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   1 /*
   2  *  linux/arch/m68k/mm/kmap.c
   3  *
   4  *  Copyright (C) 1997 Roman Hodek
   5  *
   6  *  10/01/99 cleaned up the code and changing to the same interface
   7  *           used by other architectures                /Roman Zippel
   8  */
   9
  10 #include <linux/config.h>
  11 #include <linux/mm.h>
  12 #include <linux/kernel.h>
  13 #include <linux/string.h>
  14 #include <linux/types.h>
  15 #include <linux/slab.h>
  16 #include <linux/vmalloc.h>
  17
  18 #include <asm/setup.h>
  19 #include <asm/segment.h>
  20 #include <asm/page.h>
  21 #include <asm/pgalloc.h>
  22 #include <asm/io.h>
  23 #include <asm/system.h>
  24
  25 #undef DEBUG
  26
  27 #define PTRTREESIZE     (256*1024)
  28
  29 /*
  30  * For 040/060 we can use the virtual memory area like other architectures,
  31  * but for 020/030 we want to use early termination page descriptor and we
  32  * can't mix this with normal page descriptors, so we have to copy that code
  33  * (mm/vmalloc.c) and return appriorate aligned addresses.
  34  */
  35
  36 #ifdef CPU_M68040_OR_M68060_ONLY
  37
  38 #define IO_SIZE         PAGE_SIZE
  39
  40 static inline struct vm_struct *get_io_area(unsigned long size)
  41 {
  42         return get_vm_area(size, VM_IOREMAP);
  43 }
  44
  45
  46 static inline void free_io_area(void *addr)
  47 {
  48         vfree((void *)(PAGE_MASK & (unsigned long)addr));
  49 }
  50
  51 #else
  52
  53 #define IO_SIZE         (256*1024)
  54
  55 static struct vm_struct *iolist;
  56
  57 static struct vm_struct *get_io_area(unsigned long size)
  58 {
  59         unsigned long addr;
  60         struct vm_struct **p, *tmp, *area;
  61
  62         area = (struct vm_struct *)kmalloc(sizeof(*area), GFP_KERNEL);
  63         if (!area)
  64                 return NULL;
  65         addr = KMAP_START;
  66         for (p = &iolist; (tmp = *p) ; p = &tmp->next) {
  67                 if (size + addr < (unsigned long)tmp->addr)
  68                         break;
  69                 if (addr > KMAP_END-size)
  70                         return NULL;
  71                 addr = tmp->size + (unsigned long)tmp->addr;
  72         }
  73         area->addr = (void *)addr;
  74         area->size = size + IO_SIZE;
  75         area->next = *p;
  76         *p = area;
  77         return area;
  78 }
  79
  80 static inline void free_io_area(void *addr)
  81 {
  82         struct vm_struct **p, *tmp;
  83
  84         if (!addr)
  85                 return;
  86         addr = (void *)((unsigned long)addr & -IO_SIZE);
  87         for (p = &iolist ; (tmp = *p) ; p = &tmp->next) {
  88                 if (tmp->addr == addr) {
  89                         *p = tmp->next;
  90                         __iounmap(tmp->addr, tmp->size);
  91                         kfree(tmp);
  92                         return;
  93                 }
  94         }
  95 }
  96
  97 #endif
  98
  99 /*
 100  * Map some physical address range into the kernel address space. The
 101  * code is copied and adapted from map_chunk().
 102  */
 103 /* Rewritten by Andreas Schwab to remove all races. */
 104
 105 void *__ioremap(unsigned long physaddr, unsigned long size, int cacheflag)
 106 {
 107         struct vm_struct *area;
 108         unsigned long virtaddr, retaddr;
 109         long offset;
 110         pgd_t *pgd_dir;
 111         pmd_t *pmd_dir;
 112         pte_t *pte_dir;
 113
 114         /*
 115          * Don't allow mappings that wrap..
 116          */
 117         if (!size || size > physaddr + size)
 118                 return NULL;
 119
 120 #ifdef CONFIG_AMIGA
 121         if (MACH_IS_AMIGA) {
 122                 if ((physaddr >= 0x40000000) && (physaddr + size < 0x60000000)
 123                     && (cacheflag == IOMAP_NOCACHE_SER))
 124                         return (void *)physaddr;
 125         }
 126 #endif
 127
 128 #ifdef DEBUG
 129         printk("ioremap: 0x%lx,0x%lx(%d) - ", physaddr, size, cacheflag);
 130 #endif
 131         /*
 132          * Mappings have to be aligned
 133          */
 134         offset = physaddr & (IO_SIZE - 1);
 135         physaddr &= -IO_SIZE;
 136         size = (size + offset + IO_SIZE - 1) & -IO_SIZE;
 137
 138         /*
 139          * Ok, go for it..
 140          */
 141         area = get_io_area(size);
 142         if (!area)
 143                 return NULL;
 144
 145         virtaddr = (unsigned long)area->addr;
 146         retaddr = virtaddr + offset;
 147 #ifdef DEBUG
 148         printk("0x%lx,0x%lx,0x%lx", physaddr, virtaddr, retaddr);
 149 #endif
 150
 151         /*
 152          * add cache and table flags to physical address
 153          */
 154         if (CPU_IS_040_OR_060) {
 155                 physaddr |= (_PAGE_PRESENT | _PAGE_GLOBAL040 |
 156                              _PAGE_ACCESSED | _PAGE_DIRTY);
 157                 switch (cacheflag) {
 158                 case IOMAP_FULL_CACHING:
 159                         physaddr |= _PAGE_CACHE040;
 160                         break;
 161                 case IOMAP_NOCACHE_SER:
 162                 default:
 163                         physaddr |= _PAGE_NOCACHE_S;
 164                         break;
 165                 case IOMAP_NOCACHE_NONSER:
 166                         physaddr |= _PAGE_NOCACHE;
 167                         break;
 168                 case IOMAP_WRITETHROUGH:
 169                         physaddr |= _PAGE_CACHE040W;
 170                         break;
 171                 }
 172         } else {
 173                 physaddr |= (_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY);
 174                 switch (cacheflag) {
 175                 case IOMAP_NOCACHE_SER:
 176                 case IOMAP_NOCACHE_NONSER:
 177                 default:
 178                         physaddr |= _PAGE_NOCACHE030;
 179                         break;
 180                 case IOMAP_FULL_CACHING:
 181                 case IOMAP_WRITETHROUGH:
 182                         break;
 183                 }
 184         }
 185
 186         while ((long)size > 0) {
 187 #ifdef DEBUG
 188                 if (!(virtaddr & (PTRTREESIZE-1)))
 189                         printk ("\npa=%#lx va=%#lx ", physaddr, virtaddr);
 190 #endif
 191                 pgd_dir = pgd_offset_k(virtaddr);
 192                 pmd_dir = pmd_alloc(&init_mm, pgd_dir, virtaddr);
 193                 if (!pmd_dir) {
 194                         printk("ioremap: no mem for pmd_dir\n");
 195                         return NULL;
 196                 }
 197
 198                 if (CPU_IS_020_OR_030) {
 199                         pmd_dir->pmd[(virtaddr/PTRTREESIZE) & 15] = physaddr;
 200                         physaddr += PTRTREESIZE;
 201                         virtaddr += PTRTREESIZE;
 202                         size -= PTRTREESIZE;
 203                 } else {
 204                         pte_dir = pte_alloc_kernel(pmd_dir, virtaddr);
 205                         if (!pte_dir) {
 206                                 printk("ioremap: no mem for pte_dir\n");
 207                                 return NULL;
 208                         }
 209
 210                         pte_val(*pte_dir) = physaddr;
 211                         virtaddr += PAGE_SIZE;
 212                         physaddr += PAGE_SIZE;
 213                         size -= PAGE_SIZE;
 214                 }
 215         }
 216 #ifdef DEBUG
 217         printk("\n");
 218 #endif
 219         flush_tlb_all();
 220
 221         return (void *)retaddr;
 222 }
 223
 224 /*
 225  * Unmap a ioremap()ed region again
 226  */
 227 void iounmap(void *addr)
 228 {
 229 #ifdef CONFIG_AMIGA
 230         if ((!MACH_IS_AMIGA) ||
 231             (((unsigned long)addr < 0x40000000) ||
 232              ((unsigned long)addr > 0x60000000)))
 233                         free_io_area(addr);
 234 #else
 235         free_io_area(addr);
 236 #endif
 237 }
 238
 239 /*
 240  * __iounmap unmaps nearly everything, so be careful
 241  * it doesn't free currently pointer/page tables anymore but it
 242  * wans't used anyway and might be added later.
 243  */
 244 void __iounmap(void *addr, unsigned long size)
 245 {
 246         unsigned long virtaddr = (unsigned long)addr;
 247         pgd_t *pgd_dir;
 248         pmd_t *pmd_dir;
 249         pte_t *pte_dir;
 250
 251         while ((long)size > 0) {
 252                 pgd_dir = pgd_offset_k(virtaddr);
 253                 if (pgd_bad(*pgd_dir)) {
 254                         printk("iounmap: bad pgd(%08lx)\n", pgd_val(*pgd_dir));
 255                         pgd_clear(pgd_dir);
 256                         return;
 257                 }
 258                 pmd_dir = pmd_offset(pgd_dir, virtaddr);
 259
 260                 if (CPU_IS_020_OR_030) {
 261                         int pmd_off = (virtaddr/PTRTREESIZE) & 15;
 262
 263                         if ((pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK) == _PAGE_PRESENT) {
 264                                 pmd_dir->pmd[pmd_off] = 0;
 265                                 virtaddr += PTRTREESIZE;
 266                                 size -= PTRTREESIZE;
 267                                 continue;
 268                         }
 269                 }
 270
 271                 if (pmd_bad(*pmd_dir)) {
 272                         printk("iounmap: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
 273                         pmd_clear(pmd_dir);
 274                         return;
 275                 }
 276                 pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
 277
 278                 pte_val(*pte_dir) = 0;
 279                 virtaddr += PAGE_SIZE;
 280                 size -= PAGE_SIZE;
 281         }
 282
 283         flush_tlb_all();
 284 }
 285
 286 /*
 287  * Set new cache mode for some kernel address space.
 288  * The caller must push data for that range itself, if such data may already
 289  * be in the cache.
 290  */
 291 void kernel_set_cachemode(void *addr, unsigned long size, int cmode)
 292 {
 293         unsigned long virtaddr = (unsigned long)addr;
 294         pgd_t *pgd_dir;
 295         pmd_t *pmd_dir;
 296         pte_t *pte_dir;
 297
 298         if (CPU_IS_040_OR_060) {
 299                 switch (cmode) {
 300                 case IOMAP_FULL_CACHING:
 301                         cmode = _PAGE_CACHE040;
 302                         break;
 303                 case IOMAP_NOCACHE_SER:
 304                 default:
 305                         cmode = _PAGE_NOCACHE_S;
 306                         break;
 307                 case IOMAP_NOCACHE_NONSER:
 308                         cmode = _PAGE_NOCACHE;
 309                         break;
 310                 case IOMAP_WRITETHROUGH:
 311                         cmode = _PAGE_CACHE040W;
 312                         break;
 313                 }
 314         } else {
 315                 switch (cmode) {
 316                 case IOMAP_NOCACHE_SER:
 317                 case IOMAP_NOCACHE_NONSER:
 318                 default:
 319                         cmode = _PAGE_NOCACHE030;
 320                         break;
 321                 case IOMAP_FULL_CACHING:
 322                 case IOMAP_WRITETHROUGH:
 323                         cmode = 0;
 324                 }
 325         }
 326
 327         while ((long)size > 0) {
 328                 pgd_dir = pgd_offset_k(virtaddr);
 329                 if (pgd_bad(*pgd_dir)) {
 330                         printk("iocachemode: bad pgd(%08lx)\n", pgd_val(*pgd_dir));
 331                         pgd_clear(pgd_dir);
 332                         return;
 333                 }
 334                 pmd_dir = pmd_offset(pgd_dir, virtaddr);
 335
 336                 if (CPU_IS_020_OR_030) {
 337                         int pmd_off = (virtaddr/PTRTREESIZE) & 15;
 338
 339                         if ((pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK) == _PAGE_PRESENT) {
 340                                 pmd_dir->pmd[pmd_off] = (pmd_dir->pmd[pmd_off] &
 341                                                          _CACHEMASK040) | cmode;
 342                                 virtaddr += PTRTREESIZE;
 343                                 size -= PTRTREESIZE;
 344                                 continue;
 345                         }
 346                 }
 347
 348                 if (pmd_bad(*pmd_dir)) {
 349                         printk("iocachemode: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
 350                         pmd_clear(pmd_dir);
 351                         return;
 352                 }
 353                 pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
 354
 355                 pte_val(*pte_dir) = (pte_val(*pte_dir) & _CACHEMASK040) | cmode;
 356                 virtaddr += PAGE_SIZE;
 357                 size -= PAGE_SIZE;
 358         }
 359
 360         flush_tlb_all();
 361 }