arch/sh/mm/pmb.c

   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 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);