i386: move mm
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Thomas Gleixner
278
arch/x86/mm/pageattr_32.c
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278
arch/x86/mm/pageattr_32.c
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/*
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* Copyright 2002 Andi Kleen, SuSE Labs.
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* Thanks to Ben LaHaise for precious feedback.
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*/
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#include <linux/mm.h>
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#include <linux/sched.h>
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#include <linux/highmem.h>
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#include <linux/module.h>
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#include <linux/slab.h>
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#include <asm/uaccess.h>
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#include <asm/processor.h>
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#include <asm/tlbflush.h>
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#include <asm/pgalloc.h>
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#include <asm/sections.h>
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static DEFINE_SPINLOCK(cpa_lock);
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static struct list_head df_list = LIST_HEAD_INIT(df_list);
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pte_t *lookup_address(unsigned long address)
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{
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pgd_t *pgd = pgd_offset_k(address);
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pud_t *pud;
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pmd_t *pmd;
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if (pgd_none(*pgd))
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return NULL;
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pud = pud_offset(pgd, address);
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if (pud_none(*pud))
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return NULL;
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pmd = pmd_offset(pud, address);
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if (pmd_none(*pmd))
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return NULL;
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if (pmd_large(*pmd))
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return (pte_t *)pmd;
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return pte_offset_kernel(pmd, address);
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}
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static struct page *split_large_page(unsigned long address, pgprot_t prot,
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pgprot_t ref_prot)
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{
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int i;
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unsigned long addr;
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struct page *base;
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pte_t *pbase;
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spin_unlock_irq(&cpa_lock);
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base = alloc_pages(GFP_KERNEL, 0);
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spin_lock_irq(&cpa_lock);
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if (!base)
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return NULL;
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/*
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* page_private is used to track the number of entries in
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* the page table page that have non standard attributes.
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*/
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SetPagePrivate(base);
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page_private(base) = 0;
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address = __pa(address);
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addr = address & LARGE_PAGE_MASK;
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pbase = (pte_t *)page_address(base);
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paravirt_alloc_pt(&init_mm, page_to_pfn(base));
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for (i = 0; i < PTRS_PER_PTE; i++, addr += PAGE_SIZE) {
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set_pte(&pbase[i], pfn_pte(addr >> PAGE_SHIFT,
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addr == address ? prot : ref_prot));
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}
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return base;
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}
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static void cache_flush_page(struct page *p)
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{
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unsigned long adr = (unsigned long)page_address(p);
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int i;
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for (i = 0; i < PAGE_SIZE; i += boot_cpu_data.x86_clflush_size)
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asm volatile("clflush (%0)" :: "r" (adr + i));
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}
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static void flush_kernel_map(void *arg)
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{
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struct list_head *lh = (struct list_head *)arg;
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struct page *p;
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/* High level code is not ready for clflush yet */
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if (0 && cpu_has_clflush) {
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list_for_each_entry (p, lh, lru)
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cache_flush_page(p);
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} else if (boot_cpu_data.x86_model >= 4)
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wbinvd();
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/* Flush all to work around Errata in early athlons regarding
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* large page flushing.
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*/
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__flush_tlb_all();
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}
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static void set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
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{
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struct page *page;
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unsigned long flags;
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set_pte_atomic(kpte, pte); /* change init_mm */
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if (SHARED_KERNEL_PMD)
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return;
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spin_lock_irqsave(&pgd_lock, flags);
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for (page = pgd_list; page; page = (struct page *)page->index) {
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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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pgd = (pgd_t *)page_address(page) + pgd_index(address);
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pud = pud_offset(pgd, address);
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pmd = pmd_offset(pud, address);
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set_pte_atomic((pte_t *)pmd, pte);
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}
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spin_unlock_irqrestore(&pgd_lock, flags);
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}
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/*
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* No more special protections in this 2/4MB area - revert to a
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* large page again.
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*/
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static inline void revert_page(struct page *kpte_page, unsigned long address)
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{
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pgprot_t ref_prot;
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pte_t *linear;
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ref_prot =
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((address & LARGE_PAGE_MASK) < (unsigned long)&_etext)
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? PAGE_KERNEL_LARGE_EXEC : PAGE_KERNEL_LARGE;
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linear = (pte_t *)
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pmd_offset(pud_offset(pgd_offset_k(address), address), address);
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set_pmd_pte(linear, address,
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pfn_pte((__pa(address) & LARGE_PAGE_MASK) >> PAGE_SHIFT,
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ref_prot));
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}
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static inline void save_page(struct page *kpte_page)
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{
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if (!test_and_set_bit(PG_arch_1, &kpte_page->flags))
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list_add(&kpte_page->lru, &df_list);
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}
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static int
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__change_page_attr(struct page *page, pgprot_t prot)
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{
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pte_t *kpte;
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unsigned long address;
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struct page *kpte_page;
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BUG_ON(PageHighMem(page));
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address = (unsigned long)page_address(page);
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kpte = lookup_address(address);
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if (!kpte)
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return -EINVAL;
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kpte_page = virt_to_page(kpte);
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BUG_ON(PageLRU(kpte_page));
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BUG_ON(PageCompound(kpte_page));
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if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL)) {
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if (!pte_huge(*kpte)) {
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set_pte_atomic(kpte, mk_pte(page, prot));
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} else {
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pgprot_t ref_prot;
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struct page *split;
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ref_prot =
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((address & LARGE_PAGE_MASK) < (unsigned long)&_etext)
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? PAGE_KERNEL_EXEC : PAGE_KERNEL;
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split = split_large_page(address, prot, ref_prot);
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if (!split)
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return -ENOMEM;
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set_pmd_pte(kpte,address,mk_pte(split, ref_prot));
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kpte_page = split;
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}
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page_private(kpte_page)++;
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} else if (!pte_huge(*kpte)) {
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set_pte_atomic(kpte, mk_pte(page, PAGE_KERNEL));
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BUG_ON(page_private(kpte_page) == 0);
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page_private(kpte_page)--;
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} else
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BUG();
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/*
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* If the pte was reserved, it means it was created at boot
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* time (not via split_large_page) and in turn we must not
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* replace it with a largepage.
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*/
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save_page(kpte_page);
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if (!PageReserved(kpte_page)) {
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if (cpu_has_pse && (page_private(kpte_page) == 0)) {
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paravirt_release_pt(page_to_pfn(kpte_page));
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revert_page(kpte_page, address);
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}
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}
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return 0;
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}
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static inline void flush_map(struct list_head *l)
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{
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on_each_cpu(flush_kernel_map, l, 1, 1);
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}
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/*
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* Change the page attributes of an page in the linear mapping.
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*
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* This should be used when a page is mapped with a different caching policy
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* than write-back somewhere - some CPUs do not like it when mappings with
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* different caching policies exist. This changes the page attributes of the
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* in kernel linear mapping too.
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*
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* The caller needs to ensure that there are no conflicting mappings elsewhere.
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* This function only deals with the kernel linear map.
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*
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* Caller must call global_flush_tlb() after this.
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*/
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int change_page_attr(struct page *page, int numpages, pgprot_t prot)
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{
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int err = 0;
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int i;
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unsigned long flags;
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spin_lock_irqsave(&cpa_lock, flags);
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for (i = 0; i < numpages; i++, page++) {
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err = __change_page_attr(page, prot);
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if (err)
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break;
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}
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spin_unlock_irqrestore(&cpa_lock, flags);
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return err;
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}
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void global_flush_tlb(void)
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{
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struct list_head l;
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struct page *pg, *next;
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BUG_ON(irqs_disabled());
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spin_lock_irq(&cpa_lock);
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list_replace_init(&df_list, &l);
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spin_unlock_irq(&cpa_lock);
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flush_map(&l);
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list_for_each_entry_safe(pg, next, &l, lru) {
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list_del(&pg->lru);
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clear_bit(PG_arch_1, &pg->flags);
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if (PageReserved(pg) || !cpu_has_pse || page_private(pg) != 0)
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continue;
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ClearPagePrivate(pg);
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__free_page(pg);
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}
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}
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#ifdef CONFIG_DEBUG_PAGEALLOC
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void kernel_map_pages(struct page *page, int numpages, int enable)
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{
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if (PageHighMem(page))
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return;
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if (!enable)
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debug_check_no_locks_freed(page_address(page),
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numpages * PAGE_SIZE);
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/* the return value is ignored - the calls cannot fail,
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* large pages are disabled at boot time.
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*/
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change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0));
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/* we should perform an IPI and flush all tlbs,
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* but that can deadlock->flush only current cpu.
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*/
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__flush_tlb_all();
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}
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#endif
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EXPORT_SYMBOL(change_page_attr);
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EXPORT_SYMBOL(global_flush_tlb);
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