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/mm.h>
  11 #include <linux/kernel.h>
  12 #include <linux/string.h>
  13 #include <linux/types.h>
  14 #include <linux/slab.h>
  15 #include <linux/vmalloc.h>
  16
  17 #include <asm/setup.h>
  18 #include <asm/segment.h>
  19 #include <asm/page.h>
  20 #include <asm/pgalloc.h>
  21 #include <asm/io.h>
  22 #include <asm/system.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 descriptor and we
  31  * can't mix this with normal page descriptors, so we have to copy that code
  32  * (mm/vmalloc.c) and return appriorate 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 = (struct vm_struct *)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                         return NULL;
  70                 addr = tmp->size + (unsigned long)tmp->addr;
  71         }
  72         area->addr = (void *)addr;
  73         area->size = size + IO_SIZE;
  74         area->next = *p;
  75         *p = area;
  76         return area;
  77 }
  78
  79 static inline void free_io_area(void *addr)
  80 {
  81         struct vm_struct **p, *tmp;
  82
  83         if (!addr)
  84                 return;
  85         addr = (void *)((unsigned long)addr & -IO_SIZE);
  86         for (p = &iolist ; (tmp = *p) ; p = &tmp->next) {
  87                 if (tmp->addr == addr) {
  88                         *p = tmp->next;
  89                         __iounmap(tmp->addr, tmp->size);
  90                         kfree(tmp);
  91                         return;
  92                 }
  93         }
  94 }
  95
  96 #endif
  97
  98 /*
  99  * Map some physical address range into the kernel address space. The
 100  * code is copied and adapted from map_chunk().
 101  */
 102 /* Rewritten by Andreas Schwab to remove all races. */
 103
 104 void __iomem *__ioremap(unsigned long physaddr, unsigned long size, int cacheflag)
 105 {
 106         struct vm_struct *area;
 107         unsigned long virtaddr, retaddr;
 108         long offset;
 109         pgd_t *pgd_dir;
 110         pmd_t *pmd_dir;
 111         pte_t *pte_dir;
 112
 113         /*
 114          * Don't allow mappings that wrap..
 115          */
 116         if (!size || size > physaddr + size)
 117                 return NULL;
 118
 119 #ifdef CONFIG_AMIGA
 120         if (MACH_IS_AMIGA) {
 121                 if ((physaddr >= 0x40000000) && (physaddr + size < 0x60000000)
 122                     && (cacheflag == IOMAP_NOCACHE_SER))
 123                         return (void __iomem *)physaddr;
 124         }
 125 #endif
 126
 127 #ifdef DEBUG
 128         printk("ioremap: 0x%lx,0x%lx(%d) - ", physaddr, size, cacheflag);
 129 #endif
 130         /*
 131          * Mappings have to be aligned
 132          */
 133         offset = physaddr & (IO_SIZE - 1);
 134         physaddr &= -IO_SIZE;
 135         size = (size + offset + IO_SIZE - 1) & -IO_SIZE;
 136
 137         /*
 138          * Ok, go for it..
 139          */
 140         area = get_io_area(size);
 141         if (!area)
 142                 return NULL;
 143
 144         virtaddr = (unsigned long)area->addr;
 145         retaddr = virtaddr + offset;
 146 #ifdef DEBUG
 147         printk("0x%lx,0x%lx,0x%lx", physaddr, virtaddr, retaddr);
 148 #endif
 149
 150         /*
 151          * add cache and table flags to physical address
 152          */
 153         if (CPU_IS_040_OR_060) {
 154                 physaddr |= (_PAGE_PRESENT | _PAGE_GLOBAL040 |
 155                              _PAGE_ACCESSED | _PAGE_DIRTY);
 156                 switch (cacheflag) {
 157                 case IOMAP_FULL_CACHING:
 158                         physaddr |= _PAGE_CACHE040;
 159                         break;
 160                 case IOMAP_NOCACHE_SER:
 161                 default:
 162                         physaddr |= _PAGE_NOCACHE_S;
 163                         break;
 164                 case IOMAP_NOCACHE_NONSER:
 165                         physaddr |= _PAGE_NOCACHE;
 166                         break;
 167                 case IOMAP_WRITETHROUGH:
 168                         physaddr |= _PAGE_CACHE040W;
 169                         break;
 170                 }
 171         } else {
 172                 physaddr |= (_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY);
 173                 switch (cacheflag) {
 174                 case IOMAP_NOCACHE_SER:
 175                 case IOMAP_NOCACHE_NONSER:
 176                 default:
 177                         physaddr |= _PAGE_NOCACHE030;
 178                         break;
 179                 case IOMAP_FULL_CACHING:
 180                 case IOMAP_WRITETHROUGH:
 181                         break;
 182                 }
 183         }
 184
 185         while ((long)size > 0) {
 186 #ifdef DEBUG
 187                 if (!(virtaddr & (PTRTREESIZE-1)))
 188                         printk ("\npa=%#lx va=%#lx ", physaddr, virtaddr);
 189 #endif
 190                 pgd_dir = pgd_offset_k(virtaddr);
 191                 pmd_dir = pmd_alloc(&init_mm, pgd_dir, virtaddr);
 192                 if (!pmd_dir) {
 193                         printk("ioremap: no mem for pmd_dir\n");
 194                         return NULL;
 195                 }
 196
 197                 if (CPU_IS_020_OR_030) {
 198                         pmd_dir->pmd[(virtaddr/PTRTREESIZE) & 15] = physaddr;
 199                         physaddr += PTRTREESIZE;
 200                         virtaddr += PTRTREESIZE;
 201                         size -= PTRTREESIZE;
 202                 } else {
 203                         pte_dir = pte_alloc_kernel(pmd_dir, virtaddr);
 204                         if (!pte_dir) {
 205                                 printk("ioremap: no mem for pte_dir\n");
 206                                 return NULL;
 207                         }
 208
 209                         pte_val(*pte_dir) = physaddr;
 210                         virtaddr += PAGE_SIZE;
 211                         physaddr += PAGE_SIZE;
 212                         size -= PAGE_SIZE;
 213                 }
 214         }
 215 #ifdef DEBUG
 216         printk("\n");
 217 #endif
 218         flush_tlb_all();
 219
 220         return (void __iomem *)retaddr;
 221 }
 222
 223 /*
 224  * Unmap a ioremap()ed region again
 225  */
 226 void iounmap(void __iomem *addr)
 227 {
 228 #ifdef CONFIG_AMIGA
 229         if ((!MACH_IS_AMIGA) ||
 230             (((unsigned long)addr < 0x40000000) ||
 231              ((unsigned long)addr > 0x60000000)))
 232                         free_io_area((__force void *)addr);
 233 #else
 234         free_io_area((__force void *)addr);
 235 #endif
 236 }
 237
 238 /*
 239  * __iounmap unmaps nearly everything, so be careful
 240  * it doesn't free currently pointer/page tables anymore but it
 241  * wans't used anyway and might be added later.
 242  */
 243 void __iounmap(void *addr, unsigned long size)
 244 {
 245         unsigned long virtaddr = (unsigned long)addr;
 246         pgd_t *pgd_dir;
 247         pmd_t *pmd_dir;
 248         pte_t *pte_dir;
 249
 250         while ((long)size > 0) {
 251                 pgd_dir = pgd_offset_k(virtaddr);
 252                 if (pgd_bad(*pgd_dir)) {
 253                         printk("iounmap: bad pgd(%08lx)\n", pgd_val(*pgd_dir));
 254                         pgd_clear(pgd_dir);
 255                         return;
 256                 }
 257                 pmd_dir = pmd_offset(pgd_dir, virtaddr);
 258
 259                 if (CPU_IS_020_OR_030) {
 260                         int pmd_off = (virtaddr/PTRTREESIZE) & 15;
 261                         int pmd_type = pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK;
 262
 263                         if (pmd_type == _PAGE_PRESENT) {
 264                                 pmd_dir->pmd[pmd_off] = 0;
 265                                 virtaddr += PTRTREESIZE;
 266                                 size -= PTRTREESIZE;
 267                                 continue;
 268                         } else if (pmd_type == 0)
 269                                 continue;
 270                 }
 271
 272                 if (pmd_bad(*pmd_dir)) {
 273                         printk("iounmap: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
 274                         pmd_clear(pmd_dir);
 275                         return;
 276                 }
 277                 pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
 278
 279                 pte_val(*pte_dir) = 0;
 280                 virtaddr += PAGE_SIZE;
 281                 size -= PAGE_SIZE;
 282         }
 283
 284         flush_tlb_all();
 285 }
 286
 287 /*
 288  * Set new cache mode for some kernel address space.
 289  * The caller must push data for that range itself, if such data may already
 290  * be in the cache.
 291  */
 292 void kernel_set_cachemode(void *addr, unsigned long size, int cmode)
 293 {
 294         unsigned long virtaddr = (unsigned long)addr;
 295         pgd_t *pgd_dir;
 296         pmd_t *pmd_dir;
 297         pte_t *pte_dir;
 298
 299         if (CPU_IS_040_OR_060) {
 300                 switch (cmode) {
 301                 case IOMAP_FULL_CACHING:
 302                         cmode = _PAGE_CACHE040;
 303                         break;
 304                 case IOMAP_NOCACHE_SER:
 305                 default:
 306                         cmode = _PAGE_NOCACHE_S;
 307                         break;
 308                 case IOMAP_NOCACHE_NONSER:
 309                         cmode = _PAGE_NOCACHE;
 310                         break;
 311                 case IOMAP_WRITETHROUGH:
 312                         cmode = _PAGE_CACHE040W;
 313                         break;
 314                 }
 315         } else {
 316                 switch (cmode) {
 317                 case IOMAP_NOCACHE_SER:
 318                 case IOMAP_NOCACHE_NONSER:
 319                 default:
 320                         cmode = _PAGE_NOCACHE030;
 321                         break;
 322                 case IOMAP_FULL_CACHING:
 323                 case IOMAP_WRITETHROUGH:
 324                         cmode = 0;
 325                 }
 326         }
 327
 328         while ((long)size > 0) {
 329                 pgd_dir = pgd_offset_k(virtaddr);
 330                 if (pgd_bad(*pgd_dir)) {
 331                         printk("iocachemode: bad pgd(%08lx)\n", pgd_val(*pgd_dir));
 332                         pgd_clear(pgd_dir);
 333                         return;
 334                 }
 335                 pmd_dir = pmd_offset(pgd_dir, virtaddr);
 336
 337                 if (CPU_IS_020_OR_030) {
 338                         int pmd_off = (virtaddr/PTRTREESIZE) & 15;
 339
 340                         if ((pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK) == _PAGE_PRESENT) {
 341                                 pmd_dir->pmd[pmd_off] = (pmd_dir->pmd[pmd_off] &
 342                                                          _CACHEMASK040) | cmode;
 343                                 virtaddr += PTRTREESIZE;
 344                                 size -= PTRTREESIZE;
 345                                 continue;
 346                         }
 347                 }
 348
 349                 if (pmd_bad(*pmd_dir)) {
 350                         printk("iocachemode: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
 351                         pmd_clear(pmd_dir);
 352                         return;
 353                 }
 354                 pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
 355
 356                 pte_val(*pte_dir) = (pte_val(*pte_dir) & _CACHEMASK040) | cmode;
 357                 virtaddr += PAGE_SIZE;
 358                 size -= PAGE_SIZE;
 359         }
 360
 361         flush_tlb_all();
 362 }