1 /* 2 * arch/sh/mm/pmb.c 3 * 4 * Privileged Space Mapping Buffer (PMB) Support. 5 * 6 * Copyright (C) 2005 - 2010 Paul Mundt 7 * Copyright (C) 2010 Matt Fleming 8 * 9 * This file is subject to the terms and conditions of the GNU General Public 10 * License. See the file "COPYING" in the main directory of this archive 11 * for more details. 12 */ 13 #include <linux/init.h> 14 #include <linux/kernel.h> 15 #include <linux/sysdev.h> 16 #include <linux/cpu.h> 17 #include <linux/module.h> 18 #include <linux/slab.h> 19 #include <linux/bitops.h> 20 #include <linux/debugfs.h> 21 #include <linux/fs.h> 22 #include <linux/seq_file.h> 23 #include <linux/err.h> 24 #include <asm/system.h> 25 #include <asm/uaccess.h> 26 #include <asm/pgtable.h> 27 #include <asm/mmu.h> 28 #include <asm/io.h> 29 #include <asm/mmu_context.h> 30 31 #define NR_PMB_ENTRIES 16 32 33 static void __pmb_unmap(struct pmb_entry *); 34 35 static struct pmb_entry pmb_entry_list[NR_PMB_ENTRIES]; 36 static unsigned long pmb_map; 37 38 static inline unsigned long mk_pmb_entry(unsigned int entry) 39 { 40 return (entry & PMB_E_MASK) << PMB_E_SHIFT; 41 } 42 43 static inline unsigned long mk_pmb_addr(unsigned int entry) 44 { 45 return mk_pmb_entry(entry) | PMB_ADDR; 46 } 47 48 static inline unsigned long mk_pmb_data(unsigned int entry) 49 { 50 return mk_pmb_entry(entry) | PMB_DATA; 51 } 52 53 static int pmb_alloc_entry(void) 54 { 55 unsigned int pos; 56 57 repeat: 58 pos = find_first_zero_bit(&pmb_map, NR_PMB_ENTRIES); 59 60 if (unlikely(pos > NR_PMB_ENTRIES)) 61 return -ENOSPC; 62 63 if (test_and_set_bit(pos, &pmb_map)) 64 goto repeat; 65 66 return pos; 67 } 68 69 static struct pmb_entry *pmb_alloc(unsigned long vpn, unsigned long ppn, 70 unsigned long flags, int entry) 71 { 72 struct pmb_entry *pmbe; 73 int pos; 74 75 if (entry == PMB_NO_ENTRY) { 76 pos = pmb_alloc_entry(); 77 if (pos < 0) 78 return ERR_PTR(pos); 79 } else { 80 if (test_bit(entry, &pmb_map)) 81 return ERR_PTR(-ENOSPC); 82 pos = entry; 83 } 84 85 pmbe = &pmb_entry_list[pos]; 86 if (!pmbe) 87 return ERR_PTR(-ENOMEM); 88 89 pmbe->vpn = vpn; 90 pmbe->ppn = ppn; 91 pmbe->flags = flags; 92 pmbe->entry = pos; 93 94 return pmbe; 95 } 96 97 static void pmb_free(struct pmb_entry *pmbe) 98 { 99 int pos = pmbe->entry; 100 101 pmbe->vpn = 0; 102 pmbe->ppn = 0; 103 pmbe->flags = 0; 104 pmbe->entry = 0; 105 106 clear_bit(pos, &pmb_map); 107 } 108 109 /* 110 * Must be in P2 for __set_pmb_entry() 111 */ 112 static void __set_pmb_entry(unsigned long vpn, unsigned long ppn, 113 unsigned long flags, int pos) 114 { 115 __raw_writel(vpn | PMB_V, mk_pmb_addr(pos)); 116 117 #ifdef CONFIG_CACHE_WRITETHROUGH 118 /* 119 * When we are in 32-bit address extended mode, CCR.CB becomes 120 * invalid, so care must be taken to manually adjust cacheable 121 * translations. 122 */ 123 if (likely(flags & PMB_C)) 124 flags |= PMB_WT; 125 #endif 126 127 __raw_writel(ppn | flags | PMB_V, mk_pmb_data(pos)); 128 } 129 130 static void set_pmb_entry(struct pmb_entry *pmbe) 131 { 132 jump_to_uncached(); 133 __set_pmb_entry(pmbe->vpn, pmbe->ppn, pmbe->flags, pmbe->entry); 134 back_to_cached(); 135 } 136 137 static void clear_pmb_entry(struct pmb_entry *pmbe) 138 { 139 unsigned int entry = pmbe->entry; 140 unsigned long addr; 141 142 if (unlikely(entry >= NR_PMB_ENTRIES)) 143 return; 144 145 jump_to_uncached(); 146 147 /* Clear V-bit */ 148 addr = mk_pmb_addr(entry); 149 __raw_writel(__raw_readl(addr) & ~PMB_V, addr); 150 151 addr = mk_pmb_data(entry); 152 __raw_writel(__raw_readl(addr) & ~PMB_V, addr); 153 154 back_to_cached(); 155 } 156 157 158 static struct { 159 unsigned long size; 160 int flag; 161 } pmb_sizes[] = { 162 { .size = 0x20000000, .flag = PMB_SZ_512M, }, 163 { .size = 0x08000000, .flag = PMB_SZ_128M, }, 164 { .size = 0x04000000, .flag = PMB_SZ_64M, }, 165 { .size = 0x01000000, .flag = PMB_SZ_16M, }, 166 }; 167 168 long pmb_remap(unsigned long vaddr, unsigned long phys, 169 unsigned long size, unsigned long flags) 170 { 171 struct pmb_entry *pmbp, *pmbe; 172 unsigned long wanted; 173 int pmb_flags, i; 174 long err; 175 176 /* Convert typical pgprot value to the PMB equivalent */ 177 if (flags & _PAGE_CACHABLE) { 178 if (flags & _PAGE_WT) 179 pmb_flags = PMB_WT; 180 else 181 pmb_flags = PMB_C; 182 } else 183 pmb_flags = PMB_WT | PMB_UB; 184 185 pmbp = NULL; 186 wanted = size; 187 188 again: 189 for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++) { 190 if (size < pmb_sizes[i].size) 191 continue; 192 193 pmbe = pmb_alloc(vaddr, phys, pmb_flags | pmb_sizes[i].flag, 194 PMB_NO_ENTRY); 195 if (IS_ERR(pmbe)) { 196 err = PTR_ERR(pmbe); 197 goto out; 198 } 199 200 set_pmb_entry(pmbe); 201 202 phys += pmb_sizes[i].size; 203 vaddr += pmb_sizes[i].size; 204 size -= pmb_sizes[i].size; 205 206 /* 207 * Link adjacent entries that span multiple PMB entries 208 * for easier tear-down. 209 */ 210 if (likely(pmbp)) 211 pmbp->link = pmbe; 212 213 pmbp = pmbe; 214 215 /* 216 * Instead of trying smaller sizes on every iteration 217 * (even if we succeed in allocating space), try using 218 * pmb_sizes[i].size again. 219 */ 220 i--; 221 } 222 223 if (size >= 0x1000000) 224 goto again; 225 226 return wanted - size; 227 228 out: 229 if (pmbp) 230 __pmb_unmap(pmbp); 231 232 return err; 233 } 234 235 void pmb_unmap(unsigned long addr) 236 { 237 struct pmb_entry *pmbe = NULL; 238 int i; 239 240 for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) { 241 if (test_bit(i, &pmb_map)) { 242 pmbe = &pmb_entry_list[i]; 243 if (pmbe->vpn == addr) 244 break; 245 } 246 } 247 248 if (unlikely(!pmbe)) 249 return; 250 251 __pmb_unmap(pmbe); 252 } 253 254 static void __pmb_unmap(struct pmb_entry *pmbe) 255 { 256 BUG_ON(!test_bit(pmbe->entry, &pmb_map)); 257 258 do { 259 struct pmb_entry *pmblink = pmbe; 260 261 /* 262 * We may be called before this pmb_entry has been 263 * entered into the PMB table via set_pmb_entry(), but 264 * that's OK because we've allocated a unique slot for 265 * this entry in pmb_alloc() (even if we haven't filled 266 * it yet). 267 * 268 * Therefore, calling clear_pmb_entry() is safe as no 269 * other mapping can be using that slot. 270 */ 271 clear_pmb_entry(pmbe); 272 273 pmbe = pmblink->link; 274 275 pmb_free(pmblink); 276 } while (pmbe); 277 } 278 279 #ifdef CONFIG_PMB_LEGACY 280 static inline unsigned int pmb_ppn_in_range(unsigned long ppn) 281 { 282 return ppn >= __MEMORY_START && ppn < __MEMORY_START + __MEMORY_SIZE; 283 } 284 285 static int pmb_apply_legacy_mappings(void) 286 { 287 unsigned int applied = 0; 288 int i; 289 290 pr_info("PMB: Preserving legacy mappings:\n"); 291 292 /* 293 * The following entries are setup by the bootloader. 294 * 295 * Entry VPN PPN V SZ C UB 296 * -------------------------------------------------------- 297 * 0 0xA0000000 0x00000000 1 64MB 0 0 298 * 1 0xA4000000 0x04000000 1 16MB 0 0 299 * 2 0xA6000000 0x08000000 1 16MB 0 0 300 * 9 0x88000000 0x48000000 1 128MB 1 1 301 * 10 0x90000000 0x50000000 1 128MB 1 1 302 * 11 0x98000000 0x58000000 1 128MB 1 1 303 * 13 0xA8000000 0x48000000 1 128MB 0 0 304 * 14 0xB0000000 0x50000000 1 128MB 0 0 305 * 15 0xB8000000 0x58000000 1 128MB 0 0 306 * 307 * The only entries the we need are the ones that map the kernel 308 * at the cached and uncached addresses. 309 */ 310 for (i = 0; i < PMB_ENTRY_MAX; i++) { 311 unsigned long addr, data; 312 unsigned long addr_val, data_val; 313 unsigned long ppn, vpn; 314 315 addr = mk_pmb_addr(i); 316 data = mk_pmb_data(i); 317 318 addr_val = __raw_readl(addr); 319 data_val = __raw_readl(data); 320 321 /* 322 * Skip over any bogus entries 323 */ 324 if (!(data_val & PMB_V) || !(addr_val & PMB_V)) 325 continue; 326 327 ppn = data_val & PMB_PFN_MASK; 328 vpn = addr_val & PMB_PFN_MASK; 329 330 /* 331 * Only preserve in-range mappings. 332 */ 333 if (pmb_ppn_in_range(ppn)) { 334 unsigned int size; 335 char *sz_str = NULL; 336 337 size = data_val & PMB_SZ_MASK; 338 339 sz_str = (size == PMB_SZ_16M) ? " 16MB": 340 (size == PMB_SZ_64M) ? " 64MB": 341 (size == PMB_SZ_128M) ? "128MB": 342 "512MB"; 343 344 pr_info("\t0x%08lx -> 0x%08lx [ %s %scached ]\n", 345 vpn >> PAGE_SHIFT, ppn >> PAGE_SHIFT, sz_str, 346 (data_val & PMB_C) ? "" : "un"); 347 348 applied++; 349 } else { 350 /* 351 * Invalidate anything out of bounds. 352 */ 353 __raw_writel(addr_val & ~PMB_V, addr); 354 __raw_writel(data_val & ~PMB_V, data); 355 } 356 } 357 358 return (applied == 0); 359 } 360 #else 361 static inline int pmb_apply_legacy_mappings(void) 362 { 363 return 1; 364 } 365 #endif 366 367 int pmb_init(void) 368 { 369 int i; 370 unsigned long addr, data; 371 unsigned long ret; 372 373 jump_to_uncached(); 374 375 /* 376 * Attempt to apply the legacy boot mappings if configured. If 377 * this is successful then we simply carry on with those and 378 * don't bother establishing additional memory mappings. Dynamic 379 * device mappings through pmb_remap() can still be bolted on 380 * after this. 381 */ 382 ret = pmb_apply_legacy_mappings(); 383 if (ret == 0) { 384 back_to_cached(); 385 return 0; 386 } 387 388 /* 389 * Sync our software copy of the PMB mappings with those in 390 * hardware. The mappings in the hardware PMB were either set up 391 * by the bootloader or very early on by the kernel. 392 */ 393 for (i = 0; i < PMB_ENTRY_MAX; i++) { 394 struct pmb_entry *pmbe; 395 unsigned long vpn, ppn, flags; 396 397 addr = PMB_DATA + (i << PMB_E_SHIFT); 398 data = __raw_readl(addr); 399 if (!(data & PMB_V)) 400 continue; 401 402 if (data & PMB_C) { 403 #if defined(CONFIG_CACHE_WRITETHROUGH) 404 data |= PMB_WT; 405 #elif defined(CONFIG_CACHE_WRITEBACK) 406 data &= ~PMB_WT; 407 #else 408 data &= ~(PMB_C | PMB_WT); 409 #endif 410 } 411 __raw_writel(data, addr); 412 413 ppn = data & PMB_PFN_MASK; 414 415 flags = data & (PMB_C | PMB_WT | PMB_UB); 416 flags |= data & PMB_SZ_MASK; 417 418 addr = PMB_ADDR + (i << PMB_E_SHIFT); 419 data = __raw_readl(addr); 420 421 vpn = data & PMB_PFN_MASK; 422 423 pmbe = pmb_alloc(vpn, ppn, flags, i); 424 WARN_ON(IS_ERR(pmbe)); 425 } 426 427 __raw_writel(0, PMB_IRMCR); 428 429 /* Flush out the TLB */ 430 i = __raw_readl(MMUCR); 431 i |= MMUCR_TI; 432 __raw_writel(i, MMUCR); 433 434 back_to_cached(); 435 436 return 0; 437 } 438 439 bool __in_29bit_mode(void) 440 { 441 return (__raw_readl(PMB_PASCR) & PASCR_SE) == 0; 442 } 443 444 static int pmb_seq_show(struct seq_file *file, void *iter) 445 { 446 int i; 447 448 seq_printf(file, "V: Valid, C: Cacheable, WT: Write-Through\n" 449 "CB: Copy-Back, B: Buffered, UB: Unbuffered\n"); 450 seq_printf(file, "ety vpn ppn size flags\n"); 451 452 for (i = 0; i < NR_PMB_ENTRIES; i++) { 453 unsigned long addr, data; 454 unsigned int size; 455 char *sz_str = NULL; 456 457 addr = __raw_readl(mk_pmb_addr(i)); 458 data = __raw_readl(mk_pmb_data(i)); 459 460 size = data & PMB_SZ_MASK; 461 sz_str = (size == PMB_SZ_16M) ? " 16MB": 462 (size == PMB_SZ_64M) ? " 64MB": 463 (size == PMB_SZ_128M) ? "128MB": 464 "512MB"; 465 466 /* 02: V 0x88 0x08 128MB C CB B */ 467 seq_printf(file, "%02d: %c 0x%02lx 0x%02lx %s %c %s %s\n", 468 i, ((addr & PMB_V) && (data & PMB_V)) ? 'V' : ' ', 469 (addr >> 24) & 0xff, (data >> 24) & 0xff, 470 sz_str, (data & PMB_C) ? 'C' : ' ', 471 (data & PMB_WT) ? "WT" : "CB", 472 (data & PMB_UB) ? "UB" : " B"); 473 } 474 475 return 0; 476 } 477 478 static int pmb_debugfs_open(struct inode *inode, struct file *file) 479 { 480 return single_open(file, pmb_seq_show, NULL); 481 } 482 483 static const struct file_operations pmb_debugfs_fops = { 484 .owner = THIS_MODULE, 485 .open = pmb_debugfs_open, 486 .read = seq_read, 487 .llseek = seq_lseek, 488 .release = single_release, 489 }; 490 491 static int __init pmb_debugfs_init(void) 492 { 493 struct dentry *dentry; 494 495 dentry = debugfs_create_file("pmb", S_IFREG | S_IRUGO, 496 sh_debugfs_root, NULL, &pmb_debugfs_fops); 497 if (!dentry) 498 return -ENOMEM; 499 if (IS_ERR(dentry)) 500 return PTR_ERR(dentry); 501 502 return 0; 503 } 504 postcore_initcall(pmb_debugfs_init); 505 506 #ifdef CONFIG_PM 507 static int pmb_sysdev_suspend(struct sys_device *dev, pm_message_t state) 508 { 509 static pm_message_t prev_state; 510 int i; 511 512 /* Restore the PMB after a resume from hibernation */ 513 if (state.event == PM_EVENT_ON && 514 prev_state.event == PM_EVENT_FREEZE) { 515 struct pmb_entry *pmbe; 516 for (i = 0; i < ARRAY_SIZE(pmb_entry_list); i++) { 517 if (test_bit(i, &pmb_map)) { 518 pmbe = &pmb_entry_list[i]; 519 set_pmb_entry(pmbe); 520 } 521 } 522 } 523 prev_state = state; 524 return 0; 525 } 526 527 static int pmb_sysdev_resume(struct sys_device *dev) 528 { 529 return pmb_sysdev_suspend(dev, PMSG_ON); 530 } 531 532 static struct sysdev_driver pmb_sysdev_driver = { 533 .suspend = pmb_sysdev_suspend, 534 .resume = pmb_sysdev_resume, 535 }; 536 537 static int __init pmb_sysdev_init(void) 538 { 539 return sysdev_driver_register(&cpu_sysdev_class, &pmb_sysdev_driver); 540 } 541 subsys_initcall(pmb_sysdev_init); 542 #endif 543