linux/arch/riscv/mm/init.c
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   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 * Copyright (C) 2020 FORTH-ICS/CARV
   6 *  Nick Kossifidis <mick@ics.forth.gr>
   7 */
   8
   9#include <linux/init.h>
  10#include <linux/mm.h>
  11#include <linux/memblock.h>
  12#include <linux/initrd.h>
  13#include <linux/swap.h>
  14#include <linux/swiotlb.h>
  15#include <linux/sizes.h>
  16#include <linux/of_fdt.h>
  17#include <linux/of_reserved_mem.h>
  18#include <linux/libfdt.h>
  19#include <linux/set_memory.h>
  20#include <linux/dma-map-ops.h>
  21#include <linux/crash_dump.h>
  22
  23#include <asm/fixmap.h>
  24#include <asm/tlbflush.h>
  25#include <asm/sections.h>
  26#include <asm/soc.h>
  27#include <asm/io.h>
  28#include <asm/ptdump.h>
  29#include <asm/numa.h>
  30
  31#include "../kernel/head.h"
  32
  33struct kernel_mapping kernel_map __ro_after_init;
  34EXPORT_SYMBOL(kernel_map);
  35#ifdef CONFIG_XIP_KERNEL
  36#define kernel_map      (*(struct kernel_mapping *)XIP_FIXUP(&kernel_map))
  37#endif
  38
  39phys_addr_t phys_ram_base __ro_after_init;
  40EXPORT_SYMBOL(phys_ram_base);
  41
  42#ifdef CONFIG_XIP_KERNEL
  43extern char _xiprom[], _exiprom[];
  44#endif
  45
  46unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
  47                                                        __page_aligned_bss;
  48EXPORT_SYMBOL(empty_zero_page);
  49
  50extern char _start[];
  51#define DTB_EARLY_BASE_VA      PGDIR_SIZE
  52void *_dtb_early_va __initdata;
  53uintptr_t _dtb_early_pa __initdata;
  54
  55struct pt_alloc_ops {
  56        pte_t *(*get_pte_virt)(phys_addr_t pa);
  57        phys_addr_t (*alloc_pte)(uintptr_t va);
  58#ifndef __PAGETABLE_PMD_FOLDED
  59        pmd_t *(*get_pmd_virt)(phys_addr_t pa);
  60        phys_addr_t (*alloc_pmd)(uintptr_t va);
  61#endif
  62};
  63
  64static phys_addr_t dma32_phys_limit __initdata;
  65
  66static void __init zone_sizes_init(void)
  67{
  68        unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, };
  69
  70#ifdef CONFIG_ZONE_DMA32
  71        max_zone_pfns[ZONE_DMA32] = PFN_DOWN(dma32_phys_limit);
  72#endif
  73        max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
  74
  75        free_area_init(max_zone_pfns);
  76}
  77
  78#if defined(CONFIG_MMU) && defined(CONFIG_DEBUG_VM)
  79static inline void print_mlk(char *name, unsigned long b, unsigned long t)
  80{
  81        pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld kB)\n", name, b, t,
  82                  (((t) - (b)) >> 10));
  83}
  84
  85static inline void print_mlm(char *name, unsigned long b, unsigned long t)
  86{
  87        pr_notice("%12s : 0x%08lx - 0x%08lx   (%4ld MB)\n", name, b, t,
  88                  (((t) - (b)) >> 20));
  89}
  90
  91static void __init print_vm_layout(void)
  92{
  93        pr_notice("Virtual kernel memory layout:\n");
  94        print_mlk("fixmap", (unsigned long)FIXADDR_START,
  95                  (unsigned long)FIXADDR_TOP);
  96        print_mlm("pci io", (unsigned long)PCI_IO_START,
  97                  (unsigned long)PCI_IO_END);
  98        print_mlm("vmemmap", (unsigned long)VMEMMAP_START,
  99                  (unsigned long)VMEMMAP_END);
 100        print_mlm("vmalloc", (unsigned long)VMALLOC_START,
 101                  (unsigned long)VMALLOC_END);
 102        print_mlm("lowmem", (unsigned long)PAGE_OFFSET,
 103                  (unsigned long)high_memory);
 104#ifdef CONFIG_64BIT
 105        print_mlm("kernel", (unsigned long)KERNEL_LINK_ADDR,
 106                  (unsigned long)ADDRESS_SPACE_END);
 107#endif
 108}
 109#else
 110static void print_vm_layout(void) { }
 111#endif /* CONFIG_DEBUG_VM */
 112
 113void __init mem_init(void)
 114{
 115#ifdef CONFIG_FLATMEM
 116        BUG_ON(!mem_map);
 117#endif /* CONFIG_FLATMEM */
 118
 119#ifdef CONFIG_SWIOTLB
 120        if (swiotlb_force == SWIOTLB_FORCE ||
 121            max_pfn > PFN_DOWN(dma32_phys_limit))
 122                swiotlb_init(1);
 123        else
 124                swiotlb_force = SWIOTLB_NO_FORCE;
 125#endif
 126        high_memory = (void *)(__va(PFN_PHYS(max_low_pfn)));
 127        memblock_free_all();
 128
 129        print_vm_layout();
 130}
 131
 132/*
 133 * The default maximal physical memory size is -PAGE_OFFSET for 32-bit kernel,
 134 * whereas for 64-bit kernel, the end of the virtual address space is occupied
 135 * by the modules/BPF/kernel mappings which reduces the available size of the
 136 * linear mapping.
 137 * Limit the memory size via mem.
 138 */
 139#ifdef CONFIG_64BIT
 140static phys_addr_t memory_limit = -PAGE_OFFSET - SZ_4G;
 141#else
 142static phys_addr_t memory_limit = -PAGE_OFFSET;
 143#endif
 144
 145static int __init early_mem(char *p)
 146{
 147        u64 size;
 148
 149        if (!p)
 150                return 1;
 151
 152        size = memparse(p, &p) & PAGE_MASK;
 153        memory_limit = min_t(u64, size, memory_limit);
 154
 155        pr_notice("Memory limited to %lldMB\n", (u64)memory_limit >> 20);
 156
 157        return 0;
 158}
 159early_param("mem", early_mem);
 160
 161static void __init setup_bootmem(void)
 162{
 163        phys_addr_t vmlinux_end = __pa_symbol(&_end);
 164        phys_addr_t vmlinux_start = __pa_symbol(&_start);
 165        phys_addr_t __maybe_unused max_mapped_addr;
 166        phys_addr_t phys_ram_end;
 167
 168#ifdef CONFIG_XIP_KERNEL
 169        vmlinux_start = __pa_symbol(&_sdata);
 170#endif
 171
 172        memblock_enforce_memory_limit(memory_limit);
 173
 174        /*
 175         * Reserve from the start of the kernel to the end of the kernel
 176         */
 177#if defined(CONFIG_64BIT) && defined(CONFIG_STRICT_KERNEL_RWX)
 178        /*
 179         * Make sure we align the reservation on PMD_SIZE since we will
 180         * map the kernel in the linear mapping as read-only: we do not want
 181         * any allocation to happen between _end and the next pmd aligned page.
 182         */
 183        vmlinux_end = (vmlinux_end + PMD_SIZE - 1) & PMD_MASK;
 184#endif
 185        memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start);
 186
 187
 188        phys_ram_end = memblock_end_of_DRAM();
 189#ifndef CONFIG_64BIT
 190#ifndef CONFIG_XIP_KERNEL
 191        phys_ram_base = memblock_start_of_DRAM();
 192#endif
 193        /*
 194         * memblock allocator is not aware of the fact that last 4K bytes of
 195         * the addressable memory can not be mapped because of IS_ERR_VALUE
 196         * macro. Make sure that last 4k bytes are not usable by memblock
 197         * if end of dram is equal to maximum addressable memory.  For 64-bit
 198         * kernel, this problem can't happen here as the end of the virtual
 199         * address space is occupied by the kernel mapping then this check must
 200         * be done as soon as the kernel mapping base address is determined.
 201         */
 202        max_mapped_addr = __pa(~(ulong)0);
 203        if (max_mapped_addr == (phys_ram_end - 1))
 204                memblock_set_current_limit(max_mapped_addr - 4096);
 205#endif
 206
 207        min_low_pfn = PFN_UP(phys_ram_base);
 208        max_low_pfn = max_pfn = PFN_DOWN(phys_ram_end);
 209
 210        dma32_phys_limit = min(4UL * SZ_1G, (unsigned long)PFN_PHYS(max_low_pfn));
 211        set_max_mapnr(max_low_pfn - ARCH_PFN_OFFSET);
 212
 213        reserve_initrd_mem();
 214        /*
 215         * If DTB is built in, no need to reserve its memblock.
 216         * Otherwise, do reserve it but avoid using
 217         * early_init_fdt_reserve_self() since __pa() does
 218         * not work for DTB pointers that are fixmap addresses
 219         */
 220        if (!IS_ENABLED(CONFIG_BUILTIN_DTB))
 221                memblock_reserve(dtb_early_pa, fdt_totalsize(dtb_early_va));
 222
 223        early_init_fdt_scan_reserved_mem();
 224        dma_contiguous_reserve(dma32_phys_limit);
 225        memblock_allow_resize();
 226}
 227
 228#ifdef CONFIG_MMU
 229static struct pt_alloc_ops _pt_ops __initdata;
 230
 231#ifdef CONFIG_XIP_KERNEL
 232#define pt_ops (*(struct pt_alloc_ops *)XIP_FIXUP(&_pt_ops))
 233#else
 234#define pt_ops _pt_ops
 235#endif
 236
 237unsigned long pfn_base __ro_after_init;
 238EXPORT_SYMBOL(pfn_base);
 239
 240pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
 241pgd_t trampoline_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
 242static pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss;
 243
 244pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
 245
 246#ifdef CONFIG_XIP_KERNEL
 247#define trampoline_pg_dir      ((pgd_t *)XIP_FIXUP(trampoline_pg_dir))
 248#define fixmap_pte             ((pte_t *)XIP_FIXUP(fixmap_pte))
 249#define early_pg_dir           ((pgd_t *)XIP_FIXUP(early_pg_dir))
 250#endif /* CONFIG_XIP_KERNEL */
 251
 252void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot)
 253{
 254        unsigned long addr = __fix_to_virt(idx);
 255        pte_t *ptep;
 256
 257        BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
 258
 259        ptep = &fixmap_pte[pte_index(addr)];
 260
 261        if (pgprot_val(prot))
 262                set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
 263        else
 264                pte_clear(&init_mm, addr, ptep);
 265        local_flush_tlb_page(addr);
 266}
 267
 268static inline pte_t *__init get_pte_virt_early(phys_addr_t pa)
 269{
 270        return (pte_t *)((uintptr_t)pa);
 271}
 272
 273static inline pte_t *__init get_pte_virt_fixmap(phys_addr_t pa)
 274{
 275        clear_fixmap(FIX_PTE);
 276        return (pte_t *)set_fixmap_offset(FIX_PTE, pa);
 277}
 278
 279static inline pte_t *__init get_pte_virt_late(phys_addr_t pa)
 280{
 281        return (pte_t *) __va(pa);
 282}
 283
 284static inline phys_addr_t __init alloc_pte_early(uintptr_t va)
 285{
 286        /*
 287         * We only create PMD or PGD early mappings so we
 288         * should never reach here with MMU disabled.
 289         */
 290        BUG();
 291}
 292
 293static inline phys_addr_t __init alloc_pte_fixmap(uintptr_t va)
 294{
 295        return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
 296}
 297
 298static phys_addr_t __init alloc_pte_late(uintptr_t va)
 299{
 300        unsigned long vaddr;
 301
 302        vaddr = __get_free_page(GFP_KERNEL);
 303        BUG_ON(!vaddr || !pgtable_pte_page_ctor(virt_to_page(vaddr)));
 304
 305        return __pa(vaddr);
 306}
 307
 308static void __init create_pte_mapping(pte_t *ptep,
 309                                      uintptr_t va, phys_addr_t pa,
 310                                      phys_addr_t sz, pgprot_t prot)
 311{
 312        uintptr_t pte_idx = pte_index(va);
 313
 314        BUG_ON(sz != PAGE_SIZE);
 315
 316        if (pte_none(ptep[pte_idx]))
 317                ptep[pte_idx] = pfn_pte(PFN_DOWN(pa), prot);
 318}
 319
 320#ifndef __PAGETABLE_PMD_FOLDED
 321
 322static pmd_t trampoline_pmd[PTRS_PER_PMD] __page_aligned_bss;
 323static pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss;
 324static pmd_t early_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE);
 325static pmd_t early_dtb_pmd[PTRS_PER_PMD] __initdata __aligned(PAGE_SIZE);
 326
 327#ifdef CONFIG_XIP_KERNEL
 328#define trampoline_pmd ((pmd_t *)XIP_FIXUP(trampoline_pmd))
 329#define fixmap_pmd     ((pmd_t *)XIP_FIXUP(fixmap_pmd))
 330#define early_pmd      ((pmd_t *)XIP_FIXUP(early_pmd))
 331#endif /* CONFIG_XIP_KERNEL */
 332
 333static pmd_t *__init get_pmd_virt_early(phys_addr_t pa)
 334{
 335        /* Before MMU is enabled */
 336        return (pmd_t *)((uintptr_t)pa);
 337}
 338
 339static pmd_t *__init get_pmd_virt_fixmap(phys_addr_t pa)
 340{
 341        clear_fixmap(FIX_PMD);
 342        return (pmd_t *)set_fixmap_offset(FIX_PMD, pa);
 343}
 344
 345static pmd_t *__init get_pmd_virt_late(phys_addr_t pa)
 346{
 347        return (pmd_t *) __va(pa);
 348}
 349
 350static phys_addr_t __init alloc_pmd_early(uintptr_t va)
 351{
 352        BUG_ON((va - kernel_map.virt_addr) >> PGDIR_SHIFT);
 353
 354        return (uintptr_t)early_pmd;
 355}
 356
 357static phys_addr_t __init alloc_pmd_fixmap(uintptr_t va)
 358{
 359        return memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
 360}
 361
 362static phys_addr_t __init alloc_pmd_late(uintptr_t va)
 363{
 364        unsigned long vaddr;
 365
 366        vaddr = __get_free_page(GFP_KERNEL);
 367        BUG_ON(!vaddr);
 368        return __pa(vaddr);
 369}
 370
 371static void __init create_pmd_mapping(pmd_t *pmdp,
 372                                      uintptr_t va, phys_addr_t pa,
 373                                      phys_addr_t sz, pgprot_t prot)
 374{
 375        pte_t *ptep;
 376        phys_addr_t pte_phys;
 377        uintptr_t pmd_idx = pmd_index(va);
 378
 379        if (sz == PMD_SIZE) {
 380                if (pmd_none(pmdp[pmd_idx]))
 381                        pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pa), prot);
 382                return;
 383        }
 384
 385        if (pmd_none(pmdp[pmd_idx])) {
 386                pte_phys = pt_ops.alloc_pte(va);
 387                pmdp[pmd_idx] = pfn_pmd(PFN_DOWN(pte_phys), PAGE_TABLE);
 388                ptep = pt_ops.get_pte_virt(pte_phys);
 389                memset(ptep, 0, PAGE_SIZE);
 390        } else {
 391                pte_phys = PFN_PHYS(_pmd_pfn(pmdp[pmd_idx]));
 392                ptep = pt_ops.get_pte_virt(pte_phys);
 393        }
 394
 395        create_pte_mapping(ptep, va, pa, sz, prot);
 396}
 397
 398#define pgd_next_t              pmd_t
 399#define alloc_pgd_next(__va)    pt_ops.alloc_pmd(__va)
 400#define get_pgd_next_virt(__pa) pt_ops.get_pmd_virt(__pa)
 401#define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)      \
 402        create_pmd_mapping(__nextp, __va, __pa, __sz, __prot)
 403#define fixmap_pgd_next         fixmap_pmd
 404#else
 405#define pgd_next_t              pte_t
 406#define alloc_pgd_next(__va)    pt_ops.alloc_pte(__va)
 407#define get_pgd_next_virt(__pa) pt_ops.get_pte_virt(__pa)
 408#define create_pgd_next_mapping(__nextp, __va, __pa, __sz, __prot)      \
 409        create_pte_mapping(__nextp, __va, __pa, __sz, __prot)
 410#define fixmap_pgd_next         fixmap_pte
 411#endif
 412
 413void __init create_pgd_mapping(pgd_t *pgdp,
 414                                      uintptr_t va, phys_addr_t pa,
 415                                      phys_addr_t sz, pgprot_t prot)
 416{
 417        pgd_next_t *nextp;
 418        phys_addr_t next_phys;
 419        uintptr_t pgd_idx = pgd_index(va);
 420
 421        if (sz == PGDIR_SIZE) {
 422                if (pgd_val(pgdp[pgd_idx]) == 0)
 423                        pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(pa), prot);
 424                return;
 425        }
 426
 427        if (pgd_val(pgdp[pgd_idx]) == 0) {
 428                next_phys = alloc_pgd_next(va);
 429                pgdp[pgd_idx] = pfn_pgd(PFN_DOWN(next_phys), PAGE_TABLE);
 430                nextp = get_pgd_next_virt(next_phys);
 431                memset(nextp, 0, PAGE_SIZE);
 432        } else {
 433                next_phys = PFN_PHYS(_pgd_pfn(pgdp[pgd_idx]));
 434                nextp = get_pgd_next_virt(next_phys);
 435        }
 436
 437        create_pgd_next_mapping(nextp, va, pa, sz, prot);
 438}
 439
 440static uintptr_t __init best_map_size(phys_addr_t base, phys_addr_t size)
 441{
 442        /* Upgrade to PMD_SIZE mappings whenever possible */
 443        if ((base & (PMD_SIZE - 1)) || (size & (PMD_SIZE - 1)))
 444                return PAGE_SIZE;
 445
 446        return PMD_SIZE;
 447}
 448
 449#ifdef CONFIG_XIP_KERNEL
 450/* called from head.S with MMU off */
 451asmlinkage void __init __copy_data(void)
 452{
 453        void *from = (void *)(&_sdata);
 454        void *end = (void *)(&_end);
 455        void *to = (void *)CONFIG_PHYS_RAM_BASE;
 456        size_t sz = (size_t)(end - from + 1);
 457
 458        memcpy(to, from, sz);
 459}
 460#endif
 461
 462#ifdef CONFIG_STRICT_KERNEL_RWX
 463static __init pgprot_t pgprot_from_va(uintptr_t va)
 464{
 465        if (is_va_kernel_text(va))
 466                return PAGE_KERNEL_READ_EXEC;
 467
 468        /*
 469         * In 64-bit kernel, the kernel mapping is outside the linear mapping so
 470         * we must protect its linear mapping alias from being executed and
 471         * written.
 472         * And rodata section is marked readonly in mark_rodata_ro.
 473         */
 474        if (IS_ENABLED(CONFIG_64BIT) && is_va_kernel_lm_alias_text(va))
 475                return PAGE_KERNEL_READ;
 476
 477        return PAGE_KERNEL;
 478}
 479
 480void mark_rodata_ro(void)
 481{
 482        set_kernel_memory(__start_rodata, _data, set_memory_ro);
 483        if (IS_ENABLED(CONFIG_64BIT))
 484                set_kernel_memory(lm_alias(__start_rodata), lm_alias(_data),
 485                                  set_memory_ro);
 486
 487        debug_checkwx();
 488}
 489#else
 490static __init pgprot_t pgprot_from_va(uintptr_t va)
 491{
 492        if (IS_ENABLED(CONFIG_64BIT) && !is_kernel_mapping(va))
 493                return PAGE_KERNEL;
 494
 495        return PAGE_KERNEL_EXEC;
 496}
 497#endif /* CONFIG_STRICT_KERNEL_RWX */
 498
 499/*
 500 * setup_vm() is called from head.S with MMU-off.
 501 *
 502 * Following requirements should be honoured for setup_vm() to work
 503 * correctly:
 504 * 1) It should use PC-relative addressing for accessing kernel symbols.
 505 *    To achieve this we always use GCC cmodel=medany.
 506 * 2) The compiler instrumentation for FTRACE will not work for setup_vm()
 507 *    so disable compiler instrumentation when FTRACE is enabled.
 508 *
 509 * Currently, the above requirements are honoured by using custom CFLAGS
 510 * for init.o in mm/Makefile.
 511 */
 512
 513#ifndef __riscv_cmodel_medany
 514#error "setup_vm() is called from head.S before relocate so it should not use absolute addressing."
 515#endif
 516
 517#ifdef CONFIG_XIP_KERNEL
 518static void __init create_kernel_page_table(pgd_t *pgdir, uintptr_t map_size,
 519                                            __always_unused bool early)
 520{
 521        uintptr_t va, end_va;
 522
 523        /* Map the flash resident part */
 524        end_va = kernel_map.virt_addr + kernel_map.xiprom_sz;
 525        for (va = kernel_map.virt_addr; va < end_va; va += map_size)
 526                create_pgd_mapping(pgdir, va,
 527                                   kernel_map.xiprom + (va - kernel_map.virt_addr),
 528                                   map_size, PAGE_KERNEL_EXEC);
 529
 530        /* Map the data in RAM */
 531        end_va = kernel_map.virt_addr + XIP_OFFSET + kernel_map.size;
 532        for (va = kernel_map.virt_addr + XIP_OFFSET; va < end_va; va += map_size)
 533                create_pgd_mapping(pgdir, va,
 534                                   kernel_map.phys_addr + (va - (kernel_map.virt_addr + XIP_OFFSET)),
 535                                   map_size, PAGE_KERNEL);
 536}
 537#else
 538static void __init create_kernel_page_table(pgd_t *pgdir, uintptr_t map_size,
 539                                            bool early)
 540{
 541        uintptr_t va, end_va;
 542
 543        end_va = kernel_map.virt_addr + kernel_map.size;
 544        for (va = kernel_map.virt_addr; va < end_va; va += map_size)
 545                create_pgd_mapping(pgdir, va,
 546                                   kernel_map.phys_addr + (va - kernel_map.virt_addr),
 547                                   map_size,
 548                                   early ?
 549                                        PAGE_KERNEL_EXEC : pgprot_from_va(va));
 550}
 551#endif
 552
 553asmlinkage void __init setup_vm(uintptr_t dtb_pa)
 554{
 555        uintptr_t __maybe_unused pa;
 556        uintptr_t map_size;
 557#ifndef __PAGETABLE_PMD_FOLDED
 558        pmd_t fix_bmap_spmd, fix_bmap_epmd;
 559#endif
 560
 561        kernel_map.virt_addr = KERNEL_LINK_ADDR;
 562
 563#ifdef CONFIG_XIP_KERNEL
 564        kernel_map.xiprom = (uintptr_t)CONFIG_XIP_PHYS_ADDR;
 565        kernel_map.xiprom_sz = (uintptr_t)(&_exiprom) - (uintptr_t)(&_xiprom);
 566
 567        phys_ram_base = CONFIG_PHYS_RAM_BASE;
 568        kernel_map.phys_addr = (uintptr_t)CONFIG_PHYS_RAM_BASE;
 569        kernel_map.size = (uintptr_t)(&_end) - (uintptr_t)(&_sdata);
 570
 571        kernel_map.va_kernel_xip_pa_offset = kernel_map.virt_addr - kernel_map.xiprom;
 572#else
 573        kernel_map.phys_addr = (uintptr_t)(&_start);
 574        kernel_map.size = (uintptr_t)(&_end) - kernel_map.phys_addr;
 575#endif
 576
 577        kernel_map.va_pa_offset = PAGE_OFFSET - kernel_map.phys_addr;
 578#ifdef CONFIG_64BIT
 579        kernel_map.va_kernel_pa_offset = kernel_map.virt_addr - kernel_map.phys_addr;
 580#endif
 581
 582        pfn_base = PFN_DOWN(kernel_map.phys_addr);
 583
 584        /*
 585         * Enforce boot alignment requirements of RV32 and
 586         * RV64 by only allowing PMD or PGD mappings.
 587         */
 588        map_size = PMD_SIZE;
 589
 590        /* Sanity check alignment and size */
 591        BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0);
 592        BUG_ON((kernel_map.phys_addr % map_size) != 0);
 593
 594#ifdef CONFIG_64BIT
 595        /*
 596         * The last 4K bytes of the addressable memory can not be mapped because
 597         * of IS_ERR_VALUE macro.
 598         */
 599        BUG_ON((kernel_map.virt_addr + kernel_map.size) > ADDRESS_SPACE_END - SZ_4K);
 600#endif
 601
 602        pt_ops.alloc_pte = alloc_pte_early;
 603        pt_ops.get_pte_virt = get_pte_virt_early;
 604#ifndef __PAGETABLE_PMD_FOLDED
 605        pt_ops.alloc_pmd = alloc_pmd_early;
 606        pt_ops.get_pmd_virt = get_pmd_virt_early;
 607#endif
 608        /* Setup early PGD for fixmap */
 609        create_pgd_mapping(early_pg_dir, FIXADDR_START,
 610                           (uintptr_t)fixmap_pgd_next, PGDIR_SIZE, PAGE_TABLE);
 611
 612#ifndef __PAGETABLE_PMD_FOLDED
 613        /* Setup fixmap PMD */
 614        create_pmd_mapping(fixmap_pmd, FIXADDR_START,
 615                           (uintptr_t)fixmap_pte, PMD_SIZE, PAGE_TABLE);
 616        /* Setup trampoline PGD and PMD */
 617        create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr,
 618                           (uintptr_t)trampoline_pmd, PGDIR_SIZE, PAGE_TABLE);
 619#ifdef CONFIG_XIP_KERNEL
 620        create_pmd_mapping(trampoline_pmd, kernel_map.virt_addr,
 621                           kernel_map.xiprom, PMD_SIZE, PAGE_KERNEL_EXEC);
 622#else
 623        create_pmd_mapping(trampoline_pmd, kernel_map.virt_addr,
 624                           kernel_map.phys_addr, PMD_SIZE, PAGE_KERNEL_EXEC);
 625#endif
 626#else
 627        /* Setup trampoline PGD */
 628        create_pgd_mapping(trampoline_pg_dir, kernel_map.virt_addr,
 629                           kernel_map.phys_addr, PGDIR_SIZE, PAGE_KERNEL_EXEC);
 630#endif
 631
 632        /*
 633         * Setup early PGD covering entire kernel which will allow
 634         * us to reach paging_init(). We map all memory banks later
 635         * in setup_vm_final() below.
 636         */
 637        create_kernel_page_table(early_pg_dir, map_size, true);
 638
 639#ifndef __PAGETABLE_PMD_FOLDED
 640        /* Setup early PMD for DTB */
 641        create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA,
 642                           (uintptr_t)early_dtb_pmd, PGDIR_SIZE, PAGE_TABLE);
 643#ifndef CONFIG_BUILTIN_DTB
 644        /* Create two consecutive PMD mappings for FDT early scan */
 645        pa = dtb_pa & ~(PMD_SIZE - 1);
 646        create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA,
 647                           pa, PMD_SIZE, PAGE_KERNEL);
 648        create_pmd_mapping(early_dtb_pmd, DTB_EARLY_BASE_VA + PMD_SIZE,
 649                           pa + PMD_SIZE, PMD_SIZE, PAGE_KERNEL);
 650        dtb_early_va = (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PMD_SIZE - 1));
 651#else /* CONFIG_BUILTIN_DTB */
 652#ifdef CONFIG_64BIT
 653        /*
 654         * __va can't be used since it would return a linear mapping address
 655         * whereas dtb_early_va will be used before setup_vm_final installs
 656         * the linear mapping.
 657         */
 658        dtb_early_va = kernel_mapping_pa_to_va(XIP_FIXUP(dtb_pa));
 659#else
 660        dtb_early_va = __va(dtb_pa);
 661#endif /* CONFIG_64BIT */
 662#endif /* CONFIG_BUILTIN_DTB */
 663#else
 664#ifndef CONFIG_BUILTIN_DTB
 665        /* Create two consecutive PGD mappings for FDT early scan */
 666        pa = dtb_pa & ~(PGDIR_SIZE - 1);
 667        create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA,
 668                           pa, PGDIR_SIZE, PAGE_KERNEL);
 669        create_pgd_mapping(early_pg_dir, DTB_EARLY_BASE_VA + PGDIR_SIZE,
 670                           pa + PGDIR_SIZE, PGDIR_SIZE, PAGE_KERNEL);
 671        dtb_early_va = (void *)DTB_EARLY_BASE_VA + (dtb_pa & (PGDIR_SIZE - 1));
 672#else /* CONFIG_BUILTIN_DTB */
 673#ifdef CONFIG_64BIT
 674        dtb_early_va = kernel_mapping_pa_to_va(XIP_FIXUP(dtb_pa));
 675#else
 676        dtb_early_va = __va(dtb_pa);
 677#endif /* CONFIG_64BIT */
 678#endif /* CONFIG_BUILTIN_DTB */
 679#endif
 680        dtb_early_pa = dtb_pa;
 681
 682        /*
 683         * Bootime fixmap only can handle PMD_SIZE mapping. Thus, boot-ioremap
 684         * range can not span multiple pmds.
 685         */
 686        BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
 687                     != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
 688
 689#ifndef __PAGETABLE_PMD_FOLDED
 690        /*
 691         * Early ioremap fixmap is already created as it lies within first 2MB
 692         * of fixmap region. We always map PMD_SIZE. Thus, both FIX_BTMAP_END
 693         * FIX_BTMAP_BEGIN should lie in the same pmd. Verify that and warn
 694         * the user if not.
 695         */
 696        fix_bmap_spmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_BEGIN))];
 697        fix_bmap_epmd = fixmap_pmd[pmd_index(__fix_to_virt(FIX_BTMAP_END))];
 698        if (pmd_val(fix_bmap_spmd) != pmd_val(fix_bmap_epmd)) {
 699                WARN_ON(1);
 700                pr_warn("fixmap btmap start [%08lx] != end [%08lx]\n",
 701                        pmd_val(fix_bmap_spmd), pmd_val(fix_bmap_epmd));
 702                pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
 703                        fix_to_virt(FIX_BTMAP_BEGIN));
 704                pr_warn("fix_to_virt(FIX_BTMAP_END):   %08lx\n",
 705                        fix_to_virt(FIX_BTMAP_END));
 706
 707                pr_warn("FIX_BTMAP_END:       %d\n", FIX_BTMAP_END);
 708                pr_warn("FIX_BTMAP_BEGIN:     %d\n", FIX_BTMAP_BEGIN);
 709        }
 710#endif
 711}
 712
 713static void __init setup_vm_final(void)
 714{
 715        uintptr_t va, map_size;
 716        phys_addr_t pa, start, end;
 717        u64 i;
 718
 719        /**
 720         * MMU is enabled at this point. But page table setup is not complete yet.
 721         * fixmap page table alloc functions should be used at this point
 722         */
 723        pt_ops.alloc_pte = alloc_pte_fixmap;
 724        pt_ops.get_pte_virt = get_pte_virt_fixmap;
 725#ifndef __PAGETABLE_PMD_FOLDED
 726        pt_ops.alloc_pmd = alloc_pmd_fixmap;
 727        pt_ops.get_pmd_virt = get_pmd_virt_fixmap;
 728#endif
 729        /* Setup swapper PGD for fixmap */
 730        create_pgd_mapping(swapper_pg_dir, FIXADDR_START,
 731                           __pa_symbol(fixmap_pgd_next),
 732                           PGDIR_SIZE, PAGE_TABLE);
 733
 734        /* Map all memory banks in the linear mapping */
 735        for_each_mem_range(i, &start, &end) {
 736                if (start >= end)
 737                        break;
 738                if (start <= __pa(PAGE_OFFSET) &&
 739                    __pa(PAGE_OFFSET) < end)
 740                        start = __pa(PAGE_OFFSET);
 741                if (end >= __pa(PAGE_OFFSET) + memory_limit)
 742                        end = __pa(PAGE_OFFSET) + memory_limit;
 743
 744                map_size = best_map_size(start, end - start);
 745                for (pa = start; pa < end; pa += map_size) {
 746                        va = (uintptr_t)__va(pa);
 747
 748                        create_pgd_mapping(swapper_pg_dir, va, pa, map_size,
 749                                           pgprot_from_va(va));
 750                }
 751        }
 752
 753#ifdef CONFIG_64BIT
 754        /* Map the kernel */
 755        create_kernel_page_table(swapper_pg_dir, PMD_SIZE, false);
 756#endif
 757
 758        /* Clear fixmap PTE and PMD mappings */
 759        clear_fixmap(FIX_PTE);
 760        clear_fixmap(FIX_PMD);
 761
 762        /* Move to swapper page table */
 763        csr_write(CSR_SATP, PFN_DOWN(__pa_symbol(swapper_pg_dir)) | SATP_MODE);
 764        local_flush_tlb_all();
 765
 766        /* generic page allocation functions must be used to setup page table */
 767        pt_ops.alloc_pte = alloc_pte_late;
 768        pt_ops.get_pte_virt = get_pte_virt_late;
 769#ifndef __PAGETABLE_PMD_FOLDED
 770        pt_ops.alloc_pmd = alloc_pmd_late;
 771        pt_ops.get_pmd_virt = get_pmd_virt_late;
 772#endif
 773}
 774#else
 775asmlinkage void __init setup_vm(uintptr_t dtb_pa)
 776{
 777        dtb_early_va = (void *)dtb_pa;
 778        dtb_early_pa = dtb_pa;
 779}
 780
 781static inline void setup_vm_final(void)
 782{
 783}
 784#endif /* CONFIG_MMU */
 785
 786#ifdef CONFIG_KEXEC_CORE
 787/*
 788 * reserve_crashkernel() - reserves memory for crash kernel
 789 *
 790 * This function reserves memory area given in "crashkernel=" kernel command
 791 * line parameter. The memory reserved is used by dump capture kernel when
 792 * primary kernel is crashing.
 793 */
 794static void __init reserve_crashkernel(void)
 795{
 796        unsigned long long crash_base = 0;
 797        unsigned long long crash_size = 0;
 798        unsigned long search_start = memblock_start_of_DRAM();
 799        unsigned long search_end = memblock_end_of_DRAM();
 800
 801        int ret = 0;
 802
 803        /*
 804         * Don't reserve a region for a crash kernel on a crash kernel
 805         * since it doesn't make much sense and we have limited memory
 806         * resources.
 807         */
 808#ifdef CONFIG_CRASH_DUMP
 809        if (is_kdump_kernel()) {
 810                pr_info("crashkernel: ignoring reservation request\n");
 811                return;
 812        }
 813#endif
 814
 815        ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
 816                                &crash_size, &crash_base);
 817        if (ret || !crash_size)
 818                return;
 819
 820        crash_size = PAGE_ALIGN(crash_size);
 821
 822        if (crash_base == 0) {
 823                /*
 824                 * Current riscv boot protocol requires 2MB alignment for
 825                 * RV64 and 4MB alignment for RV32 (hugepage size)
 826                 */
 827                crash_base = memblock_find_in_range(search_start, search_end,
 828                                                    crash_size, PMD_SIZE);
 829
 830                if (crash_base == 0) {
 831                        pr_warn("crashkernel: couldn't allocate %lldKB\n",
 832                                crash_size >> 10);
 833                        return;
 834                }
 835        } else {
 836                /* User specifies base address explicitly. */
 837                if (!memblock_is_region_memory(crash_base, crash_size)) {
 838                        pr_warn("crashkernel: requested region is not memory\n");
 839                        return;
 840                }
 841
 842                if (memblock_is_region_reserved(crash_base, crash_size)) {
 843                        pr_warn("crashkernel: requested region is reserved\n");
 844                        return;
 845                }
 846
 847
 848                if (!IS_ALIGNED(crash_base, PMD_SIZE)) {
 849                        pr_warn("crashkernel: requested region is misaligned\n");
 850                        return;
 851                }
 852        }
 853        memblock_reserve(crash_base, crash_size);
 854
 855        pr_info("crashkernel: reserved 0x%016llx - 0x%016llx (%lld MB)\n",
 856                crash_base, crash_base + crash_size, crash_size >> 20);
 857
 858        crashk_res.start = crash_base;
 859        crashk_res.end = crash_base + crash_size - 1;
 860}
 861#endif /* CONFIG_KEXEC_CORE */
 862
 863#ifdef CONFIG_CRASH_DUMP
 864/*
 865 * We keep track of the ELF core header of the crashed
 866 * kernel with a reserved-memory region with compatible
 867 * string "linux,elfcorehdr". Here we register a callback
 868 * to populate elfcorehdr_addr/size when this region is
 869 * present. Note that this region will be marked as
 870 * reserved once we call early_init_fdt_scan_reserved_mem()
 871 * later on.
 872 */
 873static int __init elfcore_hdr_setup(struct reserved_mem *rmem)
 874{
 875        elfcorehdr_addr = rmem->base;
 876        elfcorehdr_size = rmem->size;
 877        return 0;
 878}
 879
 880RESERVEDMEM_OF_DECLARE(elfcorehdr, "linux,elfcorehdr", elfcore_hdr_setup);
 881#endif
 882
 883void __init paging_init(void)
 884{
 885        setup_bootmem();
 886        setup_vm_final();
 887}
 888
 889void __init misc_mem_init(void)
 890{
 891        early_memtest(min_low_pfn << PAGE_SHIFT, max_low_pfn << PAGE_SHIFT);
 892        arch_numa_init();
 893        sparse_init();
 894        zone_sizes_init();
 895#ifdef CONFIG_KEXEC_CORE
 896        reserve_crashkernel();
 897#endif
 898        memblock_dump_all();
 899}
 900
 901#ifdef CONFIG_SPARSEMEM_VMEMMAP
 902int __meminit vmemmap_populate(unsigned long start, unsigned long end, int node,
 903                               struct vmem_altmap *altmap)
 904{
 905        return vmemmap_populate_basepages(start, end, node, NULL);
 906}
 907#endif
 908
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