arch/riscv/mm/init.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2012 Regents of the University of California
   4  * Copyright (C) 2019 Western Digital Corporation or its affiliates.
   5  */
   6
   7 #include <linux/init.h>
   8 #include <linux/mm.h>
   9 #include <linux/memblock.h>
  10 #include <linux/initrd.h>
  11 #include <linux/swap.h>
  12 #include <linux/sizes.h>
  13 #include <linux/of_fdt.h>
  14 #include <linux/libfdt.h>
  15 #include <linux/set_memory.h>
  16 #include <linux/dma-map-ops.h>
  17
  18 #include <asm/fixmap.h>
  19 #include <asm/tlbflush.h>
  20 #include <asm/sections.h>
  21 #include <asm/soc.h>
  22 #include <asm/io.h>
  23 #include <asm/ptdump.h>
  24
  25 #include "../kernel/head.h"
  26
  27 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
  28                                                         __page_aligned_bss;
  29 EXPORT_SYMBOL(empty_zero_page);
  30
  31 extern char _start[];
  32 #define DTB_EARLY_BASE_VA      PGDIR_SIZE
  33 void *dtb_early_va __initdata;
  34 uintptr_t dtb_early_pa __initdata;
  35
  36 struct pt_alloc_ops {
  37         pte_t *(*get_pte_virt)(phys_addr_t pa);
  38         phys_addr_t (*alloc_pte)(uintptr_t va);
  39 #ifndef __PAGETABLE_PMD_FOLDED
  40         pmd_t *(*get_pmd_virt)(phys_addr_t pa);
  41         phys_addr_t (*alloc_pmd)(uintptr_t va);
  42 #endif
  43 };
  44
  45 static phys_addr_t dma32_phys_limit __ro_after_init;
  46
  47 static void __init zone_sizes_init(void)
  48 {
  49         unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, };
  50
  51 #ifdef CONFIG_ZONE_DMA32
  52         max_zone_pfns[ZONE_DMA32] = PFN_DOWN(dma32_phys_limit);
  53 #endif
  54         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
  55
  56         free_area_init(max_zone_pfns);
  57 }
  58
  59 static void setup_zero_page(void)
  60 {
  61         memset((void *)empty_zero_page, 0, PAGE_SIZE);
  62 }
  63
  64 #if defined(CONFIG_MMU) && defined(CONFIG_DEBUG_VM)
  65 static inline void print_mlk(char *name, unsigned long b, unsigned long t)
  66 {
  67         pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld kB)\n", name, b, t,
  68                   (((t) - (b)) >> 10));
  69 }
  70
  71 static inline void print_mlm(char *name, unsigned long b, unsigned long t)
  72 {
  73         pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld MB)\n", name, b, t,
  74                   (((t) - (b)) >> 20));
  75 }
  76
  77 static void print_vm_layout(void)
  78 {
  79         pr_notice("Virtual kernel memory layout:\n");
  80         print_mlk("fixmap", (unsigned long)FIXADDR_START,
  81                   (unsigned long)FIXADDR_TOP);
  82         print_mlm("pci io", (unsigned long)PCI_IO_START,
  83                   (unsigned long)PCI_IO_END);
  84         print_mlm("vmemmap", (unsigned long)VMEMMAP_START,
  85                   (unsigned long)VMEMMAP_END);
  86         print_mlm("vmalloc", (unsigned long)VMALLOC_START,
  87                   (unsigned long)VMALLOC_END);
  88         print_mlm("lowmem", (unsigned long)PAGE_OFFSET,
  89                   (unsigned long)high_memory);
  90 }
  91 #else
  92 static void print_vm_layout(void) { }
  93 #endif /* CONFIG_DEBUG_VM */
  94
  95 void __init mem_init(void)
  96 {
  97 #ifdef CONFIG_FLATMEM
  98         BUG_ON(!mem_map);
  99 #endif /* CONFIG_FLATMEM */
 100
 101         high_memory = (void *)(__va(PFN_PHYS(max_low_pfn)));
 102         memblock_free_all();
 103
 104         mem_init_print_info(NULL);
 105         print_vm_layout();
 106 }
 107
 108 #ifdef CONFIG_BLK_DEV_INITRD
 109 static void __init setup_initrd(void)
 110 {
 111         phys_addr_t start;
 112         unsigned long size;
 113
 114         /* Ignore the virtul address computed during device tree parsing */
 115         initrd_start = initrd_end = 0;
 116
 117         if (!phys_initrd_size)
 118                 return;
 119         /*
 120          * Round the memory region to page boundaries as per free_initrd_mem()
 121          * This allows us to detect whether the pages overlapping the initrd
 122          * are in use, but more importantly, reserves the entire set of pages
 123          * as we don't want these pages allocated for other purposes.
 124          */
 125         start = round_down(phys_initrd_start, PAGE_SIZE);
 126         size = phys_initrd_size + (phys_initrd_start - start);
 127         size = round_up(size, PAGE_SIZE);
 128
 129         if (!memblock_is_region_memory(start, size)) {
 130                 pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region",
 131                        (u64)start, size);
 132                 goto disable;
 133         }
 134
 135         if (memblock_is_region_reserved(start, size)) {
 136                 pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region\n",
 137                        (u64)start, size);
 138                 goto disable;
 139         }
 140
 141         memblock_reserve(start, size);
 142         /* Now convert initrd to virtual addresses */
 143         initrd_start = (unsigned long)__va(phys_initrd_start);
 144         initrd_end = initrd_start + phys_initrd_size;
 145         initrd_below_start_ok = 1;
 146
 147         pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n",
 148                 (void *)(initrd_start), size);
 149         return;
 150 disable:
 151         pr_cont(" - disabling initrd\n");
 152         initrd_start = 0;
 153         initrd_end = 0;
 154 }
 155 #endif /* CONFIG_BLK_DEV_INITRD */
 156
 157 void __init setup_bootmem(void)
 158 {
 159         phys_addr_t mem_start = 0;
 160         phys_addr_t start, dram_end, end = 0;
 161         phys_addr_t vmlinux_end = __pa_symbol(&_end);
 162         phys_addr_t vmlinux_start = __pa_symbol(&_start);
 163         phys_addr_t max_mapped_addr = __pa(~(ulong)0);
 164         u64 i;
 165
 166         /* Find the memory region containing the kernel */
 167         for_each_mem_range(i, &start, &end) {
 168                 phys_addr_t size = end - start;
 169                 if (!mem_start)
 170                         mem_start = start;
 171                 if (start <= vmlinux_start && vmlinux_end <= end)
 172                         BUG_ON(size == 0);
 173         }
 174
 175         /*
 176          * The maximal physical memory size is -PAGE_OFFSET.
 177          * Make sure that any memory beyond mem_start + (-PAGE_OFFSET) is removed
 178          * as it is unusable by kernel.
 179          */
 180         memblock_enforce_memory_limit(-PAGE_OFFSET);
 181
 182         /* Reserve from the start of the kernel to the end of the kernel */
 183         memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
 184
 185         dram_end = memblock_end_of_DRAM();
 186
 187         /*
 188          * memblock allocator is not aware of the fact that last 4K bytes of
 189          * the addressable memory can not be mapped because of IS_ERR_VALUE
 190          * macro. Make sure that last 4k bytes are not usable by memblock
 191          * if end of dram is equal to maximum addressable memory.
 192          */
 193         if (max_mapped_addr == (dram_end - 1))
 194                 memblock_set_current_limit(max_mapped_addr - 4096);
 195
 196         max_pfn = PFN_DOWN(dram_end);
 197         max_low_pfn = max_pfn;
 198         dma32_phys_limit = min(4UL * SZ_1G, (unsigned long)PFN_PHYS(max_low_pfn));
 199         set_max_mapnr(max_low_pfn - ARCH_PFN_OFFSET);
 200
 201 #ifdef CONFIG_BLK_DEV_INITRD
 202         setup_initrd();
 203 #endif /* CONFIG_BLK_DEV_INITRD */
 204
 205         /*
 206          * Avoid using early_init_fdt_reserve_self() since __pa() does
 207          * not work for DTB pointers that are fixmap addresses
 208          */
 209         memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
 210
 211         early_init_fdt_scan_reserved_mem();
 212         dma_contiguous_reserve(dma32_phys_limit);
 213         memblock_allow_resize();
 214         memblock_dump_all();
 215 }
 216
 217 #ifdef CONFIG_MMU
 218 static struct pt_alloc_ops pt_ops;
 219
 220 unsigned long va_pa_offset;
 221 EXPORT_SYMBOL(va_pa_offset);
 222 unsigned long pfn_base;
 223 EXPORT_SYMBOL(pfn_base);
 224
 225 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
 226 pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
 227 pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
 228
 229 #define MAX_EARLY_MAPPING_SIZE  SZ_128M
 230
 231 pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
 232
 233 void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
 234 {
 235         unsigned long addr = __fix_to_virt(idx);
 236         pte_t *ptep;
 237
 238         BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
 239
 240         ptep = &fixmap_pte[pte_index(addr)];
 241
 242         if (pgprot_val(prot))
 243                 set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
 244         else
 245                 pte_clear(&init_mm, addr, ptep);
 246         local_flush_tlb_page(addr);
 247 }
 248
 249 static inline pte_t *__init get_pte_virt_early(phys_addr_t pa)
 250 {
 251         return (pte_t *)((uintptr_t)pa);
 252 }
 253
 254 static inline pte_t *__init get_pte_virt_fixmap(phys_addr_t pa)
 255 {
 256         clear_fixmap(FIX_PTE);
 257         return (pte_t *)set_fixmap_offset(FIX_PTE, pa);
 258 }
 259
 260 static inline pte_t *get_pte_virt_late(phys_addr_t pa)
 261 {
 262         return (pte_t *) __va(pa);
 263 }
 264
 265 static inline phys_addr_t __init alloc_pte_early(uintptr_t va)
 266 {
 267         /*
 268          * We only create PMD or PGD early mappings so we
 269          * should never reach here with MMU disabled.
 270          */
 271         BUG();
 272 }
 273
 274 static inline phys_addr_t __init alloc_pte_fixmap(uintptr_t va)
 275 {
 276         return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
 277 }
 278
 279 static phys_addr_t alloc_pte_late(uintptr_t va)
 280 {
 281         unsigned long vaddr;
 282
 283         vaddr = __get_free_page(GFP_KERNEL);
 284         if (!vaddr || !pgtable_pte_page_ctor(virt_to_page(vaddr)))
 285                 BUG();
 286         return __pa(vaddr);
 287 }
 288
 289 static void __init create_pte_mapping(pte_t *ptep,
 290                                       uintptr_t va, phys_addr_t pa,
 291                                       phys_addr_t sz, pgprot_t prot)
 292 {
 293         uintptr_t pte_idx = pte_index(va);
 294
 295         BUG_ON(sz != PAGE_SIZE);
 296
 297         if (pte_none(ptep[pte_idx]))
 298                 ptep[pte_idx] = pfn_pte(PFN_DOWN(pa), prot);
 299 }
 300
 301 #ifndef __PAGETABLE_PMD_FOLDED
 302
 303 pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss;
 304 pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
 305
 306 #if MAX_EARLY_MAPPING_SIZE < PGDIR_SIZE
 307 #define NUM_EARLY_PMDS          1UL
 308 #else
 309 #define NUM_EARLY_PMDS          (1UL + MAX_EARLY_MAPPING_SIZE / PGDIR_SIZE)
 310 #endif
 311 pmd_t early_pmd[PTRS_PER_PMD * NUM_EARLY_PMDS] __initdata __aligned(PAGE_SIZE);
 312 pmd_t early_dtb_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE);
 313
 314 static pmd_t *__init get_pmd_virt_early(phys_addr_t pa)
 315 {
 316         /* Before MMU is enabled */
 317         return (pmd_t *)((uintptr_t)pa);
 318 }
 319
 320 static pmd_t *__init get_pmd_virt_fixmap(phys_addr_t pa)
 321 {
 322         clear_fixmap(FIX_PMD);
 323         return (pmd_t *)set_fixmap_offset(FIX_PMD, pa);
 324 }
 325
 326 static pmd_t *get_pmd_virt_late(phys_addr_t pa)
 327 {
 328         return (pmd_t *) __va(pa);
 329 }
 330
 331 static phys_addr_t __init alloc_pmd_early(uintptr_t va)
 332 {
 333         uintptr_t pmd_num;
 334
 335         pmd_num = (va - PAGE_OFFSET) >> PGDIR_SHIFT;
 336         BUG_ON(pmd_num >= NUM_EARLY_PMDS);
 337         return (uintptr_t)&early_pmd[pmd_num * PTRS_PER_PMD];
 338 }
 339
 340 static phys_addr_t __init alloc_pmd_fixmap(uintptr_t va)
 341 {
 342         return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
 343 }
 344
 345 static phys_addr_t alloc_pmd_late(uintptr_t va)
 346 {
 347         unsigned long vaddr;
 348
 349         vaddr = __get_free_page(GFP_KERNEL);
 350         BUG_ON(!vaddr);
 351         return __pa(vaddr);
 352 }
 353
 354 static void __init create_pmd_mapping(pmd_t *pmdp,
 355                                       uintptr_t va, phys_addr_t pa,
 356                                       phys_addr_t sz, pgprot_t prot)
 357 {
 358         pte_t *ptep;
 359         phys_addr_t pte_phys;
 360         uintptr_t pmd_idx = pmd_index(va);
 361
 362         if (sz == PMD_SIZE) {
 363                 if (pmd_none(pmdp[pmd_idx]))
 364                         pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pa), prot);
 365                 return;
 366         }
 367
 368         if (pmd_none(pmdp[pmd_idx])) {
 369                 pte_phys = pt_ops.alloc_pte(va);
 370                 pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE);
 371                 ptep = pt_ops.get_pte_virt(pte_phys);
 372                 memset(ptep, 0, PAGE_SIZE);
 373         } else {
 374                 pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_idx]));
 375                 ptep = pt_ops.get_pte_virt(pte_phys);
 376         }
 377
 378         create_pte_mapping(ptep, va, pa, sz, prot);
 379 }
 380
 381 #define pgd_next_t              pmd_t
 382 #define alloc_pgd_next(__va)    pt_ops.alloc_pmd(__va)
 383 #define get_pgd_next_virt(__pa) pt_ops.get_pmd_virt(__pa)
 384 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)      \
 385         create_pmd_mapping(__nextp, __va, __pa, __sz, __prot)
 386 #define fixmap_pgd_next         fixmap_pmd
 387 #else
 388 #define pgd_next_t              pte_t
 389 #define alloc_pgd_next(__va)    pt_ops.alloc_pte(__va)
 390 #define get_pgd_next_virt(__pa) pt_ops.get_pte_virt(__pa)
 391 #define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)      \
 392         create_pte_mapping(__nextp, __va, __pa, __sz, __prot)
 393 #define fixmap_pgd_next         fixmap_pte
 394 #endif
 395
 396 void __init create_pgd_mapping(pgd_t *pgdp,
 397                                       uintptr_t va, phys_addr_t pa,
 398                                       phys_addr_t sz, pgprot_t prot)
 399 {
 400         pgd_next_t *nextp;
 401         phys_addr_t next_phys;
 402         uintptr_t pgd_idx = pgd_index(va);
 403
 404         if (sz == PGDIR_SIZE) {
 405                 if (pgd_val(pgdp[pgd_idx]) == 0)
 406                         pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(pa), prot);
 407                 return;
 408         }
 409
 410         if (pgd_val(pgdp[pgd_idx]) == 0) {
 411                 next_phys = alloc_pgd_next(va);
 412                 pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE);
 413                 nextp = get_pgd_next_virt(next_phys);
 414                 memset(nextp, 0, PAGE_SIZE);
 415         } else {
 416                 next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_idx]));
 417                 nextp = get_pgd_next_virt(next_phys);
 418         }
 419
 420         create_pgd_next_mapping(nextp, va, pa, sz, prot);
 421 }
 422
 423 static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size)
 424 {
 425         /* Upgrade to PMD_SIZE mappings whenever possible */
 426         if ((base & (PMD_SIZE - 1)) || (size & (PMD_SIZE - 1)))
 427                 return PAGE_SIZE;
 428
 429         return PMD_SIZE;
 430 }
 431
 432 /*
 433  * setup_vm() is called from head.S with MMU-off.
 434  *
 435  * Following requirements should be honoured for setup_vm() to work
 436  * correctly:
 437  * 1) It should use PC-relative addressing for accessing kernel symbols.
 438  *    To achieve this we always use GCC cmodel=medany.
 439  * 2) The compiler instrumentation for FTRACE will not work for setup_vm()
 440  *    so disable compiler instrumentation when FTRACE is enabled.
 441  *
 442  * Currently, the above requirements are honoured by using custom CFLAGS
 443  * for init.o in mm/Makefile.
 444  */
 445
 446 #ifndef __riscv_cmodel_medany
 447 #error "setup_vm() is called from head.S before relocate so it should not use absolute addressing."
 448 #endif
 449
 450 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
 451 {
 452         uintptr_t va, pa, end_va;
 453         uintptr_t load_pa = (uintptr_t)(&_start);
 454         uintptr_t load_sz = (uintptr_t)(&_end) - load_pa;
 455         uintptr_t map_size = best_map_size(load_pa, MAX_EARLY_MAPPING_SIZE);
 456 #ifndef __PAGETABLE_PMD_FOLDED
 457         pmd_t fix_bmap_spmd, fix_bmap_epmd;
 458 #endif
 459
 460         va_pa_offset = PAGE_OFFSET - load_pa;
 461         pfn_base = PFN_DOWN(load_pa);
 462
 463         /*
 464          * Enforce boot alignment requirements of RV32 and
 465          * RV64 by only allowing PMD or PGD mappings.
 466          */
 467         BUG_ON(map_size == PAGE_SIZE);
 468
 469         /* Sanity check alignment and size */
 470         BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
 471         BUG_ON((load_pa % map_size) != 0);
 472         BUG_ON(load_sz > MAX_EARLY_MAPPING_SIZE);
 473
 474         pt_ops.alloc_pte = alloc_pte_early;
 475         pt_ops.get_pte_virt = get_pte_virt_early;
 476 #ifndef __PAGETABLE_PMD_FOLDED
 477         pt_ops.alloc_pmd = alloc_pmd_early;
 478         pt_ops.get_pmd_virt = get_pmd_virt_early;
 479 #endif
 480         /* Setup early PGD for fixmap */
 481         create_pgd_mapping(early_pg_dir, FIXADDR_START,
 482                            (uintptr_t)fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE);
 483
 484 #ifndef __PAGETABLE_PMD_FOLDED
 485         /* Setup fixmap PMD */
 486         create_pmd_mapping(fixmap_pmd, FIXADDR_START,
 487                            (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE);
 488         /* Setup trampoline PGD and PMD */
 489         create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
 490                            (uintptr_t)trampoline_pmd, PGDIR_SIZE, PAGE_TABLE);
 491         create_pmd_mapping(trampoline_pmd, PAGE_OFFSET,
 492                            load_pa, PMD_SIZE, PAGE_KERNEL_EXEC);
 493 #else
 494         /* Setup trampoline PGD */
 495         create_pgd_mapping(trampoline_pg_dir, PAGE_OFFSET,
 496                            load_pa, PGDIR_SIZE, PAGE_KERNEL_EXEC);
 497 #endif
 498
 499         /*
 500          * Setup early PGD covering entire kernel which will allows
 501          * us to reach paging_init(). We map all memory banks later
 502          * in setup_vm_final() below.
 503          */
 504         end_va = PAGE_OFFSET + load_sz;
 505         for (va = PAGE_OFFSET; va < end_va; va += map_size)
 506                 create_pgd_mapping(early_pg_dir, va,
 507                                    load_pa + (va - PAGE_OFFSET),
 508                                    map_size, PAGE_KERNEL_EXEC);
 509
 510 #ifndef __PAGETABLE_PMD_FOLDED
 511         /* Setup early PMD for DTB */
 512         create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA,
 513                            (uintptr_t)early_dtb_pmd, PGDIR_SIZE, PAGE_TABLE);
 514         /* Create two consecutive PMD mappings for FDT early scan */
 515         pa = dtb_pa & ~(PMD_SIZE - 1);
 516         create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA,
 517                            pa, PMD_SIZE, PAGE_KERNEL);
 518         create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA + PMD_SIZE,
 519                            pa + PMD_SIZE, PMD_SIZE, PAGE_KERNEL);
 520         dtb_early_va = (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PMD_SIZE - 1));
 521 #else
 522         /* Create two consecutive PGD mappings for FDT early scan */
 523         pa = dtb_pa & ~(PGDIR_SIZE - 1);
 524         create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA,
 525                            pa, PGDIR_SIZE, PAGE_KERNEL);
 526         create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA + PGDIR_SIZE,
 527                            pa + PGDIR_SIZE, PGDIR_SIZE, PAGE_KERNEL);
 528         dtb_early_va = (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PGDIR_SIZE - 1));
 529 #endif
 530         dtb_early_pa = dtb_pa;
 531
 532         /*
 533          * Bootime fixmap only can handle PMD_SIZE mapping. Thus, boot-ioremap
 534          * range can not span multiple pmds.
 535          */
 536         BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
 537                      != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
 538
 539 #ifndef __PAGETABLE_PMD_FOLDED
 540         /*
 541          * Early ioremap fixmap is already created as it lies within first 2MB
 542          * of fixmap region. We always map PMD_SIZE. Thus, both FIX_BTMAP_END
 543          * FIX_BTMAP_BEGIN should lie in the same pmd. Verify that and warn
 544          * the user if not.
 545          */
 546         fix_bmap_spmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_BEGIN))];
 547         fix_bmap_epmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_END))];
 548         if (pmd_val(fix_bmap_spmd) != pmd_val(fix_bmap_epmd)) {
 549                 WARN_ON(1);
 550                 pr_warn("fixmap btmap start [%08lx] != end [%08lx]\n",
 551                         pmd_val(fix_bmap_spmd), pmd_val(fix_bmap_epmd));
 552                 pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
 553                         fix_to_virt(FIX_BTMAP_BEGIN));
 554                 pr_warn("fix_to_virt(FIX_BTMAP_END):   %08lx\n",
 555                         fix_to_virt(FIX_BTMAP_END));
 556
 557                 pr_warn("FIX_BTMAP_END:       %d\n", FIX_BTMAP_END);
 558                 pr_warn("FIX_BTMAP_BEGIN:     %d\n", FIX_BTMAP_BEGIN);
 559         }
 560 #endif
 561 }
 562
 563 static void __init setup_vm_final(void)
 564 {
 565         uintptr_t va, map_size;
 566         phys_addr_t pa, start, end;
 567         u64 i;
 568
 569         /**
 570          * MMU is enabled at this point. But page table setup is not complete yet.
 571          * fixmap page table alloc functions should be used at this point
 572          */
 573         pt_ops.alloc_pte = alloc_pte_fixmap;
 574         pt_ops.get_pte_virt = get_pte_virt_fixmap;
 575 #ifndef __PAGETABLE_PMD_FOLDED
 576         pt_ops.alloc_pmd = alloc_pmd_fixmap;
 577         pt_ops.get_pmd_virt = get_pmd_virt_fixmap;
 578 #endif
 579         /* Setup swapper PGD for fixmap */
 580         create_pgd_mapping(swapper_pg_dir, FIXADDR_START,
 581                            __pa_symbol(fixmap_pgd_next),
 582                            PGDIR_SIZE, PAGE_TABLE);
 583
 584         /* Map all memory banks */
 585         for_each_mem_range(i, &start, &end) {
 586                 if (start >= end)
 587                         break;
 588                 if (start <= __pa(PAGE_OFFSET) &&
 589                     __pa(PAGE_OFFSET) < end)
 590                         start = __pa(PAGE_OFFSET);
 591
 592                 map_size = best_map_size(start, end - start);
 593                 for (pa = start; pa < end; pa += map_size) {
 594                         va = (uintptr_t)__va(pa);
 595                         create_pgd_mapping(swapper_pg_dir, va, pa,
 596                                            map_size, PAGE_KERNEL_EXEC);
 597                 }
 598         }
 599
 600         /* Clear fixmap PTE and PMD mappings */
 601         clear_fixmap(FIX_PTE);
 602         clear_fixmap(FIX_PMD);
 603
 604         /* Move to swapper page table */
 605         csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | SATP_MODE);
 606         local_flush_tlb_all();
 607
 608         /* generic page allocation functions must be used to setup page table */
 609         pt_ops.alloc_pte = alloc_pte_late;
 610         pt_ops.get_pte_virt = get_pte_virt_late;
 611 #ifndef __PAGETABLE_PMD_FOLDED
 612         pt_ops.alloc_pmd = alloc_pmd_late;
 613         pt_ops.get_pmd_virt = get_pmd_virt_late;
 614 #endif
 615 }
 616 #else
 617 asmlinkage void __init setup_vm(uintptr_t dtb_pa)
 618 {
 619 #ifdef CONFIG_BUILTIN_DTB
 620         dtb_early_va = soc_lookup_builtin_dtb();
 621         if (!dtb_early_va) {
 622                 /* Fallback to first available DTS */
 623                 dtb_early_va = (void *) __dtb_start;
 624         }
 625 #else
 626         dtb_early_va = (void *)dtb_pa;
 627 #endif
 628         dtb_early_pa = dtb_pa;
 629 }
 630
 631 static inline void setup_vm_final(void)
 632 {
 633 }
 634 #endif /* CONFIG_MMU */
 635
 636 #ifdef CONFIG_STRICT_KERNEL_RWX
 637 void protect_kernel_text_data(void)
 638 {
 639         unsigned long text_start = (unsigned long)_start;
 640         unsigned long init_text_start = (unsigned long)__init_text_begin;
 641         unsigned long init_data_start = (unsigned long)__init_data_begin;
 642         unsigned long rodata_start = (unsigned long)__start_rodata;
 643         unsigned long data_start = (unsigned long)_data;
 644         unsigned long max_low = (unsigned long)(__va(PFN_PHYS(max_low_pfn)));
 645
 646         set_memory_ro(text_start, (init_text_start - text_start) >> PAGE_SHIFT);
 647         set_memory_ro(init_text_start, (init_data_start - init_text_start) >> PAGE_SHIFT);
 648         set_memory_nx(init_data_start, (rodata_start - init_data_start) >> PAGE_SHIFT);
 649         /* rodata section is marked readonly in mark_rodata_ro */
 650         set_memory_nx(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT);
 651         set_memory_nx(data_start, (max_low - data_start) >> PAGE_SHIFT);
 652 }
 653
 654 void mark_rodata_ro(void)
 655 {
 656         unsigned long rodata_start = (unsigned long)__start_rodata;
 657         unsigned long data_start = (unsigned long)_data;
 658
 659         set_memory_ro(rodata_start, (data_start - rodata_start) >> PAGE_SHIFT);
 660
 661         debug_checkwx();
 662 }
 663 #endif
 664
 665 void __init paging_init(void)
 666 {
 667         setup_vm_final();
 668         sparse_init();
 669         setup_zero_page();
 670         zone_sizes_init();
 671 }
 672
 673 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 674 int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
 675                                struct vmem_altmap *altmap)
 676 {
 677         return vmemmap_populate_basepages(start, end, node, NULL);
 678 }
 679 #endif