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 #ifndef CONFIG_PHYS_64BIT 145 void __iomem * 146 ioremap(phys_addr_t addr, unsigned long size) 147 { 148 return __ioremap(addr, size, _PAGE_NO_CACHE); 149 } 150 #else /* CONFIG_PHYS_64BIT */ 151 void __iomem * 152 ioremap64(unsigned long long addr, unsigned long size) 153 { 154 return __ioremap(addr, size, _PAGE_NO_CACHE); 155 } 156 EXPORT_SYMBOL(ioremap64); 157 158 void __iomem * 159 ioremap(phys_addr_t addr, unsigned long size) 160 { 161 phys_addr_t addr64 = fixup_bigphys_addr(addr, size); 162 163 return ioremap64(addr64, size); 164 } 165 #endif /* CONFIG_PHYS_64BIT */ 166 EXPORT_SYMBOL(ioremap); 167 168 void __iomem * 169 __ioremap(phys_addr_t addr, unsigned long size, unsigned long flags) 170 { 171 unsigned long v, i; 172 phys_addr_t p; 173 int err; 174 175 /* 176 * Choose an address to map it to. 177 * Once the vmalloc system is running, we use it. 178 * Before then, we use space going down from ioremap_base 179 * (ioremap_bot records where we're up to). 180 */ 181 p = addr & PAGE_MASK; 182 size = PAGE_ALIGN(addr + size) - p; 183 184 /* 185 * If the address lies within the first 16 MB, assume it's in ISA 186 * memory space 187 */ 188 if (p < 16*1024*1024) 189 p += _ISA_MEM_BASE; 190 191 /* 192 * Don't allow anybody to remap normal RAM that we're using. 193 * mem_init() sets high_memory so only do the check after that. 194 */ 195 if (mem_init_done && (p < virt_to_phys(high_memory))) { 196 printk("__ioremap(): phys addr "PHYS_FMT" is RAM lr %p\n", p, 197 __builtin_return_address(0)); 198 return NULL; 199 } 200 201 if (size == 0) 202 return NULL; 203 204 /* 205 * Is it already mapped? Perhaps overlapped by a previous 206 * BAT mapping. If the whole area is mapped then we're done, 207 * otherwise remap it since we want to keep the virt addrs for 208 * each request contiguous. 209 * 210 * We make the assumption here that if the bottom and top 211 * of the range we want are mapped then it's mapped to the 212 * same virt address (and this is contiguous). 213 * -- Cort 214 */ 215 if ((v = p_mapped_by_bats(p)) /*&& p_mapped_by_bats(p+size-1)*/ ) 216 goto out; 217 218 if ((v = p_mapped_by_tlbcam(p))) 219 goto out; 220 221 if (mem_init_done) { 222 struct vm_struct *area; 223 area = get_vm_area(size, VM_IOREMAP); 224 if (area == 0) 225 return NULL; 226 v = (unsigned long) area->addr; 227 } else { 228 v = (ioremap_bot -= size); 229 } 230 231 if ((flags & _PAGE_PRESENT) == 0) 232 flags |= _PAGE_KERNEL; 233 if (flags & _PAGE_NO_CACHE) 234 flags |= _PAGE_GUARDED; 235 236 /* 237 * Should check if it is a candidate for a BAT mapping 238 */ 239 240 err = 0; 241 for (i = 0; i < size && err == 0; i += PAGE_SIZE) 242 err = map_page(v+i, p+i, flags); 243 if (err) { 244 if (mem_init_done) 245 vunmap((void *)v); 246 return NULL; 247 } 248 249 out: 250 return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK)); 251 } 252 EXPORT_SYMBOL(__ioremap); 253 254 void iounmap(volatile void __iomem *addr) 255 { 256 /* 257 * If mapped by BATs then there is nothing to do. 258 * Calling vfree() generates a benign warning. 259 */ 260 if (v_mapped_by_bats((unsigned long)addr)) return; 261 262 if (addr > high_memory && (unsigned long) addr < ioremap_bot) 263 vunmap((void *) (PAGE_MASK & (unsigned long)addr)); 264 } 265 EXPORT_SYMBOL(iounmap); 266 267 void __iomem *ioport_map(unsigned long port, unsigned int len) 268 { 269 return (void __iomem *) (port + _IO_BASE); 270 } 271 272 void ioport_unmap(void __iomem *addr) 273 { 274 /* Nothing to do */ 275 } 276 EXPORT_SYMBOL(ioport_map); 277 EXPORT_SYMBOL(ioport_unmap); 278 279 int 280 map_page(unsigned long va, phys_addr_t pa, int flags) 281 { 282 pmd_t *pd; 283 pte_t *pg; 284 int err = -ENOMEM; 285 286 /* Use upper 10 bits of VA to index the first level map */ 287 pd = pmd_offset(pgd_offset_k(va), va); 288 /* Use middle 10 bits of VA to index the second-level map */ 289 pg = pte_alloc_kernel(pd, va); 290 if (pg != 0) { 291 err = 0; 292 set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, __pgprot(flags))); 293 if (mem_init_done) 294 flush_HPTE(0, va, pmd_val(*pd)); 295 } 296 return err; 297 } 298 299 /* 300 * Map in all of physical memory starting at KERNELBASE. 301 */ 302 void __init mapin_ram(void) 303 { 304 unsigned long v, p, s, f; 305 306 s = mmu_mapin_ram(); 307 v = KERNELBASE + s; 308 p = PPC_MEMSTART + s; 309 for (; s < total_lowmem; s += PAGE_SIZE) { 310 if ((char *) v >= _stext && (char *) v < etext) 311 f = _PAGE_RAM_TEXT; 312 else 313 f = _PAGE_RAM; 314 map_page(v, p, f); 315 v += PAGE_SIZE; 316 p += PAGE_SIZE; 317 } 318 } 319 320 /* is x a power of 2? */ 321 #define is_power_of_2(x) ((x) != 0 && (((x) & ((x) - 1)) == 0)) 322 323 /* is x a power of 4? */ 324 #define is_power_of_4(x) ((x) != 0 && (((x) & (x-1)) == 0) && (ffs(x) & 1)) 325 326 /* 327 * Set up a mapping for a block of I/O. 328 * virt, phys, size must all be page-aligned. 329 * This should only be called before ioremap is called. 330 */ 331 void __init io_block_mapping(unsigned long virt, phys_addr_t phys, 332 unsigned int size, int flags) 333 { 334 int i; 335 336 if (virt > KERNELBASE && virt < ioremap_bot) 337 ioremap_bot = ioremap_base = virt; 338 339 #ifdef HAVE_BATS 340 /* 341 * Use a BAT for this if possible... 342 */ 343 if (io_bat_index < 2 && is_power_of_2(size) 344 && (virt & (size - 1)) == 0 && (phys & (size - 1)) == 0) { 345 setbat(io_bat_index, virt, phys, size, flags); 346 ++io_bat_index; 347 return; 348 } 349 #endif /* HAVE_BATS */ 350 351 #ifdef HAVE_TLBCAM 352 /* 353 * Use a CAM for this if possible... 354 */ 355 if (tlbcam_index < num_tlbcam_entries && is_power_of_4(size) 356 && (virt & (size - 1)) == 0 && (phys & (size - 1)) == 0) { 357 settlbcam(tlbcam_index, virt, phys, size, flags, 0); 358 ++tlbcam_index; 359 return; 360 } 361 #endif /* HAVE_TLBCAM */ 362 363 /* No BATs available, put it in the page tables. */ 364 for (i = 0; i < size; i += PAGE_SIZE) 365 map_page(virt + i, phys + i, flags); 366 } 367 368 /* Scan the real Linux page tables and return a PTE pointer for 369 * a virtual address in a context. 370 * Returns true (1) if PTE was found, zero otherwise. The pointer to 371 * the PTE pointer is unmodified if PTE is not found. 372 */ 373 int 374 get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp) 375 { 376 pgd_t *pgd; 377 pmd_t *pmd; 378 pte_t *pte; 379 int retval = 0; 380 381 pgd = pgd_offset(mm, addr & PAGE_MASK); 382 if (pgd) { 383 pmd = pmd_offset(pgd, addr & PAGE_MASK); 384 if (pmd_present(*pmd)) { 385 pte = pte_offset_map(pmd, addr & PAGE_MASK); 386 if (pte) { 387 retval = 1; 388 *ptep = pte; 389 if (pmdp) 390 *pmdp = pmd; 391 /* XXX caller needs to do pte_unmap, yuck */ 392 } 393 } 394 } 395 return(retval); 396 } 397 398 /* Find physical address for this virtual address. Normally used by 399 * I/O functions, but anyone can call it. 400 */ 401 unsigned long iopa(unsigned long addr) 402 { 403 unsigned long pa; 404 405 /* I don't know why this won't work on PMacs or CHRP. It 406 * appears there is some bug, or there is some implicit 407 * mapping done not properly represented by BATs or in page 408 * tables.......I am actively working on resolving this, but 409 * can't hold up other stuff. -- Dan 410 */ 411 pte_t *pte; 412 struct mm_struct *mm; 413 414 /* Check the BATs */ 415 pa = v_mapped_by_bats(addr); 416 if (pa) 417 return pa; 418 419 /* Allow mapping of user addresses (within the thread) 420 * for DMA if necessary. 421 */ 422 if (addr < TASK_SIZE) 423 mm = current->mm; 424 else 425 mm = &init_mm; 426 427 pa = 0; 428 if (get_pteptr(mm, addr, &pte, NULL)) { 429 pa = (pte_val(*pte) & PAGE_MASK) | (addr & ~PAGE_MASK); 430 pte_unmap(pte); 431 } 432 433 return(pa); 434 } 435 436 /* This is will find the virtual address for a physical one.... 437 * Swiped from APUS, could be dangerous :-). 438 * This is only a placeholder until I really find a way to make this 439 * work. -- Dan 440 */ 441 unsigned long 442 mm_ptov (unsigned long paddr) 443 { 444 unsigned long ret; 445 #if 0 446 if (paddr < 16*1024*1024) 447 ret = ZTWO_VADDR(paddr); 448 else { 449 int i; 450 451 for (i = 0; i < kmap_chunk_count;){ 452 unsigned long phys = kmap_chunks[i++]; 453 unsigned long size = kmap_chunks[i++]; 454 unsigned long virt = kmap_chunks[i++]; 455 if (paddr >= phys 456 && paddr < (phys + size)){ 457 ret = virt + paddr - phys; 458 goto exit; 459 } 460 } 461 462 ret = (unsigned long) __va(paddr); 463 } 464 exit: 465 #ifdef DEBUGPV 466 printk ("PTOV(%lx)=%lx\n", paddr, ret); 467 #endif 468 #else 469 ret = (unsigned long)paddr + KERNELBASE; 470 #endif 471 return ret; 472 } 473 474