB_V) && (data & PMB_V)) ? 'V' : ' ', 410 (addr >> 24) & 0xff, (data >> 24) & 0xff, 411 sz_str, (data & PMB_C) ? 'C' : ' ', 412 (data & PMB_WT) ? "WT" : "CB", 413 (data & PMB_UB) ? "UB" : " B"); 414 } 415 416 return 0; 417 } 418 419 static int pmb_debugfs_open(struct inode *inode, struct file *file) 420 { 421 return single_open(file, pmb_seq_show, NULL); 422 } 423 424 static const struct file_operations pmb_debugfs_fops = { 425 .owner = THIS_MODULE, 426 .open = pmb_debugfs_open, 427 .read = seq_read, 428 .llseek = seq_lseek, 429 .release = single_release, 430 }; 431 432 static int __init pmb_debugfs_init(void) 433 { 434 struct dentry *dentry; 435 436 dentry = debugfs_create_file("pmb", S_IFREG | S_IRUGO, 437 sh_debugfs_root, NULL, &pmb_debugfs_fops); 438 if (!dentry) 439 return -ENOMEM; 440 if (IS_ERR(dentry)) 441 return PTR_ERR(dentry); 442 443 return 0; 444 } 445 postcore_initcall(pmb_debugfs_init); 446 447 #ifdef CONFIG_PM 448 static int pmb_sysdev_suspend(struct sys_device *dev, pm_message_t state) 449 { 450 static pm_message_t prev_state; 451 int i; 452 453 /* Restore the PMB after a resume from hibernation */ 454 if (state.event == PM_EVENT_ON && 455 prev_state.event == PM_EVENT_FREEZE) { 456 struct pmb_entry *pmbe; 457 for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) { 458 if (test_bit(i, &pmb_map)) { 459 pmbe = &pmb_entry_list[i]; 460 set_pmb_entry(pmbe); 461 } 462 } 463 } 464 prev_state = state; 465 return 0; 466 } 467 468 static int pmb_sysdev_resume(struct sys_device *dev) 469 { 470 return pmb_sysdev_suspend(dev, PMSG_ON); 471 } 472 473 static struct sysdev_driver pmb_sysdev_driver = { 474 .suspend = pmb_sysdev_suspend, 475 .resume = pmb_sysdev_resume, 476 }; 477 478 static int __init pmb_sysdev_init(void) 479 { 480 return sysdev_driver_register(&cpu_sysdev_class, &pmb_sysdev_driver); 481 } 482 subsys_initcall(pmb_sysdev_init); 483 #endif 484