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 30 #include <asm/pgtable.h> 31 #include <asm/pgalloc.h> 32 #include <asm/io.h> 33 34 #include "mmu_decl.h" 35 36 unsigned long ioremap_base; 37 unsigned long ioremap_bot; 38 EXPORT_SYMBOL(ioremap_bot); /* aka VMALLOC_END */ 39 40 #if defined(CONFIG_6xx) || defined(CONFIG_POWER3) 41 #define HAVE_BATS 1 42 #endif 43 44 #if defined(CONFIG_FSL_BOOKE) 45 #define HAVE_TLBCAM 1 46 #endif 47 48 extern char etext[], _stext[]; 49 50 #ifdef CONFIG_SMP 51 extern void hash_page_sync(void); 52 #endif 53 54 #ifdef HAVE_BATS 55 extern unsigned long v_mapped_by_bats(unsigned long va); 56 extern unsigned long p_mapped_by_bats(unsigned long pa); 57 void setbat(int index, unsigned long virt, unsigned long 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 unsigned long v_mapped_by_tlbcam(unsigned long va); 68 extern unsigned long p_mapped_by_tlbcam(unsigned long 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 #ifdef CONFIG_PTE_64BIT 75 /* 44x uses an 8kB pgdir because it has 8-byte Linux PTEs. */ 76 #define PGDIR_ORDER 1 77 #else 78 #define PGDIR_ORDER 0 79 #endif 80 81 pgd_t *pgd_alloc(struct mm_struct *mm) 82 { 83 pgd_t *ret; 84 85 ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, PGDIR_ORDER); 86 return ret; 87 } 88 89 void pgd_free(struct mm_struct *mm, pgd_t *pgd) 90 { 91 free_pages((unsigned long)pgd, PGDIR_ORDER); 92 } 93 94 __init_refok pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) 95 { 96 pte_t *pte; 97 extern int mem_init_done; 98 extern void *early_get_page(void); 99 100 if (mem_init_done) { 101 pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); 102 } else { 103 pte = (pte_t *)early_get_page(); 104 if (pte) 105 clear_page(pte); 106 } 107 return pte; 108 } 109 110 pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address) 111 { 112 struct page *ptepage; 113 114 #ifdef CONFIG_HIGHPTE 115 gfp_t flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_REPEAT | __GFP_ZERO; 116 #else 117 gfp_t flags = GFP_KERNEL | __GFP_REPEAT | __GFP_ZERO; 118 #endif 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 pte_free_kernel(struct mm_struct *mm, pte_t *pte) 128 { 129 #ifdef CONFIG_SMP 130 hash_page_sync(); 131 #endif 132 free_page((unsigned long)pte); 133 } 134 135 void pte_free(struct mm_struct *mm, pgtable_t ptepage) 136 { 137 #ifdef CONFIG_SMP 138 hash_page_sync(); 139 #endif 140 pgtable_page_dtor(ptepage); 141 __free_page(ptepage); 142 } 143 144 void __iomem * 145 ioremap(phys_addr_t addr, unsigned long size) 146 { 147 return __ioremap(addr, size, _PAGE_NO_CACHE); 148 } 149 EXPORT_SYMBOL(ioremap); 150 151 void __iomem * 152 ioremap_flags(phys_addr_t addr, unsigned long size, unsigned long flags) 153 { 154 return __ioremap(addr, size, flags); 155 } 156 EXPORT_SYMBOL(ioremap_flags); 157 158 void __iomem * 159 __ioremap(phys_addr_t addr, unsigned long size, unsigned long flags) 160 { 161 unsigned long v, i; 162 phys_addr_t p; 163 int err; 164 165 /* 166 * Choose an address to map it to. 167 * Once the vmalloc system is running, we use it. 168 * Before then, we use space going down from ioremap_base 169 * (ioremap_bot records where we're up to). 170 */ 171 p = addr & PAGE_MASK; 172 size = PAGE_ALIGN(addr + size) - p; 173 174 /* 175 * If the address lies within the first 16 MB, assume it's in ISA 176 * memory space 177 */ 178 if (p < 16*1024*1024) 179 p += _ISA_MEM_BASE; 180 181 /* 182 * Don't allow anybody to remap normal RAM that we're using. 183 * mem_init() sets high_memory so only do the check after that. 184 */ 185 if (mem_init_done && (p < virt_to_phys(high_memory))) { 186 printk("__ioremap(): phys addr 0x%llx is RAM lr %p\n", 187 (unsigned long long)p, __builtin_return_address(0)); 188 return NULL; 189 } 190 191 if (size == 0) 192 return NULL; 193 194 /* 195 * Is it already mapped? Perhaps overlapped by a previous 196 * BAT mapping. If the whole area is mapped then we're done, 197 * otherwise remap it since we want to keep the virt addrs for 198 * each request contiguous. 199 * 200 * We make the assumption here that if the bottom and top 201 * of the range we want are mapped then it's mapped to the 202 * same virt address (and this is contiguous). 203 * -- Cort 204 */ 205 if ((v = p_mapped_by_bats(p)) /*&& p_mapped_by_bats(p+size-1)*/ ) 206 goto out; 207 208 if ((v = p_mapped_by_tlbcam(p))) 209 goto out; 210 211 if (mem_init_done) { 212 struct vm_struct *area; 213 area = get_vm_area(size, VM_IOREMAP); 214 if (area == 0) 215 return NULL; 216 v = (unsigned long) area->addr; 217 } else { 218 v = (ioremap_bot -= size); 219 } 220 221 if ((flags & _PAGE_PRESENT) == 0) 222 flags |= _PAGE_KERNEL; 223 if (flags & _PAGE_NO_CACHE) 224 flags |= _PAGE_GUARDED; 225 226 /* 227 * Should check if it is a candidate for a BAT mapping 228 */ 229 230 err = 0; 231 for (i = 0; i < size && err == 0; i += PAGE_SIZE) 232 err = map_page(v+i, p+i, flags); 233 if (err) { 234 if (mem_init_done) 235 vunmap((void *)v); 236 return NULL; 237 } 238 239 out: 240 return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK)); 241 } 242 EXPORT_SYMBOL(__ioremap); 243 244 void iounmap(volatile void __iomem *addr) 245 { 246 /* 247 * If mapped by BATs then there is nothing to do. 248 * Calling vfree() generates a benign warning. 249 */ 250 if (v_mapped_by_bats((unsigned long)addr)) return; 251 252 if (addr > high_memory && (unsigned long) addr < ioremap_bot) 253 vunmap((void *) (PAGE_MASK & (unsigned long)addr)); 254 } 255 EXPORT_SYMBOL(iounmap); 256 257 int map_page(unsigned long va, phys_addr_t pa, int flags) 258 { 259 pmd_t *pd; 260 pte_t *pg; 261 int err = -ENOMEM; 262 263 /* Use upper 10 bits of VA to index the first level map */ 264 pd = pmd_offset(pud_offset(pgd_offset_k(va), va), va); 265 /* Use middle 10 bits of VA to index the second-level map */ 266 pg = pte_alloc_kernel(pd, va); 267 if (pg != 0) { 268 err = 0; 269 /* The PTE should never be already set nor present in the 270 * hash table 271 */ 272 BUG_ON(pte_val(*pg) & (_PAGE_PRESENT | _PAGE_HASHPTE)); 273 set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, 274 __pgprot(flags))); 275 } 276 return err; 277 } 278 279 /* 280 * Map in all of physical memory starting at KERNELBASE. 281 */ 282 void __init mapin_ram(void) 283 { 284 unsigned long v, p, s, f; 285 int ktext; 286 287 s = mmu_mapin_ram(); 288 v = KERNELBASE + s; 289 p = PPC_MEMSTART + s; 290 for (; s < total_lowmem; s += PAGE_SIZE) { 291 ktext = ((char *) v >= _stext && (char *) v < etext); 292 f = ktext ?_PAGE_RAM_TEXT : _PAGE_RAM; 293 map_page(v, p, f); 294 #ifdef CONFIG_PPC_STD_MMU_32 295 if (ktext) 296 hash_preload(&init_mm, v, 0, 0x300); 297 #endif 298 v += PAGE_SIZE; 299 p += PAGE_SIZE; 300 } 301 } 302 303 /* Scan the real Linux page tables and return a PTE pointer for 304 * a virtual address in a context. 305 * Returns true (1) if PTE was found, zero otherwise. The pointer to 306 * the PTE pointer is unmodified if PTE is not found. 307 */ 308 int 309 get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp) 310 { 311 pgd_t *pgd; 312 pud_t *pud; 313 pmd_t *pmd; 314 pte_t *pte; 315 int retval = 0; 316 317 pgd = pgd_offset(mm, addr & PAGE_MASK); 318 if (pgd) { 319 pud = pud_offset(pgd, addr & PAGE_MASK); 320 if (pud && pud_present(*pud)) { 321 pmd = pmd_offset(pud, addr & PAGE_MASK); 322 if (pmd_present(*pmd)) { 323 pte = pte_offset_map(pmd, addr & PAGE_MASK); 324 if (pte) { 325 retval = 1; 326 *ptep = pte; 327 if (pmdp) 328 *pmdp = pmd; 329 /* XXX caller needs to do pte_unmap, yuck */ 330 } 331 } 332 } 333 } 334 return(retval); 335 } 336 337 #ifdef CONFIG_DEBUG_PAGEALLOC 338 339 static int __change_page_attr(struct page *page, pgprot_t prot) 340 { 341 pte_t *kpte; 342 pmd_t *kpmd; 343 unsigned long address; 344 345 BUG_ON(PageHighMem(page)); 346 address = (unsigned long)page_address(page); 347 348 if (v_mapped_by_bats(address) || v_mapped_by_tlbcam(address)) 349 return 0; 350 if (!get_pteptr(&init_mm, address, &kpte, &kpmd)) 351 return -EINVAL; 352 set_pte_at(&init_mm, address, kpte, mk_pte(page, prot)); 353 wmb(); 354 flush_HPTE(0, address, pmd_val(*kpmd)); 355 pte_unmap(kpte); 356 357 return 0; 358 } 359 360 /* 361 * Change the page attributes of an page in the linear mapping. 362 * 363 * THIS CONFLICTS WITH BAT MAPPINGS, DEBUG USE ONLY 364 */ 365 static int change_page_attr(struct page *page, int numpages, pgprot_t prot) 366 { 367 int i, err = 0; 368 unsigned long flags; 369 370 local_irq_save(flags); 371 for (i = 0; i < numpages; i++, page++) { 372 err = __change_page_attr(page, prot); 373 if (err) 374 break; 375 } 376 local_irq_restore(flags); 377 return err; 378 } 379 380 381 void kernel_map_pages(struct page *page, int numpages, int enable) 382 { 383 if (PageHighMem(page)) 384 return; 385 386 change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0)); 387 } 388 #endif /* CONFIG_DEBUG_PAGEALLOC */ 389