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/pgtable.h>
  44 #include <asm/pgalloc.h>
  45 #include <asm/tlb.h>
  46 #include <asm/fixmap.h>
  47
  48 /*
  49  * We have up to 8 empty zeroed pages so we can map one of the right colour
  50  * when needed.  This is necessary only on R4000 / R4400 SC and MC versions
  51  * where we have to avoid VCED / VECI exceptions for good performance at
  52  * any price.  Since page is never written to after the initialization we
  53  * don't have to care about aliases on other CPUs.
  54  */
  55 unsigned long empty_zero_page, zero_page_mask;
  56 EXPORT_SYMBOL_GPL(empty_zero_page);
  57 EXPORT_SYMBOL(zero_page_mask);
  58
  59 /*
  60  * Not static inline because used by IP27 special magic initialization code
  61  */
  62 void setup_zero_pages(void)
  63 {
  64         unsigned int order, i;
  65         struct page *page;
  66
  67         if (cpu_has_vce)
  68                 order = 3;
  69         else
  70                 order = 0;
  71
  72         empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
  73         if (!empty_zero_page)
  74                 panic("Oh boy, that early out of memory?");
  75
  76         page = virt_to_page((void *)empty_zero_page);
  77         split_page(page, order);
  78         for (i = 0; i < (1 << order); i++, page++)
  79                 mark_page_reserved(page);
  80
  81         zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
  82 }
  83
  84 static void *__kmap_pgprot(struct page *page, unsigned long addr, pgprot_t prot)
  85 {
  86         enum fixed_addresses idx;
  87         unsigned int uninitialized_var(old_mmid);
  88         unsigned long vaddr, flags, entrylo;
  89         unsigned long old_ctx;
  90         pte_t pte;
  91         int tlbidx;
  92
  93         BUG_ON(Page_dcache_dirty(page));
  94
  95         preempt_disable();
  96         pagefault_disable();
  97         idx = (addr >> PAGE_SHIFT) & (FIX_N_COLOURS - 1);
  98         idx += in_interrupt() ? FIX_N_COLOURS : 0;
  99         vaddr = __fix_to_virt(FIX_CMAP_END - idx);
 100         pte = mk_pte(page, prot);
 101 #if defined(CONFIG_XPA)
 102         entrylo = pte_to_entrylo(pte.pte_high);
 103 #elif defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
 104         entrylo = pte.pte_high;
 105 #else
 106         entrylo = pte_to_entrylo(pte_val(pte));
 107 #endif
 108
 109         local_irq_save(flags);
 110         old_ctx = read_c0_entryhi();
 111         write_c0_entryhi(vaddr & (PAGE_MASK << 1));
 112         write_c0_entrylo0(entrylo);
 113         write_c0_entrylo1(entrylo);
 114         if (cpu_has_mmid) {
 115                 old_mmid = read_c0_memorymapid();
 116                 write_c0_memorymapid(MMID_KERNEL_WIRED);
 117         }
 118 #ifdef CONFIG_XPA
 119         if (cpu_has_xpa) {
 120                 entrylo = (pte.pte_low & _PFNX_MASK);
 121                 writex_c0_entrylo0(entrylo);
 122                 writex_c0_entrylo1(entrylo);
 123         }
 124 #endif
 125         tlbidx = num_wired_entries();
 126         write_c0_wired(tlbidx + 1);
 127         write_c0_index(tlbidx);
 128         mtc0_tlbw_hazard();
 129         tlb_write_indexed();
 130         tlbw_use_hazard();
 131         write_c0_entryhi(old_ctx);
 132         if (cpu_has_mmid)
 133                 write_c0_memorymapid(old_mmid);
 134         local_irq_restore(flags);
 135
 136         return (void*) vaddr;
 137 }
 138
 139 void *kmap_coherent(struct page *page, unsigned long addr)
 140 {
 141         return __kmap_pgprot(page, addr, PAGE_KERNEL);
 142 }
 143
 144 void *kmap_noncoherent(struct page *page, unsigned long addr)
 145 {
 146         return __kmap_pgprot(page, addr, PAGE_KERNEL_NC);
 147 }
 148
 149 void kunmap_coherent(void)
 150 {
 151         unsigned int wired;
 152         unsigned long flags, old_ctx;
 153
 154         local_irq_save(flags);
 155         old_ctx = read_c0_entryhi();
 156         wired = num_wired_entries() - 1;
 157         write_c0_wired(wired);
 158         write_c0_index(wired);
 159         write_c0_entryhi(UNIQUE_ENTRYHI(wired));
 160         write_c0_entrylo0(0);
 161         write_c0_entrylo1(0);
 162         mtc0_tlbw_hazard();
 163         tlb_write_indexed();
 164         tlbw_use_hazard();
 165         write_c0_entryhi(old_ctx);
 166         local_irq_restore(flags);
 167         pagefault_enable();
 168         preempt_enable();
 169 }
 170
 171 void copy_user_highpage(struct page *to, struct page *from,
 172         unsigned long vaddr, struct vm_area_struct *vma)
 173 {
 174         void *vfrom, *vto;
 175
 176         vto = kmap_atomic(to);
 177         if (cpu_has_dc_aliases &&
 178             page_mapcount(from) && !Page_dcache_dirty(from)) {
 179                 vfrom = kmap_coherent(from, vaddr);
 180                 copy_page(vto, vfrom);
 181                 kunmap_coherent();
 182         } else {
 183                 vfrom = kmap_atomic(from);
 184                 copy_page(vto, vfrom);
 185                 kunmap_atomic(vfrom);
 186         }
 187         if ((!cpu_has_ic_fills_f_dc) ||
 188             pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK))
 189                 flush_data_cache_page((unsigned long)vto);
 190         kunmap_atomic(vto);
 191         /* Make sure this page is cleared on other CPU's too before using it */
 192         smp_wmb();
 193 }
 194
 195 void copy_to_user_page(struct vm_area_struct *vma,
 196         struct page *page, unsigned long vaddr, void *dst, const void *src,
 197         unsigned long len)
 198 {
 199         if (cpu_has_dc_aliases &&
 200             page_mapcount(page) && !Page_dcache_dirty(page)) {
 201                 void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 202                 memcpy(vto, src, len);
 203                 kunmap_coherent();
 204         } else {
 205                 memcpy(dst, src, len);
 206                 if (cpu_has_dc_aliases)
 207                         SetPageDcacheDirty(page);
 208         }
 209         if (vma->vm_flags & VM_EXEC)
 210                 flush_cache_page(vma, vaddr, page_to_pfn(page));
 211 }
 212
 213 void copy_from_user_page(struct vm_area_struct *vma,
 214         struct page *page, unsigned long vaddr, void *dst, const void *src,
 215         unsigned long len)
 216 {
 217         if (cpu_has_dc_aliases &&
 218             page_mapcount(page) && !Page_dcache_dirty(page)) {
 219                 void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 220                 memcpy(dst, vfrom, len);
 221                 kunmap_coherent();
 222         } else {
 223                 memcpy(dst, src, len);
 224                 if (cpu_has_dc_aliases)
 225                         SetPageDcacheDirty(page);
 226         }
 227 }
 228 EXPORT_SYMBOL_GPL(copy_from_user_page);
 229
 230 void __init fixrange_init(unsigned long start, unsigned long end,
 231         pgd_t *pgd_base)
 232 {
 233 #ifdef CONFIG_HIGHMEM
 234         pgd_t *pgd;
 235         pud_t *pud;
 236         pmd_t *pmd;
 237         pte_t *pte;
 238         int i, j, k;
 239         unsigned long vaddr;
 240
 241         vaddr = start;
 242         i = pgd_index(vaddr);
 243         j = pud_index(vaddr);
 244         k = pmd_index(vaddr);
 245         pgd = pgd_base + i;
 246
 247         for ( ; (i < PTRS_PER_PGD) && (vaddr < end); pgd++, i++) {
 248                 pud = (pud_t *)pgd;
 249                 for ( ; (j < PTRS_PER_PUD) && (vaddr < end); pud++, j++) {
 250                         pmd = (pmd_t *)pud;
 251                         for (; (k < PTRS_PER_PMD) && (vaddr < end); pmd++, k++) {
 252                                 if (pmd_none(*pmd)) {
 253                                         pte = (pte_t *) memblock_alloc_low(PAGE_SIZE,
 254                                                                            PAGE_SIZE);
 255                                         if (!pte)
 256                                                 panic("%s: Failed to allocate %lu bytes align=%lx\n",
 257                                                       __func__, PAGE_SIZE,
 258                                                       PAGE_SIZE);
 259
 260                                         set_pmd(pmd, __pmd((unsigned long)pte));
 261                                         BUG_ON(pte != pte_offset_kernel(pmd, 0));
 262                                 }
 263                                 vaddr += PMD_SIZE;
 264                         }
 265                         k = 0;
 266                 }
 267                 j = 0;
 268         }
 269 #endif
 270 }
 271
 272 struct maar_walk_info {
 273         struct maar_config cfg[16];
 274         unsigned int num_cfg;
 275 };
 276
 277 static int maar_res_walk(unsigned long start_pfn, unsigned long nr_pages,
 278                          void *data)
 279 {
 280         struct maar_walk_info *wi = data;
 281         struct maar_config *cfg = &wi->cfg[wi->num_cfg];
 282         unsigned int maar_align;
 283
 284         /* MAAR registers hold physical addresses right shifted by 4 bits */
 285         maar_align = BIT(MIPS_MAAR_ADDR_SHIFT + 4);
 286
 287         /* Fill in the MAAR config entry */
 288         cfg->lower = ALIGN(PFN_PHYS(start_pfn), maar_align);
 289         cfg->upper = ALIGN_DOWN(PFN_PHYS(start_pfn + nr_pages), maar_align) - 1;
 290         cfg->attrs = MIPS_MAAR_S;
 291
 292         /* Ensure we don't overflow the cfg array */
 293         if (!WARN_ON(wi->num_cfg >= ARRAY_SIZE(wi->cfg)))
 294                 wi->num_cfg++;
 295
 296         return 0;
 297 }
 298
 299
 300 unsigned __weak platform_maar_init(unsigned num_pairs)
 301 {
 302         unsigned int num_configured;
 303         struct maar_walk_info wi;
 304
 305         wi.num_cfg = 0;
 306         walk_system_ram_range(0, max_pfn, &wi, maar_res_walk);
 307
 308         num_configured = maar_config(wi.cfg, wi.num_cfg, num_pairs);
 309         if (num_configured < wi.num_cfg)
 310                 pr_warn("Not enough MAAR pairs (%u) for all memory regions (%u)\n",
 311                         num_pairs, wi.num_cfg);
 312
 313         return num_configured;
 314 }
 315
 316 void maar_init(void)
 317 {
 318         unsigned num_maars, used, i;
 319         phys_addr_t lower, upper, attr;
 320         static struct {
 321                 struct maar_config cfgs[3];
 322                 unsigned used;
 323         } recorded = { { { 0 } }, 0 };
 324
 325         if (!cpu_has_maar)
 326                 return;
 327
 328         /* Detect the number of MAARs */
 329         write_c0_maari(~0);
 330         back_to_back_c0_hazard();
 331         num_maars = read_c0_maari() + 1;
 332
 333         /* MAARs should be in pairs */
 334         WARN_ON(num_maars % 2);
 335
 336         /* Set MAARs using values we recorded already */
 337         if (recorded.used) {
 338                 used = maar_config(recorded.cfgs, recorded.used, num_maars / 2);
 339                 BUG_ON(used != recorded.used);
 340         } else {
 341                 /* Configure the required MAARs */
 342                 used = platform_maar_init(num_maars / 2);
 343         }
 344
 345         /* Disable any further MAARs */
 346         for (i = (used * 2); i < num_maars; i++) {
 347                 write_c0_maari(i);
 348                 back_to_back_c0_hazard();
 349                 write_c0_maar(0);
 350                 back_to_back_c0_hazard();
 351         }
 352
 353         if (recorded.used)
 354                 return;
 355
 356         pr_info("MAAR configuration:\n");
 357         for (i = 0; i < num_maars; i += 2) {
 358                 write_c0_maari(i);
 359                 back_to_back_c0_hazard();
 360                 upper = read_c0_maar();
 361
 362                 write_c0_maari(i + 1);
 363                 back_to_back_c0_hazard();
 364                 lower = read_c0_maar();
 365
 366                 attr = lower & upper;
 367                 lower = (lower & MIPS_MAAR_ADDR) << 4;
 368                 upper = ((upper & MIPS_MAAR_ADDR) << 4) | 0xffff;
 369
 370                 pr_info("  [%d]: ", i / 2);
 371                 if (!(attr & MIPS_MAAR_VL)) {
 372                         pr_cont("disabled\n");
 373                         continue;
 374                 }
 375
 376                 pr_cont("%pa-%pa", &lower, &upper);
 377
 378                 if (attr & MIPS_MAAR_S)
 379                         pr_cont(" speculate");
 380
 381                 pr_cont("\n");
 382
 383                 /* Record the setup for use on secondary CPUs */
 384                 if (used <= ARRAY_SIZE(recorded.cfgs)) {
 385                         recorded.cfgs[recorded.used].lower = lower;
 386                         recorded.cfgs[recorded.used].upper = upper;
 387                         recorded.cfgs[recorded.used].attrs = attr;
 388                         recorded.used++;
 389                 }
 390         }
 391 }
 392
 393 #ifndef CONFIG_NEED_MULTIPLE_NODES
 394 void __init paging_init(void)
 395 {
 396         unsigned long max_zone_pfns[MAX_NR_ZONES];
 397
 398         pagetable_init();
 399
 400 #ifdef CONFIG_HIGHMEM
 401         kmap_init();
 402 #endif
 403 #ifdef CONFIG_ZONE_DMA
 404         max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
 405 #endif
 406 #ifdef CONFIG_ZONE_DMA32
 407         max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
 408 #endif
 409         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 410 #ifdef CONFIG_HIGHMEM
 411         max_zone_pfns[ZONE_HIGHMEM] = highend_pfn;
 412
 413         if (cpu_has_dc_aliases && max_low_pfn != highend_pfn) {
 414                 printk(KERN_WARNING "This processor doesn't support highmem."
 415                        " %ldk highmem ignored\n",
 416                        (highend_pfn - max_low_pfn) << (PAGE_SHIFT - 10));
 417                 max_zone_pfns[ZONE_HIGHMEM] = max_low_pfn;
 418         }
 419 #endif
 420
 421         free_area_init_nodes(max_zone_pfns);
 422 }
 423
 424 #ifdef CONFIG_64BIT
 425 static struct kcore_list kcore_kseg0;
 426 #endif
 427
 428 static inline void __init mem_init_free_highmem(void)
 429 {
 430 #ifdef CONFIG_HIGHMEM
 431         unsigned long tmp;
 432
 433         if (cpu_has_dc_aliases)
 434                 return;
 435
 436         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
 437                 struct page *page = pfn_to_page(tmp);
 438
 439                 if (!memblock_is_memory(PFN_PHYS(tmp)))
 440                         SetPageReserved(page);
 441                 else
 442                         free_highmem_page(page);
 443         }
 444 #endif
 445 }
 446
 447 void __init mem_init(void)
 448 {
 449         /*
 450          * When _PFN_SHIFT is greater than PAGE_SHIFT we won't have enough PTE
 451          * bits to hold a full 32b physical address on MIPS32 systems.
 452          */
 453         BUILD_BUG_ON(IS_ENABLED(CONFIG_32BIT) && (_PFN_SHIFT > PAGE_SHIFT));
 454
 455 #ifdef CONFIG_HIGHMEM
 456 #ifdef CONFIG_DISCONTIGMEM
 457 #error "CONFIG_HIGHMEM and CONFIG_DISCONTIGMEM dont work together yet"
 458 #endif
 459         max_mapnr = highend_pfn ? highend_pfn : max_low_pfn;
 460 #else
 461         max_mapnr = max_low_pfn;
 462 #endif
 463         high_memory = (void *) __va(max_low_pfn << 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);