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/memblock.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 #include <asm/setup.h> 37 38 #include "mmu_decl.h" 39 40 unsigned long ioremap_base; 41 unsigned long ioremap_bot; 42 EXPORT_SYMBOL(ioremap_bot); /* aka VMALLOC_END */ 43 44 #ifdef CONFIG_6xx 45 #define HAVE_BATS 1 46 #endif 47 48 #if defined(CONFIG_FSL_BOOKE) 49 #define HAVE_TLBCAM 1 50 #endif 51 52 extern char etext[], _stext[]; 53 54 #ifdef HAVE_BATS 55 extern phys_addr_t v_mapped_by_bats(unsigned long va); 56 extern unsigned long p_mapped_by_bats(phys_addr_t pa); 57 #else /* !HAVE_BATS */ 58 #define v_mapped_by_bats(x) (0UL) 59 #define p_mapped_by_bats(x) (0UL) 60 #endif /* HAVE_BATS */ 61 62 #ifdef HAVE_TLBCAM 63 extern phys_addr_t v_mapped_by_tlbcam(unsigned long va); 64 extern unsigned long p_mapped_by_tlbcam(phys_addr_t pa); 65 #else /* !HAVE_TLBCAM */ 66 #define v_mapped_by_tlbcam(x) (0UL) 67 #define p_mapped_by_tlbcam(x) (0UL) 68 #endif /* HAVE_TLBCAM */ 69 70 #define PGDIR_ORDER (32 + PGD_T_LOG2 - PGDIR_SHIFT) 71 72 #ifndef CONFIG_PPC_4K_PAGES 73 static struct kmem_cache *pgtable_cache; 74 75 void pgtable_cache_init(void) 76 { 77 pgtable_cache = kmem_cache_create("PGDIR cache", 1 << PGDIR_ORDER, 78 1 << PGDIR_ORDER, 0, NULL); 79 if (pgtable_cache == NULL) 80 panic("Couldn't allocate pgtable caches"); 81 } 82 #endif 83 84 pgd_t *pgd_alloc(struct mm_struct *mm) 85 { 86 pgd_t *ret; 87 88 /* pgdir take page or two with 4K pages and a page fraction otherwise */ 89 #ifndef CONFIG_PPC_4K_PAGES 90 ret = kmem_cache_alloc(pgtable_cache, GFP_KERNEL | __GFP_ZERO); 91 #else 92 ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, 93 PGDIR_ORDER - PAGE_SHIFT); 94 #endif 95 return ret; 96 } 97 98 void pgd_free(struct mm_struct *mm, pgd_t *pgd) 99 { 100 #ifndef CONFIG_PPC_4K_PAGES 101 kmem_cache_free(pgtable_cache, (void *)pgd); 102 #else 103 free_pages((unsigned long)pgd, PGDIR_ORDER - PAGE_SHIFT); 104 #endif 105 } 106 107 __init_refok pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) 108 { 109 pte_t *pte; 110 111 if (slab_is_available()) { 112 pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); 113 } else { 114 pte = __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE)); 115 if (pte) 116 clear_page(pte); 117 } 118 return pte; 119 } 120 121 pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address) 122 { 123 struct page *ptepage; 124 125 gfp_t flags = GFP_KERNEL | __GFP_REPEAT | __GFP_ZERO; 126 127 ptepage = alloc_pages(flags, 0); 128 if (!ptepage) 129 return NULL; 130 if (!pgtable_page_ctor(ptepage)) { 131 __free_page(ptepage); 132 return NULL; 133 } 134 return ptepage; 135 } 136 137 void __iomem * 138 ioremap(phys_addr_t addr, unsigned long size) 139 { 140 return __ioremap_caller(addr, size, _PAGE_NO_CACHE | _PAGE_GUARDED, 141 __builtin_return_address(0)); 142 } 143 EXPORT_SYMBOL(ioremap); 144 145 void __iomem * 146 ioremap_wc(phys_addr_t addr, unsigned long size) 147 { 148 return __ioremap_caller(addr, size, _PAGE_NO_CACHE, 149 __builtin_return_address(0)); 150 } 151 EXPORT_SYMBOL(ioremap_wc); 152 153 void __iomem * 154 ioremap_prot(phys_addr_t addr, unsigned long size, unsigned long flags) 155 { 156 /* writeable implies dirty for kernel addresses */ 157 if ((flags & (_PAGE_RW | _PAGE_RO)) != _PAGE_RO) 158 flags |= _PAGE_DIRTY | _PAGE_HWWRITE; 159 160 /* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */ 161 flags &= ~(_PAGE_USER | _PAGE_EXEC); 162 163 #ifdef _PAGE_BAP_SR 164 /* _PAGE_USER contains _PAGE_BAP_SR on BookE using the new PTE format 165 * which means that we just cleared supervisor access... oops ;-) This 166 * restores it 167 */ 168 flags |= _PAGE_BAP_SR; 169 #endif 170 171 return __ioremap_caller(addr, size, flags, __builtin_return_address(0)); 172 } 173 EXPORT_SYMBOL(ioremap_prot); 174 175 void __iomem * 176 __ioremap(phys_addr_t addr, unsigned long size, unsigned long flags) 177 { 178 return __ioremap_caller(addr, size, flags, __builtin_return_address(0)); 179 } 180 181 void __iomem * 182 __ioremap_caller(phys_addr_t addr, unsigned long size, unsigned long flags, 183 void *caller) 184 { 185 unsigned long v, i; 186 phys_addr_t p; 187 int err; 188 189 /* Make sure we have the base flags */ 190 if ((flags & _PAGE_PRESENT) == 0) 191 flags |= pgprot_val(PAGE_KERNEL); 192 193 /* Non-cacheable page cannot be coherent */ 194 if (flags & _PAGE_NO_CACHE) 195 flags &= ~_PAGE_COHERENT; 196 197 /* 198 * Choose an address to map it to. 199 * Once the vmalloc system is running, we use it. 200 * Before then, we use space going down from ioremap_base 201 * (ioremap_bot records where we're up to). 202 */ 203 p = addr & PAGE_MASK; 204 size = PAGE_ALIGN(addr + size) - p; 205 206 /* 207 * If the address lies within the first 16 MB, assume it's in ISA 208 * memory space 209 */ 210 if (p < 16*1024*1024) 211 p += _ISA_MEM_BASE; 212 213 #ifndef CONFIG_CRASH_DUMP 214 /* 215 * Don't allow anybody to remap normal RAM that we're using. 216 * mem_init() sets high_memory so only do the check after that. 217 */ 218 if (slab_is_available() && (p < virt_to_phys(high_memory)) && 219 !(__allow_ioremap_reserved && memblock_is_region_reserved(p, size))) { 220 printk("__ioremap(): phys addr 0x%llx is RAM lr %ps\n", 221 (unsigned long long)p, __builtin_return_address(0)); 222 return NULL; 223 } 224 #endif 225 226 if (size == 0) 227 return NULL; 228 229 /* 230 * Is it already mapped? Perhaps overlapped by a previous 231 * BAT mapping. If the whole area is mapped then we're done, 232 * otherwise remap it since we want to keep the virt addrs for 233 * each request contiguous. 234 * 235 * We make the assumption here that if the bottom and top 236 * of the range we want are mapped then it's mapped to the 237 * same virt address (and this is contiguous). 238 * -- Cort 239 */ 240 if ((v = p_mapped_by_bats(p)) /*&& p_mapped_by_bats(p+size-1)*/ ) 241 goto out; 242 243 if ((v = p_mapped_by_tlbcam(p))) 244 goto out; 245 246 if (slab_is_available()) { 247 struct vm_struct *area; 248 area = get_vm_area_caller(size, VM_IOREMAP, caller); 249 if (area == 0) 250 return NULL; 251 area->phys_addr = p; 252 v = (unsigned long) area->addr; 253 } else { 254 v = (ioremap_bot -= size); 255 } 256 257 /* 258 * Should check if it is a candidate for a BAT mapping 259 */ 260 261 err = 0; 262 for (i = 0; i < size && err == 0; i += PAGE_SIZE) 263 err = map_page(v+i, p+i, flags); 264 if (err) { 265 if (slab_is_available()) 266 vunmap((void *)v); 267 return NULL; 268 } 269 270 out: 271 return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK)); 272 } 273 EXPORT_SYMBOL(__ioremap); 274 275 void iounmap(volatile void __iomem *addr) 276 { 277 /* 278 * If mapped by BATs then there is nothing to do. 279 * Calling vfree() generates a benign warning. 280 */ 281 if (v_mapped_by_bats((unsigned long)addr)) return; 282 283 if (addr > high_memory && (unsigned long) addr < ioremap_bot) 284 vunmap((void *) (PAGE_MASK & (unsigned long)addr)); 285 } 286 EXPORT_SYMBOL(iounmap); 287 288 int map_page(unsigned long va, phys_addr_t pa, int flags) 289 { 290 pmd_t *pd; 291 pte_t *pg; 292 int err = -ENOMEM; 293 294 /* Use upper 10 bits of VA to index the first level map */ 295 pd = pmd_offset(pud_offset(pgd_offset_k(va), va), va); 296 /* Use middle 10 bits of VA to index the second-level map */ 297 pg = pte_alloc_kernel(pd, va); 298 if (pg != 0) { 299 err = 0; 300 /* The PTE should never be already set nor present in the 301 * hash table 302 */ 303 BUG_ON((pte_val(*pg) & (_PAGE_PRESENT | _PAGE_HASHPTE)) && 304 flags); 305 set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, 306 __pgprot(flags))); 307 } 308 smp_wmb(); 309 return err; 310 } 311 312 /* 313 * Map in a chunk of physical memory starting at start. 314 */ 315 void __init __mapin_ram_chunk(unsigned long offset, unsigned long top) 316 { 317 unsigned long v, s, f; 318 phys_addr_t p; 319 int ktext; 320 321 s = offset; 322 v = PAGE_OFFSET + s; 323 p = memstart_addr + s; 324 for (; s < top; s += PAGE_SIZE) { 325 ktext = ((char *) v >= _stext && (char *) v < etext); 326 f = ktext ? pgprot_val(PAGE_KERNEL_TEXT) : pgprot_val(PAGE_KERNEL); 327 map_page(v, p, f); 328 #ifdef CONFIG_PPC_STD_MMU_32 329 if (ktext) 330 hash_preload(&init_mm, v, 0, 0x300); 331 #endif 332 v += PAGE_SIZE; 333 p += PAGE_SIZE; 334 } 335 } 336 337 void __init mapin_ram(void) 338 { 339 unsigned long s, top; 340 341 #ifndef CONFIG_WII 342 top = total_lowmem; 343 s = mmu_mapin_ram(top); 344 __mapin_ram_chunk(s, top); 345 #else 346 if (!wii_hole_size) { 347 s = mmu_mapin_ram(total_lowmem); 348 __mapin_ram_chunk(s, total_lowmem); 349 } else { 350 top = wii_hole_start; 351 s = mmu_mapin_ram(top); 352 __mapin_ram_chunk(s, top); 353 354 top = memblock_end_of_DRAM(); 355 s = wii_mmu_mapin_mem2(top); 356 __mapin_ram_chunk(s, top); 357 } 358 #endif 359 } 360 361 /* Scan the real Linux page tables and return a PTE pointer for 362 * a virtual address in a context. 363 * Returns true (1) if PTE was found, zero otherwise. The pointer to 364 * the PTE pointer is unmodified if PTE is not found. 365 */ 366 int 367 get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp) 368 { 369 pgd_t *pgd; 370 pud_t *pud; 371 pmd_t *pmd; 372 pte_t *pte; 373 int retval = 0; 374 375 pgd = pgd_offset(mm, addr & PAGE_MASK); 376 if (pgd) { 377 pud = pud_offset(pgd, addr & PAGE_MASK); 378 if (pud && pud_present(*pud)) { 379 pmd = pmd_offset(pud, addr & PAGE_MASK); 380 if (pmd_present(*pmd)) { 381 pte = pte_offset_map(pmd, addr & PAGE_MASK); 382 if (pte) { 383 retval = 1; 384 *ptep = pte; 385 if (pmdp) 386 *pmdp = pmd; 387 /* XXX caller needs to do pte_unmap, yuck */ 388 } 389 } 390 } 391 } 392 return(retval); 393 } 394 395 #ifdef CONFIG_DEBUG_PAGEALLOC 396 397 static int __change_page_attr(struct page *page, pgprot_t prot) 398 { 399 pte_t *kpte; 400 pmd_t *kpmd; 401 unsigned long address; 402 403 BUG_ON(PageHighMem(page)); 404 address = (unsigned long)page_address(page); 405 406 if (v_mapped_by_bats(address) || v_mapped_by_tlbcam(address)) 407 return 0; 408 if (!get_pteptr(&init_mm, address, &kpte, &kpmd)) 409 return -EINVAL; 410 __set_pte_at(&init_mm, address, kpte, mk_pte(page, prot), 0); 411 wmb(); 412 flush_tlb_page(NULL, address); 413 pte_unmap(kpte); 414 415 return 0; 416 } 417 418 /* 419 * Change the page attributes of an page in the linear mapping. 420 * 421 * THIS CONFLICTS WITH BAT MAPPINGS, DEBUG USE ONLY 422 */ 423 static int change_page_attr(struct page *page, int numpages, pgprot_t prot) 424 { 425 int i, err = 0; 426 unsigned long flags; 427 428 local_irq_save(flags); 429 for (i = 0; i < numpages; i++, page++) { 430 err = __change_page_attr(page, prot); 431 if (err) 432 break; 433 } 434 local_irq_restore(flags); 435 return err; 436 } 437 438 439 void __kernel_map_pages(struct page *page, int numpages, int enable) 440 { 441 if (PageHighMem(page)) 442 return; 443 444 change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0)); 445 } 446 #endif /* CONFIG_DEBUG_PAGEALLOC */ 447 448 static int fixmaps; 449 450 void __set_fixmap (enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags) 451 { 452 unsigned long address = __fix_to_virt(idx); 453 454 if (idx >= __end_of_fixed_addresses) { 455 BUG(); 456 return; 457 } 458 459 map_page(address, phys, pgprot_val(flags)); 460 fixmaps++; 461 } 462 463 void __this_fixmap_does_not_exist(void) 464 { 465 WARN_ON(1); 466 } 467