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
  21 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  22 DEFINE_SPINLOCK(anon_alias_lock);
  23 extern 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  */
  29 struct page *empty_zero_page;
  30 EXPORT_SYMBOL(empty_zero_page);
  31
  32 static 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  */
  53 static void __init map_ram(void)
  54 {
  55         unsigned long v, p, e;
  56         pgd_t *pge;
  57         p4d_t *p4e;
  58         pud_t *pue;
  59         pmd_t *pme;
  60         pte_t *pte;
  61         /* These mark extents of read-only kernel pages...
  62          * ...from vmlinux.lds.S
  63          */
  64
  65         p = (u32) memblock_start_of_DRAM() & PAGE_MASK;
  66         e = min((u32) memblock_end_of_DRAM(), (u32) __pa(high_memory));
  67
  68         v = (u32) __va(p);
  69         pge = pgd_offset_k(v);
  70
  71         while (p < e) {
  72                 int j;
  73                 p4e = p4d_offset(pge, v);
  74                 pue = pud_offset(p4e, 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 = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
  84                 if (!pte)
  85                         panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
  86                               __func__, PAGE_SIZE, PAGE_SIZE);
  87                 set_pmd(pme, __pmd(__pa(pte) + _PAGE_KERNEL_TABLE));
  88
  89                 /* Fill the newly allocated page with PTE'S */
  90                 for (j = 0; p < e && j < PTRS_PER_PTE;
  91                      v += PAGE_SIZE, p += PAGE_SIZE, j++, pte++) {
  92                         /* Create mapping between p and v. */
  93                         /* TODO: more fine grant for page access permission */
  94                         set_pte(pte, __pte(p + pgprot_val(PAGE_KERNEL)));
  95                 }
  96
  97                 pge++;
  98         }
  99 }
 100 static pmd_t *fixmap_pmd_p;
 101 static void __init fixedrange_init(void)
 102 {
 103         unsigned long vaddr;
 104         pgd_t *pgd;
 105         p4d_t *p4d;
 106         pud_t *pud;
 107         pmd_t *pmd;
 108 #ifdef CONFIG_HIGHMEM
 109         pte_t *pte;
 110 #endif /* CONFIG_HIGHMEM */
 111
 112         /*
 113          * Fixed mappings:
 114          */
 115         vaddr = __fix_to_virt(__end_of_fixed_addresses - 1);
 116         pgd = swapper_pg_dir + pgd_index(vaddr);
 117         p4d = p4d_offset(pgd, vaddr);
 118         pud = pud_offset(p4d, vaddr);
 119         pmd = pmd_offset(pud, vaddr);
 120         fixmap_pmd_p = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
 121         if (!fixmap_pmd_p)
 122                 panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
 123                       __func__, PAGE_SIZE, PAGE_SIZE);
 124         set_pmd(pmd, __pmd(__pa(fixmap_pmd_p) + _PAGE_KERNEL_TABLE));
 125
 126 #ifdef CONFIG_HIGHMEM
 127         /*
 128          * Permanent kmaps:
 129          */
 130         vaddr = PKMAP_BASE;
 131
 132         pgd = swapper_pg_dir + pgd_index(vaddr);
 133         p4d = p4d_offset(pgd, vaddr);
 134         pud = pud_offset(p4d, vaddr);
 135         pmd = pmd_offset(pud, vaddr);
 136         pte = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
 137         if (!pte)
 138                 panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
 139                       __func__, PAGE_SIZE, PAGE_SIZE);
 140         set_pmd(pmd, __pmd(__pa(pte) + _PAGE_KERNEL_TABLE));
 141         pkmap_page_table = pte;
 142 #endif /* CONFIG_HIGHMEM */
 143 }
 144
 145 /*
 146  * paging_init() sets up the page tables, initialises the zone memory
 147  * maps, and sets up the zero page, bad page and bad page tables.
 148  */
 149 void __init paging_init(void)
 150 {
 151         int i;
 152         void *zero_page;
 153
 154         pr_info("Setting up paging and PTEs.\n");
 155         /* clear out the init_mm.pgd that will contain the kernel's mappings */
 156         for (i = 0; i < PTRS_PER_PGD; i++)
 157                 swapper_pg_dir[i] = __pgd(1);
 158
 159         map_ram();
 160
 161         fixedrange_init();
 162
 163         /* allocate space for empty_zero_page */
 164         zero_page = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
 165         if (!zero_page)
 166                 panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
 167                       __func__, PAGE_SIZE, PAGE_SIZE);
 168         zone_sizes_init();
 169
 170         empty_zero_page = virt_to_page(zero_page);
 171         flush_dcache_page(empty_zero_page);
 172 }
 173
 174 static inline void __init free_highmem(void)
 175 {
 176 #ifdef CONFIG_HIGHMEM
 177         unsigned long pfn;
 178         for (pfn = PFN_UP(__pa(high_memory)); pfn < max_pfn; pfn++) {
 179                 phys_addr_t paddr = (phys_addr_t) pfn << PAGE_SHIFT;
 180                 if (!memblock_is_reserved(paddr))
 181                         free_highmem_page(pfn_to_page(pfn));
 182         }
 183 #endif
 184 }
 185
 186 static void __init set_max_mapnr_init(void)
 187 {
 188         max_mapnr = max_pfn;
 189 }
 190
 191 /*
 192  * mem_init() marks the free areas in the mem_map and tells us how much
 193  * memory is free.  This is done after various parts of the system have
 194  * claimed their memory after the kernel image.
 195  */
 196 void __init mem_init(void)
 197 {
 198         phys_addr_t memory_start = memblock_start_of_DRAM();
 199         BUG_ON(!mem_map);
 200         set_max_mapnr_init();
 201
 202         free_highmem();
 203
 204         /* this will put all low memory onto the freelists */
 205         memblock_free_all();
 206         mem_init_print_info(NULL);
 207
 208         pr_info("virtual kernel memory layout:\n"
 209                 "    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 210 #ifdef CONFIG_HIGHMEM
 211                 "    pkmap   : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 212 #endif
 213                 "    consist : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 214                 "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 215                 "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 216                 "      .init : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 217                 "      .data : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 218                 "      .text : 0x%08lx - 0x%08lx   (%4ld kB)\n",
 219                 FIXADDR_START, FIXADDR_TOP, (FIXADDR_TOP - FIXADDR_START) >> 10,
 220 #ifdef CONFIG_HIGHMEM
 221                 PKMAP_BASE, PKMAP_BASE + LAST_PKMAP * PAGE_SIZE,
 222                 (LAST_PKMAP * PAGE_SIZE) >> 10,
 223 #endif
 224                 CONSISTENT_BASE, CONSISTENT_END,
 225                 ((CONSISTENT_END) - (CONSISTENT_BASE)) >> 20, VMALLOC_START,
 226                 (unsigned long)VMALLOC_END, (VMALLOC_END - VMALLOC_START) >> 20,
 227                 (unsigned long)__va(memory_start), (unsigned long)high_memory,
 228                 ((unsigned long)high_memory -
 229                  (unsigned long)__va(memory_start)) >> 20,
 230                 (unsigned long)&__init_begin, (unsigned long)&__init_end,
 231                 ((unsigned long)&__init_end -
 232                  (unsigned long)&__init_begin) >> 10, (unsigned long)&_etext,
 233                 (unsigned long)&_edata,
 234                 ((unsigned long)&_edata - (unsigned long)&_etext) >> 10,
 235                 (unsigned long)&_text, (unsigned long)&_etext,
 236                 ((unsigned long)&_etext - (unsigned long)&_text) >> 10);
 237
 238         /*
 239          * Check boundaries twice: Some fundamental inconsistencies can
 240          * be detected at build time already.
 241          */
 242 #ifdef CONFIG_HIGHMEM
 243         BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > FIXADDR_START);
 244         BUILD_BUG_ON((CONSISTENT_END) > PKMAP_BASE);
 245 #endif
 246         BUILD_BUG_ON(VMALLOC_END > CONSISTENT_BASE);
 247         BUILD_BUG_ON(VMALLOC_START >= VMALLOC_END);
 248
 249 #ifdef CONFIG_HIGHMEM
 250         BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > FIXADDR_START);
 251         BUG_ON(CONSISTENT_END > PKMAP_BASE);
 252 #endif
 253         BUG_ON(VMALLOC_END > CONSISTENT_BASE);
 254         BUG_ON(VMALLOC_START >= VMALLOC_END);
 255         BUG_ON((unsigned long)high_memory > VMALLOC_START);
 256
 257         return;
 258 }
 259
 260 void __set_fixmap(enum fixed_addresses idx,
 261                                phys_addr_t phys, pgprot_t flags)
 262 {
 263         unsigned long addr = __fix_to_virt(idx);
 264         pte_t *pte;
 265
 266         BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
 267
 268         pte = (pte_t *)&fixmap_pmd_p[pte_index(addr)];
 269
 270         if (pgprot_val(flags)) {
 271                 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
 272         } else {
 273                 pte_clear(&init_mm, addr, pte);
 274                 flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
 275         }
 276 }