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         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 }
  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 = 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  */
 144 void __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
 169 static 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
 181 static 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  */
 191 void __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
 255 void __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 }