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/pgtable.h>
  28 #include <asm/pgalloc.h>
  29 #include <asm/mmu_context.h>
  30 #include <asm/sections.h>
  31 #include <asm/tlb.h>
  32
  33 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
  34 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;
  35 EXPORT_SYMBOL(invalid_pte_table);
  36 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
  37                                                 __page_aligned_bss;
  38 EXPORT_SYMBOL(empty_zero_page);
  39
  40 #ifdef CONFIG_BLK_DEV_INITRD
  41 static void __init setup_initrd(void)
  42 {
  43         unsigned long size;
  44
  45         if (initrd_start >= initrd_end) {
  46                 pr_err("initrd not found or empty");
  47                 goto disable;
  48         }
  49
  50         if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
  51                 pr_err("initrd extends beyond end of memory");
  52                 goto disable;
  53         }
  54
  55         size = initrd_end - initrd_start;
  56
  57         if (memblock_is_region_reserved(__pa(initrd_start), size)) {
  58                 pr_err("INITRD: 0x%08lx+0x%08lx overlaps in-use memory region",
  59                        __pa(initrd_start), size);
  60                 goto disable;
  61         }
  62
  63         memblock_reserve(__pa(initrd_start), size);
  64
  65         pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n",
  66                 (void *)(initrd_start), size);
  67
  68         initrd_below_start_ok = 1;
  69
  70         return;
  71
  72 disable:
  73         initrd_start = initrd_end = 0;
  74
  75         pr_err(" - disabling initrd\n");
  76 }
  77 #endif
  78
  79 void __init mem_init(void)
  80 {
  81 #ifdef CONFIG_HIGHMEM
  82         unsigned long tmp;
  83
  84         max_mapnr = highend_pfn;
  85 #else
  86         max_mapnr = max_low_pfn;
  87 #endif
  88         high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
  89
  90 #ifdef CONFIG_BLK_DEV_INITRD
  91         setup_initrd();
  92 #endif
  93
  94         memblock_free_all();
  95
  96 #ifdef CONFIG_HIGHMEM
  97         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
  98                 struct page *page = pfn_to_page(tmp);
  99
 100                 /* FIXME not sure about */
 101                 if (!memblock_is_reserved(tmp << PAGE_SHIFT))
 102                         free_highmem_page(page);
 103         }
 104 #endif
 105         mem_init_print_info(NULL);
 106 }
 107
 108 extern char __init_begin[], __init_end[];
 109
 110 void free_initmem(void)
 111 {
 112         unsigned long addr;
 113
 114         addr = (unsigned long) &__init_begin;
 115
 116         while (addr < (unsigned long) &__init_end) {
 117                 ClearPageReserved(virt_to_page(addr));
 118                 init_page_count(virt_to_page(addr));
 119                 free_page(addr);
 120                 totalram_pages_inc();
 121                 addr += PAGE_SIZE;
 122         }
 123
 124         pr_info("Freeing unused kernel memory: %dk freed\n",
 125         ((unsigned int)&__init_end - (unsigned int)&__init_begin) >> 10);
 126 }
 127
 128 void pgd_init(unsigned long *p)
 129 {
 130         int i;
 131
 132         for (i = 0; i < PTRS_PER_PGD; i++)
 133                 p[i] = __pa(invalid_pte_table);
 134 }
 135
 136 void __init pre_mmu_init(void)
 137 {
 138         /*
 139          * Setup page-table and enable TLB-hardrefill
 140          */
 141         flush_tlb_all();
 142         pgd_init((unsigned long *)swapper_pg_dir);
 143         TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir);
 144         TLBMISS_HANDLER_SETUP_PGD_KERNEL(swapper_pg_dir);
 145
 146         /* Setup page mask to 4k */
 147         write_mmu_pagemask(0);
 148 }
 149
 150 void __init fixrange_init(unsigned long start, unsigned long end,
 151                         pgd_t *pgd_base)
 152 {
 153         pgd_t *pgd;
 154         pud_t *pud;
 155         pmd_t *pmd;
 156         pte_t *pte;
 157         int i, j, k;
 158         unsigned long vaddr;
 159
 160         vaddr = start;
 161         i = __pgd_offset(vaddr);
 162         j = __pud_offset(vaddr);
 163         k = __pmd_offset(vaddr);
 164         pgd = pgd_base + i;
 165
 166         for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
 167                 pud = (pud_t *)pgd;
 168                 for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
 169                         pmd = (pmd_t *)pud;
 170                         for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
 171                                 if (pmd_none(*pmd)) {
 172                                         pte = (pte_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
 173                                         if (!pte)
 174                                                 panic("%s: Failed to allocate %lu bytes align=%lx\n",
 175                                                       __func__, PAGE_SIZE,
 176                                                       PAGE_SIZE);
 177
 178                                         set_pmd(pmd, __pmd(__pa(pte)));
 179                                         BUG_ON(pte != pte_offset_kernel(pmd, 0));
 180                                 }
 181                                 vaddr += PMD_SIZE;
 182                         }
 183                         k = 0;
 184                 }
 185                 j = 0;
 186         }
 187 }
 188
 189 void __init fixaddr_init(void)
 190 {
 191         unsigned long vaddr;
 192
 193         vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
 194         fixrange_init(vaddr, vaddr + PMD_SIZE, swapper_pg_dir);
 195 }