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 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(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 /* 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 /* is x a power of 4? */ 304 #define is_power_of_4(x) is_power_of_2(x) && (ffs(x) & 1) 305 306 /* 307 * Set up a mapping for a block of I/O. 308 * virt, phys, size must all be page-aligned. 309 * This should only be called before ioremap is called. 310 */ 311 void __init io_block_mapping(unsigned long virt, phys_addr_t phys, 312 unsigned int size, int flags) 313 { 314 int i; 315 316 if (virt > KERNELBASE && virt < ioremap_bot) 317 ioremap_bot = ioremap_base = virt; 318 319 #ifdef HAVE_BATS 320 /* 321 * Use a BAT for this if possible... 322 */ 323 if (io_bat_index < 2 && is_power_of_2(size) 324 && (virt & (size - 1)) == 0 && (phys & (size - 1)) == 0) { 325 setbat(io_bat_index, virt, phys, size, flags); 326 ++io_bat_index; 327 return; 328 } 329 #endif /* HAVE_BATS */ 330 331 #ifdef HAVE_TLBCAM 332 /* 333 * Use a CAM for this if possible... 334 */ 335 if (tlbcam_index < num_tlbcam_entries && is_power_of_4(size) 336 && (virt & (size - 1)) == 0 && (phys & (size - 1)) == 0) { 337 settlbcam(tlbcam_index, virt, phys, size, flags, 0); 338 ++tlbcam_index; 339 return; 340 } 341 #endif /* HAVE_TLBCAM */ 342 343 /* No BATs available, put it in the page tables. */ 344 for (i = 0; i < size; i += PAGE_SIZE) 345 map_page(virt + i, phys + i, flags); 346 } 347 348 /* Scan the real Linux page tables and return a PTE pointer for 349 * a virtual address in a context. 350 * Returns true (1) if PTE was found, zero otherwise. The pointer to 351 * the PTE pointer is unmodified if PTE is not found. 352 */ 353 int 354 get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp) 355 { 356 pgd_t *pgd; 357 pmd_t *pmd; 358 pte_t *pte; 359 int retval = 0; 360 361 pgd = pgd_offset(mm, addr & PAGE_MASK); 362 if (pgd) { 363 pmd = pmd_offset(pgd, 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 return(retval); 376 } 377 378 /* Find physical address for this virtual address. Normally used by 379 * I/O functions, but anyone can call it. 380 */ 381 unsigned long iopa(unsigned long addr) 382 { 383 unsigned long pa; 384 385 /* I don't know why this won't work on PMacs or CHRP. It 386 * appears there is some bug, or there is some implicit 387 * mapping done not properly represented by BATs or in page 388 * tables.......I am actively working on resolving this, but 389 * can't hold up other stuff. -- Dan 390 */ 391 pte_t *pte; 392 struct mm_struct *mm; 393 394 /* Check the BATs */ 395 pa = v_mapped_by_bats(addr); 396 if (pa) 397 return pa; 398 399 /* Allow mapping of user addresses (within the thread) 400 * for DMA if necessary. 401 */ 402 if (addr < TASK_SIZE) 403 mm = current->mm; 404 else 405 mm = &init_mm; 406 407 pa = 0; 408 if (get_pteptr(mm, addr, &pte, NULL)) { 409 pa = (pte_val(*pte) & PAGE_MASK) | (addr & ~PAGE_MASK); 410 pte_unmap(pte); 411 } 412 413 return(pa); 414 } 415 416 /* This is will find the virtual address for a physical one.... 417 * Swiped from APUS, could be dangerous :-). 418 * This is only a placeholder until I really find a way to make this 419 * work. -- Dan 420 */ 421 unsigned long 422 mm_ptov (unsigned long paddr) 423 { 424 unsigned long ret; 425 #if 0 426 if (paddr < 16*1024*1024) 427 ret = ZTWO_VADDR(paddr); 428 else { 429 int i; 430 431 for (i = 0; i < kmap_chunk_count;){ 432 unsigned long phys = kmap_chunks[i++]; 433 unsigned long size = kmap_chunks[i++]; 434 unsigned long virt = kmap_chunks[i++]; 435 if (paddr >= phys 436 && paddr < (phys + size)){ 437 ret = virt + paddr - phys; 438 goto exit; 439 } 440 } 441 442 ret = (unsigned long) __va(paddr); 443 } 444 exit: 445 #ifdef DEBUGPV 446 printk ("PTOV(%lx)=%lx\n", paddr, ret); 447 #endif 448 #else 449 ret = (unsigned long)paddr + KERNELBASE; 450 #endif 451 return ret; 452 } 453 454 #ifdef CONFIG_DEBUG_PAGEALLOC 455 456 static int __change_page_attr(struct page *page, pgprot_t prot) 457 { 458 pte_t *kpte; 459 pmd_t *kpmd; 460 unsigned long address; 461 462 BUG_ON(PageHighMem(page)); 463 address = (unsigned long)page_address(page); 464 465 if (v_mapped_by_bats(address) || v_mapped_by_tlbcam(address)) 466 return 0; 467 if (!get_pteptr(&init_mm, address, &kpte, &kpmd)) 468 return -EINVAL; 469 set_pte_at(&init_mm, address, kpte, mk_pte(page, prot)); 470 wmb(); 471 flush_HPTE(0, address, pmd_val(*kpmd)); 472 pte_unmap(kpte); 473 474 return 0; 475 } 476 477 /* 478 * Change the page attributes of an page in the linear mapping. 479 * 480 * THIS CONFLICTS WITH BAT MAPPINGS, DEBUG USE ONLY 481 */ 482 static int change_page_attr(struct page *page, int numpages, pgprot_t prot) 483 { 484 int i, err = 0; 485 unsigned long flags; 486 487 local_irq_save(flags); 488 for (i = 0; i < numpages; i++, page++) { 489 err = __change_page_attr(page, prot); 490 if (err) 491 break; 492 } 493 local_irq_restore(flags); 494 return err; 495 } 496 497 498 void kernel_map_pages(struct page *page, int numpages, int enable) 499 { 500 if (PageHighMem(page)) 501 return; 502 503 change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0)); 504 } 505 #endif /* CONFIG_DEBUG_PAGEALLOC */ 506