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/bootmem.h>
  11 #include <linux/mman.h>
  12 #include <linux/nodemask.h>
  13 #include <linux/initrd.h>
  14 #include <linux/highmem.h>
  15 #include <linux/memblock.h>
  16
  17 #include <asm/sections.h>
  18 #include <asm/setup.h>
  19 #include <asm/tlb.h>
  20 #include <asm/page.h>
  21
  22 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  23 DEFINE_SPINLOCK(anon_alias_lock);
  24 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
  25 extern unsigned long phys_initrd_start;
  26 extern unsigned long phys_initrd_size;
  27
  28 /*
  29  * empty_zero_page is a special page that is used for
  30  * zero-initialized data and COW.
  31  */
  32 struct page *empty_zero_page;
  33
  34 static void __init zone_sizes_init(void)
  35 {
  36         unsigned long zones_size[MAX_NR_ZONES];
  37
  38         /* Clear the zone sizes */
  39         memset(zones_size, 0, sizeof(zones_size));
  40
  41         zones_size[ZONE_NORMAL] = max_low_pfn;
  42 #ifdef CONFIG_HIGHMEM
  43         zones_size[ZONE_HIGHMEM] = max_pfn;
  44 #endif
  45         free_area_init(zones_size);
  46
  47 }
  48
  49 /*
  50  * Map all physical memory under high_memory into kernel's address space.
  51  *
  52  * This is explicitly coded for two-level page tables, so if you need
  53  * something else then this needs to change.
  54  */
  55 static void __init map_ram(void)
  56 {
  57         unsigned long v, p, e;
  58         pgd_t *pge;
  59         pud_t *pue;
  60         pmd_t *pme;
  61         pte_t *pte;
  62         /* These mark extents of read-only kernel pages...
  63          * ...from vmlinux.lds.S
  64          */
  65
  66         p = (u32) memblock_start_of_DRAM() & PAGE_MASK;
  67         e = min((u32) memblock_end_of_DRAM(), (u32) __pa(high_memory));
  68
  69         v = (u32) __va(p);
  70         pge = pgd_offset_k(v);
  71
  72         while (p < e) {
  73                 int j;
  74                 pue = pud_offset(pge, v);
  75                 pme = pmd_offset(pue, v);
  76
  77                 if ((u32) pue != (u32) pge || (u32) pme != (u32) pge) {
  78                         panic("%s: Kernel hardcoded for "
  79                               "two-level page tables", __func__);
  80                 }
  81
  82                 /* Alloc one page for holding PTE's... */
  83                 pte = (pte_t *) __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE));
  84                 memset(pte, 0, 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 }
  98 static pmd_t *fixmap_pmd_p;
  99 static 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 = (pmd_t *) __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE));
 117         memset(fixmap_pmd_p, 0, PAGE_SIZE);
 118         set_pmd(pmd, __pmd(__pa(fixmap_pmd_p) + _PAGE_KERNEL_TABLE));
 119
 120 #ifdef CONFIG_HIGHMEM
 121         /*
 122          * Permanent kmaps:
 123          */
 124         vaddr = PKMAP_BASE;
 125
 126         pgd = swapper_pg_dir + pgd_index(vaddr);
 127         pud = pud_offset(pgd, vaddr);
 128         pmd = pmd_offset(pud, vaddr);
 129         pte = (pte_t *) __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE));
 130         memset(pte, 0, PAGE_SIZE);
 131         set_pmd(pmd, __pmd(__pa(pte) + _PAGE_KERNEL_TABLE));
 132         pkmap_page_table = pte;
 133 #endif /* CONFIG_HIGHMEM */
 134 }
 135
 136 /*
 137  * paging_init() sets up the page tables, initialises the zone memory
 138  * maps, and sets up the zero page, bad page and bad page tables.
 139  */
 140 void __init paging_init(void)
 141 {
 142         int i;
 143         void *zero_page;
 144
 145         pr_info("Setting up paging and PTEs.\n");
 146         /* clear out the init_mm.pgd that will contain the kernel's mappings */
 147         for (i = 0; i < PTRS_PER_PGD; i++)
 148                 swapper_pg_dir[i] = __pgd(1);
 149
 150         map_ram();
 151
 152         fixedrange_init();
 153
 154         /* allocate space for empty_zero_page */
 155         zero_page = __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE));
 156         memset(zero_page, 0, PAGE_SIZE);
 157         zone_sizes_init();
 158
 159         empty_zero_page = virt_to_page(zero_page);
 160         flush_dcache_page(empty_zero_page);
 161 }
 162
 163 static inline void __init free_highmem(void)
 164 {
 165 #ifdef CONFIG_HIGHMEM
 166         unsigned long pfn;
 167         for (pfn = PFN_UP(__pa(high_memory)); pfn < max_pfn; pfn++) {
 168                 phys_addr_t paddr = (phys_addr_t) pfn << PAGE_SHIFT;
 169                 if (!memblock_is_reserved(paddr))
 170                         free_highmem_page(pfn_to_page(pfn));
 171         }
 172 #endif
 173 }
 174
 175 static void __init set_max_mapnr_init(void)
 176 {
 177         max_mapnr = max_pfn;
 178 }
 179
 180 /*
 181  * mem_init() marks the free areas in the mem_map and tells us how much
 182  * memory is free.  This is done after various parts of the system have
 183  * claimed their memory after the kernel image.
 184  */
 185 void __init mem_init(void)
 186 {
 187         phys_addr_t memory_start = memblock_start_of_DRAM();
 188         BUG_ON(!mem_map);
 189         set_max_mapnr_init();
 190
 191         free_highmem();
 192
 193         /* this will put all low memory onto the freelists */
 194         free_all_bootmem();
 195         mem_init_print_info(NULL);
 196
 197         pr_info("virtual kernel memory layout:\n"
 198                 "    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 199 #ifdef CONFIG_HIGHMEM
 200                 "    pkmap   : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 201 #endif
 202                 "    consist : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 203                 "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 204                 "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 205                 "      .init : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 206                 "      .data : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 207                 "      .text : 0x%08lx - 0x%08lx   (%4ld kB)\n",
 208                 FIXADDR_START, FIXADDR_TOP, (FIXADDR_TOP - FIXADDR_START) >> 10,
 209 #ifdef CONFIG_HIGHMEM
 210                 PKMAP_BASE, PKMAP_BASE + LAST_PKMAP * PAGE_SIZE,
 211                 (LAST_PKMAP * PAGE_SIZE) >> 10,
 212 #endif
 213                 CONSISTENT_BASE, CONSISTENT_END,
 214                 ((CONSISTENT_END) - (CONSISTENT_BASE)) >> 20, VMALLOC_START,
 215                 (unsigned long)VMALLOC_END, (VMALLOC_END - VMALLOC_START) >> 20,
 216                 (unsigned long)__va(memory_start), (unsigned long)high_memory,
 217                 ((unsigned long)high_memory -
 218                  (unsigned long)__va(memory_start)) >> 20,
 219                 (unsigned long)&__init_begin, (unsigned long)&__init_end,
 220                 ((unsigned long)&__init_end -
 221                  (unsigned long)&__init_begin) >> 10, (unsigned long)&_etext,
 222                 (unsigned long)&_edata,
 223                 ((unsigned long)&_edata - (unsigned long)&_etext) >> 10,
 224                 (unsigned long)&_text, (unsigned long)&_etext,
 225                 ((unsigned long)&_etext - (unsigned long)&_text) >> 10);
 226
 227         /*
 228          * Check boundaries twice: Some fundamental inconsistencies can
 229          * be detected at build time already.
 230          */
 231 #ifdef CONFIG_HIGHMEM
 232         BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > FIXADDR_START);
 233         BUILD_BUG_ON((CONSISTENT_END) > PKMAP_BASE);
 234 #endif
 235         BUILD_BUG_ON(VMALLOC_END > CONSISTENT_BASE);
 236         BUILD_BUG_ON(VMALLOC_START >= VMALLOC_END);
 237
 238 #ifdef CONFIG_HIGHMEM
 239         BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > FIXADDR_START);
 240         BUG_ON(CONSISTENT_END > PKMAP_BASE);
 241 #endif
 242         BUG_ON(VMALLOC_END > CONSISTENT_BASE);
 243         BUG_ON(VMALLOC_START >= VMALLOC_END);
 244         BUG_ON((unsigned long)high_memory > VMALLOC_START);
 245
 246         return;
 247 }
 248
 249 void free_initmem(void)
 250 {
 251         free_initmem_default(-1);
 252 }
 253
 254 #ifdef CONFIG_BLK_DEV_INITRD
 255 void free_initrd_mem(unsigned long start, unsigned long end)
 256 {
 257         free_reserved_area((void *)start, (void *)end, -1, "initrd");
 258 }
 259 #endif
 260
 261 void __set_fixmap(enum fixed_addresses idx,
 262                                phys_addr_t phys, pgprot_t flags)
 263 {
 264         unsigned long addr = __fix_to_virt(idx);
 265         pte_t *pte;
 266
 267         BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
 268
 269         pte = (pte_t *)&fixmap_pmd_p[pte_index(addr)];;
 270
 271         if (pgprot_val(flags)) {
 272                 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
 273         } else {
 274                 pte_clear(&init_mm, addr, pte);
 275                 flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
 276         }
 277 }