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 EXPORT_SYMBOL(empty_zero_page);
  34
  35 static void __init zone_sizes_init(void)
  36 {
  37         unsigned long zones_size[MAX_NR_ZONES];
  38
  39         /* Clear the zone sizes */
  40         memset(zones_size, 0, sizeof(zones_size));
  41
  42         zones_size[ZONE_NORMAL] = max_low_pfn;
  43 #ifdef CONFIG_HIGHMEM
  44         zones_size[ZONE_HIGHMEM] = max_pfn;
  45 #endif
  46         free_area_init(zones_size);
  47
  48 }
  49
  50 /*
  51  * Map all physical memory under high_memory into kernel's address space.
  52  *
  53  * This is explicitly coded for two-level page tables, so if you need
  54  * something else then this needs to change.
  55  */
  56 static void __init map_ram(void)
  57 {
  58         unsigned long v, p, e;
  59         pgd_t *pge;
  60         pud_t *pue;
  61         pmd_t *pme;
  62         pte_t *pte;
  63         /* These mark extents of read-only kernel pages...
  64          * ...from vmlinux.lds.S
  65          */
  66
  67         p = (u32) memblock_start_of_DRAM() & PAGE_MASK;
  68         e = min((u32) memblock_end_of_DRAM(), (u32) __pa(high_memory));
  69
  70         v = (u32) __va(p);
  71         pge = pgd_offset_k(v);
  72
  73         while (p < e) {
  74                 int j;
  75                 pue = pud_offset(pge, v);
  76                 pme = pmd_offset(pue, v);
  77
  78                 if ((u32) pue != (u32) pge || (u32) pme != (u32) pge) {
  79                         panic("%s: Kernel hardcoded for "
  80                               "two-level page tables", __func__);
  81                 }
  82
  83                 /* Alloc one page for holding PTE's... */
  84                 pte = (pte_t *) __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE));
  85                 memset(pte, 0, PAGE_SIZE);
  86                 set_pmd(pme, __pmd(__pa(pte) + _PAGE_KERNEL_TABLE));
  87
  88                 /* Fill the newly allocated page with PTE'S */
  89                 for (j = 0; p < e && j < PTRS_PER_PTE;
  90                      v += PAGE_SIZE, p += PAGE_SIZE, j++, pte++) {
  91                         /* Create mapping between p and v. */
  92                         /* TODO: more fine grant for page access permission */
  93                         set_pte(pte, __pte(p + pgprot_val(PAGE_KERNEL)));
  94                 }
  95
  96                 pge++;
  97         }
  98 }
  99 static pmd_t *fixmap_pmd_p;
 100 static void __init fixedrange_init(void)
 101 {
 102         unsigned long vaddr;
 103         pgd_t *pgd;
 104         pud_t *pud;
 105         pmd_t *pmd;
 106 #ifdef CONFIG_HIGHMEM
 107         pte_t *pte;
 108 #endif /* CONFIG_HIGHMEM */
 109
 110         /*
 111          * Fixed mappings:
 112          */
 113         vaddr = __fix_to_virt(__end_of_fixed_addresses - 1);
 114         pgd = swapper_pg_dir + pgd_index(vaddr);
 115         pud = pud_offset(pgd, vaddr);
 116         pmd = pmd_offset(pud, vaddr);
 117         fixmap_pmd_p = (pmd_t *) __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE));
 118         memset(fixmap_pmd_p, 0, PAGE_SIZE);
 119         set_pmd(pmd, __pmd(__pa(fixmap_pmd_p) + _PAGE_KERNEL_TABLE));
 120
 121 #ifdef CONFIG_HIGHMEM
 122         /*
 123          * Permanent kmaps:
 124          */
 125         vaddr = PKMAP_BASE;
 126
 127         pgd = swapper_pg_dir + pgd_index(vaddr);
 128         pud = pud_offset(pgd, vaddr);
 129         pmd = pmd_offset(pud, vaddr);
 130         pte = (pte_t *) __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE));
 131         memset(pte, 0, PAGE_SIZE);
 132         set_pmd(pmd, __pmd(__pa(pte) + _PAGE_KERNEL_TABLE));
 133         pkmap_page_table = pte;
 134 #endif /* CONFIG_HIGHMEM */
 135 }
 136
 137 /*
 138  * paging_init() sets up the page tables, initialises the zone memory
 139  * maps, and sets up the zero page, bad page and bad page tables.
 140  */
 141 void __init paging_init(void)
 142 {
 143         int i;
 144         void *zero_page;
 145
 146         pr_info("Setting up paging and PTEs.\n");
 147         /* clear out the init_mm.pgd that will contain the kernel's mappings */
 148         for (i = 0; i < PTRS_PER_PGD; i++)
 149                 swapper_pg_dir[i] = __pgd(1);
 150
 151         map_ram();
 152
 153         fixedrange_init();
 154
 155         /* allocate space for empty_zero_page */
 156         zero_page = __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE));
 157         memset(zero_page, 0, PAGE_SIZE);
 158         zone_sizes_init();
 159
 160         empty_zero_page = virt_to_page(zero_page);
 161         flush_dcache_page(empty_zero_page);
 162 }
 163
 164 static inline void __init free_highmem(void)
 165 {
 166 #ifdef CONFIG_HIGHMEM
 167         unsigned long pfn;
 168         for (pfn = PFN_UP(__pa(high_memory)); pfn < max_pfn; pfn++) {
 169                 phys_addr_t paddr = (phys_addr_t) pfn << PAGE_SHIFT;
 170                 if (!memblock_is_reserved(paddr))
 171                         free_highmem_page(pfn_to_page(pfn));
 172         }
 173 #endif
 174 }
 175
 176 static void __init set_max_mapnr_init(void)
 177 {
 178         max_mapnr = max_pfn;
 179 }
 180
 181 /*
 182  * mem_init() marks the free areas in the mem_map and tells us how much
 183  * memory is free.  This is done after various parts of the system have
 184  * claimed their memory after the kernel image.
 185  */
 186 void __init mem_init(void)
 187 {
 188         phys_addr_t memory_start = memblock_start_of_DRAM();
 189         BUG_ON(!mem_map);
 190         set_max_mapnr_init();
 191
 192         free_highmem();
 193
 194         /* this will put all low memory onto the freelists */
 195         free_all_bootmem();
 196         mem_init_print_info(NULL);
 197
 198         pr_info("virtual kernel memory layout:\n"
 199                 "    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 200 #ifdef CONFIG_HIGHMEM
 201                 "    pkmap   : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 202 #endif
 203                 "    consist : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 204                 "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 205                 "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
 206                 "      .init : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 207                 "      .data : 0x%08lx - 0x%08lx   (%4ld kB)\n"
 208                 "      .text : 0x%08lx - 0x%08lx   (%4ld kB)\n",
 209                 FIXADDR_START, FIXADDR_TOP, (FIXADDR_TOP - FIXADDR_START) >> 10,
 210 #ifdef CONFIG_HIGHMEM
 211                 PKMAP_BASE, PKMAP_BASE + LAST_PKMAP * PAGE_SIZE,
 212                 (LAST_PKMAP * PAGE_SIZE) >> 10,
 213 #endif
 214                 CONSISTENT_BASE, CONSISTENT_END,
 215                 ((CONSISTENT_END) - (CONSISTENT_BASE)) >> 20, VMALLOC_START,
 216                 (unsigned long)VMALLOC_END, (VMALLOC_END - VMALLOC_START) >> 20,
 217                 (unsigned long)__va(memory_start), (unsigned long)high_memory,
 218                 ((unsigned long)high_memory -
 219                  (unsigned long)__va(memory_start)) >> 20,
 220                 (unsigned long)&__init_begin, (unsigned long)&__init_end,
 221                 ((unsigned long)&__init_end -
 222                  (unsigned long)&__init_begin) >> 10, (unsigned long)&_etext,
 223                 (unsigned long)&_edata,
 224                 ((unsigned long)&_edata - (unsigned long)&_etext) >> 10,
 225                 (unsigned long)&_text, (unsigned long)&_etext,
 226                 ((unsigned long)&_etext - (unsigned long)&_text) >> 10);
 227
 228         /*
 229          * Check boundaries twice: Some fundamental inconsistencies can
 230          * be detected at build time already.
 231          */
 232 #ifdef CONFIG_HIGHMEM
 233         BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > FIXADDR_START);
 234         BUILD_BUG_ON((CONSISTENT_END) > PKMAP_BASE);
 235 #endif
 236         BUILD_BUG_ON(VMALLOC_END > CONSISTENT_BASE);
 237         BUILD_BUG_ON(VMALLOC_START >= VMALLOC_END);
 238
 239 #ifdef CONFIG_HIGHMEM
 240         BUG_ON(PKMAP_BASE + LAST_PKMAP * PAGE_SIZE > FIXADDR_START);
 241         BUG_ON(CONSISTENT_END > PKMAP_BASE);
 242 #endif
 243         BUG_ON(VMALLOC_END > CONSISTENT_BASE);
 244         BUG_ON(VMALLOC_START >= VMALLOC_END);
 245         BUG_ON((unsigned long)high_memory > VMALLOC_START);
 246
 247         return;
 248 }
 249
 250 void free_initmem(void)
 251 {
 252         free_initmem_default(-1);
 253 }
 254
 255 #ifdef CONFIG_BLK_DEV_INITRD
 256 void free_initrd_mem(unsigned long start, unsigned long end)
 257 {
 258         free_reserved_area((void *)start, (void *)end, -1, "initrd");
 259 }
 260 #endif
 261
 262 void __set_fixmap(enum fixed_addresses idx,
 263                                phys_addr_t phys, pgprot_t flags)
 264 {
 265         unsigned long addr = __fix_to_virt(idx);
 266         pte_t *pte;
 267
 268         BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses);
 269
 270         pte = (pte_t *)&fixmap_pmd_p[pte_index(addr)];;
 271
 272         if (pgprot_val(flags)) {
 273                 set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
 274         } else {
 275                 pte_clear(&init_mm, addr, pte);
 276                 flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
 277         }
 278 }