![Oscar Salvador](/assets/img/avatar_default.png)
Patch series "Do not touch pages in hot-remove path", v2. This patchset aims for two things: 1) A better definition about offline and hot-remove stage 2) Solving bugs where we can access non-initialized pages during hot-remove operations [2] [3]. This is achieved by moving all page/zone handling to the offline stage, so we do not need to access pages when hot-removing memory. [1] https://patchwork.kernel.org/cover/10691415/ [2] https://patchwork.kernel.org/patch/10547445/ [3] https://www.spinics.net/lists/linux-mm/msg161316.html This patch (of 5): This is a preparation for the following-up patches. The idea of passing the nid is that it will allow us to get rid of the zone parameter afterwards. Link: http://lkml.kernel.org/r/20181127162005.15833-2-osalvador@suse.de Signed-off-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
944 lines
25 KiB
C
944 lines
25 KiB
C
/*
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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/pgtable.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 "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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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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{
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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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pte_t *kmap_pte;
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static inline pte_t *kmap_get_fixmap_pte(unsigned long vaddr)
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{
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pgd_t *pgd = pgd_offset_k(vaddr);
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p4d_t *p4d = p4d_offset(pgd, vaddr);
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pud_t *pud = pud_offset(p4d, vaddr);
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pmd_t *pmd = pmd_offset(pud, vaddr);
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return pte_offset_kernel(pmd, vaddr);
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}
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static void __init kmap_init(void)
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{
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unsigned long kmap_vstart;
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/*
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* Cache the first kmap pte:
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*/
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kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
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kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
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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;
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pgd_t *pgd;
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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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vaddr = PKMAP_BASE;
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page_table_range_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
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pgd = swapper_pg_dir + pgd_index(vaddr);
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p4d = p4d_offset(pgd, vaddr);
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pud = pud_offset(p4d, vaddr);
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pmd = pmd_offset(pud, vaddr);
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pte = pte_offset_kernel(pmd, vaddr);
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pkmap_page_table = pte;
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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
|
|
* in the 32-bit EFI stub.
|
|
*/
|
|
clone_pgd_range(initial_page_table,
|
|
swapper_pg_dir + KERNEL_PGD_BOUNDARY,
|
|
min(KERNEL_PGD_PTRS, KERNEL_PGD_BOUNDARY));
|
|
}
|
|
|
|
void __init native_pagetable_init(void)
|
|
{
|
|
unsigned long pfn, va;
|
|
pgd_t *pgd, *base = swapper_pg_dir;
|
|
p4d_t *p4d;
|
|
pud_t *pud;
|
|
pmd_t *pmd;
|
|
pte_t *pte;
|
|
|
|
/*
|
|
* Remove any mappings which extend past the end of physical
|
|
* memory from the boot time page table.
|
|
* In virtual address space, we should have at least two pages
|
|
* from VMALLOC_END to pkmap or fixmap according to VMALLOC_END
|
|
* definition. And max_low_pfn is set to VMALLOC_END physical
|
|
* address. If initial memory mapping is doing right job, we
|
|
* should have pte used near max_low_pfn or one pmd is not present.
|
|
*/
|
|
for (pfn = max_low_pfn; pfn < 1<<(32-PAGE_SHIFT); pfn++) {
|
|
va = PAGE_OFFSET + (pfn<<PAGE_SHIFT);
|
|
pgd = base + pgd_index(va);
|
|
if (!pgd_present(*pgd))
|
|
break;
|
|
|
|
p4d = p4d_offset(pgd, va);
|
|
pud = pud_offset(p4d, va);
|
|
pmd = pmd_offset(pud, va);
|
|
if (!pmd_present(*pmd))
|
|
break;
|
|
|
|
/* should not be large page here */
|
|
if (pmd_large(*pmd)) {
|
|
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",
|
|
pfn, pmd, __pa(pmd));
|
|
BUG_ON(1);
|
|
}
|
|
|
|
pte = pte_offset_kernel(pmd, va);
|
|
if (!pte_present(*pte))
|
|
break;
|
|
|
|
printk(KERN_DEBUG "clearing pte for ram above max_low_pfn: pfn: %lx pmd: %p pmd phys: %lx pte: %p pte phys: %lx\n",
|
|
pfn, pmd, __pa(pmd), pte, __pa(pte));
|
|
pte_clear(NULL, va, pte);
|
|
}
|
|
paravirt_alloc_pmd(&init_mm, __pa(base) >> PAGE_SHIFT);
|
|
paging_init();
|
|
}
|
|
|
|
/*
|
|
* Build a proper pagetable for the kernel mappings. Up until this
|
|
* point, we've been running on some set of pagetables constructed by
|
|
* the boot process.
|
|
*
|
|
* If we're booting on native hardware, this will be a pagetable
|
|
* constructed in arch/x86/kernel/head_32.S. The root of the
|
|
* pagetable will be swapper_pg_dir.
|
|
*
|
|
* If we're booting paravirtualized under a hypervisor, then there are
|
|
* more options: we may already be running PAE, and the pagetable may
|
|
* or may not be based in swapper_pg_dir. In any case,
|
|
* paravirt_pagetable_init() will set up swapper_pg_dir
|
|
* appropriately for the rest of the initialization to work.
|
|
*
|
|
* In general, pagetable_init() assumes that the pagetable may already
|
|
* be partially populated, and so it avoids stomping on any existing
|
|
* mappings.
|
|
*/
|
|
void __init early_ioremap_page_table_range_init(void)
|
|
{
|
|
pgd_t *pgd_base = swapper_pg_dir;
|
|
unsigned long vaddr, end;
|
|
|
|
/*
|
|
* Fixed mappings, only the page table structure has to be
|
|
* created - mappings will be set by set_fixmap():
|
|
*/
|
|
vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
|
|
end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
|
|
page_table_range_init(vaddr, end, pgd_base);
|
|
early_ioremap_reset();
|
|
}
|
|
|
|
static void __init pagetable_init(void)
|
|
{
|
|
pgd_t *pgd_base = swapper_pg_dir;
|
|
|
|
permanent_kmaps_init(pgd_base);
|
|
}
|
|
|
|
#define DEFAULT_PTE_MASK ~(_PAGE_NX | _PAGE_GLOBAL)
|
|
/* Bits supported by the hardware: */
|
|
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);
|
|
sparse_memory_present_with_active_regions(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();
|
|
|
|
kmap_init();
|
|
|
|
/*
|
|
* NOTE: at this point the bootmem allocator is fully available.
|
|
*/
|
|
olpc_dt_build_devicetree();
|
|
sparse_memory_present_with_active_regions(MAX_NUMNODES);
|
|
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 (probe_kernel_write((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);
|
|
printk(KERN_INFO "virtual kernel memory layout:\n"
|
|
" fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
|
|
" cpu_entry : 0x%08lx - 0x%08lx (%4ld kB)\n"
|
|
#ifdef CONFIG_HIGHMEM
|
|
" pkmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
|
|
#endif
|
|
" vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n"
|
|
" lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n"
|
|
" .init : 0x%08lx - 0x%08lx (%4ld kB)\n"
|
|
" .data : 0x%08lx - 0x%08lx (%4ld kB)\n"
|
|
" .text : 0x%08lx - 0x%08lx (%4ld kB)\n",
|
|
FIXADDR_START, FIXADDR_TOP,
|
|
(FIXADDR_TOP - FIXADDR_START) >> 10,
|
|
|
|
CPU_ENTRY_AREA_BASE,
|
|
CPU_ENTRY_AREA_BASE + CPU_ENTRY_AREA_MAP_SIZE,
|
|
CPU_ENTRY_AREA_MAP_SIZE >> 10,
|
|
|
|
#ifdef CONFIG_HIGHMEM
|
|
PKMAP_BASE, PKMAP_BASE+LAST_PKMAP*PAGE_SIZE,
|
|
(LAST_PKMAP*PAGE_SIZE) >> 10,
|
|
#endif
|
|
|
|
VMALLOC_START, VMALLOC_END,
|
|
(VMALLOC_END - VMALLOC_START) >> 20,
|
|
|
|
(unsigned long)__va(0), (unsigned long)high_memory,
|
|
((unsigned long)high_memory - (unsigned long)__va(0)) >> 20,
|
|
|
|
(unsigned long)&__init_begin, (unsigned long)&__init_end,
|
|
((unsigned long)&__init_end -
|
|
(unsigned long)&__init_begin) >> 10,
|
|
|
|
(unsigned long)&_etext, (unsigned long)&_edata,
|
|
((unsigned long)&_edata - (unsigned long)&_etext) >> 10,
|
|
|
|
(unsigned long)&_text, (unsigned long)&_etext,
|
|
((unsigned long)&_etext - (unsigned long)&_text) >> 10);
|
|
|
|
/*
|
|
* 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 vmem_altmap *altmap,
|
|
bool want_memblock)
|
|
{
|
|
unsigned long start_pfn = start >> PAGE_SHIFT;
|
|
unsigned long nr_pages = size >> PAGE_SHIFT;
|
|
|
|
return __add_pages(nid, start_pfn, nr_pages, altmap, want_memblock);
|
|
}
|
|
|
|
#ifdef CONFIG_MEMORY_HOTREMOVE
|
|
int 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;
|
|
struct zone *zone;
|
|
|
|
zone = page_zone(pfn_to_page(start_pfn));
|
|
return __remove_pages(zone, start_pfn, nr_pages, altmap);
|
|
}
|
|
#endif
|
|
#endif
|
|
|
|
int kernel_set_to_readonly __read_mostly;
|
|
|
|
void set_kernel_text_rw(void)
|
|
{
|
|
unsigned long start = PFN_ALIGN(_text);
|
|
unsigned long size = PFN_ALIGN(_etext) - start;
|
|
|
|
if (!kernel_set_to_readonly)
|
|
return;
|
|
|
|
pr_debug("Set kernel text: %lx - %lx for read write\n",
|
|
start, start+size);
|
|
|
|
set_pages_rw(virt_to_page(start), size >> PAGE_SHIFT);
|
|
}
|
|
|
|
void set_kernel_text_ro(void)
|
|
{
|
|
unsigned long start = PFN_ALIGN(_text);
|
|
unsigned long size = PFN_ALIGN(_etext) - start;
|
|
|
|
if (!kernel_set_to_readonly)
|
|
return;
|
|
|
|
pr_debug("Set kernel text: %lx - %lx for read only\n",
|
|
start, start+size);
|
|
|
|
set_pages_ro(virt_to_page(start), size >> PAGE_SHIFT);
|
|
}
|
|
|
|
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_pages_nx(virt_to_page(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();
|
|
}
|