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
  23 #include <asm/setup.h>
  24 #include <asm/cachectl.h>
  25 #include <asm/dma.h>
  26 #include <asm/pgtable.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 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
  35                                                 __page_aligned_bss;
  36 EXPORT_SYMBOL(empty_zero_page);
  37
  38 void __init mem_init(void)
  39 {
  40 #ifdef CONFIG_HIGHMEM
  41         unsigned long tmp;
  42
  43         max_mapnr = highend_pfn;
  44 #else
  45         max_mapnr = max_low_pfn;
  46 #endif
  47         high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
  48
  49         memblock_free_all();
  50
  51 #ifdef CONFIG_HIGHMEM
  52         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
  53                 struct page *page = pfn_to_page(tmp);
  54
  55                 /* FIXME not sure about */
  56                 if (!memblock_is_reserved(tmp << PAGE_SHIFT))
  57                         free_highmem_page(page);
  58         }
  59 #endif
  60         mem_init_print_info(NULL);
  61 }
  62
  63 extern char __init_begin[], __init_end[];
  64
  65 void free_initmem(void)
  66 {
  67         unsigned long addr;
  68
  69         addr = (unsigned long) &__init_begin;
  70
  71         while (addr < (unsigned long) &__init_end) {
  72                 ClearPageReserved(virt_to_page(addr));
  73                 init_page_count(virt_to_page(addr));
  74                 free_page(addr);
  75                 totalram_pages_inc();
  76                 addr += PAGE_SIZE;
  77         }
  78
  79         pr_info("Freeing unused kernel memory: %dk freed\n",
  80         ((unsigned int)&__init_end - (unsigned int)&__init_begin) >> 10);
  81 }
  82
  83 void pgd_init(unsigned long *p)
  84 {
  85         int i;
  86
  87         for (i = 0; i < PTRS_PER_PGD; i++)
  88                 p[i] = __pa(invalid_pte_table);
  89 }
  90
  91 void __init pre_mmu_init(void)
  92 {
  93         /*
  94          * Setup page-table and enable TLB-hardrefill
  95          */
  96         flush_tlb_all();
  97         pgd_init((unsigned long *)swapper_pg_dir);
  98         TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir);
  99         TLBMISS_HANDLER_SETUP_PGD_KERNEL(swapper_pg_dir);
 100
 101         /* Setup page mask to 4k */
 102         write_mmu_pagemask(0);
 103 }
 104
 105 void __init fixrange_init(unsigned long start, unsigned long end,
 106                         pgd_t *pgd_base)
 107 {
 108         pgd_t *pgd;
 109         pud_t *pud;
 110         pmd_t *pmd;
 111         pte_t *pte;
 112         int i, j, k;
 113         unsigned long vaddr;
 114
 115         vaddr = start;
 116         i = __pgd_offset(vaddr);
 117         j = __pud_offset(vaddr);
 118         k = __pmd_offset(vaddr);
 119         pgd = pgd_base + i;
 120
 121         for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
 122                 pud = (pud_t *)pgd;
 123                 for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
 124                         pmd = (pmd_t *)pud;
 125                         for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
 126                                 if (pmd_none(*pmd)) {
 127                                         pte = (pte_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
 128                                         if (!pte)
 129                                                 panic("%s: Failed to allocate %lu bytes align=%lx\n",
 130                                                       __func__, PAGE_SIZE,
 131                                                       PAGE_SIZE);
 132
 133                                         set_pmd(pmd, __pmd(__pa(pte)));
 134                                         BUG_ON(pte != pte_offset_kernel(pmd, 0));
 135                                 }
 136                                 vaddr += PMD_SIZE;
 137                         }
 138                         k = 0;
 139                 }
 140                 j = 0;
 141         }
 142 }
 143
 144 void __init fixaddr_init(void)
 145 {
 146         unsigned long vaddr;
 147
 148         vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
 149         fixrange_init(vaddr, vaddr + PMD_SIZE, swapper_pg_dir);
 150 }