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 39unsigned long ioremap_base; 40unsigned long ioremap_bot; 41EXPORT_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 51extern char etext[], _stext[]; 52 53#ifdef HAVE_BATS 54extern phys_addr_t v_mapped_by_bats(unsigned long va); 55extern unsigned long p_mapped_by_bats(phys_addr_t pa); 56void 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 65extern unsigned int tlbcam_index; 66extern phys_addr_t v_mapped_by_tlbcam(unsigned long va); 67extern 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 75pgd_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 89void 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 114pgtable_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 127void __iomem * 128ioremap(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} 133EXPORT_SYMBOL(ioremap); 134 135void __iomem * 136ioremap_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} 155EXPORT_SYMBOL(ioremap_flags); 156 157void __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 163void __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 v = (unsigned long) area->addr; 234 } else { 235 v = (ioremap_bot -= size); 236 } 237 238 /* 239 * Should check if it is a candidate for a BAT mapping 240 */ 241 242 err = 0; 243 for (i = 0; i < size && err == 0; i += PAGE_SIZE) 244 err = map_page(v+i, p+i, flags); 245 if (err) { 246 if (mem_init_done) 247 vunmap((void *)v); 248 return NULL; 249 } 250 251out: 252 return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK)); 253} 254EXPORT_SYMBOL(__ioremap); 255 256void iounmap(volatile void __iomem *addr) 257{ 258 /* 259 * If mapped by BATs then there is nothing to do. 260 * Calling vfree() generates a benign warning. 261 */ 262 if (v_mapped_by_bats((unsigned long)addr)) return; 263 264 if (addr > high_memory && (unsigned long) addr < ioremap_bot) 265 vunmap((void *) (PAGE_MASK & (unsigned long)addr)); 266} 267EXPORT_SYMBOL(iounmap); 268 269int map_page(unsigned long va, phys_addr_t pa, int flags) 270{ 271 pmd_t *pd; 272 pte_t *pg; 273 int err = -ENOMEM; 274 275 /* Use upper 10 bits of VA to index the first level map */ 276 pd = pmd_offset(pud_offset(pgd_offset_k(va), va), va); 277 /* Use middle 10 bits of VA to index the second-level map */ 278 pg = pte_alloc_kernel(pd, va); 279 if (pg != 0) { 280 err = 0; 281 /* The PTE should never be already set nor present in the 282 * hash table 283 */ 284 BUG_ON((pte_val(*pg) & (_PAGE_PRESENT | _PAGE_HASHPTE)) && 285 flags); 286 set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, 287 __pgprot(flags))); 288 } 289 return err; 290} 291 292/* 293 * Map in a chunk of physical memory starting at start. 294 */ 295void __init __mapin_ram_chunk(unsigned long offset, unsigned long top) 296{ 297 unsigned long v, s, f; 298 phys_addr_t p; 299 int ktext; 300 301 s = offset; 302 v = PAGE_OFFSET + s; 303 p = memstart_addr + s; 304 for (; s < top; s += PAGE_SIZE) { 305 ktext = ((char *) v >= _stext && (char *) v < etext); 306 f = ktext ? PAGE_KERNEL_TEXT : PAGE_KERNEL; 307 map_page(v, p, f); 308#ifdef CONFIG_PPC_STD_MMU_32 309 if (ktext) 310 hash_preload(&init_mm, v, 0, 0x300); 311#endif 312 v += PAGE_SIZE; 313 p += PAGE_SIZE; 314 } 315} 316 317void __init mapin_ram(void) 318{ 319 unsigned long s, top; 320 321#ifndef CONFIG_WII 322 top = total_lowmem; 323 s = mmu_mapin_ram(top); 324 __mapin_ram_chunk(s, top); 325#else 326 if (!wii_hole_size) { 327 s = mmu_mapin_ram(total_lowmem); 328 __mapin_ram_chunk(s, total_lowmem); 329 } else { 330 top = wii_hole_start; 331 s = mmu_mapin_ram(top); 332 __mapin_ram_chunk(s, top); 333 334 top = memblock_end_of_DRAM(); 335 s = wii_mmu_mapin_mem2(top); 336 __mapin_ram_chunk(s, top); 337 } 338#endif 339} 340 341/* Scan the real Linux page tables and return a PTE pointer for 342 * a virtual address in a context. 343 * Returns true (1) if PTE was found, zero otherwise. The pointer to 344 * the PTE pointer is unmodified if PTE is not found. 345 */ 346int 347get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp) 348{ 349 pgd_t *pgd; 350 pud_t *pud; 351 pmd_t *pmd; 352 pte_t *pte; 353 int retval = 0; 354 355 pgd = pgd_offset(mm, addr & PAGE_MASK); 356 if (pgd) { 357 pud = pud_offset(pgd, addr & PAGE_MASK); 358 if (pud && pud_present(*pud)) { 359 pmd = pmd_offset(pud, addr & PAGE_MASK); 360 if (pmd_present(*pmd)) { 361 pte = pte_offset_map(pmd, addr & PAGE_MASK); 362 if (pte) { 363 retval = 1; 364 *ptep = pte; 365 if (pmdp) 366 *pmdp = pmd; 367 } 368 } 369 } 370 } 371 return(retval); 372} 373 374#ifdef CONFIG_DEBUG_PAGEALLOC 375 376static int __change_page_attr(struct page *page, pgprot_t prot) 377{ 378 pte_t *kpte; 379 pmd_t *kpmd; 380 unsigned long address; 381 382 BUG_ON(PageHighMem(page)); 383 address = (unsigned long)page_address(page); 384 385 if (v_mapped_by_bats(address) || v_mapped_by_tlbcam(address)) 386 return 0; 387 if (!get_pteptr(&init_mm, address, &kpte, &kpmd)) 388 return -EINVAL; 389 __set_pte_at(&init_mm, address, kpte, mk_pte(page, prot), 0); 390 wmb(); 391 flush_tlb_page(NULL, address); 392 pte_unmap(kpte); 393 394 return 0; 395} 396 397/* 398 * Change the page attributes of an page in the linear mapping. 399 * 400 * THIS CONFLICTS WITH BAT MAPPINGS, DEBUG USE ONLY 401 */ 402static int change_page_attr(struct page *page, int numpages, pgprot_t prot) 403{ 404 int i, err = 0; 405 unsigned long flags; 406 407 local_irq_save(flags); 408 for (i = 0; i < numpages; i++, page++) { 409 err = __change_page_attr(page, prot); 410 if (err) 411 break; 412 } 413 local_irq_restore(flags); 414 return err; 415} 416 417 418void kernel_map_pages(struct page *page, int numpages, int enable) 419{ 420 if (PageHighMem(page)) 421 return; 422 423 change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0)); 424} 425#endif /* CONFIG_DEBUG_PAGEALLOC */ 426 427static int fixmaps; 428 429void __set_fixmap (enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags) 430{ 431 unsigned long address = __fix_to_virt(idx); 432 433 if (idx >= __end_of_fixed_addresses) { 434 BUG(); 435 return; 436 } 437 438 map_page(address, phys, pgprot_val(flags)); 439 fixmaps++; 440} 441 442void __this_fixmap_does_not_exist(void) 443{ 444 WARN_ON(1); 445} 446