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(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 struct page *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; 116 #else 117 gfp_t flags = GFP_KERNEL | __GFP_REPEAT; 118 #endif 119 120 ptepage = alloc_pages(flags, 0); 121 if (ptepage) 122 clear_highpage(ptepage); 123 return ptepage; 124 } 125 126 void pte_free_kernel(pte_t *pte) 127 { 128 #ifdef CONFIG_SMP 129 hash_page_sync(); 130 #endif 131 free_page((unsigned long)pte); 132 } 133 134 void pte_free(struct page *ptepage) 135 { 136 #ifdef CONFIG_SMP 137 hash_page_sync(); 138 #endif 139 __free_page(ptepage); 140 } 141 142 void __iomem * 143 ioremap(phys_addr_t addr, unsigned long size) 144 { 145 return __ioremap(addr, size, _PAGE_NO_CACHE); 146 } 147 EXPORT_SYMBOL(ioremap); 148 149 void __iomem * 150 ioremap_flags(phys_addr_t addr, unsigned long size, unsigned long flags) 151 { 152 return __ioremap(addr, size, flags); 153 } 154 EXPORT_SYMBOL(ioremap_flags); 155 156 void __iomem * 157 __ioremap(phys_addr_t addr, unsigned long size, unsigned long flags) 158 { 159 unsigned long v, i; 160 phys_addr_t p; 161 int err; 162 163 /* 164 * Choose an address to map it to. 165 * Once the vmalloc system is running, we use it. 166 * Before then, we use space going down from ioremap_base 167 * (ioremap_bot records where we're up to). 168 */ 169 p = addr & PAGE_MASK; 170 size = PAGE_ALIGN(addr + size) - p; 171 172 /* 173 * If the address lies within the first 16 MB, assume it's in ISA 174 * memory space 175 */ 176 if (p < 16*1024*1024) 177 p += _ISA_MEM_BASE; 178 179 /* 180 * Don't allow anybody to remap normal RAM that we're using. 181 * mem_init() sets high_memory so only do the check after that. 182 */ 183 if (mem_init_done && (p < virt_to_phys(high_memory))) { 184 printk("__ioremap(): phys addr 0x%llx is RAM lr %p\n", 185 (unsigned long long)p, __builtin_return_address(0)); 186 return NULL; 187 } 188 189 if (size == 0) 190 return NULL; 191 192 /* 193 * Is it already mapped? Perhaps overlapped by a previous 194 * BAT mapping. If the whole area is mapped then we're done, 195 * otherwise remap it since we want to keep the virt addrs for 196 * each request contiguous. 197 * 198 * We make the assumption here that if the bottom and top 199 * of the range we want are mapped then it's mapped to the 200 * same virt address (and this is contiguous). 201 * -- Cort 202 */ 203 if ((v = p_mapped_by_bats(p)) /*&& p_mapped_by_bats(p+size-1)*/ ) 204 goto out; 205 206 if ((v = p_mapped_by_tlbcam(p))) 207 goto out; 208 209 if (mem_init_done) { 210 struct vm_struct *area; 211 area = get_vm_area(size, VM_IOREMAP); 212 if (area == 0) 213 return NULL; 214 v = (unsigned long) area->addr; 215 } else { 216 v = (ioremap_bot -= size); 217 } 218 219 if ((flags & _PAGE_PRESENT) == 0) 220 flags |= _PAGE_KERNEL; 221 if (flags & _PAGE_NO_CACHE) 222 flags |= _PAGE_GUARDED; 223 224 /* 225 * Should check if it is a candidate for a BAT mapping 226 */ 227 228 err = 0; 229 for (i = 0; i < size && err == 0; i += PAGE_SIZE) 230 err = map_page(v+i, p+i, flags); 231 if (err) { 232 if (mem_init_done) 233 vunmap((void *)v); 234 return NULL; 235 } 236 237 out: 238 return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK)); 239 } 240 EXPORT_SYMBOL(__ioremap); 241 242 void iounmap(volatile void __iomem *addr) 243 { 244 /* 245 * If mapped by BATs then there is nothing to do. 246 * Calling vfree() generates a benign warning. 247 */ 248 if (v_mapped_by_bats((unsigned long)addr)) return; 249 250 if (addr > high_memory && (unsigned long) addr < ioremap_bot) 251 vunmap((void *) (PAGE_MASK & (unsigned long)addr)); 252 } 253 EXPORT_SYMBOL(iounmap); 254 255 int map_page(unsigned long va, phys_addr_t pa, int flags) 256 { 257 pmd_t *pd; 258 pte_t *pg; 259 int err = -ENOMEM; 260 261 /* Use upper 10 bits of VA to index the first level map */ 262 pd = pmd_offset(pud_offset(pgd_offset_k(va), va), va); 263 /* Use middle 10 bits of VA to index the second-level map */ 264 pg = pte_alloc_kernel(pd, va); 265 if (pg != 0) { 266 err = 0; 267 /* The PTE should never be already set nor present in the 268 * hash table 269 */ 270 BUG_ON(pte_val(*pg) & (_PAGE_PRESENT | _PAGE_HASHPTE)); 271 set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, 272 __pgprot(flags))); 273 } 274 return err; 275 } 276 277 /* 278 * Map in all of physical memory starting at KERNELBASE. 279 */ 280 void __init mapin_ram(void) 281 { 282 unsigned long v, p, s, f; 283 int ktext; 284 285 s = mmu_mapin_ram(); 286 v = KERNELBASE + s; 287 p = PPC_MEMSTART + s; 288 for (; s < total_lowmem; s += PAGE_SIZE) { 289 ktext = ((char *) v >= _stext && (char *) v < etext); 290 f = ktext ?_PAGE_RAM_TEXT : _PAGE_RAM; 291 map_page(v, p, f); 292 #ifdef CONFIG_PPC_STD_MMU_32 293 if (ktext) 294 hash_preload(&init_mm, v, 0, 0x300); 295 #endif 296 v += PAGE_SIZE; 297 p += PAGE_SIZE; 298 } 299 } 300 301 /* Scan the real Linux page tables and return a PTE pointer for 302 * a virtual address in a context. 303 * Returns true (1) if PTE was found, zero otherwise. The pointer to 304 * the PTE pointer is unmodified if PTE is not found. 305 */ 306 int 307 get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp) 308 { 309 pgd_t *pgd; 310 pud_t *pud; 311 pmd_t *pmd; 312 pte_t *pte; 313 int retval = 0; 314 315 pgd = pgd_offset(mm, addr & PAGE_MASK); 316 if (pgd) { 317 pud = pud_offset(pgd, addr & PAGE_MASK); 318 if (pud && pud_present(*pud)) { 319 pmd = pmd_offset(pud, addr & PAGE_MASK); 320 if (pmd_present(*pmd)) { 321 pte = pte_offset_map(pmd, addr & PAGE_MASK); 322 if (pte) { 323 retval = 1; 324 *ptep = pte; 325 if (pmdp) 326 *pmdp = pmd; 327 /* XXX caller needs to do pte_unmap, yuck */ 328 } 329 } 330 } 331 } 332 return(retval); 333 } 334 335 #ifdef CONFIG_DEBUG_PAGEALLOC 336 337 static int __change_page_attr(struct page *page, pgprot_t prot) 338 { 339 pte_t *kpte; 340 pmd_t *kpmd; 341 unsigned long address; 342 343 BUG_ON(PageHighMem(page)); 344 address = (unsigned long)page_address(page); 345 346 if (v_mapped_by_bats(address) || v_mapped_by_tlbcam(address)) 347 return 0; 348 if (!get_pteptr(&init_mm, address, &kpte, &kpmd)) 349 return -EINVAL; 350 set_pte_at(&init_mm, address, kpte, mk_pte(page, prot)); 351 wmb(); 352 flush_HPTE(0, address, pmd_val(*kpmd)); 353 pte_unmap(kpte); 354 355 return 0; 356 } 357 358 /* 359 * Change the page attributes of an page in the linear mapping. 360 * 361 * THIS CONFLICTS WITH BAT MAPPINGS, DEBUG USE ONLY 362 */ 363 static int change_page_attr(struct page *page, int numpages, pgprot_t prot) 364 { 365 int i, err = 0; 366 unsigned long flags; 367 368 local_irq_save(flags); 369 for (i = 0; i < numpages; i++, page++) { 370 err = __change_page_attr(page, prot); 371 if (err) 372 break; 373 } 374 local_irq_restore(flags); 375 return err; 376 } 377 378 379 void kernel_map_pages(struct page *page, int numpages, int enable) 380 { 381 if (PageHighMem(page)) 382 return; 383 384 change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0)); 385 } 386 #endif /* CONFIG_DEBUG_PAGEALLOC */ 387