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 #ifdef CONFIG_COLDFIRE
 130         if (__cf_internalio(physaddr))
 131                 return (void __iomem *) physaddr;
 132 #endif
 133
 134 #ifdef DEBUG
 135         printk("ioremap: 0x%lx,0x%lx(%d) - ", physaddr, size, cacheflag);
 136 #endif
 137         /*
 138          * Mappings have to be aligned
 139          */
 140         offset = physaddr & (IO_SIZE - 1);
 141         physaddr &= -IO_SIZE;
 142         size = (size + offset + IO_SIZE - 1) & -IO_SIZE;
 143
 144         /*
 145          * Ok, go for it..
 146          */
 147         area = get_io_area(size);
 148         if (!area)
 149                 return NULL;
 150
 151         virtaddr = (unsigned long)area->addr;
 152         retaddr = virtaddr + offset;
 153 #ifdef DEBUG
 154         printk("0x%lx,0x%lx,0x%lx", physaddr, virtaddr, retaddr);
 155 #endif
 156
 157         /*
 158          * add cache and table flags to physical address
 159          */
 160         if (CPU_IS_040_OR_060) {
 161                 physaddr |= (_PAGE_PRESENT | _PAGE_GLOBAL040 |
 162                              _PAGE_ACCESSED | _PAGE_DIRTY);
 163                 switch (cacheflag) {
 164                 case IOMAP_FULL_CACHING:
 165                         physaddr |= _PAGE_CACHE040;
 166                         break;
 167                 case IOMAP_NOCACHE_SER:
 168                 default:
 169                         physaddr |= _PAGE_NOCACHE_S;
 170                         break;
 171                 case IOMAP_NOCACHE_NONSER:
 172                         physaddr |= _PAGE_NOCACHE;
 173                         break;
 174                 case IOMAP_WRITETHROUGH:
 175                         physaddr |= _PAGE_CACHE040W;
 176                         break;
 177                 }
 178         } else {
 179                 physaddr |= (_PAGE_PRESENT | _PAGE_ACCESSED |
 180                              _PAGE_DIRTY | _PAGE_READWRITE);
 181                 switch (cacheflag) {
 182                 case IOMAP_NOCACHE_SER:
 183                 case IOMAP_NOCACHE_NONSER:
 184                 default:
 185                         physaddr |= _PAGE_NOCACHE030;
 186                         break;
 187                 case IOMAP_FULL_CACHING:
 188                 case IOMAP_WRITETHROUGH:
 189                         break;
 190                 }
 191         }
 192
 193         while ((long)size > 0) {
 194 #ifdef DEBUG
 195                 if (!(virtaddr & (PTRTREESIZE-1)))
 196                         printk ("\npa=%#lx va=%#lx ", physaddr, virtaddr);
 197 #endif
 198                 pgd_dir = pgd_offset_k(virtaddr);
 199                 pmd_dir = pmd_alloc(&init_mm, pgd_dir, virtaddr);
 200                 if (!pmd_dir) {
 201                         printk("ioremap: no mem for pmd_dir\n");
 202                         return NULL;
 203                 }
 204
 205                 if (CPU_IS_020_OR_030) {
 206                         pmd_dir->pmd[(virtaddr/PTRTREESIZE) & 15] = physaddr;
 207                         physaddr += PTRTREESIZE;
 208                         virtaddr += PTRTREESIZE;
 209                         size -= PTRTREESIZE;
 210                 } else {
 211                         pte_dir = pte_alloc_kernel(pmd_dir, virtaddr);
 212                         if (!pte_dir) {
 213                                 printk("ioremap: no mem for pte_dir\n");
 214                                 return NULL;
 215                         }
 216
 217                         pte_val(*pte_dir) = physaddr;
 218                         virtaddr += PAGE_SIZE;
 219                         physaddr += PAGE_SIZE;
 220                         size -= PAGE_SIZE;
 221                 }
 222         }
 223 #ifdef DEBUG
 224         printk("\n");
 225 #endif
 226         flush_tlb_all();
 227
 228         return (void __iomem *)retaddr;
 229 }
 230 EXPORT_SYMBOL(__ioremap);
 231
 232 /*
 233  * Unmap an ioremap()ed region again
 234  */
 235 void iounmap(void __iomem *addr)
 236 {
 237 #ifdef CONFIG_AMIGA
 238         if ((!MACH_IS_AMIGA) ||
 239             (((unsigned long)addr < 0x40000000) ||
 240              ((unsigned long)addr > 0x60000000)))
 241                         free_io_area((__force void *)addr);
 242 #else
 243 #ifdef CONFIG_COLDFIRE
 244         if (cf_internalio(addr))
 245                 return;
 246 #endif
 247         free_io_area((__force void *)addr);
 248 #endif
 249 }
 250 EXPORT_SYMBOL(iounmap);
 251
 252 /*
 253  * __iounmap unmaps nearly everything, so be careful
 254  * Currently it doesn't free pointer/page tables anymore but this
 255  * wasn't used anyway and might be added later.
 256  */
 257 void __iounmap(void *addr, unsigned long size)
 258 {
 259         unsigned long virtaddr = (unsigned long)addr;
 260         pgd_t *pgd_dir;
 261         pmd_t *pmd_dir;
 262         pte_t *pte_dir;
 263
 264         while ((long)size > 0) {
 265                 pgd_dir = pgd_offset_k(virtaddr);
 266                 if (pgd_bad(*pgd_dir)) {
 267                         printk("iounmap: bad pgd(%08lx)\n", pgd_val(*pgd_dir));
 268                         pgd_clear(pgd_dir);
 269                         return;
 270                 }
 271                 pmd_dir = pmd_offset(pgd_dir, virtaddr);
 272
 273                 if (CPU_IS_020_OR_030) {
 274                         int pmd_off = (virtaddr/PTRTREESIZE) & 15;
 275                         int pmd_type = pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK;
 276
 277                         if (pmd_type == _PAGE_PRESENT) {
 278                                 pmd_dir->pmd[pmd_off] = 0;
 279                                 virtaddr += PTRTREESIZE;
 280                                 size -= PTRTREESIZE;
 281                                 continue;
 282                         } else if (pmd_type == 0)
 283                                 continue;
 284                 }
 285
 286                 if (pmd_bad(*pmd_dir)) {
 287                         printk("iounmap: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
 288                         pmd_clear(pmd_dir);
 289                         return;
 290                 }
 291                 pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
 292
 293                 pte_val(*pte_dir) = 0;
 294                 virtaddr += PAGE_SIZE;
 295                 size -= PAGE_SIZE;
 296         }
 297
 298         flush_tlb_all();
 299 }
 300
 301 /*
 302  * Set new cache mode for some kernel address space.
 303  * The caller must push data for that range itself, if such data may already
 304  * be in the cache.
 305  */
 306 void kernel_set_cachemode(void *addr, unsigned long size, int cmode)
 307 {
 308         unsigned long virtaddr = (unsigned long)addr;
 309         pgd_t *pgd_dir;
 310         pmd_t *pmd_dir;
 311         pte_t *pte_dir;
 312
 313         if (CPU_IS_040_OR_060) {
 314                 switch (cmode) {
 315                 case IOMAP_FULL_CACHING:
 316                         cmode = _PAGE_CACHE040;
 317                         break;
 318                 case IOMAP_NOCACHE_SER:
 319                 default:
 320                         cmode = _PAGE_NOCACHE_S;
 321                         break;
 322                 case IOMAP_NOCACHE_NONSER:
 323                         cmode = _PAGE_NOCACHE;
 324                         break;
 325                 case IOMAP_WRITETHROUGH:
 326                         cmode = _PAGE_CACHE040W;
 327                         break;
 328                 }
 329         } else {
 330                 switch (cmode) {
 331                 case IOMAP_NOCACHE_SER:
 332                 case IOMAP_NOCACHE_NONSER:
 333                 default:
 334                         cmode = _PAGE_NOCACHE030;
 335                         break;
 336                 case IOMAP_FULL_CACHING:
 337                 case IOMAP_WRITETHROUGH:
 338                         cmode = 0;
 339                 }
 340         }
 341
 342         while ((long)size > 0) {
 343                 pgd_dir = pgd_offset_k(virtaddr);
 344                 if (pgd_bad(*pgd_dir)) {
 345                         printk("iocachemode: bad pgd(%08lx)\n", pgd_val(*pgd_dir));
 346                         pgd_clear(pgd_dir);
 347                         return;
 348                 }
 349                 pmd_dir = pmd_offset(pgd_dir, virtaddr);
 350
 351                 if (CPU_IS_020_OR_030) {
 352                         int pmd_off = (virtaddr/PTRTREESIZE) & 15;
 353
 354                         if ((pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK) == _PAGE_PRESENT) {
 355                                 pmd_dir->pmd[pmd_off] = (pmd_dir->pmd[pmd_off] &
 356                                                          _CACHEMASK040) | cmode;
 357                                 virtaddr += PTRTREESIZE;
 358                                 size -= PTRTREESIZE;
 359                                 continue;
 360                         }
 361                 }
 362
 363                 if (pmd_bad(*pmd_dir)) {
 364                         printk("iocachemode: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
 365                         pmd_clear(pmd_dir);
 366                         return;
 367                 }
 368                 pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
 369
 370                 pte_val(*pte_dir) = (pte_val(*pte_dir) & _CACHEMASK040) | cmode;
 371                 virtaddr += PAGE_SIZE;
 372                 size -= PAGE_SIZE;
 373         }
 374
 375         flush_tlb_all();
 376 }
 377 EXPORT_SYMBOL(kernel_set_cachemode);