linux/arch/m68k/mm/kmap.c
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   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
  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        vfree((void *)(PAGE_MASK & (unsigned long)addr));
  49}
  50
  51#else
  52
  53#define IO_SIZE         (256*1024)
  54
  55static struct vm_struct *iolist;
  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 = 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
  82static 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
 107void __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}
 230EXPORT_SYMBOL(__ioremap);
 231
 232/*
 233 * Unmap an ioremap()ed region again
 234 */
 235void 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}
 250EXPORT_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 */
 257void __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 */
 306void 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}
 377EXPORT_SYMBOL(kernel_set_cachemode);
 378