arch/csky/mm/init.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 // Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
   3
   4 #include <linux/bug.h>
   5 #include <linux/module.h>
   6 #include <linux/init.h>
   7 #include <linux/signal.h>
   8 #include <linux/sched.h>
   9 #include <linux/kernel.h>
  10 #include <linux/errno.h>
  11 #include <linux/string.h>
  12 #include <linux/types.h>
  13 #include <linux/pagemap.h>
  14 #include <linux/ptrace.h>
  15 #include <linux/mman.h>
  16 #include <linux/mm.h>
  17 #include <linux/highmem.h>
  18 #include <linux/memblock.h>
  19 #include <linux/swap.h>
  20 #include <linux/proc_fs.h>
  21 #include <linux/pfn.h>
  22 #include <linux/initrd.h>
  23
  24 #include <asm/setup.h>
  25 #include <asm/cachectl.h>
  26 #include <asm/dma.h>
  27 #include <asm/pgalloc.h>
  28 #include <asm/mmu_context.h>
  29 #include <asm/sections.h>
  30 #include <asm/tlb.h>
  31
  32 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
  33 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;
  34 EXPORT_SYMBOL(invalid_pte_table);
  35 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
  36                                                 __page_aligned_bss;
  37 EXPORT_SYMBOL(empty_zero_page);
  38
  39 #ifdef CONFIG_BLK_DEV_INITRD
  40 static void __init setup_initrd(void)
  41 {
  42         unsigned long size;
  43
  44         if (initrd_start >= initrd_end) {
  45                 pr_err("initrd not found or empty");
  46                 goto disable;
  47         }
  48
  49         if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
  50                 pr_err("initrd extends beyond end of memory");
  51                 goto disable;
  52         }
  53
  54         size = initrd_end - initrd_start;
  55
  56         if (memblock_is_region_reserved(__pa(initrd_start), size)) {
  57                 pr_err("INITRD: 0x%08lx+0x%08lx overlaps in-use memory region",
  58                        __pa(initrd_start), size);
  59                 goto disable;
  60         }
  61
  62         memblock_reserve(__pa(initrd_start), size);
  63
  64         pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n",
  65                 (void *)(initrd_start), size);
  66
  67         initrd_below_start_ok = 1;
  68
  69         return;
  70
  71 disable:
  72         initrd_start = initrd_end = 0;
  73
  74         pr_err(" - disabling initrd\n");
  75 }
  76 #endif
  77
  78 void __init mem_init(void)
  79 {
  80 #ifdef CONFIG_HIGHMEM
  81         unsigned long tmp;
  82
  83         max_mapnr = highend_pfn;
  84 #else
  85         max_mapnr = max_low_pfn;
  86 #endif
  87         high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
  88
  89 #ifdef CONFIG_BLK_DEV_INITRD
  90         setup_initrd();
  91 #endif
  92
  93         memblock_free_all();
  94
  95 #ifdef CONFIG_HIGHMEM
  96         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
  97                 struct page *page = pfn_to_page(tmp);
  98
  99                 /* FIXME not sure about */
 100                 if (!memblock_is_reserved(tmp << PAGE_SHIFT))
 101                         free_highmem_page(page);
 102         }
 103 #endif
 104         mem_init_print_info(NULL);
 105 }
 106
 107 extern char __init_begin[], __init_end[];
 108
 109 void free_initmem(void)
 110 {
 111         unsigned long addr;
 112
 113         addr = (unsigned long) &__init_begin;
 114
 115         while (addr < (unsigned long) &__init_end) {
 116                 ClearPageReserved(virt_to_page(addr));
 117                 init_page_count(virt_to_page(addr));
 118                 free_page(addr);
 119                 totalram_pages_inc();
 120                 addr += PAGE_SIZE;
 121         }
 122
 123         pr_info("Freeing unused kernel memory: %dk freed\n",
 124         ((unsigned int)&__init_end - (unsigned int)&__init_begin) >> 10);
 125 }
 126
 127 void pgd_init(unsigned long *p)
 128 {
 129         int i;
 130
 131         for (i = 0; i < PTRS_PER_PGD; i++)
 132                 p[i] = __pa(invalid_pte_table);
 133 }
 134
 135 void __init pre_mmu_init(void)
 136 {
 137         /*
 138          * Setup page-table and enable TLB-hardrefill
 139          */
 140         flush_tlb_all();
 141         pgd_init((unsigned long *)swapper_pg_dir);
 142         TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir);
 143         TLBMISS_HANDLER_SETUP_PGD_KERNEL(swapper_pg_dir);
 144
 145         /* Setup page mask to 4k */
 146         write_mmu_pagemask(0);
 147 }
 148
 149 void __init fixrange_init(unsigned long start, unsigned long end,
 150                         pgd_t *pgd_base)
 151 {
 152         pgd_t *pgd;
 153         pud_t *pud;
 154         pmd_t *pmd;
 155         pte_t *pte;
 156         int i, j, k;
 157         unsigned long vaddr;
 158
 159         vaddr = start;
 160         i = pgd_index(vaddr);
 161         j = pud_index(vaddr);
 162         k = pmd_index(vaddr);
 163         pgd = pgd_base + i;
 164
 165         for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
 166                 pud = (pud_t *)pgd;
 167                 for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
 168                         pmd = (pmd_t *)pud;
 169                         for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
 170                                 if (pmd_none(*pmd)) {
 171                                         pte = (pte_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
 172                                         if (!pte)
 173                                                 panic("%s: Failed to allocate %lu bytes align=%lx\n",
 174                                                       __func__, PAGE_SIZE,
 175                                                       PAGE_SIZE);
 176
 177                                         set_pmd(pmd, __pmd(__pa(pte)));
 178                                         BUG_ON(pte != pte_offset_kernel(pmd, 0));
 179                                 }
 180                                 vaddr += PMD_SIZE;
 181                         }
 182                         k = 0;
 183                 }
 184                 j = 0;
 185         }
 186 }
 187
 188 void __init fixaddr_init(void)
 189 {
 190         unsigned long vaddr;
 191
 192         vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
 193         fixrange_init(vaddr, vaddr + PMD_SIZE, swapper_pg_dir);
 194 }