arch/mips/mm/init.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 1994 - 2000 Ralf Baechle
   7  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
   8  * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
   9  * Copyright (C) 2000 MIPS Technologies, Inc.  All rights reserved.
  10  */
  11 #include <linux/bug.h>
  12 #include <linux/init.h>
  13 #include <linux/export.h>
  14 #include <linux/signal.h>
  15 #include <linux/sched.h>
  16 #include <linux/smp.h>
  17 #include <linux/kernel.h>
  18 #include <linux/errno.h>
  19 #include <linux/string.h>
  20 #include <linux/types.h>
  21 #include <linux/pagemap.h>
  22 #include <linux/ptrace.h>
  23 #include <linux/mman.h>
  24 #include <linux/mm.h>
  25 #include <linux/memblock.h>
  26 #include <linux/highmem.h>
  27 #include <linux/swap.h>
  28 #include <linux/proc_fs.h>
  29 #include <linux/pfn.h>
  30 #include <linux/hardirq.h>
  31 #include <linux/gfp.h>
  32 #include <linux/kcore.h>
  33 #include <linux/initrd.h>
  34
  35 #include <asm/bootinfo.h>
  36 #include <asm/cachectl.h>
  37 #include <asm/cpu.h>
  38 #include <asm/dma.h>
  39 #include <asm/kmap_types.h>
  40 #include <asm/maar.h>
  41 #include <asm/mmu_context.h>
  42 #include <asm/sections.h>
  43 #include <asm/pgalloc.h>
  44 #include <asm/tlb.h>
  45 #include <asm/fixmap.h>
  46
  47 /*
  48  * We have up to 8 empty zeroed pages so we can map one of the right colour
  49  * when needed.  This is necessary only on R4000 / R4400 SC and MC versions
  50  * where we have to avoid VCED / VECI exceptions for good performance at
  51  * any price.  Since page is never written to after the initialization we
  52  * don't have to care about aliases on other CPUs.
  53  */
  54 unsigned long empty_zero_page, zero_page_mask;
  55 EXPORT_SYMBOL_GPL(empty_zero_page);
  56 EXPORT_SYMBOL(zero_page_mask);
  57
  58 /*
  59  * Not static inline because used by IP27 special magic initialization code
  60  */
  61 void setup_zero_pages(void)
  62 {
  63         unsigned int order, i;
  64         struct page *page;
  65
  66         if (cpu_has_vce)
  67                 order = 3;
  68         else
  69                 order = 0;
  70
  71         empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
  72         if (!empty_zero_page)
  73                 panic("Oh boy, that early out of memory?");
  74
  75         page = virt_to_page((void *)empty_zero_page);
  76         split_page(page, order);
  77         for (i = 0; i < (1 << order); i++, page++)
  78                 mark_page_reserved(page);
  79
  80         zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
  81 }
  82
  83 static void *__kmap_pgprot(struct page *page, unsigned long addr, pgprot_t prot)
  84 {
  85         enum fixed_addresses idx;
  86         unsigned int old_mmid;
  87         unsigned long vaddr, flags, entrylo;
  88         unsigned long old_ctx;
  89         pte_t pte;
  90         int tlbidx;
  91
  92         BUG_ON(Page_dcache_dirty(page));
  93
  94         preempt_disable();
  95         pagefault_disable();
  96         idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
  97         idx += in_interrupt() ? FIX_N_COLOURS : 0;
  98         vaddr = __fix_to_virt(FIX_CMAP_END - idx);
  99         pte = mk_pte(page, prot);
 100 #if defined(CONFIG_XPA)
 101         entrylo = pte_to_entrylo(pte.pte_high);
 102 #elif defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
 103         entrylo = pte.pte_high;
 104 #else
 105         entrylo = pte_to_entrylo(pte_val(pte));
 106 #endif
 107
 108         local_irq_save(flags);
 109         old_ctx = read_c0_entryhi();
 110         write_c0_entryhi(vaddr & (PAGE_MASK << 1));
 111         write_c0_entrylo0(entrylo);
 112         write_c0_entrylo1(entrylo);
 113         if (cpu_has_mmid) {
 114                 old_mmid = read_c0_memorymapid();
 115                 write_c0_memorymapid(MMID_KERNEL_WIRED);
 116         }
 117 #ifdef CONFIG_XPA
 118         if (cpu_has_xpa) {
 119                 entrylo = (pte.pte_low & _PFNX_MASK);
 120                 writex_c0_entrylo0(entrylo);
 121                 writex_c0_entrylo1(entrylo);
 122         }
 123 #endif
 124         tlbidx = num_wired_entries();
 125         write_c0_wired(tlbidx + 1);
 126         write_c0_index(tlbidx);
 127         mtc0_tlbw_hazard();
 128         tlb_write_indexed();
 129         tlbw_use_hazard();
 130         write_c0_entryhi(old_ctx);
 131         if (cpu_has_mmid)
 132                 write_c0_memorymapid(old_mmid);
 133         local_irq_restore(flags);
 134
 135         return (void*) vaddr;
 136 }
 137
 138 void *kmap_coherent(struct page *page, unsigned long addr)
 139 {
 140         return __kmap_pgprot(page, addr, PAGE_KERNEL);
 141 }
 142
 143 void *kmap_noncoherent(struct page *page, unsigned long addr)
 144 {
 145         return __kmap_pgprot(page, addr, PAGE_KERNEL_NC);
 146 }
 147
 148 void kunmap_coherent(void)
 149 {
 150         unsigned int wired;
 151         unsigned long flags, old_ctx;
 152
 153         local_irq_save(flags);
 154         old_ctx = read_c0_entryhi();
 155         wired = num_wired_entries() - 1;
 156         write_c0_wired(wired);
 157         write_c0_index(wired);
 158         write_c0_entryhi(UNIQUE_ENTRYHI(wired));
 159         write_c0_entrylo0(0);
 160         write_c0_entrylo1(0);
 161         mtc0_tlbw_hazard();
 162         tlb_write_indexed();
 163         tlbw_use_hazard();
 164         write_c0_entryhi(old_ctx);
 165         local_irq_restore(flags);
 166         pagefault_enable();
 167         preempt_enable();
 168 }
 169
 170 void copy_user_highpage(struct page *to, struct page *from,
 171         unsigned long vaddr, struct vm_area_struct *vma)
 172 {
 173         void *vfrom, *vto;
 174
 175         vto = kmap_atomic(to);
 176         if (cpu_has_dc_aliases &&
 177             page_mapcount(from) && !Page_dcache_dirty(from)) {
 178                 vfrom = kmap_coherent(from, vaddr);
 179                 copy_page(vto, vfrom);
 180                 kunmap_coherent();
 181         } else {
 182                 vfrom = kmap_atomic(from);
 183                 copy_page(vto, vfrom);
 184                 kunmap_atomic(vfrom);
 185         }
 186         if ((!cpu_has_ic_fills_f_dc) ||
 187             pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
 188                 flush_data_cache_page((unsigned long)vto);
 189         kunmap_atomic(vto);
 190         /* Make sure this page is cleared on other CPU's too before using it */
 191         smp_wmb();
 192 }
 193
 194 void copy_to_user_page(struct vm_area_struct *vma,
 195         struct page *page, unsigned long vaddr, void *dst, const void *src,
 196         unsigned long len)
 197 {
 198         if (cpu_has_dc_aliases &&
 199             page_mapcount(page) && !Page_dcache_dirty(page)) {
 200                 void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 201                 memcpy(vto, src, len);
 202                 kunmap_coherent();
 203         } else {
 204                 memcpy(dst, src, len);
 205                 if (cpu_has_dc_aliases)
 206                         SetPageDcacheDirty(page);
 207         }
 208         if (vma->vm_flags & VM_EXEC)
 209                 flush_cache_page(vma, vaddr, page_to_pfn(page));
 210 }
 211
 212 void copy_from_user_page(struct vm_area_struct *vma,
 213         struct page *page, unsigned long vaddr, void *dst, const void *src,
 214         unsigned long len)
 215 {
 216         if (cpu_has_dc_aliases &&
 217             page_mapcount(page) && !Page_dcache_dirty(page)) {
 218                 void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 219                 memcpy(dst, vfrom, len);
 220                 kunmap_coherent();
 221         } else {
 222                 memcpy(dst, src, len);
 223                 if (cpu_has_dc_aliases)
 224                         SetPageDcacheDirty(page);
 225         }
 226 }
 227 EXPORT_SYMBOL_GPL(copy_from_user_page);
 228
 229 void __init fixrange_init(unsigned long start, unsigned long end,
 230         pgd_t *pgd_base)
 231 {
 232 #ifdef CONFIG_HIGHMEM
 233         pgd_t *pgd;
 234         pud_t *pud;
 235         pmd_t *pmd;
 236         pte_t *pte;
 237         int i, j, k;
 238         unsigned long vaddr;
 239
 240         vaddr = start;
 241         i = pgd_index(vaddr);
 242         j = pud_index(vaddr);
 243         k = pmd_index(vaddr);
 244         pgd = pgd_base + i;
 245
 246         for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
 247                 pud = (pud_t *)pgd;
 248                 for ( ; (j < PTRS_PER_PUD) && (vaddr < end); pud++, j++) {
 249                         pmd = (pmd_t *)pud;
 250                         for (; (k < PTRS_PER_PMD) && (vaddr < end); pmd++, k++) {
 251                                 if (pmd_none(*pmd)) {
 252                                         pte = (pte_t *) memblock_alloc_low(PAGE_SIZE,
 253                                                                            PAGE_SIZE);
 254                                         if (!pte)
 255                                                 panic("%s: Failed to allocate %lu bytes align=%lx\n",
 256                                                       __func__, PAGE_SIZE,
 257                                                       PAGE_SIZE);
 258
 259                                         set_pmd(pmd, __pmd((unsigned long)pte));
 260                                         BUG_ON(pte != pte_offset_kernel(pmd, 0));
 261                                 }
 262                                 vaddr += PMD_SIZE;
 263                         }
 264                         k = 0;
 265                 }
 266                 j = 0;
 267         }
 268 #endif
 269 }
 270
 271 struct maar_walk_info {
 272         struct maar_config cfg[16];
 273         unsigned int num_cfg;
 274 };
 275
 276 static int maar_res_walk(unsigned long start_pfn, unsigned long nr_pages,
 277                          void *data)
 278 {
 279         struct maar_walk_info *wi = data;
 280         struct maar_config *cfg = &wi->cfg[wi->num_cfg];
 281         unsigned int maar_align;
 282
 283         /* MAAR registers hold physical addresses right shifted by 4 bits */
 284         maar_align = BIT(MIPS_MAAR_ADDR_SHIFT + 4);
 285
 286         /* Fill in the MAAR config entry */
 287         cfg->lower = ALIGN(PFN_PHYS(start_pfn), maar_align);
 288         cfg->upper = ALIGN_DOWN(PFN_PHYS(start_pfn + nr_pages), maar_align) - 1;
 289         cfg->attrs = MIPS_MAAR_S;
 290
 291         /* Ensure we don't overflow the cfg array */
 292         if (!WARN_ON(wi->num_cfg >= ARRAY_SIZE(wi->cfg)))
 293                 wi->num_cfg++;
 294
 295         return 0;
 296 }
 297
 298
 299 unsigned __weak platform_maar_init(unsigned num_pairs)
 300 {
 301         unsigned int num_configured;
 302         struct maar_walk_info wi;
 303
 304         wi.num_cfg = 0;
 305         walk_system_ram_range(0, max_pfn, &wi, maar_res_walk);
 306
 307         num_configured = maar_config(wi.cfg, wi.num_cfg, num_pairs);
 308         if (num_configured < wi.num_cfg)
 309                 pr_warn("Not enough MAAR pairs (%u) for all memory regions (%u)\n",
 310                         num_pairs, wi.num_cfg);
 311
 312         return num_configured;
 313 }
 314
 315 void maar_init(void)
 316 {
 317         unsigned num_maars, used, i;
 318         phys_addr_t lower, upper, attr;
 319         static struct {
 320                 struct maar_config cfgs[3];
 321                 unsigned used;
 322         } recorded = { { { 0 } }, 0 };
 323
 324         if (!cpu_has_maar)
 325                 return;
 326
 327         /* Detect the number of MAARs */
 328         write_c0_maari(~0);
 329         back_to_back_c0_hazard();
 330         num_maars = read_c0_maari() + 1;
 331
 332         /* MAARs should be in pairs */
 333         WARN_ON(num_maars % 2);
 334
 335         /* Set MAARs using values we recorded already */
 336         if (recorded.used) {
 337                 used = maar_config(recorded.cfgs, recorded.used, num_maars / 2);
 338                 BUG_ON(used != recorded.used);
 339         } else {
 340                 /* Configure the required MAARs */
 341                 used = platform_maar_init(num_maars / 2);
 342         }
 343
 344         /* Disable any further MAARs */
 345         for (i = (used * 2); i < num_maars; i++) {
 346                 write_c0_maari(i);
 347                 back_to_back_c0_hazard();
 348                 write_c0_maar(0);
 349                 back_to_back_c0_hazard();
 350         }
 351
 352         if (recorded.used)
 353                 return;
 354
 355         pr_info("MAAR configuration:\n");
 356         for (i = 0; i < num_maars; i += 2) {
 357                 write_c0_maari(i);
 358                 back_to_back_c0_hazard();
 359                 upper = read_c0_maar();
 360 #ifdef CONFIG_XPA
 361                 upper |= (phys_addr_t)readx_c0_maar() << MIPS_MAARX_ADDR_SHIFT;
 362 #endif
 363
 364                 write_c0_maari(i + 1);
 365                 back_to_back_c0_hazard();
 366                 lower = read_c0_maar();
 367 #ifdef CONFIG_XPA
 368                 lower |= (phys_addr_t)readx_c0_maar() << MIPS_MAARX_ADDR_SHIFT;
 369 #endif
 370
 371                 attr = lower & upper;
 372                 lower = (lower & MIPS_MAAR_ADDR) << 4;
 373                 upper = ((upper & MIPS_MAAR_ADDR) << 4) | 0xffff;
 374
 375                 pr_info("  [%d]: ", i / 2);
 376                 if ((attr & MIPS_MAAR_V) != MIPS_MAAR_V) {
 377                         pr_cont("disabled\n");
 378                         continue;
 379                 }
 380
 381                 pr_cont("%pa-%pa", &lower, &upper);
 382
 383                 if (attr & MIPS_MAAR_S)
 384                         pr_cont(" speculate");
 385
 386                 pr_cont("\n");
 387
 388                 /* Record the setup for use on secondary CPUs */
 389                 if (used <= ARRAY_SIZE(recorded.cfgs)) {
 390                         recorded.cfgs[recorded.used].lower = lower;
 391                         recorded.cfgs[recorded.used].upper = upper;
 392                         recorded.cfgs[recorded.used].attrs = attr;
 393                         recorded.used++;
 394                 }
 395         }
 396 }
 397
 398 #ifndef CONFIG_NEED_MULTIPLE_NODES
 399 void __init paging_init(void)
 400 {
 401         unsigned long max_zone_pfns[MAX_NR_ZONES];
 402
 403         pagetable_init();
 404
 405 #ifdef CONFIG_HIGHMEM
 406         kmap_init();
 407 #endif
 408 #ifdef CONFIG_ZONE_DMA
 409         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
 410 #endif
 411 #ifdef CONFIG_ZONE_DMA32
 412         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
 413 #endif
 414         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 415 #ifdef CONFIG_HIGHMEM
 416         max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
 417
 418         if (cpu_has_dc_aliases && max_low_pfn != highend_pfn) {
 419                 printk(KERN_WARNING "This processor doesn't support highmem."
 420                        " %ldk highmem ignored\n",
 421                        (highend_pfn - max_low_pfn) << (PAGE_SHIFT - 10));
 422                 max_zone_pfns[ZONE_HIGHMEM] = max_low_pfn;
 423         }
 424
 425         max_mapnr = highend_pfn ? highend_pfn : max_low_pfn;
 426 #else
 427         max_mapnr = max_low_pfn;
 428 #endif
 429         high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
 430
 431         free_area_init(max_zone_pfns);
 432 }
 433
 434 #ifdef CONFIG_64BIT
 435 static struct kcore_list kcore_kseg0;
 436 #endif
 437
 438 static inline void __init mem_init_free_highmem(void)
 439 {
 440 #ifdef CONFIG_HIGHMEM
 441         unsigned long tmp;
 442
 443         if (cpu_has_dc_aliases)
 444                 return;
 445
 446         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
 447                 struct page *page = pfn_to_page(tmp);
 448
 449                 if (!memblock_is_memory(PFN_PHYS(tmp)))
 450                         SetPageReserved(page);
 451                 else
 452                         free_highmem_page(page);
 453         }
 454 #endif
 455 }
 456
 457 void __init mem_init(void)
 458 {
 459         /*
 460          * When _PFN_SHIFT is greater than PAGE_SHIFT we won't have enough PTE
 461          * bits to hold a full 32b physical address on MIPS32 systems.
 462          */
 463         BUILD_BUG_ON(IS_ENABLED(CONFIG_32BIT) && (_PFN_SHIFT > PAGE_SHIFT));
 464
 465         maar_init();
 466         memblock_free_all();
 467         setup_zero_pages();     /* Setup zeroed pages.  */
 468         mem_init_free_highmem();
 469         mem_init_print_info(NULL);
 470
 471 #ifdef CONFIG_64BIT
 472         if ((unsigned long) &_text > (unsigned long) CKSEG0)
 473                 /* The -4 is a hack so that user tools don't have to handle
 474                    the overflow.  */
 475                 kclist_add(&kcore_kseg0, (void *) CKSEG0,
 476                                 0x80000000 - 4, KCORE_TEXT);
 477 #endif
 478 }
 479 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
 480
 481 void free_init_pages(const char *what, unsigned long begin, unsigned long end)
 482 {
 483         unsigned long pfn;
 484
 485         for (pfn = PFN_UP(begin); pfn < PFN_DOWN(end); pfn++) {
 486                 struct page *page = pfn_to_page(pfn);
 487                 void *addr = phys_to_virt(PFN_PHYS(pfn));
 488
 489                 memset(addr, POISON_FREE_INITMEM, PAGE_SIZE);
 490                 free_reserved_page(page);
 491         }
 492         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 493 }
 494
 495 void (*free_init_pages_eva)(void *begin, void *end) = NULL;
 496
 497 void __ref free_initmem(void)
 498 {
 499         prom_free_prom_memory();
 500         /*
 501          * Let the platform define a specific function to free the
 502          * init section since EVA may have used any possible mapping
 503          * between virtual and physical addresses.
 504          */
 505         if (free_init_pages_eva)
 506                 free_init_pages_eva((void *)&__init_begin, (void *)&__init_end);
 507         else
 508                 free_initmem_default(POISON_FREE_INITMEM);
 509 }
 510
 511 #ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA
 512 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
 513 EXPORT_SYMBOL(__per_cpu_offset);
 514
 515 static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
 516 {
 517         return node_distance(cpu_to_node(from), cpu_to_node(to));
 518 }
 519
 520 static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size,
 521                                        size_t align)
 522 {
 523         return memblock_alloc_try_nid(size, align, __pa(MAX_DMA_ADDRESS),
 524                                       MEMBLOCK_ALLOC_ACCESSIBLE,
 525                                       cpu_to_node(cpu));
 526 }
 527
 528 static void __init pcpu_fc_free(void *ptr, size_t size)
 529 {
 530         memblock_free_early(__pa(ptr), size);
 531 }
 532
 533 void __init setup_per_cpu_areas(void)
 534 {
 535         unsigned long delta;
 536         unsigned int cpu;
 537         int rc;
 538
 539         /*
 540          * Always reserve area for module percpu variables.  That's
 541          * what the legacy allocator did.
 542          */
 543         rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE,
 544                                     PERCPU_DYNAMIC_RESERVE, PAGE_SIZE,
 545                                     pcpu_cpu_distance,
 546                                     pcpu_fc_alloc, pcpu_fc_free);
 547         if (rc < 0)
 548                 panic("Failed to initialize percpu areas.");
 549
 550         delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
 551         for_each_possible_cpu(cpu)
 552                 __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
 553 }
 554 #endif
 555
 556 #ifndef CONFIG_MIPS_PGD_C0_CONTEXT
 557 unsigned long pgd_current[NR_CPUS];
 558 #endif
 559
 560 /*
 561  * Align swapper_pg_dir in to 64K, allows its address to be loaded
 562  * with a single LUI instruction in the TLB handlers.  If we used
 563  * __aligned(64K), its size would get rounded up to the alignment
 564  * size, and waste space.  So we place it in its own section and align
 565  * it in the linker script.
 566  */
 567 pgd_t swapper_pg_dir[PTRS_PER_PGD] __section(".bss..swapper_pg_dir");
 568 #ifndef __PAGETABLE_PUD_FOLDED
 569 pud_t invalid_pud_table[PTRS_PER_PUD] __page_aligned_bss;
 570 #endif
 571 #ifndef __PAGETABLE_PMD_FOLDED
 572 pmd_t invalid_pmd_table[PTRS_PER_PMD] __page_aligned_bss;
 573 EXPORT_SYMBOL_GPL(invalid_pmd_table);
 574 #endif
 575 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;
 576 EXPORT_SYMBOL(invalid_pte_table);