linux/arch/nds32/mm/init.c
<<
>>
Prefs
   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 max_zone_pfn[MAX_NR_ZONES] = { 0 };
  35
  36        max_zone_pfn[ZONE_NORMAL] = max_low_pfn;
  37#ifdef CONFIG_HIGHMEM
  38        max_zone_pfn[ZONE_HIGHMEM] = max_pfn;
  39#endif
  40        free_area_init(max_zone_pfn);
  41
  42}
  43
  44/*
  45 * Map all physical memory under high_memory into kernel's address space.
  46 *
  47 * This is explicitly coded for two-level page tables, so if you need
  48 * something else then this needs to change.
  49 */
  50static void __init map_ram(void)
  51{
  52        unsigned long v, p, e;
  53        pgd_t *pge;
  54        p4d_t *p4e;
  55        pud_t *pue;
  56        pmd_t *pme;
  57        pte_t *pte;
  58        /* These mark extents of read-only kernel pages...
  59         * ...from vmlinux.lds.S
  60         */
  61
  62        p = (u32) memblock_start_of_DRAM() & PAGE_MASK;
  63        e = min((u32) memblock_end_of_DRAM(), (u32) __pa(high_memory));
  64
  65        v = (u32) __va(p);
  66        pge = pgd_offset_k(v);
  67
  68        while (p < e) {
  69                int j;
  70                p4e = p4d_offset(pge, v);
  71                pue = pud_offset(p4e, v);
  72                pme = pmd_offset(pue, v);
  73
  74                if ((u32) pue != (u32) pge || (u32) pme != (u32) pge) {
  75                        panic("%s: Kernel hardcoded for "
  76                              "two-level page tables", __func__);
  77                }
  78
  79                /* Alloc one page for holding PTE's... */
  80                pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
  81                if (!pte)
  82                        panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
  83                              __func__, PAGE_SIZE, PAGE_SIZE);
  84                set_pmd(pme, __pmd(__pa(pte) + _PAGE_KERNEL_TABLE));
  85
  86                /* Fill the newly allocated page with PTE'S */
  87                for (j = 0; p < e && j < PTRS_PER_PTE;
  88                     v += PAGE_SIZE, p += PAGE_SIZE, j++, pte++) {
  89                        /* Create mapping between p and v. */
  90                        /* TODO: more fine grant for page access permission */
  91                        set_pte(pte, __pte(p + pgprot_val(PAGE_KERNEL)));
  92                }
  93
  94                pge++;
  95        }
  96}
  97static pmd_t *fixmap_pmd_p;
  98static void __init fixedrange_init(void)
  99{
 100        unsigned long vaddr;
 101        pmd_t *pmd;
 102#ifdef CONFIG_HIGHMEM
 103        pte_t *pte;
 104#endif /* CONFIG_HIGHMEM */
 105
 106        /*
 107         * Fixed mappings:
 108         */
 109        vaddr = __fix_to_virt(__end_of_fixed_addresses - 1);
 110        pmd = pmd_off_k(vaddr);
 111        fixmap_pmd_p = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
 112        if (!fixmap_pmd_p)
 113                panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
 114                      __func__, PAGE_SIZE, PAGE_SIZE);
 115        set_pmd(pmd, __pmd(__pa(fixmap_pmd_p) + _PAGE_KERNEL_TABLE));
 116
 117#ifdef CONFIG_HIGHMEM
 118        /*
 119         * Permanent kmaps:
 120         */
 121        vaddr = PKMAP_BASE;
 122
 123        pmd = pmd_off_k(vaddr);
 124        pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
 125        if (!pte)
 126                panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
 127                      __func__, PAGE_SIZE, PAGE_SIZE);
 128        set_pmd(pmd, __pmd(__pa(pte) + _PAGE_KERNEL_TABLE));
 129        pkmap_page_table = pte;
 130#endif /* CONFIG_HIGHMEM */
 131}
 132
 133/*
 134 * paging_init() sets up the page tables, initialises the zone memory
 135 * maps, and sets up the zero page, bad page and bad page tables.
 136 */
 137void __init paging_init(void)
 138{
 139        int i;
 140        void *zero_page;
 141
 142        pr_info("Setting up paging and PTEs.\n");
 143        /* clear out the init_mm.pgd that will contain the kernel's mappings */
 144        for (i = 0; i < PTRS_PER_PGD; i++)
 145                swapper_pg_dir[i] = __pgd(1);
 146
 147        map_ram();
 148
 149        fixedrange_init();
 150
 151        /* allocate space for empty_zero_page */
 152        zero_page = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
 153        if (!zero_page)
 154                panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
 155                      __func__, PAGE_SIZE, PAGE_SIZE);
 156        zone_sizes_init();
 157
 158        empty_zero_page = virt_to_page(zero_page);
 159        flush_dcache_page(empty_zero_page);
 160}
 161
 162static inline void __init free_highmem(void)
 163{
 164#ifdef CONFIG_HIGHMEM
 165        unsigned long pfn;
 166        for (pfn = PFN_UP(__pa(high_memory)); pfn < max_pfn; pfn++) {
 167                phys_addr_t paddr = (phys_addr_t) pfn << PAGE_SHIFT;
 168                if (!memblock_is_reserved(paddr))
 169                        free_highmem_page(pfn_to_page(pfn));
 170        }
 171#endif
 172}
 173
 174static void __init set_max_mapnr_init(void)
 175{
 176        max_mapnr = max_pfn;
 177}
 178
 179/*
 180 * mem_init() marks the free areas in the mem_map and tells us how much
 181 * memory is free.  This is done after various parts of the system have
 182 * claimed their memory after the kernel image.
 183 */
 184void __init mem_init(void)
 185{
 186        phys_addr_t memory_start = memblock_start_of_DRAM();
 187        BUG_ON(!mem_map);
 188        set_max_mapnr_init();
 189
 190        free_highmem();
 191
 192        /* this will put all low memory onto the freelists */
 193        memblock_free_all();
 194
 195        pr_info("virtual kernel memory layout:\n"
 196                "    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 197#ifdef CONFIG_HIGHMEM
 198                "    pkmap   : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 199#endif
 200                "    consist : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 201                "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 202                "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 203                "      .init : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 204                "      .data : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 205                "      .text : 0x%08lx - 0x%08lx   (%4ld kB)\n",
 206                FIXADDR_START, FIXADDR_TOP, (FIXADDR_TOP - FIXADDR_START) >> 10,
 207#ifdef CONFIG_HIGHMEM
 208                PKMAP_BASE, PKMAP_BASE + LAST_PKMAP * PAGE_SIZE,
 209                (LAST_PKMAP * PAGE_SIZE) >> 10,
 210#endif
 211                CONSISTENT_BASE, CONSISTENT_END,
 212                ((CONSISTENT_END) - (CONSISTENT_BASE)) >> 20, VMALLOC_START,
 213                (unsigned long)VMALLOC_END, (VMALLOC_END - VMALLOC_START) >> 20,
 214                (unsigned long)__va(memory_start), (unsigned long)high_memory,
 215                ((unsigned long)high_memory -
 216                 (unsigned long)__va(memory_start)) >> 20,
 217                (unsigned long)&__init_begin, (unsigned long)&__init_end,
 218                ((unsigned long)&__init_end -
 219                 (unsigned long)&__init_begin) >> 10, (unsigned long)&_etext,
 220                (unsigned long)&_edata,
 221                ((unsigned long)&_edata - (unsigned long)&_etext) >> 10,
 222                (unsigned long)&_text, (unsigned long)&_etext,
 223                ((unsigned long)&_etext - (unsigned long)&_text) >> 10);
 224
 225        /*
 226         * Check boundaries twice: Some fundamental inconsistencies can
 227         * be detected at build time already.
 228         */
 229#ifdef CONFIG_HIGHMEM
 230        BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > FIXADDR_START);
 231        BUILD_BUG_ON((CONSISTENT_END) > PKMAP_BASE);
 232#endif
 233        BUILD_BUG_ON(VMALLOC_END > CONSISTENT_BASE);
 234        BUILD_BUG_ON(VMALLOC_START >= VMALLOC_END);
 235
 236#ifdef CONFIG_HIGHMEM
 237        BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > FIXADDR_START);
 238        BUG_ON(CONSISTENT_END > PKMAP_BASE);
 239#endif
 240        BUG_ON(VMALLOC_END > CONSISTENT_BASE);
 241        BUG_ON(VMALLOC_START >= VMALLOC_END);
 242        BUG_ON((unsigned long)high_memory > VMALLOC_START);
 243
 244        return;
 245}
 246
 247void __set_fixmap(enum fixed_addresses idx,
 248                               phys_addr_t phys, pgprot_t flags)
 249{
 250        unsigned long addr = __fix_to_virt(idx);
 251        pte_t *pte;
 252
 253        BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
 254
 255        pte = (pte_t *)&fixmap_pmd_p[pte_index(addr)];
 256
 257        if (pgprot_val(flags)) {
 258                set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
 259        } else {
 260                pte_clear(&init_mm, addr, pte);
 261                flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
 262        }
 263}
 264
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.