aeed5fce37
Fix warning from pmd_bad() at bootup on a HIGHMEM64G HIGHPTE x86_32. That came from9fc34113f6
x86: debug pmd_bad(); but we understand now that the typecasting was wrong for PAE in the previous version: pagetable pages above 4GB looked bad and stopped Arjan from booting. And revert thatcded932b75
x86: fix pmd_bad and pud_bad to support huge pages. It was the wrong way round: we shouldn't weaken every pmd_bad and pud_bad check to let huge pages slip through - in part they check that we _don't_ have a huge page where it's not expected. Put the x86 pmd_bad() and pud_bad() definitions back to what they have long been: they can be improved (x86_32 should use PTE_MASK, to stop PAE thinking junk in the upper word is good; and x86_64 should follow x86_32's stricter comparison, to stop thinking any subset of required bits is good); but that should be a later patch. Fix Hans' good observation that follow_page() will never find pmd_huge() because that would have already failed the pmd_bad test: test pmd_huge in between the pmd_none and pmd_bad tests. Tighten x86's pmd_huge() check? No, once it's a hugepage entry, it can get quite far from a good pmd: for example, PROT_NONE leaves it with only ACCESSED of the KERN_PGTABLE bits. However... though follow_page() contains this and another test for huge pages, so it's nice to keep it working on them, where does it actually get called on a huge page? get_user_pages() checks is_vm_hugetlb_page(vma) to to call alternative hugetlb processing, as does unmap_vmas() and others. Signed-off-by: Hugh Dickins <hugh@veritas.com> Earlier-version-tested-by: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jeff Chua <jeff.chua.linux@gmail.com> Cc: Hans Rosenfeld <hans.rosenfeld@amd.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
175 lines
4.5 KiB
C
175 lines
4.5 KiB
C
#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/mm.h>
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#include <linux/nmi.h>
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#include <linux/swap.h>
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#include <linux/smp.h>
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#include <linux/highmem.h>
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#include <linux/slab.h>
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#include <linux/pagemap.h>
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#include <linux/spinlock.h>
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#include <linux/module.h>
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#include <linux/quicklist.h>
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#include <asm/system.h>
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#include <asm/pgtable.h>
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#include <asm/pgalloc.h>
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#include <asm/fixmap.h>
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#include <asm/e820.h>
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#include <asm/tlb.h>
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#include <asm/tlbflush.h>
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void show_mem(void)
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{
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int total = 0, reserved = 0;
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int shared = 0, cached = 0;
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int highmem = 0;
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struct page *page;
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pg_data_t *pgdat;
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unsigned long i;
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unsigned long flags;
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printk(KERN_INFO "Mem-info:\n");
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show_free_areas();
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for_each_online_pgdat(pgdat) {
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pgdat_resize_lock(pgdat, &flags);
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for (i = 0; i < pgdat->node_spanned_pages; ++i) {
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if (unlikely(i % MAX_ORDER_NR_PAGES == 0))
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touch_nmi_watchdog();
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page = pgdat_page_nr(pgdat, i);
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total++;
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if (PageHighMem(page))
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highmem++;
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if (PageReserved(page))
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reserved++;
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else if (PageSwapCache(page))
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cached++;
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else if (page_count(page))
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shared += page_count(page) - 1;
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}
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pgdat_resize_unlock(pgdat, &flags);
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}
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printk(KERN_INFO "%d pages of RAM\n", total);
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printk(KERN_INFO "%d pages of HIGHMEM\n", highmem);
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printk(KERN_INFO "%d reserved pages\n", reserved);
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printk(KERN_INFO "%d pages shared\n", shared);
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printk(KERN_INFO "%d pages swap cached\n", cached);
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printk(KERN_INFO "%lu pages dirty\n", global_page_state(NR_FILE_DIRTY));
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printk(KERN_INFO "%lu pages writeback\n",
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global_page_state(NR_WRITEBACK));
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printk(KERN_INFO "%lu pages mapped\n", global_page_state(NR_FILE_MAPPED));
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printk(KERN_INFO "%lu pages slab\n",
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global_page_state(NR_SLAB_RECLAIMABLE) +
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global_page_state(NR_SLAB_UNRECLAIMABLE));
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printk(KERN_INFO "%lu pages pagetables\n",
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global_page_state(NR_PAGETABLE));
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}
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/*
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* Associate a virtual page frame with a given physical page frame
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* and protection flags for that frame.
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*/
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static void set_pte_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
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{
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pgd_t *pgd;
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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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pgd = swapper_pg_dir + pgd_index(vaddr);
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if (pgd_none(*pgd)) {
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BUG();
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return;
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}
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pud = pud_offset(pgd, vaddr);
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if (pud_none(*pud)) {
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BUG();
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return;
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}
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pmd = pmd_offset(pud, vaddr);
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if (pmd_none(*pmd)) {
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BUG();
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return;
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}
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pte = pte_offset_kernel(pmd, vaddr);
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if (pgprot_val(flags))
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set_pte_present(&init_mm, vaddr, pte, pfn_pte(pfn, flags));
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else
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pte_clear(&init_mm, vaddr, pte);
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/*
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* It's enough to flush this one mapping.
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* (PGE mappings get flushed as well)
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*/
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__flush_tlb_one(vaddr);
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}
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/*
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* Associate a large virtual page frame with a given physical page frame
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* and protection flags for that frame. pfn is for the base of the page,
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* vaddr is what the page gets mapped to - both must be properly aligned.
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* The pmd must already be instantiated. Assumes PAE mode.
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*/
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void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
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{
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pgd_t *pgd;
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pud_t *pud;
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pmd_t *pmd;
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if (vaddr & (PMD_SIZE-1)) { /* vaddr is misaligned */
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printk(KERN_WARNING "set_pmd_pfn: vaddr misaligned\n");
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return; /* BUG(); */
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}
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if (pfn & (PTRS_PER_PTE-1)) { /* pfn is misaligned */
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printk(KERN_WARNING "set_pmd_pfn: pfn misaligned\n");
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return; /* BUG(); */
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}
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pgd = swapper_pg_dir + pgd_index(vaddr);
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if (pgd_none(*pgd)) {
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printk(KERN_WARNING "set_pmd_pfn: pgd_none\n");
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return; /* BUG(); */
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}
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pud = pud_offset(pgd, vaddr);
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pmd = pmd_offset(pud, vaddr);
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set_pmd(pmd, pfn_pmd(pfn, flags));
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/*
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* It's enough to flush this one mapping.
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* (PGE mappings get flushed as well)
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*/
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__flush_tlb_one(vaddr);
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}
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static int fixmaps;
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unsigned long __FIXADDR_TOP = 0xfffff000;
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EXPORT_SYMBOL(__FIXADDR_TOP);
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void __set_fixmap (enum fixed_addresses idx, unsigned long phys, pgprot_t flags)
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{
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unsigned long address = __fix_to_virt(idx);
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if (idx >= __end_of_fixed_addresses) {
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BUG();
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return;
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}
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set_pte_pfn(address, phys >> PAGE_SHIFT, flags);
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fixmaps++;
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}
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/**
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* reserve_top_address - reserves a hole in the top of kernel address space
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* @reserve - size of hole to reserve
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*
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* Can be used to relocate the fixmap area and poke a hole in the top
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* of kernel address space to make room for a hypervisor.
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*/
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void reserve_top_address(unsigned long reserve)
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{
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BUG_ON(fixmaps > 0);
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printk(KERN_INFO "Reserving virtual address space above 0x%08x\n",
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(int)-reserve);
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__FIXADDR_TOP = -reserve - PAGE_SIZE;
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__VMALLOC_RESERVE += reserve;
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}
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