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/config.h> 24 #include <linux/kernel.h> 25 #include <linux/module.h> 26 #include <linux/types.h> 27 #include <linux/mm.h> 28 #include <linux/vmalloc.h> 29 #include <linux/init.h> 30 #include <linux/highmem.h> 31 32 #include <asm/pgtable.h> 33 #include <asm/pgalloc.h> 34 #include <asm/io.h> 35 36 #include "mmu_decl.h" 37 38 unsigned long ioremap_base; 39 unsigned long ioremap_bot; 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 } 156 157 void __iomem * 158 ioremap(phys_addr_t addr, unsigned long size) 159 { 160 phys_addr_t addr64 = fixup_bigphys_addr(addr, size); 161 162 return ioremap64(addr64, size); 163 } 164 #endif /* CONFIG_PHYS_64BIT */ 165 166 void __iomem * 167 __ioremap(phys_addr_t addr, unsigned long size, unsigned long flags) 168 { 169 unsigned long v, i; 170 phys_addr_t p; 171 int err; 172 173 /* 174 * Choose an address to map it to. 175 * Once the vmalloc system is running, we use it. 176 * Before then, we use space going down from ioremap_base 177 * (ioremap_bot records where we're up to). 178 */ 179 p = addr & PAGE_MASK; 180 size = PAGE_ALIGN(addr + size) - p; 181 182 /* 183 * If the address lies within the first 16 MB, assume it's in ISA 184 * memory space 185 */ 186 if (p < 16*1024*1024) 187 p += _ISA_MEM_BASE; 188 189 /* 190 * Don't allow anybody to remap normal RAM that we're using. 191 * mem_init() sets high_memory so only do the check after that. 192 */ 193 if (mem_init_done && (p < virt_to_phys(high_memory))) { 194 printk("__ioremap(): phys addr "PHYS_FMT" is RAM lr %p\n", p, 195 __builtin_return_address(0)); 196 return NULL; 197 } 198 199 if (size == 0) 200 return NULL; 201 202 /* 203 * Is it already mapped? Perhaps overlapped by a previous 204 * BAT mapping. If the whole area is mapped then we're done, 205 * otherwise remap it since we want to keep the virt addrs for 206 * each request contiguous. 207 * 208 * We make the assumption here that if the bottom and top 209 * of the range we want are mapped then it's mapped to the 210 * same virt address (and this is contiguous). 211 * -- Cort 212 */ 213 if ((v = p_mapped_by_bats(p)) /*&& p_mapped_by_bats(p+size-1)*/ ) 214 goto out; 215 216 if ((v = p_mapped_by_tlbcam(p))) 217 goto out; 218 219 if (mem_init_done) { 220 struct vm_struct *area; 221 area = get_vm_area(size, VM_IOREMAP); 222 if (area == 0) 223 return NULL; 224 v = (unsigned long) area->addr; 225 } else { 226 v = (ioremap_bot -= size); 227 } 228 229 if ((flags & _PAGE_PRESENT) == 0) 230 flags |= _PAGE_KERNEL; 231 if (flags & _PAGE_NO_CACHE) 232 flags |= _PAGE_GUARDED; 233 234 /* 235 * Should check if it is a candidate for a BAT mapping 236 */ 237 238 err = 0; 239 for (i = 0; i < size && err == 0; i += PAGE_SIZE) 240 err = map_page(v+i, p+i, flags); 241 if (err) { 242 if (mem_init_done) 243 vunmap((void *)v); 244 return NULL; 245 } 246 247 out: 248 return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK)); 249 } 250 251 void iounmap(volatile void __iomem *addr) 252 { 253 /* 254 * If mapped by BATs then there is nothing to do. 255 * Calling vfree() generates a benign warning. 256 */ 257 if (v_mapped_by_bats((unsigned long)addr)) return; 258 259 if (addr > high_memory && (unsigned long) addr < ioremap_bot) 260 vunmap((void *) (PAGE_MASK & (unsigned long)addr)); 261 } 262 263 void __iomem *ioport_map(unsigned long port, unsigned int len) 264 { 265 return (void __iomem *) (port + _IO_BASE); 266 } 267 268 void ioport_unmap(void __iomem *addr) 269 { 270 /* Nothing to do */ 271 } 272 EXPORT_SYMBOL(ioport_map); 273 EXPORT_SYMBOL(ioport_unmap); 274 275 int 276 map_page(unsigned long va, phys_addr_t pa, int flags) 277 { 278 pmd_t *pd; 279 pte_t *pg; 280 int err = -ENOMEM; 281 282 /* Use upper 10 bits of VA to index the first level map */ 283 pd = pmd_offset(pgd_offset_k(va), va); 284 /* Use middle 10 bits of VA to index the second-level map */ 285 pg = pte_alloc_kernel(pd, va); 286 if (pg != 0) { 287 err = 0; 288 set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, __pgprot(flags))); 289 if (mem_init_done) 290 flush_HPTE(0, va, pmd_val(*pd)); 291 } 292 return err; 293 } 294 295 /* 296 * Map in all of physical memory starting at KERNELBASE. 297 */ 298 void __init mapin_ram(void) 299 { 300 unsigned long v, p, s, f; 301 302 s = mmu_mapin_ram(); 303 v = KERNELBASE + s; 304 p = PPC_MEMSTART + s; 305 for (; s < total_lowmem; s += PAGE_SIZE) { 306 if ((char *) v >= _stext && (char *) v < etext) 307 f = _PAGE_RAM_TEXT; 308 else 309 f = _PAGE_RAM; 310 map_page(v, p, f); 311 v += PAGE_SIZE; 312 p += PAGE_SIZE; 313 } 314 } 315 316 /* is x a power of 2? */ 317 #define is_power_of_2(x) ((x) != 0 && (((x) & ((x) - 1)) == 0)) 318 319 /* is x a power of 4? */ 320 #define is_power_of_4(x) ((x) != 0 && (((x) & (x-1)) == 0) && (ffs(x) & 1)) 321 322 /* 323 * Set up a mapping for a block of I/O. 324 * virt, phys, size must all be page-aligned. 325 * This should only be called before ioremap is called. 326 */ 327 void __init io_block_mapping(unsigned long virt, phys_addr_t phys, 328 unsigned int size, int flags) 329 { 330 int i; 331 332 if (virt > KERNELBASE && virt < ioremap_bot) 333 ioremap_bot = ioremap_base = virt; 334 335 #ifdef HAVE_BATS 336 /* 337 * Use a BAT for this if possible... 338 */ 339 if (io_bat_index < 2 && is_power_of_2(size) 340 && (virt & (size - 1)) == 0 && (phys & (size - 1)) == 0) { 341 setbat(io_bat_index, virt, phys, size, flags); 342 ++io_bat_index; 343 return; 344 } 345 #endif /* HAVE_BATS */ 346 347 #ifdef HAVE_TLBCAM 348 /* 349 * Use a CAM for this if possible... 350 */ 351 if (tlbcam_index < num_tlbcam_entries && is_power_of_4(size) 352 && (virt & (size - 1)) == 0 && (phys & (size - 1)) == 0) { 353 settlbcam(tlbcam_index, virt, phys, size, flags, 0); 354 ++tlbcam_index; 355 return; 356 } 357 #endif /* HAVE_TLBCAM */ 358 359 /* No BATs available, put it in the page tables. */ 360 for (i = 0; i < size; i += PAGE_SIZE) 361 map_page(virt + i, phys + i, flags); 362 } 363 364 /* Scan the real Linux page tables and return a PTE pointer for 365 * a virtual address in a context. 366 * Returns true (1) if PTE was found, zero otherwise. The pointer to 367 * the PTE pointer is unmodified if PTE is not found. 368 */ 369 int 370 get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep) 371 { 372 pgd_t *pgd; 373 pmd_t *pmd; 374 pte_t *pte; 375 int retval = 0; 376 377 pgd = pgd_offset(mm, addr & PAGE_MASK); 378 if (pgd) { 379 pmd = pmd_offset(pgd, addr & PAGE_MASK); 380 if (pmd_present(*pmd)) { 381 pte = pte_offset_map(pmd, addr & PAGE_MASK); 382 if (pte) { 383 retval = 1; 384 *ptep = pte; 385 /* XXX caller needs to do pte_unmap, yuck */ 386 } 387 } 388 } 389 return(retval); 390 } 391 392 /* Find physical address for this virtual address. Normally used by 393 * I/O functions, but anyone can call it. 394 */ 395 unsigned long iopa(unsigned long addr) 396 { 397 unsigned long pa; 398 399 /* I don't know why this won't work on PMacs or CHRP. It 400 * appears there is some bug, or there is some implicit 401 * mapping done not properly represented by BATs or in page 402 * tables.......I am actively working on resolving this, but 403 * can't hold up other stuff. -- Dan 404 */ 405 pte_t *pte; 406 struct mm_struct *mm; 407 408 /* Check the BATs */ 409 pa = v_mapped_by_bats(addr); 410 if (pa) 411 return pa; 412 413 /* Allow mapping of user addresses (within the thread) 414 * for DMA if necessary. 415 */ 416 if (addr < TASK_SIZE) 417 mm = current->mm; 418 else 419 mm = &init_mm; 420 421 pa = 0; 422 if (get_pteptr(mm, addr, &pte)) { 423 pa = (pte_val(*pte) & PAGE_MASK) | (addr & ~PAGE_MASK); 424 pte_unmap(pte); 425 } 426 427 return(pa); 428 } 429 430 /* This is will find the virtual address for a physical one.... 431 * Swiped from APUS, could be dangerous :-). 432 * This is only a placeholder until I really find a way to make this 433 * work. -- Dan 434 */ 435 unsigned long 436 mm_ptov (unsigned long paddr) 437 { 438 unsigned long ret; 439 #if 0 440 if (paddr < 16*1024*1024) 441 ret = ZTWO_VADDR(paddr); 442 else { 443 int i; 444 445 for (i = 0; i < kmap_chunk_count;){ 446 unsigned long phys = kmap_chunks[i++]; 447 unsigned long size = kmap_chunks[i++]; 448 unsigned long virt = kmap_chunks[i++]; 449 if (paddr >= phys 450 && paddr < (phys + size)){ 451 ret = virt + paddr - phys; 452 goto exit; 453 } 454 } 455 456 ret = (unsigned long) __va(paddr); 457 } 458 exit: 459 #ifdef DEBUGPV 460 printk ("PTOV(%lx)=%lx\n", paddr, ret); 461 #endif 462 #else 463 ret = (unsigned long)paddr + KERNELBASE; 464 #endif 465 return ret; 466 } 467 468