1 /* 2 * arch/sh/mm/pmb.c 3 * 4 * Privileged Space Mapping Buffer (PMB) Support. 5 * 6 * Copyright (C) 2005, 2006 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 31 #define NR_PMB_ENTRIES 16 32 33 static struct kmem_cache *pmb_cache; 34 static unsigned long pmb_map; 35 36 static struct pmb_entry pmb_init_map[] = { 37 /* vpn ppn flags (ub/sz/c/wt) */ 38 39 /* P1 Section Mappings */ 40 { 0x80000000, 0x00000000, PMB_SZ_64M | PMB_C, }, 41 { 0x84000000, 0x04000000, PMB_SZ_64M | PMB_C, }, 42 { 0x88000000, 0x08000000, PMB_SZ_128M | PMB_C, }, 43 { 0x90000000, 0x10000000, PMB_SZ_64M | PMB_C, }, 44 { 0x94000000, 0x14000000, PMB_SZ_64M | PMB_C, }, 45 { 0x98000000, 0x18000000, PMB_SZ_64M | PMB_C, }, 46 47 /* P2 Section Mappings */ 48 { 0xa0000000, 0x00000000, PMB_UB | PMB_SZ_64M | PMB_WT, }, 49 { 0xa4000000, 0x04000000, PMB_UB | PMB_SZ_64M | PMB_WT, }, 50 { 0xa8000000, 0x08000000, PMB_UB | PMB_SZ_128M | PMB_WT, }, 51 { 0xb0000000, 0x10000000, PMB_UB | PMB_SZ_64M | PMB_WT, }, 52 { 0xb4000000, 0x14000000, PMB_UB | PMB_SZ_64M | PMB_WT, }, 53 { 0xb8000000, 0x18000000, PMB_UB | PMB_SZ_64M | PMB_WT, }, 54 }; 55 56 static inline unsigned long mk_pmb_entry(unsigned int entry) 57 { 58 return (entry & PMB_E_MASK) << PMB_E_SHIFT; 59 } 60 61 static inline unsigned long mk_pmb_addr(unsigned int entry) 62 { 63 return mk_pmb_entry(entry) | PMB_ADDR; 64 } 65 66 static inline unsigned long mk_pmb_data(unsigned int entry) 67 { 68 return mk_pmb_entry(entry) | PMB_DATA; 69 } 70 71 struct pmb_entry *pmb_alloc(unsigned long vpn, unsigned long ppn, 72 unsigned long flags) 73 { 74 struct pmb_entry *pmbe; 75 76 pmbe = kmem_cache_alloc(pmb_cache, GFP_KERNEL); 77 if (!pmbe) 78 return ERR_PTR(-ENOMEM); 79 80 pmbe->vpn = vpn; 81 pmbe->ppn = ppn; 82 pmbe->flags = flags; 83 84 return pmbe; 85 } 86 87 void pmb_free(struct pmb_entry *pmbe) 88 { 89 kmem_cache_free(pmb_cache, pmbe); 90 } 91 92 /* 93 * Must be in P2 for __set_pmb_entry() 94 */ 95 int __set_pmb_entry(unsigned long vpn, unsigned long ppn, 96 unsigned long flags, int *entry) 97 { 98 unsigned int pos = *entry; 99 100 if (unlikely(pos == PMB_NO_ENTRY)) 101 pos = find_first_zero_bit(&pmb_map, NR_PMB_ENTRIES); 102 103 repeat: 104 if (unlikely(pos > NR_PMB_ENTRIES)) 105 return -ENOSPC; 106 107 if (test_and_set_bit(pos, &pmb_map)) { 108 pos = find_first_zero_bit(&pmb_map, NR_PMB_ENTRIES); 109 goto repeat; 110 } 111 112 ctrl_outl(vpn | PMB_V, mk_pmb_addr(pos)); 113 114 #ifdef CONFIG_SH_WRITETHROUGH 115 /* 116 * When we are in 32-bit address extended mode, CCR.CB becomes 117 * invalid, so care must be taken to manually adjust cacheable 118 * translations. 119 */ 120 if (likely(flags & PMB_C)) 121 flags |= PMB_WT; 122 #endif 123 124 ctrl_outl(ppn | flags | PMB_V, mk_pmb_data(pos)); 125 126 *entry = pos; 127 128 return 0; 129 } 130 131 int set_pmb_entry(struct pmb_entry *pmbe) 132 { 133 int ret; 134 135 jump_to_P2(); 136 ret = __set_pmb_entry(pmbe->vpn, pmbe->ppn, pmbe->flags, &pmbe->entry); 137 back_to_P1(); 138 139 return ret; 140 } 141 142 void clear_pmb_entry(struct pmb_entry *pmbe) 143 { 144 unsigned int entry = pmbe->entry; 145 unsigned long addr; 146 147 /* 148 * Don't allow clearing of wired init entries, P1 or P2 access 149 * without a corresponding mapping in the PMB will lead to reset 150 * by the TLB. 151 */ 152 if (unlikely(entry < ARRAY_SIZE(pmb_init_map) || 153 entry >= NR_PMB_ENTRIES)) 154 return; 155 156 jump_to_P2(); 157 158 /* Clear V-bit */ 159 addr = mk_pmb_addr(entry); 160 ctrl_outl(ctrl_inl(addr) & ~PMB_V, addr); 161 162 addr = mk_pmb_data(entry); 163 ctrl_outl(ctrl_inl(addr) & ~PMB_V, addr); 164 165 back_to_P1(); 166 167 clear_bit(entry, &pmb_map); 168 } 169 170 static DEFINE_SPINLOCK(pmb_list_lock); 171 static struct pmb_entry *pmb_list; 172 173 static inline void pmb_list_add(struct pmb_entry *pmbe) 174 { 175 struct pmb_entry **p, *tmp; 176 177 p = &pmb_list; 178 while ((tmp = *p) != NULL) 179 p = &tmp->next; 180 181 pmbe->next = tmp; 182 *p = pmbe; 183 } 184 185 static inline void pmb_list_del(struct pmb_entry *pmbe) 186 { 187 struct pmb_entry **p, *tmp; 188 189 for (p = &pmb_list; (tmp = *p); p = &tmp->next) 190 if (tmp == pmbe) { 191 *p = tmp->next; 192 return; 193 } 194 } 195 196 static struct { 197 unsigned long size; 198 int flag; 199 } pmb_sizes[] = { 200 { .size = 0x20000000, .flag = PMB_SZ_512M, }, 201 { .size = 0x08000000, .flag = PMB_SZ_128M, }, 202 { .size = 0x04000000, .flag = PMB_SZ_64M, }, 203 { .size = 0x01000000, .flag = PMB_SZ_16M, }, 204 }; 205 206 long pmb_remap(unsigned long vaddr, unsigned long phys, 207 unsigned long size, unsigned long flags) 208 { 209 struct pmb_entry *pmbp; 210 unsigned long wanted; 211 int pmb_flags, i; 212 213 /* Convert typical pgprot value to the PMB equivalent */ 214 if (flags & _PAGE_CACHABLE) { 215 if (flags & _PAGE_WT) 216 pmb_flags = PMB_WT; 217 else 218 pmb_flags = PMB_C; 219 } else 220 pmb_flags = PMB_WT | PMB_UB; 221 222 pmbp = NULL; 223 wanted = size; 224 225 again: 226 for (i = 0; i < ARRAY_SIZE(pmb_sizes); i++) { 227 struct pmb_entry *pmbe; 228 int ret; 229 230 if (size < pmb_sizes[i].size) 231 continue; 232 233 pmbe = pmb_alloc(vaddr, phys, pmb_flags | pmb_sizes[i].flag); 234 if (IS_ERR(pmbe)) 235 return PTR_ERR(pmbe); 236 237 ret = set_pmb_entry(pmbe); 238 if (ret != 0) { 239 pmb_free(pmbe); 240 return -EBUSY; 241 } 242 243 phys += pmb_sizes[i].size; 244 vaddr += pmb_sizes[i].size; 245 size -= pmb_sizes[i].size; 246 247 /* 248 * Link adjacent entries that span multiple PMB entries 249 * for easier tear-down. 250 */ 251 if (likely(pmbp)) 252 pmbp->link = pmbe; 253 254 pmbp = pmbe; 255 } 256 257 if (size >= 0x1000000) 258 goto again; 259 260 return wanted - size; 261 } 262 263 void pmb_unmap(unsigned long addr) 264 { 265 struct pmb_entry **p, *pmbe; 266 267 for (p = &pmb_list; (pmbe = *p); p = &pmbe->next) 268 if (pmbe->vpn == addr) 269 break; 270 271 if (unlikely(!pmbe)) 272 return; 273 274 WARN_ON(!test_bit(pmbe->entry, &pmb_map)); 275 276 do { 277 struct pmb_entry *pmblink = pmbe; 278 279 clear_pmb_entry(pmbe); 280 pmbe = pmblink->link; 281 282 pmb_free(pmblink); 283 } while (pmbe); 284 } 285 286 static void pmb_cache_ctor(void *pmb, struct kmem_cache *cachep, unsigned long flags) 287 { 288 struct pmb_entry *pmbe = pmb; 289 290 memset(pmb, 0, sizeof(struct pmb_entry)); 291 292 spin_lock_irq(&pmb_list_lock); 293 294 pmbe->entry = PMB_NO_ENTRY; 295 pmb_list_add(pmbe); 296 297 spin_unlock_irq(&pmb_list_lock); 298 } 299 300 static void pmb_cache_dtor(void *pmb, struct kmem_cache *cachep, unsigned long flags) 301 { 302 spin_lock_irq(&pmb_list_lock); 303 pmb_list_del(pmb); 304 spin_unlock_irq(&pmb_list_lock); 305 } 306 307 static int __init pmb_init(void) 308 { 309 unsigned int nr_entries = ARRAY_SIZE(pmb_init_map); 310 unsigned int entry; 311 312 BUG_ON(unlikely(nr_entries >= NR_PMB_ENTRIES)); 313 314 pmb_cache = kmem_cache_create("pmb", sizeof(struct pmb_entry), 315 0, 0, pmb_cache_ctor, pmb_cache_dtor); 316 BUG_ON(!pmb_cache); 317 318 jump_to_P2(); 319 320 /* 321 * Ordering is important, P2 must be mapped in the PMB before we 322 * can set PMB.SE, and P1 must be mapped before we jump back to 323 * P1 space. 324 */ 325 for (entry = 0; entry < nr_entries; entry++) { 326 struct pmb_entry *pmbe = pmb_init_map + entry; 327 328 __set_pmb_entry(pmbe->vpn, pmbe->ppn, pmbe->flags, &entry); 329 } 330 331 ctrl_outl(0, PMB_IRMCR); 332 333 /* PMB.SE and UB[7] */ 334 ctrl_outl((1 << 31) | (1 << 7), PMB_PASCR); 335 336 back_to_P1(); 337 338 return 0; 339 } 340 arch_initcall(pmb_init); 341 342 static int pmb_seq_show(struct seq_file *file, void *iter) 343 { 344 int i; 345 346 seq_printf(file, "V: Valid, C: Cacheable, WT: Write-Through\n" 347 "CB: Copy-Back, B: Buffered, UB: Unbuffered\n"); 348 seq_printf(file, "ety vpn ppn size flags\n"); 349 350 for (i = 0; i < NR_PMB_ENTRIES; i++) { 351 unsigned long addr, data; 352 unsigned int size; 353 char *sz_str = NULL; 354 355 addr = ctrl_inl(mk_pmb_addr(i)); 356 data = ctrl_inl(mk_pmb_data(i)); 357 358 size = data & PMB_SZ_MASK; 359 sz_str = (size == PMB_SZ_16M) ? " 16MB": 360 (size == PMB_SZ_64M) ? " 64MB": 361 (size == PMB_SZ_128M) ? "128MB": 362 "512MB"; 363 364 /* 02: V 0x88 0x08 128MB C CB B */ 365 seq_printf(file, "%02d: %c 0x%02lx 0x%02lx %s %c %s %s\n", 366 i, ((addr & PMB_V) && (data & PMB_V)) ? 'V' : ' ', 367 (addr >> 24) & 0xff, (data >> 24) & 0xff, 368 sz_str, (data & PMB_C) ? 'C' : ' ', 369 (data & PMB_WT) ? "WT" : "CB", 370 (data & PMB_UB) ? "UB" : " B"); 371 } 372 373 return 0; 374 } 375 376 static int pmb_debugfs_open(struct inode *inode, struct file *file) 377 { 378 return single_open(file, pmb_seq_show, NULL); 379 } 380 381 static const struct file_operations pmb_debugfs_fops = { 382 .owner = THIS_MODULE, 383 .open = pmb_debugfs_open, 384 .read = seq_read, 385 .llseek = seq_lseek, 386 .release = seq_release, 387 }; 388 389 static int __init pmb_debugfs_init(void) 390 { 391 struct dentry *dentry; 392 393 dentry = debugfs_create_file("pmb", S_IFREG | S_IRUGO, 394 NULL, NULL, &pmb_debugfs_fops); 395 if (IS_ERR(dentry)) 396 return PTR_ERR(dentry); 397 398 return 0; 399 } 400 postcore_initcall(pmb_debugfs_init); 401