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 /*
  58  * __free_io_area unmaps nearly everything, so be careful
  59  * Currently it doesn't free pointer/page tables anymore but this
  60  * wasn't used anyway and might be added later.
  61  */
  62 static void __free_io_area(void *addr, unsigned long size)
  63 {
  64         unsigned long virtaddr = (unsigned long)addr;
  65         pgd_t *pgd_dir;
  66         p4d_t *p4d_dir;
  67         pud_t *pud_dir;
  68         pmd_t *pmd_dir;
  69         pte_t *pte_dir;
  70
  71         while ((long)size > 0) {
  72                 pgd_dir = pgd_offset_k(virtaddr);
  73                 p4d_dir = p4d_offset(pgd_dir, virtaddr);
  74                 pud_dir = pud_offset(p4d_dir, virtaddr);
  75                 if (pud_bad(*pud_dir)) {
  76                         printk("iounmap: bad pud(%08lx)\n", pud_val(*pud_dir));
  77                         pud_clear(pud_dir);
  78                         return;
  79                 }
  80                 pmd_dir = pmd_offset(pud_dir, virtaddr);
  81
  82 #if CONFIG_PGTABLE_LEVELS == 3
  83                 if (CPU_IS_020_OR_030) {
  84                         int pmd_off = (virtaddr/PTRTREESIZE) & 15;
  85                         int pmd_type = pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK;
  86
  87                         if (pmd_type == _PAGE_PRESENT) {
  88                                 pmd_dir->pmd[pmd_off] = 0;
  89                                 virtaddr += PTRTREESIZE;
  90                                 size -= PTRTREESIZE;
  91                                 continue;
  92                         } else if (pmd_type == 0)
  93                                 continue;
  94                 }
  95 #endif
  96
  97                 if (pmd_bad(*pmd_dir)) {
  98                         printk("iounmap: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
  99                         pmd_clear(pmd_dir);
 100                         return;
 101                 }
 102                 pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
 103
 104                 pte_val(*pte_dir) = 0;
 105                 virtaddr += PAGE_SIZE;
 106                 size -= PAGE_SIZE;
 107         }
 108
 109         flush_tlb_all();
 110 }
 111
 112 static struct vm_struct *get_io_area(unsigned long size)
 113 {
 114         unsigned long addr;
 115         struct vm_struct **p, *tmp, *area;
 116
 117         area = kmalloc(sizeof(*area), GFP_KERNEL);
 118         if (!area)
 119                 return NULL;
 120         addr = KMAP_START;
 121         for (p = &iolist; (tmp = *p) ; p = &tmp->next) {
 122                 if (size + addr < (unsigned long)tmp->addr)
 123                         break;
 124                 if (addr > KMAP_END-size) {
 125                         kfree(area);
 126                         return NULL;
 127                 }
 128                 addr = tmp->size + (unsigned long)tmp->addr;
 129         }
 130         area->addr = (void *)addr;
 131         area->size = size + IO_SIZE;
 132         area->next = *p;
 133         *p = area;
 134         return area;
 135 }
 136
 137 static inline void free_io_area(void *addr)
 138 {
 139         struct vm_struct **p, *tmp;
 140
 141         if (!addr)
 142                 return;
 143         addr = (void *)((unsigned long)addr & -IO_SIZE);
 144         for (p = &iolist ; (tmp = *p) ; p = &tmp->next) {
 145                 if (tmp->addr == addr) {
 146                         *p = tmp->next;
 147                         /* remove gap added in get_io_area() */
 148                         __free_io_area(tmp->addr, tmp->size - IO_SIZE);
 149                         kfree(tmp);
 150                         return;
 151                 }
 152         }
 153 }
 154
 155 #endif
 156
 157 /*
 158  * Map some physical address range into the kernel address space.
 159  */
 160 /* Rewritten by Andreas Schwab to remove all races. */
 161
 162 void __iomem *__ioremap(unsigned long physaddr, unsigned long size, int cacheflag)
 163 {
 164         struct vm_struct *area;
 165         unsigned long virtaddr, retaddr;
 166         long offset;
 167         pgd_t *pgd_dir;
 168         p4d_t *p4d_dir;
 169         pud_t *pud_dir;
 170         pmd_t *pmd_dir;
 171         pte_t *pte_dir;
 172
 173         /*
 174          * Don't allow mappings that wrap..
 175          */
 176         if (!size || physaddr > (unsigned long)(-size))
 177                 return NULL;
 178
 179 #ifdef CONFIG_AMIGA
 180         if (MACH_IS_AMIGA) {
 181                 if ((physaddr >= 0x40000000) && (physaddr + size < 0x60000000)
 182                     && (cacheflag == IOMAP_NOCACHE_SER))
 183                         return (void __iomem *)physaddr;
 184         }
 185 #endif
 186 #ifdef CONFIG_COLDFIRE
 187         if (__cf_internalio(physaddr))
 188                 return (void __iomem *) physaddr;
 189 #endif
 190
 191 #ifdef DEBUG
 192         printk("ioremap: 0x%lx,0x%lx(%d) - ", physaddr, size, cacheflag);
 193 #endif
 194         /*
 195          * Mappings have to be aligned
 196          */
 197         offset = physaddr & (IO_SIZE - 1);
 198         physaddr &= -IO_SIZE;
 199         size = (size + offset + IO_SIZE - 1) & -IO_SIZE;
 200
 201         /*
 202          * Ok, go for it..
 203          */
 204         area = get_io_area(size);
 205         if (!area)
 206                 return NULL;
 207
 208         virtaddr = (unsigned long)area->addr;
 209         retaddr = virtaddr + offset;
 210 #ifdef DEBUG
 211         printk("0x%lx,0x%lx,0x%lx", physaddr, virtaddr, retaddr);
 212 #endif
 213
 214         /*
 215          * add cache and table flags to physical address
 216          */
 217         if (CPU_IS_040_OR_060) {
 218                 physaddr |= (_PAGE_PRESENT | _PAGE_GLOBAL040 |
 219                              _PAGE_ACCESSED | _PAGE_DIRTY);
 220                 switch (cacheflag) {
 221                 case IOMAP_FULL_CACHING:
 222                         physaddr |= _PAGE_CACHE040;
 223                         break;
 224                 case IOMAP_NOCACHE_SER:
 225                 default:
 226                         physaddr |= _PAGE_NOCACHE_S;
 227                         break;
 228                 case IOMAP_NOCACHE_NONSER:
 229                         physaddr |= _PAGE_NOCACHE;
 230                         break;
 231                 case IOMAP_WRITETHROUGH:
 232                         physaddr |= _PAGE_CACHE040W;
 233                         break;
 234                 }
 235         } else {
 236                 physaddr |= (_PAGE_PRESENT | _PAGE_ACCESSED |
 237                              _PAGE_DIRTY | _PAGE_READWRITE);
 238                 switch (cacheflag) {
 239                 case IOMAP_NOCACHE_SER:
 240                 case IOMAP_NOCACHE_NONSER:
 241                 default:
 242                         physaddr |= _PAGE_NOCACHE030;
 243                         break;
 244                 case IOMAP_FULL_CACHING:
 245                 case IOMAP_WRITETHROUGH:
 246                         break;
 247                 }
 248         }
 249
 250         while ((long)size > 0) {
 251 #ifdef DEBUG
 252                 if (!(virtaddr & (PTRTREESIZE-1)))
 253                         printk ("\npa=%#lx va=%#lx ", physaddr, virtaddr);
 254 #endif
 255                 pgd_dir = pgd_offset_k(virtaddr);
 256                 p4d_dir = p4d_offset(pgd_dir, virtaddr);
 257                 pud_dir = pud_offset(p4d_dir, virtaddr);
 258                 pmd_dir = pmd_alloc(&init_mm, pud_dir, virtaddr);
 259                 if (!pmd_dir) {
 260                         printk("ioremap: no mem for pmd_dir\n");
 261                         return NULL;
 262                 }
 263
 264 #if CONFIG_PGTABLE_LEVELS == 3
 265                 if (CPU_IS_020_OR_030) {
 266                         pmd_dir->pmd[(virtaddr/PTRTREESIZE) & 15] = physaddr;
 267                         physaddr += PTRTREESIZE;
 268                         virtaddr += PTRTREESIZE;
 269                         size -= PTRTREESIZE;
 270                 } else
 271 #endif
 272                 {
 273                         pte_dir = pte_alloc_kernel(pmd_dir, virtaddr);
 274                         if (!pte_dir) {
 275                                 printk("ioremap: no mem for pte_dir\n");
 276                                 return NULL;
 277                         }
 278
 279                         pte_val(*pte_dir) = physaddr;
 280                         virtaddr += PAGE_SIZE;
 281                         physaddr += PAGE_SIZE;
 282                         size -= PAGE_SIZE;
 283                 }
 284         }
 285 #ifdef DEBUG
 286         printk("\n");
 287 #endif
 288         flush_tlb_all();
 289
 290         return (void __iomem *)retaddr;
 291 }
 292 EXPORT_SYMBOL(__ioremap);
 293
 294 /*
 295  * Unmap an ioremap()ed region again
 296  */
 297 void iounmap(void __iomem *addr)
 298 {
 299 #ifdef CONFIG_AMIGA
 300         if ((!MACH_IS_AMIGA) ||
 301             (((unsigned long)addr < 0x40000000) ||
 302              ((unsigned long)addr > 0x60000000)))
 303                         free_io_area((__force void *)addr);
 304 #else
 305 #ifdef CONFIG_COLDFIRE
 306         if (cf_internalio(addr))
 307                 return;
 308 #endif
 309         free_io_area((__force void *)addr);
 310 #endif
 311 }
 312 EXPORT_SYMBOL(iounmap);
 313
 314 /*
 315  * Set new cache mode for some kernel address space.
 316  * The caller must push data for that range itself, if such data may already
 317  * be in the cache.
 318  */
 319 void kernel_set_cachemode(void *addr, unsigned long size, int cmode)
 320 {
 321         unsigned long virtaddr = (unsigned long)addr;
 322         pgd_t *pgd_dir;
 323         p4d_t *p4d_dir;
 324         pud_t *pud_dir;
 325         pmd_t *pmd_dir;
 326         pte_t *pte_dir;
 327
 328         if (CPU_IS_040_OR_060) {
 329                 switch (cmode) {
 330                 case IOMAP_FULL_CACHING:
 331                         cmode = _PAGE_CACHE040;
 332                         break;
 333                 case IOMAP_NOCACHE_SER:
 334                 default:
 335                         cmode = _PAGE_NOCACHE_S;
 336                         break;
 337                 case IOMAP_NOCACHE_NONSER:
 338                         cmode = _PAGE_NOCACHE;
 339                         break;
 340                 case IOMAP_WRITETHROUGH:
 341                         cmode = _PAGE_CACHE040W;
 342                         break;
 343                 }
 344         } else {
 345                 switch (cmode) {
 346                 case IOMAP_NOCACHE_SER:
 347                 case IOMAP_NOCACHE_NONSER:
 348                 default:
 349                         cmode = _PAGE_NOCACHE030;
 350                         break;
 351                 case IOMAP_FULL_CACHING:
 352                 case IOMAP_WRITETHROUGH:
 353                         cmode = 0;
 354                 }
 355         }
 356
 357         while ((long)size > 0) {
 358                 pgd_dir = pgd_offset_k(virtaddr);
 359                 p4d_dir = p4d_offset(pgd_dir, virtaddr);
 360                 pud_dir = pud_offset(p4d_dir, virtaddr);
 361                 if (pud_bad(*pud_dir)) {
 362                         printk("iocachemode: bad pud(%08lx)\n", pud_val(*pud_dir));
 363                         pud_clear(pud_dir);
 364                         return;
 365                 }
 366                 pmd_dir = pmd_offset(pud_dir, virtaddr);
 367
 368 #if CONFIG_PGTABLE_LEVELS == 3
 369                 if (CPU_IS_020_OR_030) {
 370                         int pmd_off = (virtaddr/PTRTREESIZE) & 15;
 371
 372                         if ((pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK) == _PAGE_PRESENT) {
 373                                 pmd_dir->pmd[pmd_off] = (pmd_dir->pmd[pmd_off] &
 374                                                          _CACHEMASK040) | cmode;
 375                                 virtaddr += PTRTREESIZE;
 376                                 size -= PTRTREESIZE;
 377                                 continue;
 378                         }
 379                 }
 380 #endif
 381
 382                 if (pmd_bad(*pmd_dir)) {
 383                         printk("iocachemode: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
 384                         pmd_clear(pmd_dir);
 385                         return;
 386                 }
 387                 pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
 388
 389                 pte_val(*pte_dir) = (pte_val(*pte_dir) & _CACHEMASK040) | cmode;
 390                 virtaddr += PAGE_SIZE;
 391                 size -= PAGE_SIZE;
 392         }
 393
 394         flush_tlb_all();
 395 }
 396 EXPORT_SYMBOL(kernel_set_cachemode);