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 #include <asm/cacheflush.h>
  32
  33 #define PTRS_KERN_TABLE \
  34                 ((PTRS_PER_PGD - USER_PTRS_PER_PGD) * PTRS_PER_PTE)
  35
  36 pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
  37 pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;
  38 pte_t kernel_pte_tables[PTRS_KERN_TABLE] __page_aligned_bss;
  39
  40 EXPORT_SYMBOL(invalid_pte_table);
  41 unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
  42                                                 __page_aligned_bss;
  43 EXPORT_SYMBOL(empty_zero_page);
  44
  45 #ifdef CONFIG_BLK_DEV_INITRD
  46 static void __init setup_initrd(void)
  47 {
  48         unsigned long size;
  49
  50         if (initrd_start >= initrd_end) {
  51                 pr_err("initrd not found or empty");
  52                 goto disable;
  53         }
  54
  55         if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
  56                 pr_err("initrd extends beyond end of memory");
  57                 goto disable;
  58         }
  59
  60         size = initrd_end - initrd_start;
  61
  62         if (memblock_is_region_reserved(__pa(initrd_start), size)) {
  63                 pr_err("INITRD: 0x%08lx+0x%08lx overlaps in-use memory region",
  64                        __pa(initrd_start), size);
  65                 goto disable;
  66         }
  67
  68         memblock_reserve(__pa(initrd_start), size);
  69
  70         pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n",
  71                 (void *)(initrd_start), size);
  72
  73         initrd_below_start_ok = 1;
  74
  75         return;
  76
  77 disable:
  78         initrd_start = initrd_end = 0;
  79
  80         pr_err(" - disabling initrd\n");
  81 }
  82 #endif
  83
  84 void __init mem_init(void)
  85 {
  86 #ifdef CONFIG_HIGHMEM
  87         unsigned long tmp;
  88
  89         set_max_mapnr(highend_pfn - ARCH_PFN_OFFSET);
  90 #else
  91         set_max_mapnr(max_low_pfn - ARCH_PFN_OFFSET);
  92 #endif
  93         high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
  94
  95 #ifdef CONFIG_BLK_DEV_INITRD
  96         setup_initrd();
  97 #endif
  98
  99         memblock_free_all();
 100
 101 #ifdef CONFIG_HIGHMEM
 102         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
 103                 struct page *page = pfn_to_page(tmp);
 104
 105                 /* FIXME not sure about */
 106                 if (!memblock_is_reserved(tmp << PAGE_SHIFT))
 107                         free_highmem_page(page);
 108         }
 109 #endif
 110         mem_init_print_info(NULL);
 111 }
 112
 113 extern char __init_begin[], __init_end[];
 114
 115 void free_initmem(void)
 116 {
 117         unsigned long addr;
 118
 119         addr = (unsigned long) &__init_begin;
 120
 121         while (addr < (unsigned long) &__init_end) {
 122                 ClearPageReserved(virt_to_page(addr));
 123                 init_page_count(virt_to_page(addr));
 124                 free_page(addr);
 125                 totalram_pages_inc();
 126                 addr += PAGE_SIZE;
 127         }
 128
 129         pr_info("Freeing unused kernel memory: %dk freed\n",
 130         ((unsigned int)&__init_end - (unsigned int)&__init_begin) >> 10);
 131 }
 132
 133 void pgd_init(unsigned long *p)
 134 {
 135         int i;
 136
 137         for (i = 0; i < PTRS_PER_PGD; i++)
 138                 p[i] = __pa(invalid_pte_table);
 139
 140         flush_tlb_all();
 141         local_icache_inv_all(NULL);
 142 }
 143
 144 void __init mmu_init(unsigned long min_pfn, unsigned long max_pfn)
 145 {
 146         int i;
 147
 148         for (i = 0; i < USER_PTRS_PER_PGD; i++)
 149                 swapper_pg_dir[i].pgd = __pa(invalid_pte_table);
 150
 151         for (i = USER_PTRS_PER_PGD; i < PTRS_PER_PGD; i++)
 152                 swapper_pg_dir[i].pgd =
 153                         __pa(kernel_pte_tables + (PTRS_PER_PTE * (i - USER_PTRS_PER_PGD)));
 154
 155         for (i = 0; i < PTRS_KERN_TABLE; i++)
 156                 set_pte(&kernel_pte_tables[i], __pte(_PAGE_GLOBAL));
 157
 158         for (i = min_pfn; i < max_pfn; i++)
 159                 set_pte(&kernel_pte_tables[i - PFN_DOWN(va_pa_offset)], pfn_pte(i, PAGE_KERNEL));
 160
 161         flush_tlb_all();
 162         local_icache_inv_all(NULL);
 163
 164         /* Setup page mask to 4k */
 165         write_mmu_pagemask(0);
 166
 167         setup_pgd(swapper_pg_dir, 0);
 168 }
 169
 170 void __init fixrange_init(unsigned long start, unsigned long end,
 171                         pgd_t *pgd_base)
 172 {
 173         pgd_t *pgd;
 174         pud_t *pud;
 175         pmd_t *pmd;
 176         pte_t *pte;
 177         int i, j, k;
 178         unsigned long vaddr;
 179
 180         vaddr = start;
 181         i = pgd_index(vaddr);
 182         j = pud_index(vaddr);
 183         k = pmd_index(vaddr);
 184         pgd = pgd_base + i;
 185
 186         for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
 187                 pud = (pud_t *)pgd;
 188                 for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
 189                         pmd = (pmd_t *)pud;
 190                         for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
 191                                 if (pmd_none(*pmd)) {
 192                                         pte = (pte_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
 193                                         if (!pte)
 194                                                 panic("%s: Failed to allocate %lu bytes align=%lx\n",
 195                                                       __func__, PAGE_SIZE,
 196                                                       PAGE_SIZE);
 197
 198                                         set_pmd(pmd, __pmd(__pa(pte)));
 199                                         BUG_ON(pte != pte_offset_kernel(pmd, 0));
 200                                 }
 201                                 vaddr += PMD_SIZE;
 202                         }
 203                         k = 0;
 204                 }
 205                 j = 0;
 206         }
 207 }
 208
 209 void __init fixaddr_init(void)
 210 {
 211         unsigned long vaddr;
 212
 213         vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
 214         fixrange_init(vaddr, vaddr + PMD_SIZE, swapper_pg_dir);
 215 }