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