1 /* 2 * This file contains the routines setting up the linux page tables. 3 * -- paulus 4 * 5 * Derived from arch/ppc/mm/init.c: 6 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) 7 * 8 * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) 9 * and Cort Dougan (PReP) (cort@cs.nmt.edu) 10 * Copyright (C) 1996 Paul Mackerras 11 * 12 * Derived from "arch/i386/mm/init.c" 13 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds 14 * 15 * This program is free software; you can redistribute it and/or 16 * modify it under the terms of the GNU General Public License 17 * as published by the Free Software Foundation; either version 18 * 2 of the License, or (at your option) any later version. 19 * 20 */ 21 22 #include <linux/kernel.h> 23 #include <linux/module.h> 24 #include <linux/types.h> 25 #include <linux/mm.h> 26 #include <linux/vmalloc.h> 27 #include <linux/init.h> 28 #include <linux/highmem.h> 29 #include <linux/lmb.h> 30 #include <linux/slab.h> 31 32 #include <asm/pgtable.h> 33 #include <asm/pgalloc.h> 34 #include <asm/fixmap.h> 35 #include <asm/io.h> 36 37 #include "mmu_decl.h" 38 39 unsigned long ioremap_base; 40 unsigned long ioremap_bot; 41 EXPORT_SYMBOL(ioremap_bot); /* aka VMALLOC_END */ 42 43 #if defined(CONFIG_6xx) || defined(CONFIG_POWER3) 44 #define HAVE_BATS 1 45 #endif 46 47 #if defined(CONFIG_FSL_BOOKE) 48 #define HAVE_TLBCAM 1 49 #endif 50 51 extern char etext[], _stext[]; 52 53 #ifdef HAVE_BATS 54 extern phys_addr_t v_mapped_by_bats(unsigned long va); 55 extern unsigned long p_mapped_by_bats(phys_addr_t pa); 56 void setbat(int index, unsigned long virt, phys_addr_t phys, 57 unsigned int size, int flags); 58 59 #else /* !HAVE_BATS */ 60 #define v_mapped_by_bats(x) (0UL) 61 #define p_mapped_by_bats(x) (0UL) 62 #endif /* HAVE_BATS */ 63 64 #ifdef HAVE_TLBCAM 65 extern unsigned int tlbcam_index; 66 extern phys_addr_t v_mapped_by_tlbcam(unsigned long va); 67 extern unsigned long p_mapped_by_tlbcam(phys_addr_t pa); 68 #else /* !HAVE_TLBCAM */ 69 #define v_mapped_by_tlbcam(x) (0UL) 70 #define p_mapped_by_tlbcam(x) (0UL) 71 #endif /* HAVE_TLBCAM */ 72 73 #define PGDIR_ORDER (32 + PGD_T_LOG2 - PGDIR_SHIFT) 74 75 pgd_t *pgd_alloc(struct mm_struct *mm) 76 { 77 pgd_t *ret; 78 79 /* pgdir take page or two with 4K pages and a page fraction otherwise */ 80 #ifndef CONFIG_PPC_4K_PAGES 81 ret = (pgd_t *)kzalloc(1 << PGDIR_ORDER, GFP_KERNEL); 82 #else 83 ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, 84 PGDIR_ORDER - PAGE_SHIFT); 85 #endif 86 return ret; 87 } 88 89 void pgd_free(struct mm_struct *mm, pgd_t *pgd) 90 { 91 #ifndef CONFIG_PPC_4K_PAGES 92 kfree((void *)pgd); 93 #else 94 free_pages((unsigned long)pgd, PGDIR_ORDER - PAGE_SHIFT); 95 #endif 96 } 97 98 __init_refok pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) 99 { 100 pte_t *pte; 101 extern int mem_init_done; 102 extern void *early_get_page(void); 103 104 if (mem_init_done) { 105 pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); 106 } else { 107 pte = (pte_t *)early_get_page(); 108 if (pte) 109 clear_page(pte); 110 } 111 return pte; 112 } 113 114 pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address) 115 { 116 struct page *ptepage; 117 118 #ifdef CONFIG_HIGHPTE 119 gfp_t flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_REPEAT | __GFP_ZERO; 120 #else 121 gfp_t flags = GFP_KERNEL | __GFP_REPEAT | __GFP_ZERO; 122 #endif 123 124 ptepage = alloc_pages(flags, 0); 125 if (!ptepage) 126 return NULL; 127 pgtable_page_ctor(ptepage); 128 return ptepage; 129 } 130 131 void __iomem * 132 ioremap(phys_addr_t addr, unsigned long size) 133 { 134 return __ioremap_caller(addr, size, _PAGE_NO_CACHE | _PAGE_GUARDED, 135 __builtin_return_address(0)); 136 } 137 EXPORT_SYMBOL(ioremap); 138 139 void __iomem * 140 ioremap_flags(phys_addr_t addr, unsigned long size, unsigned long flags) 141 { 142 /* writeable implies dirty for kernel addresses */ 143 if (flags & _PAGE_RW) 144 flags |= _PAGE_DIRTY | _PAGE_HWWRITE; 145 146 /* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */ 147 flags &= ~(_PAGE_USER | _PAGE_EXEC); 148 149 return __ioremap_caller(addr, size, flags, __builtin_return_address(0)); 150 } 151 EXPORT_SYMBOL(ioremap_flags); 152 153 void __iomem * 154 __ioremap(phys_addr_t addr, unsigned long size, unsigned long flags) 155 { 156 return __ioremap_caller(addr, size, flags, __builtin_return_address(0)); 157 } 158 159 void __iomem * 160 __ioremap_caller(phys_addr_t addr, unsigned long size, unsigned long flags, 161 void *caller) 162 { 163 unsigned long v, i; 164 phys_addr_t p; 165 int err; 166 167 /* Make sure we have the base flags */ 168 if ((flags & _PAGE_PRESENT) == 0) 169 flags |= PAGE_KERNEL; 170 171 /* Non-cacheable page cannot be coherent */ 172 if (flags & _PAGE_NO_CACHE) 173 flags &= ~_PAGE_COHERENT; 174 175 /* 176 * Choose an address to map it to. 177 * Once the vmalloc system is running, we use it. 178 * Before then, we use space going down from ioremap_base 179 * (ioremap_bot records where we're up to). 180 */ 181 p = addr & PAGE_MASK; 182 size = PAGE_ALIGN(addr + size) - p; 183 184 /* 185 * If the address lies within the first 16 MB, assume it's in ISA 186 * memory space 187 */ 188 if (p < 16*1024*1024) 189 p += _ISA_MEM_BASE; 190 191 #ifndef CONFIG_CRASH_DUMP 192 /* 193 * Don't allow anybody to remap normal RAM that we're using. 194 * mem_init() sets high_memory so only do the check after that. 195 */ 196 if (mem_init_done && (p < virt_to_phys(high_memory)) && 197 !(__allow_ioremap_reserved && lmb_is_region_reserved(p, size))) { 198 printk("__ioremap(): phys addr 0x%llx is RAM lr %p\n", 199 (unsigned long long)p, __builtin_return_address(0)); 200 return NULL; 201 } 202 #endif 203 204 if (size == 0) 205 return NULL; 206 207 /* 208 * Is it already mapped? Perhaps overlapped by a previous 209 * BAT mapping. If the whole area is mapped then we're done, 210 * otherwise remap it since we want to keep the virt addrs for 211 * each request contiguous. 212 * 213 * We make the assumption here that if the bottom and top 214 * of the range we want are mapped then it's mapped to the 215 * same virt address (and this is contiguous). 216 * -- Cort 217 */ 218 if ((v = p_mapped_by_bats(p)) /*&& p_mapped_by_bats(p+size-1)*/ ) 219 goto out; 220 221 if ((v = p_mapped_by_tlbcam(p))) 222 goto out; 223 224 if (mem_init_done) { 225 struct vm_struct *area; 226 area = get_vm_area_caller(size, VM_IOREMAP, caller); 227 if (area == 0) 228 return NULL; 229 v = (unsigned long) area->addr; 230 } else { 231 v = (ioremap_bot -= size); 232 } 233 234 /* 235 * Should check if it is a candidate for a BAT mapping 236 */ 237 238 err = 0; 239 for (i = 0; i < size && err == 0; i += PAGE_SIZE) 240 err = map_page(v+i, p+i, flags); 241 if (err) { 242 if (mem_init_done) 243 vunmap((void *)v); 244 return NULL; 245 } 246 247 out: 248 return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK)); 249 } 250 EXPORT_SYMBOL(__ioremap); 251 252 void iounmap(volatile void __iomem *addr) 253 { 254 /* 255 * If mapped by BATs then there is nothing to do. 256 * Calling vfree() generates a benign warning. 257 */ 258 if (v_mapped_by_bats((unsigned long)addr)) return; 259 260 if (addr > high_memory && (unsigned long) addr < ioremap_bot) 261 vunmap((void *) (PAGE_MASK & (unsigned long)addr)); 262 } 263 EXPORT_SYMBOL(iounmap); 264 265 int map_page(unsigned long va, phys_addr_t pa, int flags) 266 { 267 pmd_t *pd; 268 pte_t *pg; 269 int err = -ENOMEM; 270 271 /* Use upper 10 bits of VA to index the first level map */ 272 pd = pmd_offset(pud_offset(pgd_offset_k(va), va), va); 273 /* Use middle 10 bits of VA to index the second-level map */ 274 pg = pte_alloc_kernel(pd, va); 275 if (pg != 0) { 276 err = 0; 277 /* The PTE should never be already set nor present in the 278 * hash table 279 */ 280 BUG_ON((pte_val(*pg) & (_PAGE_PRESENT | _PAGE_HASHPTE)) && 281 flags); 282 set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, 283 __pgprot(flags))); 284 } 285 return err; 286 } 287 288 /* 289 * Map in a chunk of physical memory starting at start. 290 */ 291 void __init __mapin_ram_chunk(unsigned long offset, unsigned long top) 292 { 293 unsigned long v, s, f; 294 phys_addr_t p; 295 int ktext; 296 297 s = offset; 298 v = PAGE_OFFSET + s; 299 p = memstart_addr + s; 300 for (; s < top; s += PAGE_SIZE) { 301 ktext = ((char *) v >= _stext && (char *) v < etext); 302 f = ktext ? PAGE_KERNEL_TEXT : PAGE_KERNEL; 303 map_page(v, p, f); 304 #ifdef CONFIG_PPC_STD_MMU_32 305 if (ktext) 306 hash_preload(&init_mm, v, 0, 0x300); 307 #endif 308 v += PAGE_SIZE; 309 p += PAGE_SIZE; 310 } 311 } 312 313 void __init mapin_ram(void) 314 { 315 unsigned long s, top; 316 317 #ifndef CONFIG_WII 318 top = total_lowmem; 319 s = mmu_mapin_ram(top); 320 __mapin_ram_chunk(s, top); 321 #else 322 if (!wii_hole_size) { 323 s = mmu_mapin_ram(total_lowmem); 324 __mapin_ram_chunk(s, total_lowmem); 325 } else { 326 top = wii_hole_start; 327 s = mmu_mapin_ram(top); 328 __mapin_ram_chunk(s, top); 329 330 top = lmb_end_of_DRAM(); 331 s = wii_mmu_mapin_mem2(top); 332 __mapin_ram_chunk(s, top); 333 } 334 #endif 335 } 336 337 /* Scan the real Linux page tables and return a PTE pointer for 338 * a virtual address in a context. 339 * Returns true (1) if PTE was found, zero otherwise. The pointer to 340 * the PTE pointer is unmodified if PTE is not found. 341 */ 342 int 343 get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp) 344 { 345 pgd_t *pgd; 346 pud_t *pud; 347 pmd_t *pmd; 348 pte_t *pte; 349 int retval = 0; 350 351 pgd = pgd_offset(mm, addr & PAGE_MASK); 352 if (pgd) { 353 pud = pud_offset(pgd, addr & PAGE_MASK); 354 if (pud && pud_present(*pud)) { 355 pmd = pmd_offset(pud, addr & PAGE_MASK); 356 if (pmd_present(*pmd)) { 357 pte = pte_offset_map(pmd, addr & PAGE_MASK); 358 if (pte) { 359 retval = 1; 360 *ptep = pte; 361 if (pmdp) 362 *pmdp = pmd; 363 /* XXX caller needs to do pte_unmap, yuck */ 364 } 365 } 366 } 367 } 368 return(retval); 369 } 370 371 #ifdef CONFIG_DEBUG_PAGEALLOC 372 373 static int __change_page_attr(struct page *page, pgprot_t prot) 374 { 375 pte_t *kpte; 376 pmd_t *kpmd; 377 unsigned long address; 378 379 BUG_ON(PageHighMem(page)); 380 address = (unsigned long)page_address(page); 381 382 if (v_mapped_by_bats(address) || v_mapped_by_tlbcam(address)) 383 return 0; 384 if (!get_pteptr(&init_mm, address, &kpte, &kpmd)) 385 return -EINVAL; 386 __set_pte_at(&init_mm, address, kpte, mk_pte(page, prot), 0); 387 wmb(); 388 #ifdef CONFIG_PPC_STD_MMU 389 flush_hash_pages(0, address, pmd_val(*kpmd), 1); 390 #else 391 flush_tlb_page(NULL, address); 392 #endif 393 pte_unmap(kpte); 394 395 return 0; 396 } 397 398 /* 399 * Change the page attributes of an page in the linear mapping. 400 * 401 * THIS CONFLICTS WITH BAT MAPPINGS, DEBUG USE ONLY 402 */ 403 static int change_page_attr(struct page *page, int numpages, pgprot_t prot) 404 { 405 int i, err = 0; 406 unsigned long flags; 407 408 local_irq_save(flags); 409 for (i = 0; i < numpages; i++, page++) { 410 err = __change_page_attr(page, prot); 411 if (err) 412 break; 413 } 414 local_irq_restore(flags); 415 return err; 416 } 417 418 419 void kernel_map_pages(struct page *page, int numpages, int enable) 420 { 421 if (PageHighMem(page)) 422 return; 423 424 change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0)); 425 } 426 #endif /* CONFIG_DEBUG_PAGEALLOC */ 427 428 static int fixmaps; 429 430 void __set_fixmap (enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags) 431 { 432 unsigned long address = __fix_to_virt(idx); 433 434 if (idx >= __end_of_fixed_addresses) { 435 BUG(); 436 return; 437 } 438 439 map_page(address, phys, pgprot_val(flags)); 440 fixmaps++; 441 } 442 443 void __this_fixmap_does_not_exist(void) 444 { 445 WARN_ON(1); 446 } 447