arch/sh64/mm/ioremap.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * arch/sh64/mm/ioremap.c
   7  *
   8  * Copyright (C) 2000, 2001  Paolo Alberelli
   9  * Copyright (C) 2003, 2004  Paul Mundt
  10  *
  11  * Mostly derived from arch/sh/mm/ioremap.c which, in turn is mostly
  12  * derived from arch/i386/mm/ioremap.c .
  13  *
  14  *   (C) Copyright 1995 1996 Linus Torvalds
  15  */
  16 #include <linux/kernel.h>
  17 #include <linux/slab.h>
  18 #include <linux/vmalloc.h>
  19 #include <linux/sched.h>
  20 #include <linux/string.h>
  21 #include <asm/io.h>
  22 #include <asm/pgalloc.h>
  23 #include <asm/tlbflush.h>
  24 #include <linux/ioport.h>
  25 #include <linux/bootmem.h>
  26 #include <linux/proc_fs.h>
  27
  28 static void shmedia_mapioaddr(unsigned long, unsigned long);
  29 static unsigned long shmedia_ioremap(struct resource *, u32, int);
  30
  31 static inline void remap_area_pte(pte_t * pte, unsigned long address, unsigned long size,
  32         unsigned long phys_addr, unsigned long flags)
  33 {
  34         unsigned long end;
  35         unsigned long pfn;
  36         pgprot_t pgprot = __pgprot(_PAGE_PRESENT  | _PAGE_READ   |
  37                                    _PAGE_WRITE    | _PAGE_DIRTY  |
  38                                    _PAGE_ACCESSED | _PAGE_SHARED | flags);
  39
  40         address &= ~PMD_MASK;
  41         end = address + size;
  42         if (end > PMD_SIZE)
  43                 end = PMD_SIZE;
  44         if (address >= end)
  45                 BUG();
  46
  47         pfn = phys_addr >> PAGE_SHIFT;
  48
  49         pr_debug("    %s: pte %p address %lx size %lx phys_addr %lx\n",
  50                  __FUNCTION__,pte,address,size,phys_addr);
  51
  52         do {
  53                 if (!pte_none(*pte)) {
  54                         printk("remap_area_pte: page already exists\n");
  55                         BUG();
  56                 }
  57
  58                 set_pte(pte, pfn_pte(pfn, pgprot));
  59                 address += PAGE_SIZE;
  60                 pfn++;
  61                 pte++;
  62         } while (address && (address < end));
  63 }
  64
  65 static inline int remap_area_pmd(pmd_t * pmd, unsigned long address, unsigned long size,
  66         unsigned long phys_addr, unsigned long flags)
  67 {
  68         unsigned long end;
  69
  70         address &= ~PGDIR_MASK;
  71         end = address + size;
  72
  73         if (end > PGDIR_SIZE)
  74                 end = PGDIR_SIZE;
  75
  76         phys_addr -= address;
  77
  78         if (address >= end)
  79                 BUG();
  80
  81         do {
  82                 pte_t * pte = pte_alloc_kernel(pmd, address);
  83                 if (!pte)
  84                         return -ENOMEM;
  85                 remap_area_pte(pte, address, end - address, address + phys_addr, flags);
  86                 address = (address + PMD_SIZE) & PMD_MASK;
  87                 pmd++;
  88         } while (address && (address < end));
  89         return 0;
  90 }
  91
  92 static int remap_area_pages(unsigned long address, unsigned long phys_addr,
  93                                  unsigned long size, unsigned long flags)
  94 {
  95         int error;
  96         pgd_t * dir;
  97         unsigned long end = address + size;
  98
  99         phys_addr -= address;
 100         dir = pgd_offset_k(address);
 101         flush_cache_all();
 102         if (address >= end)
 103                 BUG();
 104         do {
 105                 pmd_t *pmd = pmd_alloc(&init_mm, dir, address);
 106                 error = -ENOMEM;
 107                 if (!pmd)
 108                         break;
 109                 if (remap_area_pmd(pmd, address, end - address,
 110                                    phys_addr + address, flags)) {
 111                          break;
 112                 }
 113                 error = 0;
 114                 address = (address + PGDIR_SIZE) & PGDIR_MASK;
 115                 dir++;
 116         } while (address && (address < end));
 117         flush_tlb_all();
 118         return 0;
 119 }
 120
 121 /*
 122  * Generic mapping function (not visible outside):
 123  */
 124
 125 /*
 126  * Remap an arbitrary physical address space into the kernel virtual
 127  * address space. Needed when the kernel wants to access high addresses
 128  * directly.
 129  *
 130  * NOTE! We need to allow non-page-aligned mappings too: we will obviously
 131  * have to convert them into an offset in a page-aligned mapping, but the
 132  * caller shouldn't need to know that small detail.
 133  */
 134 void * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)
 135 {
 136         void * addr;
 137         struct vm_struct * area;
 138         unsigned long offset, last_addr;
 139
 140         /* Don't allow wraparound or zero size */
 141         last_addr = phys_addr + size - 1;
 142         if (!size || last_addr < phys_addr)
 143                 return NULL;
 144
 145         /*
 146          * Mappings have to be page-aligned
 147          */
 148         offset = phys_addr & ~PAGE_MASK;
 149         phys_addr &= PAGE_MASK;
 150         size = PAGE_ALIGN(last_addr + 1) - phys_addr;
 151
 152         /*
 153          * Ok, go for it..
 154          */
 155         area = get_vm_area(size, VM_IOREMAP);
 156         pr_debug("Get vm_area returns %p addr %p\n",area,area->addr);
 157         if (!area)
 158                 return NULL;
 159         area->phys_addr = phys_addr;
 160         addr = area->addr;
 161         if (remap_area_pages((unsigned long)addr, phys_addr, size, flags)) {
 162                 vunmap(addr);
 163                 return NULL;
 164         }
 165         return (void *) (offset + (char *)addr);
 166 }
 167
 168 void iounmap(void *addr)
 169 {
 170         struct vm_struct *area;
 171
 172         vfree((void *) (PAGE_MASK & (unsigned long) addr));
 173         area = remove_vm_area((void *) (PAGE_MASK & (unsigned long) addr));
 174         if (!area) {
 175                 printk(KERN_ERR "iounmap: bad address %p\n", addr);
 176                 return;
 177         }
 178
 179         kfree(area);
 180 }
 181
 182 static struct resource shmedia_iomap = {
 183         .name   = "shmedia_iomap",
 184         .start  = IOBASE_VADDR + PAGE_SIZE,
 185         .end    = IOBASE_END - 1,
 186 };
 187
 188 static void shmedia_mapioaddr(unsigned long pa, unsigned long va);
 189 static void shmedia_unmapioaddr(unsigned long vaddr);
 190 static unsigned long shmedia_ioremap(struct resource *res, u32 pa, int sz);
 191
 192 /*
 193  * We have the same problem as the SPARC, so lets have the same comment:
 194  * Our mini-allocator...
 195  * Boy this is gross! We need it because we must map I/O for
 196  * timers and interrupt controller before the kmalloc is available.
 197  */
 198
 199 #define XNMLN  15
 200 #define XNRES  10
 201
 202 struct xresource {
 203         struct resource xres;   /* Must be first */
 204         int xflag;              /* 1 == used */
 205         char xname[XNMLN+1];
 206 };
 207
 208 static struct xresource xresv[XNRES];
 209
 210 static struct xresource *xres_alloc(void)
 211 {
 212         struct xresource *xrp;
 213         int n;
 214
 215         xrp = xresv;
 216         for (n = 0; n < XNRES; n++) {
 217                 if (xrp->xflag == 0) {
 218                         xrp->xflag = 1;
 219                         return xrp;
 220                 }
 221                 xrp++;
 222         }
 223         return NULL;
 224 }
 225
 226 static void xres_free(struct xresource *xrp)
 227 {
 228         xrp->xflag = 0;
 229 }
 230
 231 static struct resource *shmedia_find_resource(struct resource *root,
 232                                               unsigned long vaddr)
 233 {
 234         struct resource *res;
 235
 236         for (res = root->child; res; res = res->sibling)
 237                 if (res->start <= vaddr && res->end >= vaddr)
 238                         return res;
 239
 240         return NULL;
 241 }
 242
 243 static unsigned long shmedia_alloc_io(unsigned long phys, unsigned long size,
 244                                       const char *name)
 245 {
 246         static int printed_full = 0;
 247         struct xresource *xres;
 248         struct resource *res;
 249         char *tack;
 250         int tlen;
 251
 252         if (name == NULL) name = "???";
 253
 254         if ((xres = xres_alloc()) != 0) {
 255                 tack = xres->xname;
 256                 res = &xres->xres;
 257         } else {
 258                 if (!printed_full) {
 259                         printk("%s: done with statics, switching to kmalloc\n",
 260                                __FUNCTION__);
 261                         printed_full = 1;
 262                 }
 263                 tlen = strlen(name);
 264                 tack = kmalloc(sizeof (struct resource) + tlen + 1, GFP_KERNEL);
 265                 if (!tack)
 266                         return -ENOMEM;
 267                 memset(tack, 0, sizeof(struct resource));
 268                 res = (struct resource *) tack;
 269                 tack += sizeof (struct resource);
 270         }
 271
 272         strncpy(tack, name, XNMLN);
 273         tack[XNMLN] = 0;
 274         res->name = tack;
 275
 276         return shmedia_ioremap(res, phys, size);
 277 }
 278
 279 static unsigned long shmedia_ioremap(struct resource *res, u32 pa, int sz)
 280 {
 281         unsigned long offset = ((unsigned long) pa) & (~PAGE_MASK);
 282         unsigned long round_sz = (offset + sz + PAGE_SIZE-1) & PAGE_MASK;
 283         unsigned long va;
 284         unsigned int psz;
 285
 286         if (allocate_resource(&shmedia_iomap, res, round_sz,
 287                               shmedia_iomap.start, shmedia_iomap.end,
 288                               PAGE_SIZE, NULL, NULL) != 0) {
 289                 panic("alloc_io_res(%s): cannot occupy\n",
 290                     (res->name != NULL)? res->name: "???");
 291         }
 292
 293         va = res->start;
 294         pa &= PAGE_MASK;
 295
 296         psz = (res->end - res->start + (PAGE_SIZE - 1)) / PAGE_SIZE;
 297
 298         /* log at boot time ... */
 299         printk("mapioaddr: %6s  [%2d page%s]  va 0x%08lx   pa 0x%08x\n",
 300                ((res->name != NULL) ? res->name : "???"),
 301                psz, psz == 1 ? " " : "s", va, pa);
 302
 303         for (psz = res->end - res->start + 1; psz != 0; psz -= PAGE_SIZE) {
 304                 shmedia_mapioaddr(pa, va);
 305                 va += PAGE_SIZE;
 306                 pa += PAGE_SIZE;
 307         }
 308
 309         res->start += offset;
 310         res->end = res->start + sz - 1;         /* not strictly necessary.. */
 311
 312         return res->start;
 313 }
 314
 315 static void shmedia_free_io(struct resource *res)
 316 {
 317         unsigned long len = res->end - res->start + 1;
 318
 319         BUG_ON((len & (PAGE_SIZE - 1)) != 0);
 320
 321         while (len) {
 322                 len -= PAGE_SIZE;
 323                 shmedia_unmapioaddr(res->start + len);
 324         }
 325
 326         release_resource(res);
 327 }
 328
 329 static void *sh64_get_page(void)
 330 {
 331         extern int after_bootmem;
 332         void *page;
 333
 334         if (after_bootmem) {
 335                 page = (void *)get_zeroed_page(GFP_ATOMIC);
 336         } else {
 337                 page = alloc_bootmem_pages(PAGE_SIZE);
 338         }
 339
 340         if (!page || ((unsigned long)page & ~PAGE_MASK))
 341                 panic("sh64_get_page: Out of memory already?\n");
 342
 343         return page;
 344 }
 345
 346 static void shmedia_mapioaddr(unsigned long pa, unsigned long va)
 347 {
 348         pgd_t *pgdp;
 349         pmd_t *pmdp;
 350         pte_t *ptep, pte;
 351         pgprot_t prot;
 352         unsigned long flags = 1; /* 1 = CB0-1 device */
 353
 354         pr_debug("shmedia_mapiopage pa %08lx va %08lx\n",  pa, va);
 355
 356         pgdp = pgd_offset_k(va);
 357         if (pgd_none(*pgdp) || !pgd_present(*pgdp)) {
 358                 pmdp = (pmd_t *)sh64_get_page();
 359                 set_pgd(pgdp, __pgd((unsigned long)pmdp | _KERNPG_TABLE));
 360         }
 361
 362         pmdp = pmd_offset(pgdp, va);
 363         if (pmd_none(*pmdp) || !pmd_present(*pmdp) ) {
 364                 ptep = (pte_t *)sh64_get_page();
 365                 set_pmd(pmdp, __pmd((unsigned long)ptep + _PAGE_TABLE));
 366         }
 367
 368         prot = __pgprot(_PAGE_PRESENT | _PAGE_READ     | _PAGE_WRITE  |
 369                         _PAGE_DIRTY   | _PAGE_ACCESSED | _PAGE_SHARED | flags);
 370
 371         pte = pfn_pte(pa >> PAGE_SHIFT, prot);
 372         ptep = pte_offset_kernel(pmdp, va);
 373
 374         if (!pte_none(*ptep) &&
 375             pte_val(*ptep) != pte_val(pte))
 376                 pte_ERROR(*ptep);
 377
 378         set_pte(ptep, pte);
 379
 380         flush_tlb_kernel_range(va, PAGE_SIZE);
 381 }
 382
 383 static void shmedia_unmapioaddr(unsigned long vaddr)
 384 {
 385         pgd_t *pgdp;
 386         pmd_t *pmdp;
 387         pte_t *ptep;
 388
 389         pgdp = pgd_offset_k(vaddr);
 390         pmdp = pmd_offset(pgdp, vaddr);
 391
 392         if (pmd_none(*pmdp) || pmd_bad(*pmdp))
 393                 return;
 394
 395         ptep = pte_offset_kernel(pmdp, vaddr);
 396
 397         if (pte_none(*ptep) || !pte_present(*ptep))
 398                 return;
 399
 400         clear_page((void *)ptep);
 401         pte_clear(&init_mm, vaddr, ptep);
 402 }
 403
 404 unsigned long onchip_remap(unsigned long phys, unsigned long size, const char *name)
 405 {
 406         if (size < PAGE_SIZE)
 407                 size = PAGE_SIZE;
 408
 409         return shmedia_alloc_io(phys, size, name);
 410 }
 411
 412 void onchip_unmap(unsigned long vaddr)
 413 {
 414         struct resource *res;
 415         unsigned int psz;
 416
 417         res = shmedia_find_resource(&shmedia_iomap, vaddr);
 418         if (!res) {
 419                 printk(KERN_ERR "%s: Failed to free 0x%08lx\n",
 420                        __FUNCTION__, vaddr);
 421                 return;
 422         }
 423
 424         psz = (res->end - res->start + (PAGE_SIZE - 1)) / PAGE_SIZE;
 425
 426         printk(KERN_DEBUG "unmapioaddr: %6s  [%2d page%s] freed\n",
 427                res->name, psz, psz == 1 ? " " : "s");
 428
 429         shmedia_free_io(res);
 430
 431         if ((char *)res >= (char *)xresv &&
 432             (char *)res <  (char *)&xresv[XNRES]) {
 433                 xres_free((struct xresource *)res);
 434         } else {
 435                 kfree(res);
 436         }
 437 }
 438
 439 #ifdef CONFIG_PROC_FS
 440 static int
 441 ioremap_proc_info(char *buf, char **start, off_t fpos, int length, int *eof,
 442                   void *data)
 443 {
 444         char *p = buf, *e = buf + length;
 445         struct resource *r;
 446         const char *nm;
 447
 448         for (r = ((struct resource *)data)->child; r != NULL; r = r->sibling) {
 449                 if (p + 32 >= e)        /* Better than nothing */
 450                         break;
 451                 if ((nm = r->name) == 0) nm = "???";
 452                 p += sprintf(p, "%08lx-%08lx: %s\n", r->start, r->end, nm);
 453         }
 454
 455         return p-buf;
 456 }
 457 #endif /* CONFIG_PROC_FS */
 458
 459 static int __init register_proc_onchip(void)
 460 {
 461 #ifdef CONFIG_PROC_FS
 462         create_proc_read_entry("io_map",0,0, ioremap_proc_info, &shmedia_iomap);
 463 #endif
 464         return 0;
 465 }
 466
 467 __initcall(register_proc_onchip);