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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 | // SPDX-License-Identifier: GPL-2.0-or-later /* * This file contains the routines setting up the linux page tables. * -- paulus * * Derived from arch/ppc/mm/init.c: * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) * * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au) * and Cort Dougan (PReP) (cort@cs.nmt.edu) * Copyright (C) 1996 Paul Mackerras * * Derived from "arch/i386/mm/init.c" * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/types.h> #include <linux/mm.h> #include <linux/vmalloc.h> #include <linux/init.h> #include <linux/highmem.h> #include <linux/memblock.h> #include <linux/slab.h> #include <linux/set_memory.h> #include <asm/pgalloc.h> #include <asm/fixmap.h> #include <asm/setup.h> #include <asm/sections.h> #include <asm/early_ioremap.h> #include <mm/mmu_decl.h> extern char etext[], _stext[], _sinittext[], _einittext[]; static u8 early_fixmap_pagetable[FIXMAP_PTE_SIZE] __page_aligned_data; notrace void __init early_ioremap_init(void) { unsigned long addr = ALIGN_DOWN(FIXADDR_START, PGDIR_SIZE); pte_t *ptep = (pte_t *)early_fixmap_pagetable; pmd_t *pmdp = pmd_off_k(addr); for (; (s32)(FIXADDR_TOP - addr) > 0; addr += PGDIR_SIZE, ptep += PTRS_PER_PTE, pmdp++) pmd_populate_kernel(&init_mm, pmdp, ptep); early_ioremap_setup(); } static void __init *early_alloc_pgtable(unsigned long size) { void *ptr = memblock_alloc(size, size); if (!ptr) panic("%s: Failed to allocate %lu bytes align=0x%lx\n", __func__, size, size); return ptr; } pte_t __init *early_pte_alloc_kernel(pmd_t *pmdp, unsigned long va) { if (pmd_none(*pmdp)) { pte_t *ptep = early_alloc_pgtable(PTE_FRAG_SIZE); pmd_populate_kernel(&init_mm, pmdp, ptep); } return pte_offset_kernel(pmdp, va); } int __ref map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot) { pmd_t *pd; pte_t *pg; int err = -ENOMEM; /* Use upper 10 bits of VA to index the first level map */ pd = pmd_off_k(va); /* Use middle 10 bits of VA to index the second-level map */ if (likely(slab_is_available())) pg = pte_alloc_kernel(pd, va); else pg = early_pte_alloc_kernel(pd, va); if (pg) { err = 0; /* The PTE should never be already set nor present in the * hash table */ BUG_ON((pte_present(*pg) | pte_hashpte(*pg)) && pgprot_val(prot)); set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, prot)); } smp_wmb(); return err; } /* * Map in a chunk of physical memory starting at start. */ static void __init __mapin_ram_chunk(unsigned long offset, unsigned long top) { unsigned long v, s; phys_addr_t p; int ktext; s = offset; v = PAGE_OFFSET + s; p = memstart_addr + s; for (; s < top; s += PAGE_SIZE) { ktext = ((char *)v >= _stext && (char *)v < etext) || ((char *)v >= _sinittext && (char *)v < _einittext); map_kernel_page(v, p, ktext ? PAGE_KERNEL_TEXT : PAGE_KERNEL); v += PAGE_SIZE; p += PAGE_SIZE; } } void __init mapin_ram(void) { phys_addr_t base, end; u64 i; for_each_mem_range(i, &base, &end) { phys_addr_t top = min(end, total_lowmem); if (base >= top) continue; base = mmu_mapin_ram(base, top); __mapin_ram_chunk(base, top); } } void mark_initmem_nx(void) { unsigned long numpages = PFN_UP((unsigned long)_einittext) - PFN_DOWN((unsigned long)_sinittext); if (v_block_mapped((unsigned long)_sinittext)) mmu_mark_initmem_nx(); else set_memory_attr((unsigned long)_sinittext, numpages, PAGE_KERNEL); } #ifdef CONFIG_STRICT_KERNEL_RWX void mark_rodata_ro(void) { unsigned long numpages; if (v_block_mapped((unsigned long)_stext + 1)) { mmu_mark_rodata_ro(); ptdump_check_wx(); return; } numpages = PFN_UP((unsigned long)_etext) - PFN_DOWN((unsigned long)_stext); set_memory_attr((unsigned long)_stext, numpages, PAGE_KERNEL_ROX); /* * mark .rodata as read only. Use __init_begin rather than __end_rodata * to cover NOTES and EXCEPTION_TABLE. */ numpages = PFN_UP((unsigned long)__init_begin) - PFN_DOWN((unsigned long)__start_rodata); set_memory_attr((unsigned long)__start_rodata, numpages, PAGE_KERNEL_RO); // mark_initmem_nx() should have already run by now ptdump_check_wx(); } #endif #ifdef CONFIG_DEBUG_PAGEALLOC void __kernel_map_pages(struct page *page, int numpages, int enable) { unsigned long addr = (unsigned long)page_address(page); if (PageHighMem(page)) return; if (enable) set_memory_attr(addr, numpages, PAGE_KERNEL); else set_memory_attr(addr, numpages, __pgprot(0)); } #endif /* CONFIG_DEBUG_PAGEALLOC */ |