arch/sh/mm/ioremap_64.c

   1 /*
   2  * arch/sh/mm/ioremap_64.c
   3  *
   4  * Copyright (C) 2000, 2001  Paolo Alberelli
   5  * Copyright (C) 2003 - 2007  Paul Mundt
   6  *
   7  * Mostly derived from arch/sh/mm/ioremap.c which, in turn is mostly
   8  * derived from arch/i386/mm/ioremap.c .
   9  *
  10  *   (C) Copyright 1995 1996 Linus Torvalds
  11  *
  12  * This file is subject to the terms and conditions of the GNU General Public
  13  * License.  See the file "COPYING" in the main directory of this archive
  14  * for more details.
  15  */
  16 #include <linux/vmalloc.h>
  17 #include <linux/ioport.h>
  18 #include <linux/module.h>
  19 #include <linux/mm.h>
  20 #include <linux/io.h>
  21 #include <linux/bootmem.h>
  22 #include <linux/proc_fs.h>
  23 #include <asm/page.h>
  24 #include <asm/pgalloc.h>
  25 #include <asm/addrspace.h>
  26 #include <asm/cacheflush.h>
  27 #include <asm/tlbflush.h>
  28 #include <asm/mmu.h>
  29
  30 static void shmedia_mapioaddr(unsigned long, unsigned long);
  31 static unsigned long shmedia_ioremap(struct resource *, u32, int);
  32
  33 /*
  34  * Generic mapping function (not visible outside):
  35  */
  36
  37 /*
  38  * Remap an arbitrary physical address space into the kernel virtual
  39  * address space. Needed when the kernel wants to access high addresses
  40  * directly.
  41  *
  42  * NOTE! We need to allow non-page-aligned mappings too: we will obviously
  43  * have to convert them into an offset in a page-aligned mapping, but the
  44  * caller shouldn't need to know that small detail.
  45  */
  46 void *__ioremap(unsigned long phys_addr, unsigned long size,
  47                 unsigned long flags)
  48 {
  49         void * addr;
  50         struct vm_struct * area;
  51         unsigned long offset, last_addr;
  52         pgprot_t pgprot;
  53
  54         /* Don't allow wraparound or zero size */
  55         last_addr = phys_addr + size - 1;
  56         if (!size || last_addr < phys_addr)
  57                 return NULL;
  58
  59         pgprot = __pgprot(_PAGE_PRESENT  | _PAGE_READ   |
  60                           _PAGE_WRITE    | _PAGE_DIRTY  |
  61                           _PAGE_ACCESSED | _PAGE_SHARED | flags);
  62
  63         /*
  64          * Mappings have to be page-aligned
  65          */
  66         offset = phys_addr & ~PAGE_MASK;
  67         phys_addr &= PAGE_MASK;
  68         size = PAGE_ALIGN(last_addr + 1) - phys_addr;
  69
  70         /*
  71          * Ok, go for it..
  72          */
  73         area = get_vm_area(size, VM_IOREMAP);
  74         pr_debug("Get vm_area returns %p addr %p\n",area,area->addr);
  75         if (!area)
  76                 return NULL;
  77         area->phys_addr = phys_addr;
  78         addr = area->addr;
  79         if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size,
  80                                phys_addr, pgprot)) {
  81                 vunmap(addr);
  82                 return NULL;
  83         }
  84         return (void *) (offset + (char *)addr);
  85 }
  86 EXPORT_SYMBOL(__ioremap);
  87
  88 void __iounmap(void *addr)
  89 {
  90         struct vm_struct *area;
  91
  92         vfree((void *) (PAGE_MASK & (unsigned long) addr));
  93         area = remove_vm_area((void *) (PAGE_MASK & (unsigned long) addr));
  94         if (!area) {
  95                 printk(KERN_ERR "iounmap: bad address %p\n", addr);
  96                 return;
  97         }
  98
  99         kfree(area);
 100 }
 101 EXPORT_SYMBOL(__iounmap);
 102
 103 static struct resource shmedia_iomap = {
 104         .name   = "shmedia_iomap",
 105         .start  = IOBASE_VADDR + PAGE_SIZE,
 106         .end    = IOBASE_END - 1,
 107 };
 108
 109 static void shmedia_mapioaddr(unsigned long pa, unsigned long va);
 110 static void shmedia_unmapioaddr(unsigned long vaddr);
 111 static unsigned long shmedia_ioremap(struct resource *res, u32 pa, int sz);
 112
 113 /*
 114  * We have the same problem as the SPARC, so lets have the same comment:
 115  * Our mini-allocator...
 116  * Boy this is gross! We need it because we must map I/O for
 117  * timers and interrupt controller before the kmalloc is available.
 118  */
 119
 120 #define XNMLN  15
 121 #define XNRES  10
 122
 123 struct xresource {
 124         struct resource xres;   /* Must be first */
 125         int xflag;              /* 1 == used */
 126         char xname[XNMLN+1];
 127 };
 128
 129 static struct xresource xresv[XNRES];
 130
 131 static struct xresource *xres_alloc(void)
 132 {
 133         struct xresource *xrp;
 134         int n;
 135
 136         xrp = xresv;
 137         for (n = 0; n < XNRES; n++) {
 138                 if (xrp->xflag == 0) {
 139                         xrp->xflag = 1;
 140                         return xrp;
 141                 }
 142                 xrp++;
 143         }
 144         return NULL;
 145 }
 146
 147 static void xres_free(struct xresource *xrp)
 148 {
 149         xrp->xflag = 0;
 150 }
 151
 152 static struct resource *shmedia_find_resource(struct resource *root,
 153                                               unsigned long vaddr)
 154 {
 155         struct resource *res;
 156
 157         for (res = root->child; res; res = res->sibling)
 158                 if (res->start <= vaddr && res->end >= vaddr)
 159                         return res;
 160
 161         return NULL;
 162 }
 163
 164 static unsigned long shmedia_alloc_io(unsigned long phys, unsigned long size,
 165                                       const char *name)
 166 {
 167         static int printed_full = 0;
 168         struct xresource *xres;
 169         struct resource *res;
 170         char *tack;
 171         int tlen;
 172
 173         if (name == NULL) name = "???";
 174
 175         if ((xres = xres_alloc()) != 0) {
 176                 tack = xres->xname;
 177                 res = &xres->xres;
 178         } else {
 179                 if (!printed_full) {
 180                         printk("%s: done with statics, switching to kmalloc\n",
 181                                __func__);
 182                         printed_full = 1;
 183                 }
 184                 tlen = strlen(name);
 185                 tack = kmalloc(sizeof (struct resource) + tlen + 1, GFP_KERNEL);
 186                 if (!tack)
 187                         return -ENOMEM;
 188                 memset(tack, 0, sizeof(struct resource));
 189                 res = (struct resource *) tack;
 190                 tack += sizeof (struct resource);
 191         }
 192
 193         strncpy(tack, name, XNMLN);
 194         tack[XNMLN] = 0;
 195         res->name = tack;
 196
 197         return shmedia_ioremap(res, phys, size);
 198 }
 199
 200 static unsigned long shmedia_ioremap(struct resource *res, u32 pa, int sz)
 201 {
 202         unsigned long offset = ((unsigned long) pa) & (~PAGE_MASK);
 203         unsigned long round_sz = (offset + sz + PAGE_SIZE-1) & PAGE_MASK;
 204         unsigned long va;
 205         unsigned int psz;
 206
 207         if (allocate_resource(&shmedia_iomap, res, round_sz,
 208                               shmedia_iomap.start, shmedia_iomap.end,
 209                               PAGE_SIZE, NULL, NULL) != 0) {
 210                 panic("alloc_io_res(%s): cannot occupy\n",
 211                     (res->name != NULL)? res->name: "???");
 212         }
 213
 214         va = res->start;
 215         pa &= PAGE_MASK;
 216
 217         psz = (res->end - res->start + (PAGE_SIZE - 1)) / PAGE_SIZE;
 218
 219         /* log at boot time ... */
 220         printk("mapioaddr: %6s  [%2d page%s]  va 0x%08lx   pa 0x%08x\n",
 221                ((res->name != NULL) ? res->name : "???"),
 222                psz, psz == 1 ? " " : "s", va, pa);
 223
 224         for (psz = res->end - res->start + 1; psz != 0; psz -= PAGE_SIZE) {
 225                 shmedia_mapioaddr(pa, va);
 226                 va += PAGE_SIZE;
 227                 pa += PAGE_SIZE;
 228         }
 229
 230         res->start += offset;
 231         res->end = res->start + sz - 1;         /* not strictly necessary.. */
 232
 233         return res->start;
 234 }
 235
 236 static void shmedia_free_io(struct resource *res)
 237 {
 238         unsigned long len = res->end - res->start + 1;
 239
 240         BUG_ON((len & (PAGE_SIZE - 1)) != 0);
 241
 242         while (len) {
 243                 len -= PAGE_SIZE;
 244                 shmedia_unmapioaddr(res->start + len);
 245         }
 246
 247         release_resource(res);
 248 }
 249
 250 static __init_refok void *sh64_get_page(void)
 251 {
 252         extern int after_bootmem;
 253         void *page;
 254
 255         if (after_bootmem) {
 256                 page = (void *)get_zeroed_page(GFP_ATOMIC);
 257         } else {
 258                 page = alloc_bootmem_pages(PAGE_SIZE);
 259         }
 260
 261         if (!page || ((unsigned long)page & ~PAGE_MASK))
 262                 panic("sh64_get_page: Out of memory already?\n");
 263
 264         return page;
 265 }
 266
 267 static void shmedia_mapioaddr(unsigned long pa, unsigned long va)
 268 {
 269         pgd_t *pgdp;
 270         pud_t *pudp;
 271         pmd_t *pmdp;
 272         pte_t *ptep, pte;
 273         pgprot_t prot;
 274         unsigned long flags = 1; /* 1 = CB0-1 device */
 275
 276         pr_debug("shmedia_mapiopage pa %08lx va %08lx\n",  pa, va);
 277
 278         pgdp = pgd_offset_k(va);
 279         if (pgd_none(*pgdp) || !pgd_present(*pgdp)) {
 280                 pudp = (pud_t *)sh64_get_page();
 281                 set_pgd(pgdp, __pgd((unsigned long)pudp | _KERNPG_TABLE));
 282         }
 283
 284         pudp = pud_offset(pgdp, va);
 285         if (pud_none(*pudp) || !pud_present(*pudp)) {
 286                 pmdp = (pmd_t *)sh64_get_page();
 287                 set_pud(pudp, __pud((unsigned long)pmdp | _KERNPG_TABLE));
 288         }
 289
 290         pmdp = pmd_offset(pudp, va);
 291         if (pmd_none(*pmdp) || !pmd_present(*pmdp) ) {
 292                 ptep = (pte_t *)sh64_get_page();
 293                 set_pmd(pmdp, __pmd((unsigned long)ptep + _PAGE_TABLE));
 294         }
 295
 296         prot = __pgprot(_PAGE_PRESENT | _PAGE_READ     | _PAGE_WRITE  |
 297                         _PAGE_DIRTY   | _PAGE_ACCESSED | _PAGE_SHARED | flags);
 298
 299         pte = pfn_pte(pa >> PAGE_SHIFT, prot);
 300         ptep = pte_offset_kernel(pmdp, va);
 301
 302         if (!pte_none(*ptep) &&
 303             pte_val(*ptep) != pte_val(pte))
 304                 pte_ERROR(*ptep);
 305
 306         set_pte(ptep, pte);
 307
 308         flush_tlb_kernel_range(va, PAGE_SIZE);
 309 }
 310
 311 static void shmedia_unmapioaddr(unsigned long vaddr)
 312 {
 313         pgd_t *pgdp;
 314         pud_t *pudp;
 315         pmd_t *pmdp;
 316         pte_t *ptep;
 317
 318         pgdp = pgd_offset_k(vaddr);
 319         if (pgd_none(*pgdp) || pgd_bad(*pgdp))
 320                 return;
 321
 322         pudp = pud_offset(pgdp, vaddr);
 323         if (pud_none(*pudp) || pud_bad(*pudp))
 324                 return;
 325
 326         pmdp = pmd_offset(pudp, vaddr);
 327         if (pmd_none(*pmdp) || pmd_bad(*pmdp))
 328                 return;
 329
 330         ptep = pte_offset_kernel(pmdp, vaddr);
 331
 332         if (pte_none(*ptep) || !pte_present(*ptep))
 333                 return;
 334
 335         clear_page((void *)ptep);
 336         pte_clear(&init_mm, vaddr, ptep);
 337 }
 338
 339 unsigned long onchip_remap(unsigned long phys, unsigned long size, const char *name)
 340 {
 341         if (size < PAGE_SIZE)
 342                 size = PAGE_SIZE;
 343
 344         return shmedia_alloc_io(phys, size, name);
 345 }
 346
 347 void onchip_unmap(unsigned long vaddr)
 348 {
 349         struct resource *res;
 350         unsigned int psz;
 351
 352         res = shmedia_find_resource(&shmedia_iomap, vaddr);
 353         if (!res) {
 354                 printk(KERN_ERR "%s: Failed to free 0x%08lx\n",
 355                        __func__, vaddr);
 356                 return;
 357         }
 358
 359         psz = (res->end - res->start + (PAGE_SIZE - 1)) / PAGE_SIZE;
 360
 361         printk(KERN_DEBUG "unmapioaddr: %6s  [%2d page%s] freed\n",
 362                res->name, psz, psz == 1 ? " " : "s");
 363
 364         shmedia_free_io(res);
 365
 366         if ((char *)res >= (char *)xresv &&
 367             (char *)res <  (char *)&xresv[XNRES]) {
 368                 xres_free((struct xresource *)res);
 369         } else {
 370                 kfree(res);
 371         }
 372 }
 373
 374 #ifdef CONFIG_PROC_FS
 375 static int
 376 ioremap_proc_info(char *buf, char **start, off_t fpos, int length, int *eof,
 377                   void *data)
 378 {
 379         char *p = buf, *e = buf + length;
 380         struct resource *r;
 381         const char *nm;
 382
 383         for (r = ((struct resource *)data)->child; r != NULL; r = r->sibling) {
 384                 if (p + 32 >= e)        /* Better than nothing */
 385                         break;
 386                 if ((nm = r->name) == 0) nm = "???";
 387                 p += sprintf(p, "%08lx-%08lx: %s\n",
 388                              (unsigned long)r->start,
 389                              (unsigned long)r->end, nm);
 390         }
 391
 392         return p-buf;
 393 }
 394 #endif /* CONFIG_PROC_FS */
 395
 396 static int __init register_proc_onchip(void)
 397 {
 398 #ifdef CONFIG_PROC_FS
 399         create_proc_read_entry("io_map",0,0, ioremap_proc_info, &shmedia_iomap);
 400 #endif
 401         return 0;
 402 }
 403
 404 __initcall(register_proc_onchip);