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/page.h>
  21 #include <asm/io.h>
  22 #include <asm/tlbflush.h>
  23
  24 #undef DEBUG
  25
  26 /*
  27  * For 040/060 we can use the virtual memory area like other architectures,
  28  * but for 020/030 we want to use early termination page descriptors and we
  29  * can't mix this with normal page descriptors, so we have to copy that code
  30  * (mm/vmalloc.c) and return appropriately aligned addresses.
  31  */
  32
  33 #ifdef CPU_M68040_OR_M68060_ONLY
  34
  35 #define IO_SIZE         PAGE_SIZE
  36
  37 static inline struct vm_struct *get_io_area(unsigned long size)
  38 {
  39         return get_vm_area(size, VM_IOREMAP);
  40 }
  41
  42
  43 static inline void free_io_area(void *addr)
  44 {
  45         vfree((void *)(PAGE_MASK & (unsigned long)addr));
  46 }
  47
  48 #else
  49
  50 #define IO_SIZE         PMD_SIZE
  51
  52 static struct vm_struct *iolist;
  53
  54 /*
  55  * __free_io_area unmaps nearly everything, so be careful
  56  * Currently it doesn't free pointer/page tables anymore but this
  57  * wasn't used anyway and might be added later.
  58  */
  59 static void __free_io_area(void *addr, unsigned long size)
  60 {
  61         unsigned long virtaddr = (unsigned long)addr;
  62         pgd_t *pgd_dir;
  63         p4d_t *p4d_dir;
  64         pud_t *pud_dir;
  65         pmd_t *pmd_dir;
  66         pte_t *pte_dir;
  67
  68         while ((long)size > 0) {
  69                 pgd_dir = pgd_offset_k(virtaddr);
  70                 p4d_dir = p4d_offset(pgd_dir, virtaddr);
  71                 pud_dir = pud_offset(p4d_dir, virtaddr);
  72                 if (pud_bad(*pud_dir)) {
  73                         printk("iounmap: bad pud(%08lx)\n", pud_val(*pud_dir));
  74                         pud_clear(pud_dir);
  75                         return;
  76                 }
  77                 pmd_dir = pmd_offset(pud_dir, virtaddr);
  78
  79 #if CONFIG_PGTABLE_LEVELS == 3
  80                 if (CPU_IS_020_OR_030) {
  81                         int pmd_type = pmd_val(*pmd_dir) & _DESCTYPE_MASK;
  82
  83                         if (pmd_type == _PAGE_PRESENT) {
  84                                 pmd_clear(pmd_dir);
  85                                 virtaddr += PMD_SIZE;
  86                                 size -= PMD_SIZE;
  87
  88                         } else if (pmd_type == 0)
  89                                 continue;
  90                 }
  91 #endif
  92
  93                 if (pmd_bad(*pmd_dir)) {
  94                         printk("iounmap: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
  95                         pmd_clear(pmd_dir);
  96                         return;
  97                 }
  98                 pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
  99
 100                 pte_val(*pte_dir) = 0;
 101                 virtaddr += PAGE_SIZE;
 102                 size -= PAGE_SIZE;
 103         }
 104
 105         flush_tlb_all();
 106 }
 107
 108 static struct vm_struct *get_io_area(unsigned long size)
 109 {
 110         unsigned long addr;
 111         struct vm_struct **p, *tmp, *area;
 112
 113         area = kmalloc(sizeof(*area), GFP_KERNEL);
 114         if (!area)
 115                 return NULL;
 116         addr = KMAP_START;
 117         for (p = &iolist; (tmp = *p) ; p = &tmp->next) {
 118                 if (size + addr < (unsigned long)tmp->addr)
 119                         break;
 120                 if (addr > KMAP_END-size) {
 121                         kfree(area);
 122                         return NULL;
 123                 }
 124                 addr = tmp->size + (unsigned long)tmp->addr;
 125         }
 126         area->addr = (void *)addr;
 127         area->size = size + IO_SIZE;
 128         area->next = *p;
 129         *p = area;
 130         return area;
 131 }
 132
 133 static inline void free_io_area(void *addr)
 134 {
 135         struct vm_struct **p, *tmp;
 136
 137         if (!addr)
 138                 return;
 139         addr = (void *)((unsigned long)addr & -IO_SIZE);
 140         for (p = &iolist ; (tmp = *p) ; p = &tmp->next) {
 141                 if (tmp->addr == addr) {
 142                         *p = tmp->next;
 143                         /* remove gap added in get_io_area() */
 144                         __free_io_area(tmp->addr, tmp->size - IO_SIZE);
 145                         kfree(tmp);
 146                         return;
 147                 }
 148         }
 149 }
 150
 151 #endif
 152
 153 /*
 154  * Map some physical address range into the kernel address space.
 155  */
 156 /* Rewritten by Andreas Schwab to remove all races. */
 157
 158 void __iomem *__ioremap(unsigned long physaddr, unsigned long size, int cacheflag)
 159 {
 160         struct vm_struct *area;
 161         unsigned long virtaddr, retaddr;
 162         long offset;
 163         pgd_t *pgd_dir;
 164         p4d_t *p4d_dir;
 165         pud_t *pud_dir;
 166         pmd_t *pmd_dir;
 167         pte_t *pte_dir;
 168
 169         /*
 170          * Don't allow mappings that wrap..
 171          */
 172         if (!size || physaddr > (unsigned long)(-size))
 173                 return NULL;
 174
 175 #ifdef CONFIG_AMIGA
 176         if (MACH_IS_AMIGA) {
 177                 if ((physaddr >= 0x40000000) && (physaddr + size < 0x60000000)
 178                     && (cacheflag == IOMAP_NOCACHE_SER))
 179                         return (void __iomem *)physaddr;
 180         }
 181 #endif
 182 #ifdef CONFIG_COLDFIRE
 183         if (__cf_internalio(physaddr))
 184                 return (void __iomem *) physaddr;
 185 #endif
 186
 187 #ifdef DEBUG
 188         printk("ioremap: 0x%lx,0x%lx(%d) - ", physaddr, size, cacheflag);
 189 #endif
 190         /*
 191          * Mappings have to be aligned
 192          */
 193         offset = physaddr & (IO_SIZE - 1);
 194         physaddr &= -IO_SIZE;
 195         size = (size + offset + IO_SIZE - 1) & -IO_SIZE;
 196
 197         /*
 198          * Ok, go for it..
 199          */
 200         area = get_io_area(size);
 201         if (!area)
 202                 return NULL;
 203
 204         virtaddr = (unsigned long)area->addr;
 205         retaddr = virtaddr + offset;
 206 #ifdef DEBUG
 207         printk("0x%lx,0x%lx,0x%lx", physaddr, virtaddr, retaddr);
 208 #endif
 209
 210         /*
 211          * add cache and table flags to physical address
 212          */
 213         if (CPU_IS_040_OR_060) {
 214                 physaddr |= (_PAGE_PRESENT | _PAGE_GLOBAL040 |
 215                              _PAGE_ACCESSED | _PAGE_DIRTY);
 216                 switch (cacheflag) {
 217                 case IOMAP_FULL_CACHING:
 218                         physaddr |= _PAGE_CACHE040;
 219                         break;
 220                 case IOMAP_NOCACHE_SER:
 221                 default:
 222                         physaddr |= _PAGE_NOCACHE_S;
 223                         break;
 224                 case IOMAP_NOCACHE_NONSER:
 225                         physaddr |= _PAGE_NOCACHE;
 226                         break;
 227                 case IOMAP_WRITETHROUGH:
 228                         physaddr |= _PAGE_CACHE040W;
 229                         break;
 230                 }
 231         } else {
 232                 physaddr |= (_PAGE_PRESENT | _PAGE_ACCESSED |
 233                              _PAGE_DIRTY | _PAGE_READWRITE);
 234                 switch (cacheflag) {
 235                 case IOMAP_NOCACHE_SER:
 236                 case IOMAP_NOCACHE_NONSER:
 237                 default:
 238                         physaddr |= _PAGE_NOCACHE030;
 239                         break;
 240                 case IOMAP_FULL_CACHING:
 241                 case IOMAP_WRITETHROUGH:
 242                         break;
 243                 }
 244         }
 245
 246         while ((long)size > 0) {
 247 #ifdef DEBUG
 248                 if (!(virtaddr & (PMD_SIZE-1)))
 249                         printk ("\npa=%#lx va=%#lx ", physaddr, virtaddr);
 250 #endif
 251                 pgd_dir = pgd_offset_k(virtaddr);
 252                 p4d_dir = p4d_offset(pgd_dir, virtaddr);
 253                 pud_dir = pud_offset(p4d_dir, virtaddr);
 254                 pmd_dir = pmd_alloc(&init_mm, pud_dir, virtaddr);
 255                 if (!pmd_dir) {
 256                         printk("ioremap: no mem for pmd_dir\n");
 257                         return NULL;
 258                 }
 259
 260 #if CONFIG_PGTABLE_LEVELS == 3
 261                 if (CPU_IS_020_OR_030) {
 262                         pmd_val(*pmd_dir) = physaddr;
 263                         physaddr += PMD_SIZE;
 264                         virtaddr += PMD_SIZE;
 265                         size -= PMD_SIZE;
 266                 } else
 267 #endif
 268                 {
 269                         pte_dir = pte_alloc_kernel(pmd_dir, virtaddr);
 270                         if (!pte_dir) {
 271                                 printk("ioremap: no mem for pte_dir\n");
 272                                 return NULL;
 273                         }
 274
 275                         pte_val(*pte_dir) = physaddr;
 276                         virtaddr += PAGE_SIZE;
 277                         physaddr += PAGE_SIZE;
 278                         size -= PAGE_SIZE;
 279                 }
 280         }
 281 #ifdef DEBUG
 282         printk("\n");
 283 #endif
 284         flush_tlb_all();
 285
 286         return (void __iomem *)retaddr;
 287 }
 288 EXPORT_SYMBOL(__ioremap);
 289
 290 /*
 291  * Unmap an ioremap()ed region again
 292  */
 293 void iounmap(void __iomem *addr)
 294 {
 295 #ifdef CONFIG_AMIGA
 296         if ((!MACH_IS_AMIGA) ||
 297             (((unsigned long)addr < 0x40000000) ||
 298              ((unsigned long)addr > 0x60000000)))
 299                         free_io_area((__force void *)addr);
 300 #else
 301 #ifdef CONFIG_COLDFIRE
 302         if (cf_internalio(addr))
 303                 return;
 304 #endif
 305         free_io_area((__force void *)addr);
 306 #endif
 307 }
 308 EXPORT_SYMBOL(iounmap);
 309
 310 /*
 311  * Set new cache mode for some kernel address space.
 312  * The caller must push data for that range itself, if such data may already
 313  * be in the cache.
 314  */
 315 void kernel_set_cachemode(void *addr, unsigned long size, int cmode)
 316 {
 317         unsigned long virtaddr = (unsigned long)addr;
 318         pgd_t *pgd_dir;
 319         p4d_t *p4d_dir;
 320         pud_t *pud_dir;
 321         pmd_t *pmd_dir;
 322         pte_t *pte_dir;
 323
 324         if (CPU_IS_040_OR_060) {
 325                 switch (cmode) {
 326                 case IOMAP_FULL_CACHING:
 327                         cmode = _PAGE_CACHE040;
 328                         break;
 329                 case IOMAP_NOCACHE_SER:
 330                 default:
 331                         cmode = _PAGE_NOCACHE_S;
 332                         break;
 333                 case IOMAP_NOCACHE_NONSER:
 334                         cmode = _PAGE_NOCACHE;
 335                         break;
 336                 case IOMAP_WRITETHROUGH:
 337                         cmode = _PAGE_CACHE040W;
 338                         break;
 339                 }
 340         } else {
 341                 switch (cmode) {
 342                 case IOMAP_NOCACHE_SER:
 343                 case IOMAP_NOCACHE_NONSER:
 344                 default:
 345                         cmode = _PAGE_NOCACHE030;
 346                         break;
 347                 case IOMAP_FULL_CACHING:
 348                 case IOMAP_WRITETHROUGH:
 349                         cmode = 0;
 350                 }
 351         }
 352
 353         while ((long)size > 0) {
 354                 pgd_dir = pgd_offset_k(virtaddr);
 355                 p4d_dir = p4d_offset(pgd_dir, virtaddr);
 356                 pud_dir = pud_offset(p4d_dir, virtaddr);
 357                 if (pud_bad(*pud_dir)) {
 358                         printk("iocachemode: bad pud(%08lx)\n", pud_val(*pud_dir));
 359                         pud_clear(pud_dir);
 360                         return;
 361                 }
 362                 pmd_dir = pmd_offset(pud_dir, virtaddr);
 363
 364 #if CONFIG_PGTABLE_LEVELS == 3
 365                 if (CPU_IS_020_OR_030) {
 366                         unsigned long pmd = pmd_val(*pmd_dir);
 367
 368                         if ((pmd & _DESCTYPE_MASK) == _PAGE_PRESENT) {
 369                                 *pmd_dir = __pmd((pmd & _CACHEMASK040) | cmode);
 370                                 virtaddr += PMD_SIZE;
 371                                 size -= PMD_SIZE;
 372                                 continue;
 373                         }
 374                 }
 375 #endif
 376
 377                 if (pmd_bad(*pmd_dir)) {
 378                         printk("iocachemode: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
 379                         pmd_clear(pmd_dir);
 380                         return;
 381                 }
 382                 pte_dir = pte_offset_kernel(pmd_dir, virtaddr);
 383
 384                 pte_val(*pte_dir) = (pte_val(*pte_dir) & _CACHEMASK040) | cmode;
 385                 virtaddr += PAGE_SIZE;
 386                 size -= PAGE_SIZE;
 387         }
 388
 389         flush_tlb_all();
 390 }
 391 EXPORT_SYMBOL(kernel_set_cachemode);