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 #ifdef CONFIG_BLK_DEV_INITRD
  64 void free_initrd_mem(unsigned long start, unsigned long end)
  65 {
  66         if (start < end)
  67                 pr_info("Freeing initrd memory: %ldk freed\n",
  68                         (end - start) >> 10);
  69
  70         for (; start < end; start += PAGE_SIZE) {
  71                 ClearPageReserved(virt_to_page(start));
  72                 init_page_count(virt_to_page(start));
  73                 free_page(start);
  74                 totalram_pages++;
  75         }
  76 }
  77 #endif
  78
  79 extern char __init_begin[], __init_end[];
  80
  81 void free_initmem(void)
  82 {
  83         unsigned long addr;
  84
  85         addr = (unsigned long) &__init_begin;
  86
  87         while (addr < (unsigned long) &__init_end) {
  88                 ClearPageReserved(virt_to_page(addr));
  89                 init_page_count(virt_to_page(addr));
  90                 free_page(addr);
  91                 totalram_pages++;
  92                 addr += PAGE_SIZE;
  93         }
  94
  95         pr_info("Freeing unused kernel memory: %dk freed\n",
  96         ((unsigned int)&__init_end - (unsigned int)&__init_begin) >> 10);
  97 }
  98
  99 void pgd_init(unsigned long *p)
 100 {
 101         int i;
 102
 103         for (i = 0; i < PTRS_PER_PGD; i++)
 104                 p[i] = __pa(invalid_pte_table);
 105 }
 106
 107 void __init pre_mmu_init(void)
 108 {
 109         /*
 110          * Setup page-table and enable TLB-hardrefill
 111          */
 112         flush_tlb_all();
 113         pgd_init((unsigned long *)swapper_pg_dir);
 114         TLBMISS_HANDLER_SETUP_PGD(swapper_pg_dir);
 115         TLBMISS_HANDLER_SETUP_PGD_KERNEL(swapper_pg_dir);
 116
 117         asid_cache(smp_processor_id()) = ASID_FIRST_VERSION;
 118
 119         /* Setup page mask to 4k */
 120         write_mmu_pagemask(0);
 121 }