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 * Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk). 12 * 13 * Derived from "arch/i386/mm/init.c" 14 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds 15 * 16 * This program is free software; you can redistribute it and/or 17 * modify it under the terms of the GNU General Public License 18 * as published by the Free Software Foundation; either version 19 * 2 of the License, or (at your option) any later version. 20 * 21 */ 22 23 #include <linux/kernel.h> 24 #include <linux/module.h> 25 #include <linux/types.h> 26 #include <linux/mm.h> 27 #include <linux/vmalloc.h> 28 #include <linux/init.h> 29 #include <linux/highmem.h> 30 31 #include <asm/pgtable.h> 32 #include <asm/pgalloc.h> 33 #include <asm/io.h> 34 35 #include "mmu_decl.h" 36 37 unsigned long ioremap_base; 38 unsigned long ioremap_bot; 39 EXPORT_SYMBOL(ioremap_bot); /* aka VMALLOC_END */ 40 int io_bat_index; 41 42 #if defined(CONFIG_6xx) || defined(CONFIG_POWER3) 43 #define HAVE_BATS 1 44 #endif 45 46 #if defined(CONFIG_FSL_BOOKE) 47 #define HAVE_TLBCAM 1 48 #endif 49 50 extern char etext[], _stext[]; 51 52 #ifdef CONFIG_SMP 53 extern void hash_page_sync(void); 54 #endif 55 56 #ifdef HAVE_BATS 57 extern unsigned long v_mapped_by_bats(unsigned long va); 58 extern unsigned long p_mapped_by_bats(unsigned long pa); 59 void setbat(int index, unsigned long virt, unsigned long phys, 60 unsigned int size, int flags); 61 62 #else /* !HAVE_BATS */ 63 #define v_mapped_by_bats(x) (0UL) 64 #define p_mapped_by_bats(x) (0UL) 65 #endif /* HAVE_BATS */ 66 67 #ifdef HAVE_TLBCAM 68 extern unsigned int tlbcam_index; 69 extern unsigned long v_mapped_by_tlbcam(unsigned long va); 70 extern unsigned long p_mapped_by_tlbcam(unsigned long pa); 71 #else /* !HAVE_TLBCAM */ 72 #define v_mapped_by_tlbcam(x) (0UL) 73 #define p_mapped_by_tlbcam(x) (0UL) 74 #endif /* HAVE_TLBCAM */ 75 76 #ifdef CONFIG_PTE_64BIT 77 /* 44x uses an 8kB pgdir because it has 8-byte Linux PTEs. */ 78 #define PGDIR_ORDER 1 79 #else 80 #define PGDIR_ORDER 0 81 #endif 82 83 pgd_t *pgd_alloc(struct mm_struct *mm) 84 { 85 pgd_t *ret; 86 87 ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, PGDIR_ORDER); 88 return ret; 89 } 90 91 void pgd_free(pgd_t *pgd) 92 { 93 free_pages((unsigned long)pgd, PGDIR_ORDER); 94 } 95 96 pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) 97 { 98 pte_t *pte; 99 extern int mem_init_done; 100 extern void *early_get_page(void); 101 102 if (mem_init_done) { 103 pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); 104 } else { 105 pte = (pte_t *)early_get_page(); 106 if (pte) 107 clear_page(pte); 108 } 109 return pte; 110 } 111 112 struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address) 113 { 114 struct page *ptepage; 115 116 #ifdef CONFIG_HIGHPTE 117 gfp_t flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_REPEAT; 118 #else 119 gfp_t flags = GFP_KERNEL | __GFP_REPEAT; 120 #endif 121 122 ptepage = alloc_pages(flags, 0); 123 if (ptepage) 124 clear_highpage(ptepage); 125 return ptepage; 126 } 127 128 void pte_free_kernel(pte_t *pte) 129 { 130 #ifdef CONFIG_SMP 131 hash_page_sync(); 132 #endif 133 free_page((unsigned long)pte); 134 } 135 136 void pte_free(struct page *ptepage) 137 { 138 #ifdef CONFIG_SMP 139 hash_page_sync(); 140 #endif 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 "PHYS_FMT" is RAM lr %p\n", p, 187 __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(pgd_offset_k(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 set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, __pgprot(flags))); 270 if (mem_init_done) 271 flush_HPTE(0, va, pmd_val(*pd)); 272 } 273 return err; 274 } 275 276 /* 277 * Map in all of physical memory starting at KERNELBASE. 278 */ 279 void __init mapin_ram(void) 280 { 281 unsigned long v, p, s, f; 282 283 s = mmu_mapin_ram(); 284 v = KERNELBASE + s; 285 p = PPC_MEMSTART + s; 286 for (; s < total_lowmem; s += PAGE_SIZE) { 287 if ((char *) v >= _stext && (char *) v < etext) 288 f = _PAGE_RAM_TEXT; 289 else 290 f = _PAGE_RAM; 291 map_page(v, p, f); 292 v += PAGE_SIZE; 293 p += PAGE_SIZE; 294 } 295 } 296 297 /* is x a power of 4? */ 298 #define is_power_of_4(x) is_power_of_2(x) && (ffs(x) & 1) 299 300 /* 301 * Set up a mapping for a block of I/O. 302 * virt, phys, size must all be page-aligned. 303 * This should only be called before ioremap is called. 304 */ 305 void __init io_block_mapping(unsigned long virt, phys_addr_t phys, 306 unsigned int size, int flags) 307 { 308 int i; 309 310 if (virt > KERNELBASE && virt < ioremap_bot) 311 ioremap_bot = ioremap_base = virt; 312 313 #ifdef HAVE_BATS 314 /* 315 * Use a BAT for this if possible... 316 */ 317 if (io_bat_index < 2 && is_power_of_2(size) 318 && (virt & (size - 1)) == 0 && (phys & (size - 1)) == 0) { 319 setbat(io_bat_index, virt, phys, size, flags); 320 ++io_bat_index; 321 return; 322 } 323 #endif /* HAVE_BATS */ 324 325 #ifdef HAVE_TLBCAM 326 /* 327 * Use a CAM for this if possible... 328 */ 329 if (tlbcam_index < num_tlbcam_entries && is_power_of_4(size) 330 && (virt & (size - 1)) == 0 && (phys & (size - 1)) == 0) { 331 settlbcam(tlbcam_index, virt, phys, size, flags, 0); 332 ++tlbcam_index; 333 return; 334 } 335 #endif /* HAVE_TLBCAM */ 336 337 /* No BATs available, put it in the page tables. */ 338 for (i = 0; i < size; i += PAGE_SIZE) 339 map_page(virt + i, phys + i, flags); 340 } 341 342 /* Scan the real Linux page tables and return a PTE pointer for 343 * a virtual address in a context. 344 * Returns true (1) if PTE was found, zero otherwise. The pointer to 345 * the PTE pointer is unmodified if PTE is not found. 346 */ 347 int 348 get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp) 349 { 350 pgd_t *pgd; 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 pmd = pmd_offset(pgd, addr & PAGE_MASK); 358 if (pmd_present(*pmd)) { 359 pte = pte_offset_map(pmd, addr & PAGE_MASK); 360 if (pte) { 361 retval = 1; 362 *ptep = pte; 363 if (pmdp) 364 *pmdp = pmd; 365 /* XXX caller needs to do pte_unmap, yuck */ 366 } 367 } 368 } 369 return(retval); 370 } 371 372 /* Find physical address for this virtual address. Normally used by 373 * I/O functions, but anyone can call it. 374 */ 375 unsigned long iopa(unsigned long addr) 376 { 377 unsigned long pa; 378 379 /* I don't know why this won't work on PMacs or CHRP. It 380 * appears there is some bug, or there is some implicit 381 * mapping done not properly represented by BATs or in page 382 * tables.......I am actively working on resolving this, but 383 * can't hold up other stuff. -- Dan 384 */ 385 pte_t *pte; 386 struct mm_struct *mm; 387 388 /* Check the BATs */ 389 pa = v_mapped_by_bats(addr); 390 if (pa) 391 return pa; 392 393 /* Allow mapping of user addresses (within the thread) 394 * for DMA if necessary. 395 */ 396 if (addr < TASK_SIZE) 397 mm = current->mm; 398 else 399 mm = &init_mm; 400 401 pa = 0; 402 if (get_pteptr(mm, addr, &pte, NULL)) { 403 pa = (pte_val(*pte) & PAGE_MASK) | (addr & ~PAGE_MASK); 404 pte_unmap(pte); 405 } 406 407 return(pa); 408 } 409 410 /* This is will find the virtual address for a physical one.... 411 * Swiped from APUS, could be dangerous :-). 412 * This is only a placeholder until I really find a way to make this 413 * work. -- Dan 414 */ 415 unsigned long 416 mm_ptov (unsigned long paddr) 417 { 418 unsigned long ret; 419 #if 0 420 if (paddr < 16*1024*1024) 421 ret = ZTWO_VADDR(paddr); 422 else { 423 int i; 424 425 for (i = 0; i < kmap_chunk_count;){ 426 unsigned long phys = kmap_chunks[i++]; 427 unsigned long size = kmap_chunks[i++]; 428 unsigned long virt = kmap_chunks[i++]; 429 if (paddr >= phys 430 && paddr < (phys + size)){ 431 ret = virt + paddr - phys; 432 goto exit; 433 } 434 } 435 436 ret = (unsigned long) __va(paddr); 437 } 438 exit: 439 #ifdef DEBUGPV 440 printk ("PTOV(%lx)=%lx\n", paddr, ret); 441 #endif 442 #else 443 ret = (unsigned long)paddr + KERNELBASE; 444 #endif 445 return ret; 446 } 447 448