LXR linux-old/arch/m68k/mm/kmap.c

   1/*
   2 *  linux/arch/m68k/mm/kmap.c
   3 *
   4 *  Copyright (C) 1997 Roman Hodek
   5 *
   6 *  10/01/99 cleaned up the code and changing to the same interface
   7 *           used by other architectures                /Roman Zippel
   8 */
   9
  10#include <linux/config.h>
  11#include <linux/mm.h>
  12#include <linux/kernel.h>
  13#include <linux/string.h>
  14#include <linux/types.h>
  15#include <linux/slab.h>
  16#include <linux/vmalloc.h>
  17
  18#include <asm/setup.h>
  19#include <asm/segment.h>
  20#include <asm/page.h>
  21#include <asm/pgalloc.h>
  22#include <asm/io.h>
  23#include <asm/system.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 descriptor and we
  32 * can't mix this with normal page descriptors, so we have to copy that code
  33 * (mm/vmalloc.c) and return appriorate aligned addresses.
  34 */
  35
  36#ifdef CPU_M68040_OR_M68060_ONLY
  37
  38#define IO_SIZE         PAGE_SIZE
  39
  40static inline struct vm_struct *get_io_area(unsigned long size)
  41{
  42        return get_vm_area(size, VM_IOREMAP);
  43}
  44
  45
  46static inline void free_io_area(void *addr)
  47{
  48        return vfree((void *)(PAGE_MASK & (unsigned long)addr));
  49}
  50
  51#else
  52
  53#define IO_SIZE         (256*1024)
  54
  55static struct vm_struct *iolist = NULL;
  56
  57static struct vm_struct *get_io_area(unsigned long size)
  58{
  59        unsigned long addr;
  60        struct vm_struct **p, *tmp, *area;
  61
  62        area = (struct vm_struct *)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                        return NULL;
  71                addr = tmp->size + (unsigned long)tmp->addr;
  72        }
  73        area->addr = (void *)addr;
  74        area->size = size + IO_SIZE;    /* leave a gap between */
  75        area->next = *p;
  76        *p = area;
  77        return area;
  78}
  79
  80static inline void free_io_area(void *addr)
  81{
  82        struct vm_struct **p, *tmp;
  83
  84        if (!addr)
  85                return;
  86        addr = (void *)((unsigned long)addr & -IO_SIZE);
  87        for (p = &iolist ; (tmp = *p) ; p = &tmp->next) {
  88                if (tmp->addr == addr) {
  89                        *p = tmp->next;
  90                        if ( tmp->size > IO_SIZE )
  91                                __iounmap(tmp->addr, tmp->size - IO_SIZE);
  92                        else
  93                                printk("free_io_area: Invalid I/O area size %lu\n", tmp->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. The
 104 * code is copied and adapted from map_chunk().
 105 */
 106/* Rewritten by Andreas Schwab to remove all races. */
 107
 108void *__ioremap(unsigned long physaddr, unsigned long size, int cacheflag)
 109{
 110        struct vm_struct *area;
 111        unsigned long virtaddr, retaddr;
 112        long offset;
 113        pgd_t *pgd_dir;
 114        pmd_t *pmd_dir;
 115        pte_t *pte_dir;
 116
 117        /*
 118         * Don't allow mappings that wrap..
 119         */
 120        if (!size || size > physaddr + size)
 121                return NULL;
 122
 123#ifdef CONFIG_AMIGA
 124        if (MACH_IS_AMIGA) {
 125                if ((physaddr >= 0x40000000) && (physaddr + size < 0x60000000)
 126                    && (cacheflag == IOMAP_NOCACHE_SER))
 127                        return (void *)physaddr;
 128        }
 129#endif
 130
 131#ifdef DEBUG
 132        printk("ioremap: 0x%lx,0x%lx(%d) - ", physaddr, size, cacheflag);
 133#endif
 134        /*
 135         * Mappings have to be aligned
 136         */
 137        offset = physaddr & (IO_SIZE - 1);
 138        physaddr &= -IO_SIZE;
 139        size = (size + offset + IO_SIZE - 1) & -IO_SIZE;
 140
 141        /*
 142         * Ok, go for it..
 143         */
 144        area = get_io_area(size);
 145        if (!area)
 146                return NULL;
 147
 148        virtaddr = (unsigned long)area->addr;
 149        retaddr = virtaddr + offset;
 150#ifdef DEBUG
 151        printk("0x%lx,0x%lx,0x%lx", physaddr, virtaddr, retaddr);
 152#endif
 153
 154        /*
 155         * add cache and table flags to physical address
 156         */
 157        if (CPU_IS_040_OR_060) {
 158                physaddr |= (_PAGE_PRESENT | _PAGE_GLOBAL040 |
 159                             _PAGE_ACCESSED | _PAGE_DIRTY);
 160                switch (cacheflag) {
 161                case IOMAP_FULL_CACHING:
 162                        physaddr |= _PAGE_CACHE040;
 163                        break;
 164                case IOMAP_NOCACHE_SER:
 165                default:
 166                        physaddr |= _PAGE_NOCACHE_S;
 167                        break;
 168                case IOMAP_NOCACHE_NONSER:
 169                        physaddr |= _PAGE_NOCACHE;
 170                        break;
 171                case IOMAP_WRITETHROUGH:
 172                        physaddr |= _PAGE_CACHE040W;
 173                        break;
 174                }
 175        } else {
 176                physaddr |= (_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_DIRTY);
 177                switch (cacheflag) {
 178                case IOMAP_NOCACHE_SER:
 179                case IOMAP_NOCACHE_NONSER:
 180                default:
 181                        physaddr |= _PAGE_NOCACHE030;
 182                        break;
 183                case IOMAP_FULL_CACHING:
 184                case IOMAP_WRITETHROUGH:
 185                        break;
 186                }
 187        }
 188
 189        while ((long)size > 0) {
 190#ifdef DEBUG
 191                if (!(virtaddr & (PTRTREESIZE-1)))
 192                        printk ("\npa=%#lx va=%#lx ", physaddr, virtaddr);
 193#endif
 194                pgd_dir = pgd_offset_k(virtaddr);
 195                pmd_dir = pmd_alloc_kernel(pgd_dir, virtaddr);
 196                if (!pmd_dir) {
 197                        printk("ioremap: no mem for pmd_dir\n");
 198                        return NULL;
 199                }
 200
 201                if (CPU_IS_020_OR_030) {
 202                        pmd_dir->pmd[(virtaddr/PTRTREESIZE) & 15] = physaddr;
 203                        physaddr += PTRTREESIZE;
 204                        virtaddr += PTRTREESIZE;
 205                        size -= PTRTREESIZE;
 206                } else {
 207                        pte_dir = pte_alloc_kernel(pmd_dir, virtaddr);
 208                        if (!pte_dir) {
 209                                printk("ioremap: no mem for pte_dir\n");
 210                                return NULL;
 211                        }
 212
 213                        pte_val(*pte_dir) = physaddr;
 214                        virtaddr += PAGE_SIZE;
 215                        physaddr += PAGE_SIZE;
 216                        size -= PAGE_SIZE;
 217                }
 218        }
 219#ifdef DEBUG
 220        printk("\n");
 221#endif
 222        flush_tlb_all();
 223
 224        return (void *)retaddr;
 225}
 226
 227/*
 228 * Unmap a ioremap()ed region again
 229 */
 230void iounmap(void *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(addr);
 237#else
 238        free_io_area(addr);
 239#endif
 240}
 241
 242/*
 243 * __iounmap unmaps nearly everything, so be careful
 244 * it doesn't free currently pointer/page tables anymore but it
 245 * wans't used anyway and might be added later.
 246 */
 247void __iounmap(void *addr, unsigned long size)
 248{
 249        unsigned long virtaddr = (unsigned long)addr;
 250        pgd_t *pgd_dir;
 251        pmd_t *pmd_dir;
 252        pte_t *pte_dir;
 253
 254        while ((long)size > 0) {
 255                pgd_dir = pgd_offset_k(virtaddr);
 256                if (pgd_bad(*pgd_dir)) {
 257                        printk("iounmap: bad pgd(%08lx)\n", pgd_val(*pgd_dir));
 258                        pgd_clear(pgd_dir);
 259                        return;
 260                }
 261                pmd_dir = pmd_offset(pgd_dir, virtaddr);
 262
 263                if (CPU_IS_020_OR_030) {
 264                        int pmd_off = (virtaddr/PTRTREESIZE) & 15;
 265
 266                        if ((pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK) == _PAGE_PRESENT) {
 267                                pmd_dir->pmd[pmd_off] = 0;
 268                                virtaddr += PTRTREESIZE;
 269                                size -= PTRTREESIZE;
 270                                continue;
 271                        }
 272                }
 273
 274                if (pmd_bad(*pmd_dir)) {
 275                        printk("iounmap: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
 276                        pmd_clear(pmd_dir);
 277                        return;
 278                }
 279                pte_dir = pte_offset(pmd_dir, virtaddr);
 280
 281                pte_val(*pte_dir) = 0;
 282                virtaddr += PAGE_SIZE;
 283                size -= PAGE_SIZE;
 284        }
 285
 286        flush_tlb_all();
 287}
 288
 289/*
 290 * Set new cache mode for some kernel address space.
 291 * The caller must push data for that range itself, if such data may already
 292 * be in the cache.
 293 */
 294void kernel_set_cachemode(void *addr, unsigned long size, int cmode)
 295{
 296        unsigned long virtaddr = (unsigned long)addr;
 297        pgd_t *pgd_dir;
 298        pmd_t *pmd_dir;
 299        pte_t *pte_dir;
 300
 301        if (CPU_IS_040_OR_060) {
 302                switch (cmode) {
 303                case IOMAP_FULL_CACHING:
 304                        cmode = _PAGE_CACHE040;
 305                        break;
 306                case IOMAP_NOCACHE_SER:
 307                default:
 308                        cmode = _PAGE_NOCACHE_S;
 309                        break;
 310                case IOMAP_NOCACHE_NONSER:
 311                        cmode = _PAGE_NOCACHE;
 312                        break;
 313                case IOMAP_WRITETHROUGH:
 314                        cmode = _PAGE_CACHE040W;
 315                        break;
 316                }
 317        } else {
 318                switch (cmode) {
 319                case IOMAP_NOCACHE_SER:
 320                case IOMAP_NOCACHE_NONSER:
 321                default:
 322                        cmode = _PAGE_NOCACHE030;
 323                        break;
 324                case IOMAP_FULL_CACHING:
 325                case IOMAP_WRITETHROUGH:
 326                        cmode = 0;
 327                }
 328        }
 329
 330        while ((long)size > 0) {
 331                pgd_dir = pgd_offset_k(virtaddr);
 332                if (pgd_bad(*pgd_dir)) {
 333                        printk("iocachemode: bad pgd(%08lx)\n", pgd_val(*pgd_dir));
 334                        pgd_clear(pgd_dir);
 335                        return;
 336                }
 337                pmd_dir = pmd_offset(pgd_dir, virtaddr);
 338
 339                if (CPU_IS_020_OR_030) {
 340                        int pmd_off = (virtaddr/PTRTREESIZE) & 15;
 341
 342                        if ((pmd_dir->pmd[pmd_off] & _DESCTYPE_MASK) == _PAGE_PRESENT) {
 343                                pmd_dir->pmd[pmd_off] = (pmd_dir->pmd[pmd_off] &
 344                                                         _CACHEMASK040) | cmode;
 345                                virtaddr += PTRTREESIZE;
 346                                size -= PTRTREESIZE;
 347                                continue;
 348                        }
 349                }
 350
 351                if (pmd_bad(*pmd_dir)) {
 352                        printk("iocachemode: bad pmd (%08lx)\n", pmd_val(*pmd_dir));
 353                        pmd_clear(pmd_dir);
 354                        return;
 355                }
 356                pte_dir = pte_offset(pmd_dir, virtaddr);
 357
 358                pte_val(*pte_dir) = (pte_val(*pte_dir) & _CACHEMASK040) | cmode;
 359                virtaddr += PAGE_SIZE;
 360                size -= PAGE_SIZE;
 361        }
 362
 363        flush_tlb_all();
 364}
 365