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 #if defined(CONFIG_6xx) || defined(CONFIG_POWER3) 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 void setbat(int index, unsigned long virt, phys_addr_t phys, 58 unsigned int size, int flags); 59 60 #else /* !HAVE_BATS */ 61 #define v_mapped_by_bats(x) (0UL) 62 #define p_mapped_by_bats(x) (0UL) 63 #endif /* HAVE_BATS */ 64 65 #ifdef HAVE_TLBCAM 66 extern unsigned int tlbcam_index; 67 extern phys_addr_t v_mapped_by_tlbcam(unsigned long va); 68 extern unsigned long p_mapped_by_tlbcam(phys_addr_t pa); 69 #else /* !HAVE_TLBCAM */ 70 #define v_mapped_by_tlbcam(x) (0UL) 71 #define p_mapped_by_tlbcam(x) (0UL) 72 #endif /* HAVE_TLBCAM */ 73 74 #define PGDIR_ORDER (32 + PGD_T_LOG2 - PGDIR_SHIFT) 75 76 pgd_t *pgd_alloc(struct mm_struct *mm) 77 { 78 pgd_t *ret; 79 80 /* pgdir take page or two with 4K pages and a page fraction otherwise */ 81 #ifndef CONFIG_PPC_4K_PAGES 82 ret = kzalloc(1 << PGDIR_ORDER, GFP_KERNEL); 83 #else 84 ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, 85 PGDIR_ORDER - PAGE_SHIFT); 86 #endif 87 return ret; 88 } 89 90 void pgd_free(struct mm_struct *mm, pgd_t *pgd) 91 { 92 #ifndef CONFIG_PPC_4K_PAGES 93 kfree((void *)pgd); 94 #else 95 free_pages((unsigned long)pgd, PGDIR_ORDER - PAGE_SHIFT); 96 #endif 97 } 98 99 __init_refok pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) 100 { 101 pte_t *pte; 102 extern int mem_init_done; 103 extern void *early_get_page(void); 104 105 if (mem_init_done) { 106 pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); 107 } else { 108 pte = (pte_t *)early_get_page(); 109 if (pte) 110 clear_page(pte); 111 } 112 return pte; 113 } 114 115 pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address) 116 { 117 struct page *ptepage; 118 119 gfp_t flags = GFP_KERNEL | __GFP_REPEAT | __GFP_ZERO; 120 121 ptepage = alloc_pages(flags, 0); 122 if (!ptepage) 123 return NULL; 124 if (!pgtable_page_ctor(ptepage)) { 125 __free_page(ptepage); 126 return NULL; 127 } 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_wc(phys_addr_t addr, unsigned long size) 141 { 142 return __ioremap_caller(addr, size, _PAGE_NO_CACHE, 143 __builtin_return_address(0)); 144 } 145 EXPORT_SYMBOL(ioremap_wc); 146 147 void __iomem * 148 ioremap_prot(phys_addr_t addr, unsigned long size, unsigned long flags) 149 { 150 /* writeable implies dirty for kernel addresses */ 151 if (flags & _PAGE_RW) 152 flags |= _PAGE_DIRTY | _PAGE_HWWRITE; 153 154 /* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */ 155 flags &= ~(_PAGE_USER | _PAGE_EXEC); 156 157 #ifdef _PAGE_BAP_SR 158 /* _PAGE_USER contains _PAGE_BAP_SR on BookE using the new PTE format 159 * which means that we just cleared supervisor access... oops ;-) This 160 * restores it 161 */ 162 flags |= _PAGE_BAP_SR; 163 #endif 164 165 return __ioremap_caller(addr, size, flags, __builtin_return_address(0)); 166 } 167 EXPORT_SYMBOL(ioremap_prot); 168 169 void __iomem * 170 __ioremap(phys_addr_t addr, unsigned long size, unsigned long flags) 171 { 172 return __ioremap_caller(addr, size, flags, __builtin_return_address(0)); 173 } 174 175 void __iomem * 176 __ioremap_caller(phys_addr_t addr, unsigned long size, unsigned long flags, 177 void *caller) 178 { 179 unsigned long v, i; 180 phys_addr_t p; 181 int err; 182 183 /* Make sure we have the base flags */ 184 if ((flags & _PAGE_PRESENT) == 0) 185 flags |= PAGE_KERNEL; 186 187 /* Non-cacheable page cannot be coherent */ 188 if (flags & _PAGE_NO_CACHE) 189 flags &= ~_PAGE_COHERENT; 190 191 /* 192 * Choose an address to map it to. 193 * Once the vmalloc system is running, we use it. 194 * Before then, we use space going down from ioremap_base 195 * (ioremap_bot records where we're up to). 196 */ 197 p = addr & PAGE_MASK; 198 size = PAGE_ALIGN(addr + size) - p; 199 200 /* 201 * If the address lies within the first 16 MB, assume it's in ISA 202 * memory space 203 */ 204 if (p < 16*1024*1024) 205 p += _ISA_MEM_BASE; 206 207 #ifndef CONFIG_CRASH_DUMP 208 /* 209 * Don't allow anybody to remap normal RAM that we're using. 210 * mem_init() sets high_memory so only do the check after that. 211 */ 212 if (mem_init_done && (p < virt_to_phys(high_memory)) && 213 !(__allow_ioremap_reserved && memblock_is_region_reserved(p, size))) { 214 printk("__ioremap(): phys addr 0x%llx is RAM lr %pf\n", 215 (unsigned long long)p, __builtin_return_address(0)); 216 return NULL; 217 } 218 #endif 219 220 if (size == 0) 221 return NULL; 222 223 /* 224 * Is it already mapped? Perhaps overlapped by a previous 225 * BAT mapping. If the whole area is mapped then we're done, 226 * otherwise remap it since we want to keep the virt addrs for 227 * each request contiguous. 228 * 229 * We make the assumption here that if the bottom and top 230 * of the range we want are mapped then it's mapped to the 231 * same virt address (and this is contiguous). 232 * -- Cort 233 */ 234 if ((v = p_mapped_by_bats(p)) /*&& p_mapped_by_bats(p+size-1)*/ ) 235 goto out; 236 237 if ((v = p_mapped_by_tlbcam(p))) 238 goto out; 239 240 if (mem_init_done) { 241 struct vm_struct *area; 242 area = get_vm_area_caller(size, VM_IOREMAP, caller); 243 if (area == 0) 244 return NULL; 245 area->phys_addr = p; 246 v = (unsigned long) area->addr; 247 } else { 248 v = (ioremap_bot -= size); 249 } 250 251 /* 252 * Should check if it is a candidate for a BAT mapping 253 */ 254 255 err = 0; 256 for (i = 0; i < size && err == 0; i += PAGE_SIZE) 257 err = map_page(v+i, p+i, flags); 258 if (err) { 259 if (mem_init_done) 260 vunmap((void *)v); 261 return NULL; 262 } 263 264 out: 265 return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK)); 266 } 267 EXPORT_SYMBOL(__ioremap); 268 269 void iounmap(volatile void __iomem *addr) 270 { 271 /* 272 * If mapped by BATs then there is nothing to do. 273 * Calling vfree() generates a benign warning. 274 */ 275 if (v_mapped_by_bats((unsigned long)addr)) return; 276 277 if (addr > high_memory && (unsigned long) addr < ioremap_bot) 278 vunmap((void *) (PAGE_MASK & (unsigned long)addr)); 279 } 280 EXPORT_SYMBOL(iounmap); 281 282 int map_page(unsigned long va, phys_addr_t pa, int flags) 283 { 284 pmd_t *pd; 285 pte_t *pg; 286 int err = -ENOMEM; 287 288 /* Use upper 10 bits of VA to index the first level map */ 289 pd = pmd_offset(pud_offset(pgd_offset_k(va), va), va); 290 /* Use middle 10 bits of VA to index the second-level map */ 291 pg = pte_alloc_kernel(pd, va); 292 if (pg != 0) { 293 err = 0; 294 /* The PTE should never be already set nor present in the 295 * hash table 296 */ 297 BUG_ON((pte_val(*pg) & (_PAGE_PRESENT | _PAGE_HASHPTE)) && 298 flags); 299 set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, 300 __pgprot(flags))); 301 } 302 return err; 303 } 304 305 /* 306 * Map in a chunk of physical memory starting at start. 307 */ 308 void __init __mapin_ram_chunk(unsigned long offset, unsigned long top) 309 { 310 unsigned long v, s, f; 311 phys_addr_t p; 312 int ktext; 313 314 s = offset; 315 v = PAGE_OFFSET + s; 316 p = memstart_addr + s; 317 for (; s < top; s += PAGE_SIZE) { 318 ktext = ((char *) v >= _stext && (char *) v < etext); 319 f = ktext ? PAGE_KERNEL_TEXT : PAGE_KERNEL; 320 map_page(v, p, f); 321 #ifdef CONFIG_PPC_STD_MMU_32 322 if (ktext) 323 hash_preload(&init_mm, v, 0, 0x300); 324 #endif 325 v += PAGE_SIZE; 326 p += PAGE_SIZE; 327 } 328 } 329 330 void __init mapin_ram(void) 331 { 332 unsigned long s, top; 333 334 #ifndef CONFIG_WII 335 top = total_lowmem; 336 s = mmu_mapin_ram(top); 337 __mapin_ram_chunk(s, top); 338 #else 339 if (!wii_hole_size) { 340 s = mmu_mapin_ram(total_lowmem); 341 __mapin_ram_chunk(s, total_lowmem); 342 } else { 343 top = wii_hole_start; 344 s = mmu_mapin_ram(top); 345 __mapin_ram_chunk(s, top); 346 347 top = memblock_end_of_DRAM(); 348 s = wii_mmu_mapin_mem2(top); 349 __mapin_ram_chunk(s, top); 350 } 351 #endif 352 } 353 354 /* Scan the real Linux page tables and return a PTE pointer for 355 * a virtual address in a context. 356 * Returns true (1) if PTE was found, zero otherwise. The pointer to 357 * the PTE pointer is unmodified if PTE is not found. 358 */ 359 int 360 get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp) 361 { 362 pgd_t *pgd; 363 pud_t *pud; 364 pmd_t *pmd; 365 pte_t *pte; 366 int retval = 0; 367 368 pgd = pgd_offset(mm, addr & PAGE_MASK); 369 if (pgd) { 370 pud = pud_offset(pgd, addr & PAGE_MASK); 371 if (pud && pud_present(*pud)) { 372 pmd = pmd_offset(pud, addr & PAGE_MASK); 373 if (pmd_present(*pmd)) { 374 pte = pte_offset_map(pmd, addr & PAGE_MASK); 375 if (pte) { 376 retval = 1; 377 *ptep = pte; 378 if (pmdp) 379 *pmdp = pmd; 380 /* XXX caller needs to do pte_unmap, yuck */ 381 } 382 } 383 } 384 } 385 return(retval); 386 } 387 388 #ifdef CONFIG_DEBUG_PAGEALLOC 389 390 static int __change_page_attr(struct page *page, pgprot_t prot) 391 { 392 pte_t *kpte; 393 pmd_t *kpmd; 394 unsigned long address; 395 396 BUG_ON(PageHighMem(page)); 397 address = (unsigned long)page_address(page); 398 399 if (v_mapped_by_bats(address) || v_mapped_by_tlbcam(address)) 400 return 0; 401 if (!get_pteptr(&init_mm, address, &kpte, &kpmd)) 402 return -EINVAL; 403 __set_pte_at(&init_mm, address, kpte, mk_pte(page, prot), 0); 404 wmb(); 405 flush_tlb_page(NULL, address); 406 pte_unmap(kpte); 407 408 return 0; 409 } 410 411 /* 412 * Change the page attributes of an page in the linear mapping. 413 * 414 * THIS CONFLICTS WITH BAT MAPPINGS, DEBUG USE ONLY 415 */ 416 static int change_page_attr(struct page *page, int numpages, pgprot_t prot) 417 { 418 int i, err = 0; 419 unsigned long flags; 420 421 local_irq_save(flags); 422 for (i = 0; i < numpages; i++, page++) { 423 err = __change_page_attr(page, prot); 424 if (err) 425 break; 426 } 427 local_irq_restore(flags); 428 return err; 429 } 430 431 432 void kernel_map_pages(struct page *page, int numpages, int enable) 433 { 434 if (PageHighMem(page)) 435 return; 436 437 change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0)); 438 } 439 #endif /* CONFIG_DEBUG_PAGEALLOC */ 440 441 static int fixmaps; 442 443 void __set_fixmap (enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags) 444 { 445 unsigned long address = __fix_to_virt(idx); 446 447 if (idx >= __end_of_fixed_addresses) { 448 BUG(); 449 return; 450 } 451 452 map_page(address, phys, pgprot_val(flags)); 453 fixmaps++; 454 } 455 456 void __this_fixmap_does_not_exist(void) 457 { 458 WARN_ON(1); 459 } 460