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