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856 lines
23 KiB
856 lines
23 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* |
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* Copyright (C) 1995 Linus Torvalds |
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* |
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* Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 |
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*/ |
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#include <linux/signal.h> |
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#include <linux/sched.h> |
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#include <linux/kernel.h> |
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#include <linux/errno.h> |
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#include <linux/string.h> |
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#include <linux/types.h> |
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#include <linux/ptrace.h> |
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#include <linux/mman.h> |
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#include <linux/mm.h> |
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#include <linux/hugetlb.h> |
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#include <linux/swap.h> |
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#include <linux/smp.h> |
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#include <linux/init.h> |
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#include <linux/highmem.h> |
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#include <linux/pagemap.h> |
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#include <linux/pci.h> |
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#include <linux/pfn.h> |
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#include <linux/poison.h> |
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#include <linux/memblock.h> |
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#include <linux/proc_fs.h> |
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#include <linux/memory_hotplug.h> |
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#include <linux/initrd.h> |
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#include <linux/cpumask.h> |
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#include <linux/gfp.h> |
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#include <asm/asm.h> |
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#include <asm/bios_ebda.h> |
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#include <asm/processor.h> |
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#include <linux/uaccess.h> |
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#include <asm/dma.h> |
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#include <asm/fixmap.h> |
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#include <asm/e820/api.h> |
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#include <asm/apic.h> |
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#include <asm/bugs.h> |
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#include <asm/tlb.h> |
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#include <asm/tlbflush.h> |
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#include <asm/olpc_ofw.h> |
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#include <asm/pgalloc.h> |
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#include <asm/sections.h> |
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#include <asm/paravirt.h> |
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#include <asm/setup.h> |
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#include <asm/set_memory.h> |
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#include <asm/page_types.h> |
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#include <asm/cpu_entry_area.h> |
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#include <asm/init.h> |
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#include <asm/pgtable_areas.h> |
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#include <asm/numa.h> |
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#include "mm_internal.h" |
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unsigned long highstart_pfn, highend_pfn; |
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bool __read_mostly __vmalloc_start_set = false; |
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/* |
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* Creates a middle page table and puts a pointer to it in the |
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* given global directory entry. This only returns the gd entry |
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* in non-PAE compilation mode, since the middle layer is folded. |
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*/ |
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static pmd_t * __init one_md_table_init(pgd_t *pgd) |
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{ |
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p4d_t *p4d; |
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pud_t *pud; |
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pmd_t *pmd_table; |
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#ifdef CONFIG_X86_PAE |
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if (!(pgd_val(*pgd) & _PAGE_PRESENT)) { |
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pmd_table = (pmd_t *)alloc_low_page(); |
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paravirt_alloc_pmd(&init_mm, __pa(pmd_table) >> PAGE_SHIFT); |
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set_pgd(pgd, __pgd(__pa(pmd_table) | _PAGE_PRESENT)); |
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p4d = p4d_offset(pgd, 0); |
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pud = pud_offset(p4d, 0); |
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BUG_ON(pmd_table != pmd_offset(pud, 0)); |
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return pmd_table; |
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} |
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#endif |
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p4d = p4d_offset(pgd, 0); |
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pud = pud_offset(p4d, 0); |
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pmd_table = pmd_offset(pud, 0); |
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return pmd_table; |
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} |
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/* |
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* Create a page table and place a pointer to it in a middle page |
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* directory entry: |
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*/ |
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static pte_t * __init one_page_table_init(pmd_t *pmd) |
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{ |
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if (!(pmd_val(*pmd) & _PAGE_PRESENT)) { |
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pte_t *page_table = (pte_t *)alloc_low_page(); |
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paravirt_alloc_pte(&init_mm, __pa(page_table) >> PAGE_SHIFT); |
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set_pmd(pmd, __pmd(__pa(page_table) | _PAGE_TABLE)); |
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BUG_ON(page_table != pte_offset_kernel(pmd, 0)); |
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} |
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return pte_offset_kernel(pmd, 0); |
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} |
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pmd_t * __init populate_extra_pmd(unsigned long vaddr) |
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{ |
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int pgd_idx = pgd_index(vaddr); |
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int pmd_idx = pmd_index(vaddr); |
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return one_md_table_init(swapper_pg_dir + pgd_idx) + pmd_idx; |
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} |
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pte_t * __init populate_extra_pte(unsigned long vaddr) |
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{ |
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int pte_idx = pte_index(vaddr); |
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pmd_t *pmd; |
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pmd = populate_extra_pmd(vaddr); |
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return one_page_table_init(pmd) + pte_idx; |
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} |
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static unsigned long __init |
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page_table_range_init_count(unsigned long start, unsigned long end) |
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{ |
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unsigned long count = 0; |
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#ifdef CONFIG_HIGHMEM |
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int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT; |
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int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT; |
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int pgd_idx, pmd_idx; |
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unsigned long vaddr; |
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if (pmd_idx_kmap_begin == pmd_idx_kmap_end) |
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return 0; |
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vaddr = start; |
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pgd_idx = pgd_index(vaddr); |
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pmd_idx = pmd_index(vaddr); |
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for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd_idx++) { |
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for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end); |
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pmd_idx++) { |
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if ((vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin && |
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(vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end) |
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count++; |
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vaddr += PMD_SIZE; |
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} |
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pmd_idx = 0; |
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} |
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#endif |
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return count; |
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} |
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static pte_t *__init page_table_kmap_check(pte_t *pte, pmd_t *pmd, |
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unsigned long vaddr, pte_t *lastpte, |
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void **adr) |
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{ |
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#ifdef CONFIG_HIGHMEM |
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/* |
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* Something (early fixmap) may already have put a pte |
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* page here, which causes the page table allocation |
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* to become nonlinear. Attempt to fix it, and if it |
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* is still nonlinear then we have to bug. |
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*/ |
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int pmd_idx_kmap_begin = fix_to_virt(FIX_KMAP_END) >> PMD_SHIFT; |
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int pmd_idx_kmap_end = fix_to_virt(FIX_KMAP_BEGIN) >> PMD_SHIFT; |
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if (pmd_idx_kmap_begin != pmd_idx_kmap_end |
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&& (vaddr >> PMD_SHIFT) >= pmd_idx_kmap_begin |
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&& (vaddr >> PMD_SHIFT) <= pmd_idx_kmap_end) { |
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pte_t *newpte; |
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int i; |
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BUG_ON(after_bootmem); |
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newpte = *adr; |
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for (i = 0; i < PTRS_PER_PTE; i++) |
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set_pte(newpte + i, pte[i]); |
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*adr = (void *)(((unsigned long)(*adr)) + PAGE_SIZE); |
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paravirt_alloc_pte(&init_mm, __pa(newpte) >> PAGE_SHIFT); |
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set_pmd(pmd, __pmd(__pa(newpte)|_PAGE_TABLE)); |
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BUG_ON(newpte != pte_offset_kernel(pmd, 0)); |
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__flush_tlb_all(); |
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paravirt_release_pte(__pa(pte) >> PAGE_SHIFT); |
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pte = newpte; |
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} |
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BUG_ON(vaddr < fix_to_virt(FIX_KMAP_BEGIN - 1) |
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&& vaddr > fix_to_virt(FIX_KMAP_END) |
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&& lastpte && lastpte + PTRS_PER_PTE != pte); |
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#endif |
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return pte; |
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} |
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/* |
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* This function initializes a certain range of kernel virtual memory |
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* with new bootmem page tables, everywhere page tables are missing in |
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* the given range. |
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* |
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* NOTE: The pagetables are allocated contiguous on the physical space |
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* so we can cache the place of the first one and move around without |
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* checking the pgd every time. |
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*/ |
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static void __init |
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page_table_range_init(unsigned long start, unsigned long end, pgd_t *pgd_base) |
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{ |
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int pgd_idx, pmd_idx; |
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unsigned long vaddr; |
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pgd_t *pgd; |
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pmd_t *pmd; |
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pte_t *pte = NULL; |
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unsigned long count = page_table_range_init_count(start, end); |
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void *adr = NULL; |
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if (count) |
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adr = alloc_low_pages(count); |
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vaddr = start; |
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pgd_idx = pgd_index(vaddr); |
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pmd_idx = pmd_index(vaddr); |
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pgd = pgd_base + pgd_idx; |
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for ( ; (pgd_idx < PTRS_PER_PGD) && (vaddr != end); pgd++, pgd_idx++) { |
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pmd = one_md_table_init(pgd); |
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pmd = pmd + pmd_index(vaddr); |
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for (; (pmd_idx < PTRS_PER_PMD) && (vaddr != end); |
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pmd++, pmd_idx++) { |
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pte = page_table_kmap_check(one_page_table_init(pmd), |
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pmd, vaddr, pte, &adr); |
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vaddr += PMD_SIZE; |
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} |
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pmd_idx = 0; |
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} |
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} |
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/* |
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* The <linux/kallsyms.h> already defines is_kernel_text, |
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* using '__' prefix not to get in conflict. |
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*/ |
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static inline int __is_kernel_text(unsigned long addr) |
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{ |
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if (addr >= (unsigned long)_text && addr <= (unsigned long)__init_end) |
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return 1; |
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return 0; |
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} |
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/* |
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* This maps the physical memory to kernel virtual address space, a total |
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* of max_low_pfn pages, by creating page tables starting from address |
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* PAGE_OFFSET: |
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*/ |
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unsigned long __init |
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kernel_physical_mapping_init(unsigned long start, |
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unsigned long end, |
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unsigned long page_size_mask, |
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pgprot_t prot) |
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{ |
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int use_pse = page_size_mask == (1<<PG_LEVEL_2M); |
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unsigned long last_map_addr = end; |
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unsigned long start_pfn, end_pfn; |
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pgd_t *pgd_base = swapper_pg_dir; |
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int pgd_idx, pmd_idx, pte_ofs; |
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unsigned long pfn; |
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pgd_t *pgd; |
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pmd_t *pmd; |
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pte_t *pte; |
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unsigned pages_2m, pages_4k; |
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int mapping_iter; |
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start_pfn = start >> PAGE_SHIFT; |
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end_pfn = end >> PAGE_SHIFT; |
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/* |
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* First iteration will setup identity mapping using large/small pages |
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* based on use_pse, with other attributes same as set by |
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* the early code in head_32.S |
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* |
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* Second iteration will setup the appropriate attributes (NX, GLOBAL..) |
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* as desired for the kernel identity mapping. |
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* |
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* This two pass mechanism conforms to the TLB app note which says: |
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* |
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* "Software should not write to a paging-structure entry in a way |
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* that would change, for any linear address, both the page size |
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* and either the page frame or attributes." |
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*/ |
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mapping_iter = 1; |
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if (!boot_cpu_has(X86_FEATURE_PSE)) |
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use_pse = 0; |
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repeat: |
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pages_2m = pages_4k = 0; |
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pfn = start_pfn; |
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pgd_idx = pgd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET); |
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pgd = pgd_base + pgd_idx; |
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for (; pgd_idx < PTRS_PER_PGD; pgd++, pgd_idx++) { |
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pmd = one_md_table_init(pgd); |
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if (pfn >= end_pfn) |
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continue; |
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#ifdef CONFIG_X86_PAE |
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pmd_idx = pmd_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET); |
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pmd += pmd_idx; |
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#else |
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pmd_idx = 0; |
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#endif |
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for (; pmd_idx < PTRS_PER_PMD && pfn < end_pfn; |
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pmd++, pmd_idx++) { |
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unsigned int addr = pfn * PAGE_SIZE + PAGE_OFFSET; |
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/* |
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* Map with big pages if possible, otherwise |
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* create normal page tables: |
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*/ |
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if (use_pse) { |
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unsigned int addr2; |
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pgprot_t prot = PAGE_KERNEL_LARGE; |
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/* |
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* first pass will use the same initial |
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* identity mapping attribute + _PAGE_PSE. |
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*/ |
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pgprot_t init_prot = |
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__pgprot(PTE_IDENT_ATTR | |
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_PAGE_PSE); |
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pfn &= PMD_MASK >> PAGE_SHIFT; |
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addr2 = (pfn + PTRS_PER_PTE-1) * PAGE_SIZE + |
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PAGE_OFFSET + PAGE_SIZE-1; |
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if (__is_kernel_text(addr) || |
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__is_kernel_text(addr2)) |
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prot = PAGE_KERNEL_LARGE_EXEC; |
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pages_2m++; |
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if (mapping_iter == 1) |
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set_pmd(pmd, pfn_pmd(pfn, init_prot)); |
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else |
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set_pmd(pmd, pfn_pmd(pfn, prot)); |
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pfn += PTRS_PER_PTE; |
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continue; |
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} |
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pte = one_page_table_init(pmd); |
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pte_ofs = pte_index((pfn<<PAGE_SHIFT) + PAGE_OFFSET); |
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pte += pte_ofs; |
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for (; pte_ofs < PTRS_PER_PTE && pfn < end_pfn; |
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pte++, pfn++, pte_ofs++, addr += PAGE_SIZE) { |
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pgprot_t prot = PAGE_KERNEL; |
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/* |
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* first pass will use the same initial |
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* identity mapping attribute. |
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*/ |
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pgprot_t init_prot = __pgprot(PTE_IDENT_ATTR); |
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if (__is_kernel_text(addr)) |
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prot = PAGE_KERNEL_EXEC; |
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pages_4k++; |
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if (mapping_iter == 1) { |
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set_pte(pte, pfn_pte(pfn, init_prot)); |
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last_map_addr = (pfn << PAGE_SHIFT) + PAGE_SIZE; |
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} else |
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set_pte(pte, pfn_pte(pfn, prot)); |
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} |
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} |
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} |
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if (mapping_iter == 1) { |
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/* |
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* update direct mapping page count only in the first |
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* iteration. |
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*/ |
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update_page_count(PG_LEVEL_2M, pages_2m); |
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update_page_count(PG_LEVEL_4K, pages_4k); |
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/* |
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* local global flush tlb, which will flush the previous |
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* mappings present in both small and large page TLB's. |
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*/ |
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__flush_tlb_all(); |
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/* |
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* Second iteration will set the actual desired PTE attributes. |
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*/ |
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mapping_iter = 2; |
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goto repeat; |
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} |
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return last_map_addr; |
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} |
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#ifdef CONFIG_HIGHMEM |
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static void __init permanent_kmaps_init(pgd_t *pgd_base) |
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{ |
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unsigned long vaddr = PKMAP_BASE; |
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page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base); |
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pkmap_page_table = virt_to_kpte(vaddr); |
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} |
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void __init add_highpages_with_active_regions(int nid, |
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unsigned long start_pfn, unsigned long end_pfn) |
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{ |
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phys_addr_t start, end; |
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u64 i; |
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for_each_free_mem_range(i, nid, MEMBLOCK_NONE, &start, &end, NULL) { |
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unsigned long pfn = clamp_t(unsigned long, PFN_UP(start), |
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start_pfn, end_pfn); |
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unsigned long e_pfn = clamp_t(unsigned long, PFN_DOWN(end), |
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start_pfn, end_pfn); |
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for ( ; pfn < e_pfn; pfn++) |
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if (pfn_valid(pfn)) |
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free_highmem_page(pfn_to_page(pfn)); |
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} |
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} |
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#else |
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static inline void permanent_kmaps_init(pgd_t *pgd_base) |
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{ |
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} |
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#endif /* CONFIG_HIGHMEM */ |
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void __init sync_initial_page_table(void) |
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{ |
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clone_pgd_range(initial_page_table + KERNEL_PGD_BOUNDARY, |
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swapper_pg_dir + KERNEL_PGD_BOUNDARY, |
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KERNEL_PGD_PTRS); |
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/* |
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* sync back low identity map too. It is used for example |
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* in the 32-bit EFI stub. |
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*/ |
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clone_pgd_range(initial_page_table, |
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swapper_pg_dir + KERNEL_PGD_BOUNDARY, |
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min(KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY)); |
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} |
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void __init native_pagetable_init(void) |
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{ |
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unsigned long pfn, va; |
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pgd_t *pgd, *base = swapper_pg_dir; |
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p4d_t *p4d; |
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pud_t *pud; |
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pmd_t *pmd; |
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pte_t *pte; |
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/* |
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* Remove any mappings which extend past the end of physical |
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* memory from the boot time page table. |
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* In virtual address space, we should have at least two pages |
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* from VMALLOC_END to pkmap or fixmap according to VMALLOC_END |
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* definition. And max_low_pfn is set to VMALLOC_END physical |
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* address. If initial memory mapping is doing right job, we |
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* should have pte used near max_low_pfn or one pmd is not present. |
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*/ |
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for (pfn = max_low_pfn; pfn < 1<<(32-PAGE_SHIFT); pfn++) { |
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va = PAGE_OFFSET + (pfn<<PAGE_SHIFT); |
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pgd = base + pgd_index(va); |
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if (!pgd_present(*pgd)) |
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break; |
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p4d = p4d_offset(pgd, va); |
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pud = pud_offset(p4d, va); |
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pmd = pmd_offset(pud, va); |
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if (!pmd_present(*pmd)) |
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break; |
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/* should not be large page here */ |
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if (pmd_large(*pmd)) { |
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pr_warn("try to clear pte for ram above max_low_pfn: pfn: %lx pmd: %p pmd phys: %lx, but pmd is big page and is not using pte !\n", |
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pfn, pmd, __pa(pmd)); |
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BUG_ON(1); |
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} |
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pte = pte_offset_kernel(pmd, va); |
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if (!pte_present(*pte)) |
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break; |
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printk(KERN_DEBUG "clearing pte for ram above max_low_pfn: pfn: %lx pmd: %p pmd phys: %lx pte: %p pte phys: %lx\n", |
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pfn, pmd, __pa(pmd), pte, __pa(pte)); |
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pte_clear(NULL, va, pte); |
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} |
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paravirt_alloc_pmd(&init_mm, __pa(base) >> PAGE_SHIFT); |
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paging_init(); |
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} |
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/* |
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* Build a proper pagetable for the kernel mappings. Up until this |
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* point, we've been running on some set of pagetables constructed by |
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* the boot process. |
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* |
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* If we're booting on native hardware, this will be a pagetable |
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* constructed in arch/x86/kernel/head_32.S. The root of the |
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* pagetable will be swapper_pg_dir. |
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* |
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* If we're booting paravirtualized under a hypervisor, then there are |
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* more options: we may already be running PAE, and the pagetable may |
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* or may not be based in swapper_pg_dir. In any case, |
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* paravirt_pagetable_init() will set up swapper_pg_dir |
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* appropriately for the rest of the initialization to work. |
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* |
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* In general, pagetable_init() assumes that the pagetable may already |
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* be partially populated, and so it avoids stomping on any existing |
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* mappings. |
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*/ |
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void __init early_ioremap_page_table_range_init(void) |
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{ |
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pgd_t *pgd_base = swapper_pg_dir; |
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unsigned long vaddr, end; |
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|
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/* |
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* Fixed mappings, only the page table structure has to be |
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* created - mappings will be set by set_fixmap(): |
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*/ |
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vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK; |
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end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK; |
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page_table_range_init(vaddr, end, pgd_base); |
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early_ioremap_reset(); |
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} |
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static void __init pagetable_init(void) |
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{ |
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pgd_t *pgd_base = swapper_pg_dir; |
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permanent_kmaps_init(pgd_base); |
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} |
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#define DEFAULT_PTE_MASK ~(_PAGE_NX | _PAGE_GLOBAL) |
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/* Bits supported by the hardware: */ |
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pteval_t __supported_pte_mask __read_mostly = DEFAULT_PTE_MASK; |
|
/* Bits allowed in normal kernel mappings: */ |
|
pteval_t __default_kernel_pte_mask __read_mostly = DEFAULT_PTE_MASK; |
|
EXPORT_SYMBOL_GPL(__supported_pte_mask); |
|
/* Used in PAGE_KERNEL_* macros which are reasonably used out-of-tree: */ |
|
EXPORT_SYMBOL(__default_kernel_pte_mask); |
|
|
|
/* user-defined highmem size */ |
|
static unsigned int highmem_pages = -1; |
|
|
|
/* |
|
* highmem=size forces highmem to be exactly 'size' bytes. |
|
* This works even on boxes that have no highmem otherwise. |
|
* This also works to reduce highmem size on bigger boxes. |
|
*/ |
|
static int __init parse_highmem(char *arg) |
|
{ |
|
if (!arg) |
|
return -EINVAL; |
|
|
|
highmem_pages = memparse(arg, &arg) >> PAGE_SHIFT; |
|
return 0; |
|
} |
|
early_param("highmem", parse_highmem); |
|
|
|
#define MSG_HIGHMEM_TOO_BIG \ |
|
"highmem size (%luMB) is bigger than pages available (%luMB)!\n" |
|
|
|
#define MSG_LOWMEM_TOO_SMALL \ |
|
"highmem size (%luMB) results in <64MB lowmem, ignoring it!\n" |
|
/* |
|
* All of RAM fits into lowmem - but if user wants highmem |
|
* artificially via the highmem=x boot parameter then create |
|
* it: |
|
*/ |
|
static void __init lowmem_pfn_init(void) |
|
{ |
|
/* max_low_pfn is 0, we already have early_res support */ |
|
max_low_pfn = max_pfn; |
|
|
|
if (highmem_pages == -1) |
|
highmem_pages = 0; |
|
#ifdef CONFIG_HIGHMEM |
|
if (highmem_pages >= max_pfn) { |
|
printk(KERN_ERR MSG_HIGHMEM_TOO_BIG, |
|
pages_to_mb(highmem_pages), pages_to_mb(max_pfn)); |
|
highmem_pages = 0; |
|
} |
|
if (highmem_pages) { |
|
if (max_low_pfn - highmem_pages < 64*1024*1024/PAGE_SIZE) { |
|
printk(KERN_ERR MSG_LOWMEM_TOO_SMALL, |
|
pages_to_mb(highmem_pages)); |
|
highmem_pages = 0; |
|
} |
|
max_low_pfn -= highmem_pages; |
|
} |
|
#else |
|
if (highmem_pages) |
|
printk(KERN_ERR "ignoring highmem size on non-highmem kernel!\n"); |
|
#endif |
|
} |
|
|
|
#define MSG_HIGHMEM_TOO_SMALL \ |
|
"only %luMB highmem pages available, ignoring highmem size of %luMB!\n" |
|
|
|
#define MSG_HIGHMEM_TRIMMED \ |
|
"Warning: only 4GB will be used. Use a HIGHMEM64G enabled kernel!\n" |
|
/* |
|
* We have more RAM than fits into lowmem - we try to put it into |
|
* highmem, also taking the highmem=x boot parameter into account: |
|
*/ |
|
static void __init highmem_pfn_init(void) |
|
{ |
|
max_low_pfn = MAXMEM_PFN; |
|
|
|
if (highmem_pages == -1) |
|
highmem_pages = max_pfn - MAXMEM_PFN; |
|
|
|
if (highmem_pages + MAXMEM_PFN < max_pfn) |
|
max_pfn = MAXMEM_PFN + highmem_pages; |
|
|
|
if (highmem_pages + MAXMEM_PFN > max_pfn) { |
|
printk(KERN_WARNING MSG_HIGHMEM_TOO_SMALL, |
|
pages_to_mb(max_pfn - MAXMEM_PFN), |
|
pages_to_mb(highmem_pages)); |
|
highmem_pages = 0; |
|
} |
|
#ifndef CONFIG_HIGHMEM |
|
/* Maximum memory usable is what is directly addressable */ |
|
printk(KERN_WARNING "Warning only %ldMB will be used.\n", MAXMEM>>20); |
|
if (max_pfn > MAX_NONPAE_PFN) |
|
printk(KERN_WARNING "Use a HIGHMEM64G enabled kernel.\n"); |
|
else |
|
printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n"); |
|
max_pfn = MAXMEM_PFN; |
|
#else /* !CONFIG_HIGHMEM */ |
|
#ifndef CONFIG_HIGHMEM64G |
|
if (max_pfn > MAX_NONPAE_PFN) { |
|
max_pfn = MAX_NONPAE_PFN; |
|
printk(KERN_WARNING MSG_HIGHMEM_TRIMMED); |
|
} |
|
#endif /* !CONFIG_HIGHMEM64G */ |
|
#endif /* !CONFIG_HIGHMEM */ |
|
} |
|
|
|
/* |
|
* Determine low and high memory ranges: |
|
*/ |
|
void __init find_low_pfn_range(void) |
|
{ |
|
/* it could update max_pfn */ |
|
|
|
if (max_pfn <= MAXMEM_PFN) |
|
lowmem_pfn_init(); |
|
else |
|
highmem_pfn_init(); |
|
} |
|
|
|
#ifndef CONFIG_NEED_MULTIPLE_NODES |
|
void __init initmem_init(void) |
|
{ |
|
#ifdef CONFIG_HIGHMEM |
|
highstart_pfn = highend_pfn = max_pfn; |
|
if (max_pfn > max_low_pfn) |
|
highstart_pfn = max_low_pfn; |
|
printk(KERN_NOTICE "%ldMB HIGHMEM available.\n", |
|
pages_to_mb(highend_pfn - highstart_pfn)); |
|
high_memory = (void *) __va(highstart_pfn * PAGE_SIZE - 1) + 1; |
|
#else |
|
high_memory = (void *) __va(max_low_pfn * PAGE_SIZE - 1) + 1; |
|
#endif |
|
|
|
memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0); |
|
|
|
#ifdef CONFIG_FLATMEM |
|
max_mapnr = IS_ENABLED(CONFIG_HIGHMEM) ? highend_pfn : max_low_pfn; |
|
#endif |
|
__vmalloc_start_set = true; |
|
|
|
printk(KERN_NOTICE "%ldMB LOWMEM available.\n", |
|
pages_to_mb(max_low_pfn)); |
|
|
|
setup_bootmem_allocator(); |
|
} |
|
#endif /* !CONFIG_NEED_MULTIPLE_NODES */ |
|
|
|
void __init setup_bootmem_allocator(void) |
|
{ |
|
printk(KERN_INFO " mapped low ram: 0 - %08lx\n", |
|
max_pfn_mapped<<PAGE_SHIFT); |
|
printk(KERN_INFO " low ram: 0 - %08lx\n", max_low_pfn<<PAGE_SHIFT); |
|
} |
|
|
|
/* |
|
* paging_init() sets up the page tables - note that the first 8MB are |
|
* already mapped by head.S. |
|
* |
|
* This routines also unmaps the page at virtual kernel address 0, so |
|
* that we can trap those pesky NULL-reference errors in the kernel. |
|
*/ |
|
void __init paging_init(void) |
|
{ |
|
pagetable_init(); |
|
|
|
__flush_tlb_all(); |
|
|
|
/* |
|
* NOTE: at this point the bootmem allocator is fully available. |
|
*/ |
|
olpc_dt_build_devicetree(); |
|
sparse_init(); |
|
zone_sizes_init(); |
|
} |
|
|
|
/* |
|
* Test if the WP bit works in supervisor mode. It isn't supported on 386's |
|
* and also on some strange 486's. All 586+'s are OK. This used to involve |
|
* black magic jumps to work around some nasty CPU bugs, but fortunately the |
|
* switch to using exceptions got rid of all that. |
|
*/ |
|
static void __init test_wp_bit(void) |
|
{ |
|
char z = 0; |
|
|
|
printk(KERN_INFO "Checking if this processor honours the WP bit even in supervisor mode..."); |
|
|
|
__set_fixmap(FIX_WP_TEST, __pa_symbol(empty_zero_page), PAGE_KERNEL_RO); |
|
|
|
if (copy_to_kernel_nofault((char *)fix_to_virt(FIX_WP_TEST), &z, 1)) { |
|
clear_fixmap(FIX_WP_TEST); |
|
printk(KERN_CONT "Ok.\n"); |
|
return; |
|
} |
|
|
|
printk(KERN_CONT "No.\n"); |
|
panic("Linux doesn't support CPUs with broken WP."); |
|
} |
|
|
|
void __init mem_init(void) |
|
{ |
|
pci_iommu_alloc(); |
|
|
|
#ifdef CONFIG_FLATMEM |
|
BUG_ON(!mem_map); |
|
#endif |
|
/* |
|
* With CONFIG_DEBUG_PAGEALLOC initialization of highmem pages has to |
|
* be done before memblock_free_all(). Memblock use free low memory for |
|
* temporary data (see find_range_array()) and for this purpose can use |
|
* pages that was already passed to the buddy allocator, hence marked as |
|
* not accessible in the page tables when compiled with |
|
* CONFIG_DEBUG_PAGEALLOC. Otherwise order of initialization is not |
|
* important here. |
|
*/ |
|
set_highmem_pages_init(); |
|
|
|
/* this will put all low memory onto the freelists */ |
|
memblock_free_all(); |
|
|
|
after_bootmem = 1; |
|
x86_init.hyper.init_after_bootmem(); |
|
|
|
mem_init_print_info(NULL); |
|
|
|
/* |
|
* Check boundaries twice: Some fundamental inconsistencies can |
|
* be detected at build time already. |
|
*/ |
|
#define __FIXADDR_TOP (-PAGE_SIZE) |
|
#ifdef CONFIG_HIGHMEM |
|
BUILD_BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START); |
|
BUILD_BUG_ON(VMALLOC_END > PKMAP_BASE); |
|
#endif |
|
#define high_memory (-128UL << 20) |
|
BUILD_BUG_ON(VMALLOC_START >= VMALLOC_END); |
|
#undef high_memory |
|
#undef __FIXADDR_TOP |
|
|
|
#ifdef CONFIG_HIGHMEM |
|
BUG_ON(PKMAP_BASE + LAST_PKMAP*PAGE_SIZE > FIXADDR_START); |
|
BUG_ON(VMALLOC_END > PKMAP_BASE); |
|
#endif |
|
BUG_ON(VMALLOC_START >= VMALLOC_END); |
|
BUG_ON((unsigned long)high_memory > VMALLOC_START); |
|
|
|
test_wp_bit(); |
|
} |
|
|
|
#ifdef CONFIG_MEMORY_HOTPLUG |
|
int arch_add_memory(int nid, u64 start, u64 size, |
|
struct mhp_params *params) |
|
{ |
|
unsigned long start_pfn = start >> PAGE_SHIFT; |
|
unsigned long nr_pages = size >> PAGE_SHIFT; |
|
int ret; |
|
|
|
/* |
|
* The page tables were already mapped at boot so if the caller |
|
* requests a different mapping type then we must change all the |
|
* pages with __set_memory_prot(). |
|
*/ |
|
if (params->pgprot.pgprot != PAGE_KERNEL.pgprot) { |
|
ret = __set_memory_prot(start, nr_pages, params->pgprot); |
|
if (ret) |
|
return ret; |
|
} |
|
|
|
return __add_pages(nid, start_pfn, nr_pages, params); |
|
} |
|
|
|
void arch_remove_memory(int nid, u64 start, u64 size, |
|
struct vmem_altmap *altmap) |
|
{ |
|
unsigned long start_pfn = start >> PAGE_SHIFT; |
|
unsigned long nr_pages = size >> PAGE_SHIFT; |
|
|
|
__remove_pages(start_pfn, nr_pages, altmap); |
|
} |
|
#endif |
|
|
|
int kernel_set_to_readonly __read_mostly; |
|
|
|
static void mark_nxdata_nx(void) |
|
{ |
|
/* |
|
* When this called, init has already been executed and released, |
|
* so everything past _etext should be NX. |
|
*/ |
|
unsigned long start = PFN_ALIGN(_etext); |
|
/* |
|
* This comes from __is_kernel_text upper limit. Also HPAGE where used: |
|
*/ |
|
unsigned long size = (((unsigned long)__init_end + HPAGE_SIZE) & HPAGE_MASK) - start; |
|
|
|
if (__supported_pte_mask & _PAGE_NX) |
|
printk(KERN_INFO "NX-protecting the kernel data: %luk\n", size >> 10); |
|
set_memory_nx(start, size >> PAGE_SHIFT); |
|
} |
|
|
|
void mark_rodata_ro(void) |
|
{ |
|
unsigned long start = PFN_ALIGN(_text); |
|
unsigned long size = (unsigned long)__end_rodata - start; |
|
|
|
set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); |
|
pr_info("Write protecting kernel text and read-only data: %luk\n", |
|
size >> 10); |
|
|
|
kernel_set_to_readonly = 1; |
|
|
|
#ifdef CONFIG_CPA_DEBUG |
|
pr_info("Testing CPA: Reverting %lx-%lx\n", start, start + size); |
|
set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT); |
|
|
|
pr_info("Testing CPA: write protecting again\n"); |
|
set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT); |
|
#endif |
|
mark_nxdata_nx(); |
|
if (__supported_pte_mask & _PAGE_NX) |
|
debug_checkwx(); |
|
}
|
|
|