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