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 <linux/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 /*
  32  * Generic mapping function (not visible outside):
  33  */
  34
  35 /*
  36  * Remap an arbitrary physical address space into the kernel virtual
  37  * address space. Needed when the kernel wants to access high addresses
  38  * directly.
  39  *
  40  * NOTE! We need to allow non-page-aligned mappings too: we will obviously
  41  * have to convert them into an offset in a page-aligned mapping, but the
  42  * caller shouldn't need to know that small detail.
  43  */
  44 void * __ioremap(unsigned long phys_addr, unsigned long size, unsigned long flags)
  45 {
  46         void * addr;
  47         struct vm_struct * area;
  48         unsigned long offset, last_addr;
  49         pgprot_t pgprot;
  50
  51         /* Don't allow wraparound or zero size */
  52         last_addr = phys_addr + size - 1;
  53         if (!size || last_addr < phys_addr)
  54                 return NULL;
  55
  56         pgprot = __pgprot(_PAGE_PRESENT  | _PAGE_READ   |
  57                           _PAGE_WRITE    | _PAGE_DIRTY  |
  58                           _PAGE_ACCESSED | _PAGE_SHARED | flags);
  59
  60         /*
  61          * Mappings have to be page-aligned
  62          */
  63         offset = phys_addr & ~PAGE_MASK;
  64         phys_addr &= PAGE_MASK;
  65         size = PAGE_ALIGN(last_addr + 1) - phys_addr;
  66
  67         /*
  68          * Ok, go for it..
  69          */
  70         area = get_vm_area(size, VM_IOREMAP);
  71         pr_debug("Get vm_area returns %p addr %p\n",area,area->addr);
  72         if (!area)
  73                 return NULL;
  74         area->phys_addr = phys_addr;
  75         addr = area->addr;
  76         if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size,
  77                                phys_addr, pgprot)) {
  78                 vunmap(addr);
  79                 return NULL;
  80         }
  81         return (void *) (offset + (char *)addr);
  82 }
  83
  84 void iounmap(void *addr)
  85 {
  86         struct vm_struct *area;
  87
  88         vfree((void *) (PAGE_MASK & (unsigned long) addr));
  89         area = remove_vm_area((void *) (PAGE_MASK & (unsigned long) addr));
  90         if (!area) {
  91                 printk(KERN_ERR "iounmap: bad address %p\n", addr);
  92                 return;
  93         }
  94
  95         kfree(area);
  96 }
  97
  98 static struct resource shmedia_iomap = {
  99         .name   = "shmedia_iomap",
 100         .start  = IOBASE_VADDR + PAGE_SIZE,
 101         .end    = IOBASE_END - 1,
 102 };
 103
 104 static void shmedia_mapioaddr(unsigned long pa, unsigned long va);
 105 static void shmedia_unmapioaddr(unsigned long vaddr);
 106 static unsigned long shmedia_ioremap(struct resource *res, u32 pa, int sz);
 107
 108 /*
 109  * We have the same problem as the SPARC, so lets have the same comment:
 110  * Our mini-allocator...
 111  * Boy this is gross! We need it because we must map I/O for
 112  * timers and interrupt controller before the kmalloc is available.
 113  */
 114
 115 #define XNMLN  15
 116 #define XNRES  10
 117
 118 struct xresource {
 119         struct resource xres;   /* Must be first */
 120         int xflag;              /* 1 == used */
 121         char xname[XNMLN+1];
 122 };
 123
 124 static struct xresource xresv[XNRES];
 125
 126 static struct xresource *xres_alloc(void)
 127 {
 128         struct xresource *xrp;
 129         int n;
 130
 131         xrp = xresv;
 132         for (n = 0; n < XNRES; n++) {
 133                 if (xrp->xflag == 0) {
 134                         xrp->xflag = 1;
 135                         return xrp;
 136                 }
 137                 xrp++;
 138         }
 139         return NULL;
 140 }
 141
 142 static void xres_free(struct xresource *xrp)
 143 {
 144         xrp->xflag = 0;
 145 }
 146
 147 static struct resource *shmedia_find_resource(struct resource *root,
 148                                               unsigned long vaddr)
 149 {
 150         struct resource *res;
 151
 152         for (res = root->child; res; res = res->sibling)
 153                 if (res->start <= vaddr && res->end >= vaddr)
 154                         return res;
 155
 156         return NULL;
 157 }
 158
 159 static unsigned long shmedia_alloc_io(unsigned long phys, unsigned long size,
 160                                       const char *name)
 161 {
 162         static int printed_full = 0;
 163         struct xresource *xres;
 164         struct resource *res;
 165         char *tack;
 166         int tlen;
 167
 168         if (name == NULL) name = "???";
 169
 170         if ((xres = xres_alloc()) != 0) {
 171                 tack = xres->xname;
 172                 res = &xres->xres;
 173         } else {
 174                 if (!printed_full) {
 175                         printk("%s: done with statics, switching to kmalloc\n",
 176                                __FUNCTION__);
 177                         printed_full = 1;
 178                 }
 179                 tlen = strlen(name);
 180                 tack = kmalloc(sizeof (struct resource) + tlen + 1, GFP_KERNEL);
 181                 if (!tack)
 182                         return -ENOMEM;
 183                 memset(tack, 0, sizeof(struct resource));
 184                 res = (struct resource *) tack;
 185                 tack += sizeof (struct resource);
 186         }
 187
 188         strncpy(tack, name, XNMLN);
 189         tack[XNMLN] = 0;
 190         res->name = tack;
 191
 192         return shmedia_ioremap(res, phys, size);
 193 }
 194
 195 static unsigned long shmedia_ioremap(struct resource *res, u32 pa, int sz)
 196 {
 197         unsigned long offset = ((unsigned long) pa) & (~PAGE_MASK);
 198         unsigned long round_sz = (offset + sz + PAGE_SIZE-1) & PAGE_MASK;
 199         unsigned long va;
 200         unsigned int psz;
 201
 202         if (allocate_resource(&shmedia_iomap, res, round_sz,
 203                               shmedia_iomap.start, shmedia_iomap.end,
 204                               PAGE_SIZE, NULL, NULL) != 0) {
 205                 panic("alloc_io_res(%s): cannot occupy\n",
 206                     (res->name != NULL)? res->name: "???");
 207         }
 208
 209         va = res->start;
 210         pa &= PAGE_MASK;
 211
 212         psz = (res->end - res->start + (PAGE_SIZE - 1)) / PAGE_SIZE;
 213
 214         /* log at boot time ... */
 215         printk("mapioaddr: %6s  [%2d page%s]  va 0x%08lx   pa 0x%08x\n",
 216                ((res->name != NULL) ? res->name : "???"),
 217                psz, psz == 1 ? " " : "s", va, pa);
 218
 219         for (psz = res->end - res->start + 1; psz != 0; psz -= PAGE_SIZE) {
 220                 shmedia_mapioaddr(pa, va);
 221                 va += PAGE_SIZE;
 222                 pa += PAGE_SIZE;
 223         }
 224
 225         res->start += offset;
 226         res->end = res->start + sz - 1;         /* not strictly necessary.. */
 227
 228         return res->start;
 229 }
 230
 231 static void shmedia_free_io(struct resource *res)
 232 {
 233         unsigned long len = res->end - res->start + 1;
 234
 235         BUG_ON((len & (PAGE_SIZE - 1)) != 0);
 236
 237         while (len) {
 238                 len -= PAGE_SIZE;
 239                 shmedia_unmapioaddr(res->start + len);
 240         }
 241
 242         release_resource(res);
 243 }
 244
 245 static void *sh64_get_page(void)
 246 {
 247         extern int after_bootmem;
 248         void *page;
 249
 250         if (after_bootmem) {
 251                 page = (void *)get_zeroed_page(GFP_ATOMIC);
 252         } else {
 253                 page = alloc_bootmem_pages(PAGE_SIZE);
 254         }
 255
 256         if (!page || ((unsigned long)page & ~PAGE_MASK))
 257                 panic("sh64_get_page: Out of memory already?\n");
 258
 259         return page;
 260 }
 261
 262 static void shmedia_mapioaddr(unsigned long pa, unsigned long va)
 263 {
 264         pgd_t *pgdp;
 265         pmd_t *pmdp;
 266         pte_t *ptep, pte;
 267         pgprot_t prot;
 268         unsigned long flags = 1; /* 1 = CB0-1 device */
 269
 270         pr_debug("shmedia_mapiopage pa %08lx va %08lx\n",  pa, va);
 271
 272         pgdp = pgd_offset_k(va);
 273         if (pgd_none(*pgdp) || !pgd_present(*pgdp)) {
 274                 pmdp = (pmd_t *)sh64_get_page();
 275                 set_pgd(pgdp, __pgd((unsigned long)pmdp | _KERNPG_TABLE));
 276         }
 277
 278         pmdp = pmd_offset(pgdp, va);
 279         if (pmd_none(*pmdp) || !pmd_present(*pmdp) ) {
 280                 ptep = (pte_t *)sh64_get_page();
 281                 set_pmd(pmdp, __pmd((unsigned long)ptep + _PAGE_TABLE));
 282         }
 283
 284         prot = __pgprot(_PAGE_PRESENT | _PAGE_READ     | _PAGE_WRITE  |
 285                         _PAGE_DIRTY   | _PAGE_ACCESSED | _PAGE_SHARED | flags);
 286
 287         pte = pfn_pte(pa >> PAGE_SHIFT, prot);
 288         ptep = pte_offset_kernel(pmdp, va);
 289
 290         if (!pte_none(*ptep) &&
 291             pte_val(*ptep) != pte_val(pte))
 292                 pte_ERROR(*ptep);
 293
 294         set_pte(ptep, pte);
 295
 296         flush_tlb_kernel_range(va, PAGE_SIZE);
 297 }
 298
 299 static void shmedia_unmapioaddr(unsigned long vaddr)
 300 {
 301         pgd_t *pgdp;
 302         pmd_t *pmdp;
 303         pte_t *ptep;
 304
 305         pgdp = pgd_offset_k(vaddr);
 306         pmdp = pmd_offset(pgdp, vaddr);
 307
 308         if (pmd_none(*pmdp) || pmd_bad(*pmdp))
 309                 return;
 310
 311         ptep = pte_offset_kernel(pmdp, vaddr);
 312
 313         if (pte_none(*ptep) || !pte_present(*ptep))
 314                 return;
 315
 316         clear_page((void *)ptep);
 317         pte_clear(&init_mm, vaddr, ptep);
 318 }
 319
 320 unsigned long onchip_remap(unsigned long phys, unsigned long size, const char *name)
 321 {
 322         if (size < PAGE_SIZE)
 323                 size = PAGE_SIZE;
 324
 325         return shmedia_alloc_io(phys, size, name);
 326 }
 327
 328 void onchip_unmap(unsigned long vaddr)
 329 {
 330         struct resource *res;
 331         unsigned int psz;
 332
 333         res = shmedia_find_resource(&shmedia_iomap, vaddr);
 334         if (!res) {
 335                 printk(KERN_ERR "%s: Failed to free 0x%08lx\n",
 336                        __FUNCTION__, vaddr);
 337                 return;
 338         }
 339
 340         psz = (res->end - res->start + (PAGE_SIZE - 1)) / PAGE_SIZE;
 341
 342         printk(KERN_DEBUG "unmapioaddr: %6s  [%2d page%s] freed\n",
 343                res->name, psz, psz == 1 ? " " : "s");
 344
 345         shmedia_free_io(res);
 346
 347         if ((char *)res >= (char *)xresv &&
 348             (char *)res <  (char *)&xresv[XNRES]) {
 349                 xres_free((struct xresource *)res);
 350         } else {
 351                 kfree(res);
 352         }
 353 }
 354
 355 #ifdef CONFIG_PROC_FS
 356 static int
 357 ioremap_proc_info(char *buf, char **start, off_t fpos, int length, int *eof,
 358                   void *data)
 359 {
 360         char *p = buf, *e = buf + length;
 361         struct resource *r;
 362         const char *nm;
 363
 364         for (r = ((struct resource *)data)->child; r != NULL; r = r->sibling) {
 365                 if (p + 32 >= e)        /* Better than nothing */
 366                         break;
 367                 if ((nm = r->name) == 0) nm = "???";
 368                 p += sprintf(p, "%08lx-%08lx: %s\n",
 369                              (unsigned long)r->start,
 370                              (unsigned long)r->end, nm);
 371         }
 372
 373         return p-buf;
 374 }
 375 #endif /* CONFIG_PROC_FS */
 376
 377 static int __init register_proc_onchip(void)
 378 {
 379 #ifdef CONFIG_PROC_FS
 380         create_proc_read_entry("io_map",0,0, ioremap_proc_info, &shmedia_iomap);
 381 #endif
 382         return 0;
 383 }
 384
 385 __initcall(register_proc_onchip);