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