arch/m68k/mm/kmap.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  *  linux/arch/m68k/mm/kmap.c
   4  *
   5  *  Copyright (C) 1997 Roman Hodek
   6  *
   7  *  10/01/99 cleaned up the code and changing to the same interface
   8  *           used by other architectures                /Roman Zippel
   9  */
  10
  11 #include <linux/module.h>
  12 #include <linux/mm.h>
  13 #include <linux/kernel.h>
  14 #include <linux/string.h>
  15 #include <linux/types.h>
  16 #include <linux/slab.h>
  17 #include <linux/vmalloc.h>
  18
  19 #include <asm/setup.h>
  20 #include <asm/segment.h>
  21 #include <asm/page.h>
  22 #include <asm/pgalloc.h>
  23 #include <asm/io.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 descriptors and we
  32  * can't mix this with normal page descriptors, so we have to copy that code
  33  * (mm/vmalloc.c) and return appropriately 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 = 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                         kfree(area);
  71                         return NULL;
  72                 }
  73                 addr = tmp->size + (unsigned long)tmp->addr;
  74         }
  75         area->addr = (void *)addr;
  76         area->size = size + IO_SIZE;
  77         area->next = *p;
  78         *p = area;
  79         return area;
  80 }
  81
  82 static inline void free_io_area(void *addr)
  83 {
  84         struct vm_struct **p, *tmp;
  85
  86         if (!addr)
  87                 return;
  88         addr = (void *)((unsigned long)addr & -IO_SIZE);
  89         for (p = &iolist ; (tmp = *p) ; p = &tmp->next) {
  90                 if (tmp->addr == addr) {
  91                         *p = tmp->next;
  92                         /* remove gap added in get_io_area() */
  93                         __iounmap(tmp->addr, tmp->size - IO_SIZE);
  94                         kfree(tmp);
  95                         return;
  96                 }
  97         }
  98 }
  99
 100 #endif
 101
 102 /*
 103  * Map some physical address range into the kernel address space.
 104  */
 105 /* Rewritten by Andreas Schwab to remove all races. */
 106
 107 void __iomem *__ioremap(unsigned long physaddr, unsigned long size, int cacheflag)
 108 {
 109         struct vm_struct *area;
 110         unsigned long virtaddr, retaddr;
 111         long offset;
 112         pgd_t *pgd_dir;
 113         pmd_t *pmd_dir;
 114         pte_t *pte_dir;
 115
 116         /*
 117          * Don't allow mappings that wrap..
 118          */
 119         if (!size || physaddr > (unsigned long)(-size))
 120                 return NULL;
 121
 122 #ifdef CONFIG_AMIGA
 123         if (MACH_IS_AMIGA) {
 124                 if ((physaddr >= 0x40000000) && (physaddr + size < 0x60000000)
 125                     && (cacheflag == IOMAP_NOCACHE_SER))
 126                         return (void __iomem *)physaddr;
 127         }
 128 #endif
 129
 130 #ifdef DEBUG
 131         printk("ioremap: 0x%lx,0x%lx(%d) - ", physaddr, size, cacheflag);
 132 #endif
 133         /*
 134          * Mappings have to be aligned
 135          */
 136         offset = physaddr & (IO_SIZE - 1);
 137         physaddr &= -IO_SIZE;
 138         size = (size + offset + IO_SIZE - 1) & -IO_SIZE;
 139
 140         /*
 141          * Ok, go for it..
 142          */
 143         area = get_io_area(size);
 144         if (!area)
 145                 return NULL;
 146
 147         virtaddr = (unsigned long)area->addr;
 148         retaddr = virtaddr + offset;
 149 #ifdef DEBUG
 150         printk("0x%lx,0x%lx,0x%lx", physaddr, virtaddr, retaddr);
 151 #endif
 152
 153         /*
 154          * add cache and table flags to physical address
 155          */
 156         if (CPU_IS_040_OR_060) {
 157                 physaddr |= (_PAGE_PRESENT | _PAGE_GLOBAL040 |
 158                              _PAGE_ACCESSED | _PAGE_DIRTY);
 159                 switch (cacheflag) {
 160                 case IOMAP_FULL_CACHING:
 161                         physaddr |= _PAGE_CACHE040;
 162                         break;
 163                 case IOMAP_NOCACHE_SER:
 164                 default:
 165                         physaddr |= _PAGE_NOCACHE_S;
 166                         break;
 167                 case IOMAP_NOCACHE_NONSER:
 168                         physaddr |= _PAGE_NOCACHE;
 169                         break;
 170                 case IOMAP_WRITETHROUGH:
 171                         physaddr |= _PAGE_CACHE040W;
 172                         break;
 173                 }
 174         } else {
 175                 physaddr |= (_PAGE_PRESENT | _PAGE_ACCESSED |
 176                              _PAGE_DIRTY | _PAGE_READWRITE);
 177                 switch (cacheflag) {
 178                 case IOMAP_NOCACHE_SER:
 179                 case IOMAP_NOCACHE_NONSER:
 180                 default:
 181                         physaddr |= _PAGE_NOCACHE030;
 182                         break;
 183                 case IOMAP_FULL_CACHING:
 184                 case IOMAP_WRITETHROUGH:
 185                         break;
 186                 }
 187         }
 188
 189         while ((long)size > 0) {
 190 #ifdef DEBUG
 191                 if (!(virtaddr & (PTRTREESIZE-1)))
 192                         printk ("\npa=%#lx va=%#lx ", physaddr, virtaddr);
 193 #endif
 194                 pgd_dir = pgd_offset_k(virtaddr);
 195                 pmd_dir = pmd_alloc(&init_mm, pgd_dir, virtaddr);
 196                 if (!pmd_dir) {
 197                         printk("ioremap: no mem for pmd_dir\n");
 198                         return NULL;
 199                 }
 200
 201                 if (CPU_IS_020_OR_030) {
 202                         pmd_dir->pmd[(virtaddr/PTRTREESIZE) & 15] = physaddr;
 203                         physaddr += PTRTREESIZE;
 204                         virtaddr += PTRTREESIZE;
 205                         size -= PTRTREESIZE;
 206                 } else {
 207                         pte_dir = pte_alloc_kernel(pmd_dir, virtaddr);
 208                         if (!pte_dir) {
 209                                 printk("ioremap: no mem for pte_dir\n");
 210                                 return NULL;
 211                         }
 212
 213                         pte_val(*pte_dir) = physaddr;
 214                         virtaddr += PAGE_SIZE;
 215                         physaddr += PAGE_SIZE;
 216                         size -= PAGE_SIZE;
 217                 }
 218         }
 219 #ifdef DEBUG
 220         printk("\n");
 221 #endif
 222         flush_tlb_all();
 223
 224         return (void __iomem *)retaddr;
 225 }
 226 EXPORT_SYMBOL(__ioremap);
 227
 228 /*
 229  * Unmap an ioremap()ed region again
 230  */
 231 void iounmap(void __iomem *addr)
 232 {
 233 #ifdef CONFIG_AMIGA
 234         if ((!MACH_IS_AMIGA) ||
 235             (((unsigned long)addr < 0x40000000) ||
 236              ((unsigned long)addr > 0x60000000)))
 237                         free_io_area((__force void *)addr);
 238 #else
 239         free_io_area((__force void *)addr);
 240 #endif
 241 }
 242 EXPORT_SYMBOL(iounmap);
 243
 244 /*
 245  * __iounmap unmaps nearly everything, so be careful
 246  * Currently it doesn't free pointer/page tables anymore but this
 247  * wasn't used anyway and might be added later.
 248  */
 249 void __iounmap(void *addr, unsigned long size)
 250 {
 251         unsigned long virtaddr = (unsigned long)addr;
 252         pgd_t *pgd_dir;
 253         pmd_t *pmd_dir;
 254         pte_t *pte_dir;
 255
 256         while ((long)size > 0) {
 257                 pgd_dir = pgd_offset_k(virtaddr);
 258                 if (pgd_bad(*pgd_dir)) {
 259                         printk("iounmap: bad pgd(%08lx)\n", pgd_val(*pgd_dir));
 260                         pgd_clear(pgd_dir);
 261                         return;
 262                 }
 263                 pmd_dir = pmd_offset(pgd_dir, virtaddr);
 264
 265                 if (CPU_IS_020_OR_030) {
 266                         int pmd_off = (virtaddr/PTRTREESIZE) & 15;
 267                         int pmd_type = pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK;
 268
 269                         if (pmd_type == _PAGE_PRESENT) {
 270                                 pmd_dir->pmd[pmd_off] = 0;
 271                                 virtaddr += PTRTREESIZE;
 272                                 size -= PTRTREESIZE;
 273                                 continue;
 274                         } else if (pmd_type == 0)
 275                                 continue;
 276                 }
 277
 278                 if (pmd_bad(*pmd_dir)) {
 279                         printk("iounmap: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
 280                         pmd_clear(pmd_dir);
 281                         return;
 282                 }
 283                 pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
 284
 285                 pte_val(*pte_dir) = 0;
 286                 virtaddr += PAGE_SIZE;
 287                 size -= PAGE_SIZE;
 288         }
 289
 290         flush_tlb_all();
 291 }
 292
 293 /*
 294  * Set new cache mode for some kernel address space.
 295  * The caller must push data for that range itself, if such data may already
 296  * be in the cache.
 297  */
 298 void kernel_set_cachemode(void *addr, unsigned long size, int cmode)
 299 {
 300         unsigned long virtaddr = (unsigned long)addr;
 301         pgd_t *pgd_dir;
 302         pmd_t *pmd_dir;
 303         pte_t *pte_dir;
 304
 305         if (CPU_IS_040_OR_060) {
 306                 switch (cmode) {
 307                 case IOMAP_FULL_CACHING:
 308                         cmode = _PAGE_CACHE040;
 309                         break;
 310                 case IOMAP_NOCACHE_SER:
 311                 default:
 312                         cmode = _PAGE_NOCACHE_S;
 313                         break;
 314                 case IOMAP_NOCACHE_NONSER:
 315                         cmode = _PAGE_NOCACHE;
 316                         break;
 317                 case IOMAP_WRITETHROUGH:
 318                         cmode = _PAGE_CACHE040W;
 319                         break;
 320                 }
 321         } else {
 322                 switch (cmode) {
 323                 case IOMAP_NOCACHE_SER:
 324                 case IOMAP_NOCACHE_NONSER:
 325                 default:
 326                         cmode = _PAGE_NOCACHE030;
 327                         break;
 328                 case IOMAP_FULL_CACHING:
 329                 case IOMAP_WRITETHROUGH:
 330                         cmode = 0;
 331                 }
 332         }
 333
 334         while ((long)size > 0) {
 335                 pgd_dir = pgd_offset_k(virtaddr);
 336                 if (pgd_bad(*pgd_dir)) {
 337                         printk("iocachemode: bad pgd(%08lx)\n", pgd_val(*pgd_dir));
 338                         pgd_clear(pgd_dir);
 339                         return;
 340                 }
 341                 pmd_dir = pmd_offset(pgd_dir, virtaddr);
 342
 343                 if (CPU_IS_020_OR_030) {
 344                         int pmd_off = (virtaddr/PTRTREESIZE) & 15;
 345
 346                         if ((pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK) == _PAGE_PRESENT) {
 347                                 pmd_dir->pmd[pmd_off] = (pmd_dir->pmd[pmd_off] &
 348                                                          _CACHEMASK040) | cmode;
 349                                 virtaddr += PTRTREESIZE;
 350                                 size -= PTRTREESIZE;
 351                                 continue;
 352                         }
 353                 }
 354
 355                 if (pmd_bad(*pmd_dir)) {
 356                         printk("iocachemode: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
 357                         pmd_clear(pmd_dir);
 358                         return;
 359                 }
 360                 pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
 361
 362                 pte_val(*pte_dir) = (pte_val(*pte_dir) & _CACHEMASK040) | cmode;
 363                 virtaddr += PAGE_SIZE;
 364                 size -= PAGE_SIZE;
 365         }
 366
 367         flush_tlb_all();
 368 }
 369 EXPORT_SYMBOL(kernel_set_cachemode);