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 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 void __init mem_init(void)
  40 {
  41 #ifdef CONFIG_HIGHMEM
  42         unsigned long tmp;
  43
  44         max_mapnr = highend_pfn;
  45 #else
  46         max_mapnr = max_low_pfn;
  47 #endif
  48         high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT);
  49
  50         memblock_free_all();
  51
  52 #ifdef CONFIG_HIGHMEM
  53         for (tmp = highstart_pfn; tmp < highend_pfn; tmp++) {
  54                 struct page *page = pfn_to_page(tmp);
  55
  56                 /* FIXME not sure about */
  57                 if (!memblock_is_reserved(tmp << PAGE_SHIFT))
  58                         free_highmem_page(page);
  59         }
  60 #endif
  61         mem_init_print_info(NULL);
  62 }
  63
  64 extern char __init_begin[], __init_end[];
  65
  66 void free_initmem(void)
  67 {
  68         unsigned long addr;
  69
  70         addr = (unsigned long) &__init_begin;
  71
  72         while (addr < (unsigned long) &__init_end) {
  73                 ClearPageReserved(virt_to_page(addr));
  74                 init_page_count(virt_to_page(addr));
  75                 free_page(addr);
  76                 totalram_pages_inc();
  77                 addr += PAGE_SIZE;
  78         }
  79
  80         pr_info("Freeing unused kernel memory: %dk freed\n",
  81         ((unsigned int)&__init_end - (unsigned int)&__init_begin) >> 10);
  82 }
  83
  84 void pgd_init(unsigned long *p)
  85 {
  86         int i;
  87
  88         for (i = 0; i < PTRS_PER_PGD; i++)
  89                 p[i] = __pa(invalid_pte_table);
  90 }
  91
  92 void __init pre_mmu_init(void)
  93 {
  94         /*
  95          * Setup page-table and enable TLB-hardrefill
  96          */
  97         flush_tlb_all();
  98         pgd_init((unsigned long *)swapper_pg_dir);
  99         TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir);
 100         TLBMISS_HANDLER_SETUP_PGD_KERNEL(swapper_pg_dir);
 101
 102         /* Setup page mask to 4k */
 103         write_mmu_pagemask(0);
 104 }