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