linux/arch/csky/mm/init.c
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   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
  36pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
  37pte_t invalid_pte_table[PTRS_PER_PTE] __page_aligned_bss;
  38pte_t kernel_pte_tables[PTRS_KERN_TABLE] __page_aligned_bss;
  39
  40EXPORT_SYMBOL(invalid_pte_table);
  41unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
  42                                                __page_aligned_bss;
  43EXPORT_SYMBOL(empty_zero_page);
  44
  45#ifdef CONFIG_BLK_DEV_INITRD
  46static 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
  77disable:
  78        initrd_start = initrd_end = 0;
  79
  80        pr_err(" - disabling initrd\n");
  81}
  82#endif
  83
  84void __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}
 111
 112void free_initmem(void)
 113{
 114        free_initmem_default(-1);
 115}
 116
 117void pgd_init(unsigned long *p)
 118{
 119        int i;
 120
 121        for (i = 0; i < PTRS_PER_PGD; i++)
 122                p[i] = __pa(invalid_pte_table);
 123
 124        flush_tlb_all();
 125        local_icache_inv_all(NULL);
 126}
 127
 128void __init mmu_init(unsigned long min_pfn, unsigned long max_pfn)
 129{
 130        int i;
 131
 132        for (i = 0; i < USER_PTRS_PER_PGD; i++)
 133                swapper_pg_dir[i].pgd = __pa(invalid_pte_table);
 134
 135        for (i = USER_PTRS_PER_PGD; i < PTRS_PER_PGD; i++)
 136                swapper_pg_dir[i].pgd =
 137                        __pa(kernel_pte_tables + (PTRS_PER_PTE * (i - USER_PTRS_PER_PGD)));
 138
 139        for (i = 0; i < PTRS_KERN_TABLE; i++)
 140                set_pte(&kernel_pte_tables[i], __pte(_PAGE_GLOBAL));
 141
 142        for (i = min_pfn; i < max_pfn; i++)
 143                set_pte(&kernel_pte_tables[i - PFN_DOWN(va_pa_offset)], pfn_pte(i, PAGE_KERNEL));
 144
 145        flush_tlb_all();
 146        local_icache_inv_all(NULL);
 147
 148        /* Setup page mask to 4k */
 149        write_mmu_pagemask(0);
 150
 151        setup_pgd(swapper_pg_dir, 0);
 152}
 153
 154void __init fixrange_init(unsigned long start, unsigned long end,
 155                        pgd_t *pgd_base)
 156{
 157        pgd_t *pgd;
 158        pud_t *pud;
 159        pmd_t *pmd;
 160        pte_t *pte;
 161        int i, j, k;
 162        unsigned long vaddr;
 163
 164        vaddr = start;
 165        i = pgd_index(vaddr);
 166        j = pud_index(vaddr);
 167        k = pmd_index(vaddr);
 168        pgd = pgd_base + i;
 169
 170        for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
 171                pud = (pud_t *)pgd;
 172                for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
 173                        pmd = (pmd_t *)pud;
 174                        for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
 175                                if (pmd_none(*pmd)) {
 176                                        pte = (pte_t *) memblock_alloc_low(PAGE_SIZE, PAGE_SIZE);
 177                                        if (!pte)
 178                                                panic("%s: Failed to allocate %lu bytes align=%lx\n",
 179                                                      __func__, PAGE_SIZE,
 180                                                      PAGE_SIZE);
 181
 182                                        set_pmd(pmd, __pmd(__pa(pte)));
 183                                        BUG_ON(pte != pte_offset_kernel(pmd, 0));
 184                                }
 185                                vaddr += PMD_SIZE;
 186                        }
 187                        k = 0;
 188                }
 189                j = 0;
 190        }
 191}
 192
 193void __init fixaddr_init(void)
 194{
 195        unsigned long vaddr;
 196
 197        vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
 198        fixrange_init(vaddr, vaddr + PMD_SIZE, swapper_pg_dir);
 199}
 200