LXR linux/arch/nds32/mm/init.c

   1// SPDX-License-Identifier: GPL-2.0
   2// Copyright (C) 1995-2005 Russell King
   3// Copyright (C) 2012 ARM Ltd.
   4// Copyright (C) 2013-2017 Andes Technology Corporation
   5
   6#include <linux/kernel.h>
   7#include <linux/errno.h>
   8#include <linux/swap.h>
   9#include <linux/init.h>
  10#include <linux/memblock.h>
  11#include <linux/mman.h>
  12#include <linux/nodemask.h>
  13#include <linux/initrd.h>
  14#include <linux/highmem.h>
  15
  16#include <asm/sections.h>
  17#include <asm/setup.h>
  18#include <asm/tlb.h>
  19#include <asm/page.h>
  20
  21DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  22DEFINE_SPINLOCK(anon_alias_lock);
  23extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
  24
  25/*
  26 * empty_zero_page is a special page that is used for
  27 * zero-initialized data and COW.
  28 */
  29struct page *empty_zero_page;
  30EXPORT_SYMBOL(empty_zero_page);
  31
  32static void __init zone_sizes_init(void)
  33{
  34        unsigned long zones_size[MAX_NR_ZONES];
  35
  36        /* Clear the zone sizes */
  37        memset(zones_size, 0, sizeof(zones_size));
  38
  39        zones_size[ZONE_NORMAL] = max_low_pfn;
  40#ifdef CONFIG_HIGHMEM
  41        zones_size[ZONE_HIGHMEM] = max_pfn;
  42#endif
  43        free_area_init(zones_size);
  44
  45}
  46
  47/*
  48 * Map all physical memory under high_memory into kernel's address space.
  49 *
  50 * This is explicitly coded for two-level page tables, so if you need
  51 * something else then this needs to change.
  52 */
  53static void __init map_ram(void)
  54{
  55        unsigned long v, p, e;
  56        pgd_t *pge;
  57        pud_t *pue;
  58        pmd_t *pme;
  59        pte_t *pte;
  60        /* These mark extents of read-only kernel pages...
  61         * ...from vmlinux.lds.S
  62         */
  63
  64        p = (u32) memblock_start_of_DRAM() & PAGE_MASK;
  65        e = min((u32) memblock_end_of_DRAM(), (u32) __pa(high_memory));
  66
  67        v = (u32) __va(p);
  68        pge = pgd_offset_k(v);
  69
  70        while (p < e) {
  71                int j;
  72                pue = pud_offset(pge, v);
  73                pme = pmd_offset(pue, v);
  74
  75                if ((u32) pue != (u32) pge || (u32) pme != (u32) pge) {
  76                        panic("%s: Kernel hardcoded for "
  77                              "two-level page tables", __func__);
  78                }
  79
  80                /* Alloc one page for holding PTE's... */
  81                pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
  82                if (!pte)
  83                        panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
  84                              __func__, PAGE_SIZE, PAGE_SIZE);
  85                set_pmd(pme, __pmd(__pa(pte) + _PAGE_KERNEL_TABLE));
  86
  87                /* Fill the newly allocated page with PTE'S */
  88                for (j = 0; p < e && j < PTRS_PER_PTE;
  89                     v += PAGE_SIZE, p += PAGE_SIZE, j++, pte++) {
  90                        /* Create mapping between p and v. */
  91                        /* TODO: more fine grant for page access permission */
  92                        set_pte(pte, __pte(p + pgprot_val(PAGE_KERNEL)));
  93                }
  94
  95                pge++;
  96        }
  97}
  98static pmd_t *fixmap_pmd_p;
  99static void __init fixedrange_init(void)
 100{
 101        unsigned long vaddr;
 102        pgd_t *pgd;
 103        pud_t *pud;
 104        pmd_t *pmd;
 105#ifdef CONFIG_HIGHMEM
 106        pte_t *pte;
 107#endif /* CONFIG_HIGHMEM */
 108
 109        /*
 110         * Fixed mappings:
 111         */
 112        vaddr = __fix_to_virt(__end_of_fixed_addresses - 1);
 113        pgd = swapper_pg_dir + pgd_index(vaddr);
 114        pud = pud_offset(pgd, vaddr);
 115        pmd = pmd_offset(pud, vaddr);
 116        fixmap_pmd_p = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
 117        if (!fixmap_pmd_p)
 118                panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
 119                      __func__, PAGE_SIZE, PAGE_SIZE);
 120        set_pmd(pmd, __pmd(__pa(fixmap_pmd_p) + _PAGE_KERNEL_TABLE));
 121
 122#ifdef CONFIG_HIGHMEM
 123        /*
 124         * Permanent kmaps:
 125         */
 126        vaddr = PKMAP_BASE;
 127
 128        pgd = swapper_pg_dir + pgd_index(vaddr);
 129        pud = pud_offset(pgd, vaddr);
 130        pmd = pmd_offset(pud, vaddr);
 131        pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
 132        if (!pte)
 133                panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
 134                      __func__, PAGE_SIZE, PAGE_SIZE);
 135        set_pmd(pmd, __pmd(__pa(pte) + _PAGE_KERNEL_TABLE));
 136        pkmap_page_table = pte;
 137#endif /* CONFIG_HIGHMEM */
 138}
 139
 140/*
 141 * paging_init() sets up the page tables, initialises the zone memory
 142 * maps, and sets up the zero page, bad page and bad page tables.
 143 */
 144void __init paging_init(void)
 145{
 146        int i;
 147        void *zero_page;
 148
 149        pr_info("Setting up paging and PTEs.\n");
 150        /* clear out the init_mm.pgd that will contain the kernel's mappings */
 151        for (i = 0; i < PTRS_PER_PGD; i++)
 152                swapper_pg_dir[i] = __pgd(1);
 153
 154        map_ram();
 155
 156        fixedrange_init();
 157
 158        /* allocate space for empty_zero_page */
 159        zero_page = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
 160        if (!zero_page)
 161                panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
 162                      __func__, PAGE_SIZE, PAGE_SIZE);
 163        zone_sizes_init();
 164
 165        empty_zero_page = virt_to_page(zero_page);
 166        flush_dcache_page(empty_zero_page);
 167}
 168
 169static inline void __init free_highmem(void)
 170{
 171#ifdef CONFIG_HIGHMEM
 172        unsigned long pfn;
 173        for (pfn = PFN_UP(__pa(high_memory)); pfn < max_pfn; pfn++) {
 174                phys_addr_t paddr = (phys_addr_t) pfn << PAGE_SHIFT;
 175                if (!memblock_is_reserved(paddr))
 176                        free_highmem_page(pfn_to_page(pfn));
 177        }
 178#endif
 179}
 180
 181static void __init set_max_mapnr_init(void)
 182{
 183        max_mapnr = max_pfn;
 184}
 185
 186/*
 187 * mem_init() marks the free areas in the mem_map and tells us how much
 188 * memory is free.  This is done after various parts of the system have
 189 * claimed their memory after the kernel image.
 190 */
 191void __init mem_init(void)
 192{
 193        phys_addr_t memory_start = memblock_start_of_DRAM();
 194        BUG_ON(!mem_map);
 195        set_max_mapnr_init();
 196
 197        free_highmem();
 198
 199        /* this will put all low memory onto the freelists */
 200        memblock_free_all();
 201        mem_init_print_info(NULL);
 202
 203        pr_info("virtual kernel memory layout:\n"
 204                "    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 205#ifdef CONFIG_HIGHMEM
 206                "    pkmap   : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 207#endif
 208                "    consist : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 209                "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 210                "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 211                "      .init : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 212                "      .data : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 213                "      .text : 0x%08lx - 0x%08lx   (%4ld kB)\n",
 214                FIXADDR_START, FIXADDR_TOP, (FIXADDR_TOP - FIXADDR_START) >> 10,
 215#ifdef CONFIG_HIGHMEM
 216                PKMAP_BASE, PKMAP_BASE + LAST_PKMAP * PAGE_SIZE,
 217                (LAST_PKMAP * PAGE_SIZE) >> 10,
 218#endif
 219                CONSISTENT_BASE, CONSISTENT_END,
 220                ((CONSISTENT_END) - (CONSISTENT_BASE)) >> 20, VMALLOC_START,
 221                (unsigned long)VMALLOC_END, (VMALLOC_END - VMALLOC_START) >> 20,
 222                (unsigned long)__va(memory_start), (unsigned long)high_memory,
 223                ((unsigned long)high_memory -
 224                 (unsigned long)__va(memory_start)) >> 20,
 225                (unsigned long)&__init_begin, (unsigned long)&__init_end,
 226                ((unsigned long)&__init_end -
 227                 (unsigned long)&__init_begin) >> 10, (unsigned long)&_etext,
 228                (unsigned long)&_edata,
 229                ((unsigned long)&_edata - (unsigned long)&_etext) >> 10,
 230                (unsigned long)&_text, (unsigned long)&_etext,
 231                ((unsigned long)&_etext - (unsigned long)&_text) >> 10);
 232
 233        /*
 234         * Check boundaries twice: Some fundamental inconsistencies can
 235         * be detected at build time already.
 236         */
 237#ifdef CONFIG_HIGHMEM
 238        BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > FIXADDR_START);
 239        BUILD_BUG_ON((CONSISTENT_END) > PKMAP_BASE);
 240#endif
 241        BUILD_BUG_ON(VMALLOC_END > CONSISTENT_BASE);
 242        BUILD_BUG_ON(VMALLOC_START >= VMALLOC_END);
 243
 244#ifdef CONFIG_HIGHMEM
 245        BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > FIXADDR_START);
 246        BUG_ON(CONSISTENT_END > PKMAP_BASE);
 247#endif
 248        BUG_ON(VMALLOC_END > CONSISTENT_BASE);
 249        BUG_ON(VMALLOC_START >= VMALLOC_END);
 250        BUG_ON((unsigned long)high_memory > VMALLOC_START);
 251
 252        return;
 253}
 254
 255void __set_fixmap(enum fixed_addresses idx,
 256                               phys_addr_t phys, pgprot_t flags)
 257{
 258        unsigned long addr = __fix_to_virt(idx);
 259        pte_t *pte;
 260
 261        BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
 262
 263        pte = (pte_t *)&fixmap_pmd_p[pte_index(addr)];
 264
 265        if (pgprot_val(flags)) {
 266                set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
 267        } else {
 268                pte_clear(&init_mm, addr, pte);
 269                flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
 270        }
 271}
 272