arch/m68k/mm/kmap.c

   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/module.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
  24 #undef DEBUG
  25
  26 #define PTRTREESIZE     (256*1024)
  27
  28 /*
  29  * For 040/060 we can use the virtual memory area like other architectures,
  30  * but for 020/030 we want to use early termination page descriptors and we
  31  * can't mix this with normal page descriptors, so we have to copy that code
  32  * (mm/vmalloc.c) and return appropriately aligned addresses.
  33  */
  34
  35 #ifdef CPU_M68040_OR_M68060_ONLY
  36
  37 #define IO_SIZE         PAGE_SIZE
  38
  39 static inline struct vm_struct *get_io_area(unsigned long size)
  40 {
  41         return get_vm_area(size, VM_IOREMAP);
  42 }
  43
  44
  45 static inline void free_io_area(void *addr)
  46 {
  47         vfree((void *)(PAGE_MASK & (unsigned long)addr));
  48 }
  49
  50 #else
  51
  52 #define IO_SIZE         (256*1024)
  53
  54 static struct vm_struct *iolist;
  55
  56 static struct vm_struct *get_io_area(unsigned long size)
  57 {
  58         unsigned long addr;
  59         struct vm_struct **p, *tmp, *area;
  60
  61         area = kmalloc(sizeof(*area), GFP_KERNEL);
  62         if (!area)
  63                 return NULL;
  64         addr = KMAP_START;
  65         for (p = &iolist; (tmp = *p) ; p = &tmp->next) {
  66                 if (size + addr < (unsigned long)tmp->addr)
  67                         break;
  68                 if (addr > KMAP_END-size) {
  69                         kfree(area);
  70                         return NULL;
  71                 }
  72                 addr = tmp->size + (unsigned long)tmp->addr;
  73         }
  74         area->addr = (void *)addr;
  75         area->size = size + IO_SIZE;
  76         area->next = *p;
  77         *p = area;
  78         return area;
  79 }
  80
  81 static inline void free_io_area(void *addr)
  82 {
  83         struct vm_struct **p, *tmp;
  84
  85         if (!addr)
  86                 return;
  87         addr = (void *)((unsigned long)addr & -IO_SIZE);
  88         for (p = &iolist ; (tmp = *p) ; p = &tmp->next) {
  89                 if (tmp->addr == addr) {
  90                         *p = tmp->next;
  91                         __iounmap(tmp->addr, tmp->size);
  92                         kfree(tmp);
  93                         return;
  94                 }
  95         }
  96 }
  97
  98 #endif
  99
 100 /*
 101  * Map some physical address range into the kernel address space.
 102  */
 103 /* Rewritten by Andreas Schwab to remove all races. */
 104
 105 void __iomem *__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 || physaddr > (unsigned long)(-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 __iomem *)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 |
 174                              _PAGE_DIRTY | _PAGE_READWRITE);
 175                 switch (cacheflag) {
 176                 case IOMAP_NOCACHE_SER:
 177                 case IOMAP_NOCACHE_NONSER:
 178                 default:
 179                         physaddr |= _PAGE_NOCACHE030;
 180                         break;
 181                 case IOMAP_FULL_CACHING:
 182                 case IOMAP_WRITETHROUGH:
 183                         break;
 184                 }
 185         }
 186
 187         while ((long)size > 0) {
 188 #ifdef DEBUG
 189                 if (!(virtaddr & (PTRTREESIZE-1)))
 190                         printk ("\npa=%#lx va=%#lx ", physaddr, virtaddr);
 191 #endif
 192                 pgd_dir = pgd_offset_k(virtaddr);
 193                 pmd_dir = pmd_alloc(&init_mm, pgd_dir, virtaddr);
 194                 if (!pmd_dir) {
 195                         printk("ioremap: no mem for pmd_dir\n");
 196                         return NULL;
 197                 }
 198
 199                 if (CPU_IS_020_OR_030) {
 200                         pmd_dir->pmd[(virtaddr/PTRTREESIZE) & 15] = physaddr;
 201                         physaddr += PTRTREESIZE;
 202                         virtaddr += PTRTREESIZE;
 203                         size -= PTRTREESIZE;
 204                 } else {
 205                         pte_dir = pte_alloc_kernel(pmd_dir, virtaddr);
 206                         if (!pte_dir) {
 207                                 printk("ioremap: no mem for pte_dir\n");
 208                                 return NULL;
 209                         }
 210
 211                         pte_val(*pte_dir) = physaddr;
 212                         virtaddr += PAGE_SIZE;
 213                         physaddr += PAGE_SIZE;
 214                         size -= PAGE_SIZE;
 215                 }
 216         }
 217 #ifdef DEBUG
 218         printk("\n");
 219 #endif
 220         flush_tlb_all();
 221
 222         return (void __iomem *)retaddr;
 223 }
 224 EXPORT_SYMBOL(__ioremap);
 225
 226 /*
 227  * Unmap an ioremap()ed region again
 228  */
 229 void iounmap(void __iomem *addr)
 230 {
 231 #ifdef CONFIG_AMIGA
 232         if ((!MACH_IS_AMIGA) ||
 233             (((unsigned long)addr < 0x40000000) ||
 234              ((unsigned long)addr > 0x60000000)))
 235                         free_io_area((__force void *)addr);
 236 #else
 237         free_io_area((__force void *)addr);
 238 #endif
 239 }
 240 EXPORT_SYMBOL(iounmap);
 241
 242 /*
 243  * __iounmap unmaps nearly everything, so be careful
 244  * Currently it doesn't free pointer/page tables anymore but this
 245  * wasn't used anyway and might be added later.
 246  */
 247 void __iounmap(void *addr, unsigned long size)
 248 {
 249         unsigned long virtaddr = (unsigned long)addr;
 250         pgd_t *pgd_dir;
 251         pmd_t *pmd_dir;
 252         pte_t *pte_dir;
 253
 254         while ((long)size > 0) {
 255                 pgd_dir = pgd_offset_k(virtaddr);
 256                 if (pgd_bad(*pgd_dir)) {
 257                         printk("iounmap: bad pgd(%08lx)\n", pgd_val(*pgd_dir));
 258                         pgd_clear(pgd_dir);
 259                         return;
 260                 }
 261                 pmd_dir = pmd_offset(pgd_dir, virtaddr);
 262
 263                 if (CPU_IS_020_OR_030) {
 264                         int pmd_off = (virtaddr/PTRTREESIZE) & 15;
 265                         int pmd_type = pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK;
 266
 267                         if (pmd_type == _PAGE_PRESENT) {
 268                                 pmd_dir->pmd[pmd_off] = 0;
 269                                 virtaddr += PTRTREESIZE;
 270                                 size -= PTRTREESIZE;
 271                                 continue;
 272                         } else if (pmd_type == 0)
 273                                 continue;
 274                 }
 275
 276                 if (pmd_bad(*pmd_dir)) {
 277                         printk("iounmap: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
 278                         pmd_clear(pmd_dir);
 279                         return;
 280                 }
 281                 pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
 282
 283                 pte_val(*pte_dir) = 0;
 284                 virtaddr += PAGE_SIZE;
 285                 size -= PAGE_SIZE;
 286         }
 287
 288         flush_tlb_all();
 289 }
 290
 291 /*
 292  * Set new cache mode for some kernel address space.
 293  * The caller must push data for that range itself, if such data may already
 294  * be in the cache.
 295  */
 296 void kernel_set_cachemode(void *addr, unsigned long size, int cmode)
 297 {
 298         unsigned long virtaddr = (unsigned long)addr;
 299         pgd_t *pgd_dir;
 300         pmd_t *pmd_dir;
 301         pte_t *pte_dir;
 302
 303         if (CPU_IS_040_OR_060) {
 304                 switch (cmode) {
 305                 case IOMAP_FULL_CACHING:
 306                         cmode = _PAGE_CACHE040;
 307                         break;
 308                 case IOMAP_NOCACHE_SER:
 309                 default:
 310                         cmode = _PAGE_NOCACHE_S;
 311                         break;
 312                 case IOMAP_NOCACHE_NONSER:
 313                         cmode = _PAGE_NOCACHE;
 314                         break;
 315                 case IOMAP_WRITETHROUGH:
 316                         cmode = _PAGE_CACHE040W;
 317                         break;
 318                 }
 319         } else {
 320                 switch (cmode) {
 321                 case IOMAP_NOCACHE_SER:
 322                 case IOMAP_NOCACHE_NONSER:
 323                 default:
 324                         cmode = _PAGE_NOCACHE030;
 325                         break;
 326                 case IOMAP_FULL_CACHING:
 327                 case IOMAP_WRITETHROUGH:
 328                         cmode = 0;
 329                 }
 330         }
 331
 332         while ((long)size > 0) {
 333                 pgd_dir = pgd_offset_k(virtaddr);
 334                 if (pgd_bad(*pgd_dir)) {
 335                         printk("iocachemode: bad pgd(%08lx)\n", pgd_val(*pgd_dir));
 336                         pgd_clear(pgd_dir);
 337                         return;
 338                 }
 339                 pmd_dir = pmd_offset(pgd_dir, virtaddr);
 340
 341                 if (CPU_IS_020_OR_030) {
 342                         int pmd_off = (virtaddr/PTRTREESIZE) & 15;
 343
 344                         if ((pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK) == _PAGE_PRESENT) {
 345                                 pmd_dir->pmd[pmd_off] = (pmd_dir->pmd[pmd_off] &
 346                                                          _CACHEMASK040) | cmode;
 347                                 virtaddr += PTRTREESIZE;
 348                                 size -= PTRTREESIZE;
 349                                 continue;
 350                         }
 351                 }
 352
 353                 if (pmd_bad(*pmd_dir)) {
 354                         printk("iocachemode: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
 355                         pmd_clear(pmd_dir);
 356                         return;
 357                 }
 358                 pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
 359
 360                 pte_val(*pte_dir) = (pte_val(*pte_dir) & _CACHEMASK040) | cmode;
 361                 virtaddr += PAGE_SIZE;
 362                 size -= PAGE_SIZE;
 363         }
 364
 365         flush_tlb_all();
 366 }
 367 EXPORT_SYMBOL(kernel_set_cachemode);