-/*
- * Copyright 2002 Andi Kleen, SuSE Labs.
+/*
+ * Copyright 2002 Andi Kleen, SuSE Labs.
* Thanks to Ben LaHaise for precious feedback.
- */
+ */
-#include <linux/mm.h>
-#include <linux/sched.h>
#include <linux/highmem.h>
#include <linux/module.h>
+#include <linux/sched.h>
#include <linux/slab.h>
-#include <asm/uaccess.h>
+#include <linux/mm.h>
+
#include <asm/processor.h>
#include <asm/tlbflush.h>
-#include <asm/pgalloc.h>
#include <asm/sections.h>
+#include <asm/uaccess.h>
+#include <asm/pgalloc.h>
-static DEFINE_SPINLOCK(cpa_lock);
-static struct list_head df_list = LIST_HEAD_INIT(df_list);
-
-
-pte_t *lookup_address(unsigned long address)
-{
+pte_t *lookup_address(unsigned long address, int *level)
+{
pgd_t *pgd = pgd_offset_k(address);
pud_t *pud;
pmd_t *pmd;
+
if (pgd_none(*pgd))
return NULL;
pud = pud_offset(pgd, address);
pmd = pmd_offset(pud, address);
if (pmd_none(*pmd))
return NULL;
+ *level = 2;
if (pmd_large(*pmd))
return (pte_t *)pmd;
- return pte_offset_kernel(pmd, address);
-}
-
-static struct page *split_large_page(unsigned long address, pgprot_t prot,
- pgprot_t ref_prot)
-{
- int i;
- unsigned long addr;
- struct page *base;
- pte_t *pbase;
-
- spin_unlock_irq(&cpa_lock);
- base = alloc_pages(GFP_KERNEL, 0);
- spin_lock_irq(&cpa_lock);
- if (!base)
- return NULL;
-
- /*
- * page_private is used to track the number of entries in
- * the page table page that have non standard attributes.
- */
- SetPagePrivate(base);
- page_private(base) = 0;
-
- address = __pa(address);
- addr = address & LARGE_PAGE_MASK;
- pbase = (pte_t *)page_address(base);
- paravirt_alloc_pt(&init_mm, page_to_pfn(base));
- for (i = 0; i < PTRS_PER_PTE; i++, addr += PAGE_SIZE) {
- set_pte(&pbase[i], pfn_pte(addr >> PAGE_SHIFT,
- addr == address ? prot : ref_prot));
- }
- return base;
-}
+ *level = 3;
-static void cache_flush_page(struct page *p)
-{
- unsigned long adr = (unsigned long)page_address(p);
- int i;
- for (i = 0; i < PAGE_SIZE; i += boot_cpu_data.x86_clflush_size)
- asm volatile("clflush (%0)" :: "r" (adr + i));
+ return pte_offset_kernel(pmd, address);
}
-static void flush_kernel_map(void *arg)
+static void __set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
{
- struct list_head *lh = (struct list_head *)arg;
- struct page *p;
-
- /* High level code is not ready for clflush yet */
- if (0 && cpu_has_clflush) {
- list_for_each_entry (p, lh, lru)
- cache_flush_page(p);
- } else if (boot_cpu_data.x86_model >= 4)
- wbinvd();
-
- /* Flush all to work around Errata in early athlons regarding
- * large page flushing.
- */
- __flush_tlb_all();
-}
-
-static void set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
-{
struct page *page;
- unsigned long flags;
- set_pte_atomic(kpte, pte); /* change init_mm */
+ /* change init_mm */
+ set_pte_atomic(kpte, pte);
if (SHARED_KERNEL_PMD)
return;
- spin_lock_irqsave(&pgd_lock, flags);
for (page = pgd_list; page; page = (struct page *)page->index) {
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
+
pgd = (pgd_t *)page_address(page) + pgd_index(address);
pud = pud_offset(pgd, address);
pmd = pmd_offset(pud, address);
set_pte_atomic((pte_t *)pmd, pte);
}
- spin_unlock_irqrestore(&pgd_lock, flags);
}
-/*
- * No more special protections in this 2/4MB area - revert to a
- * large page again.
- */
-static inline void revert_page(struct page *kpte_page, unsigned long address)
+static int split_large_page(pte_t *kpte, unsigned long address)
{
- pgprot_t ref_prot;
- pte_t *linear;
-
- ref_prot =
- ((address & LARGE_PAGE_MASK) < (unsigned long)&_etext)
- ? PAGE_KERNEL_LARGE_EXEC : PAGE_KERNEL_LARGE;
-
- linear = (pte_t *)
- pmd_offset(pud_offset(pgd_offset_k(address), address), address);
- set_pmd_pte(linear, address,
- pfn_pte((__pa(address) & LARGE_PAGE_MASK) >> PAGE_SHIFT,
- ref_prot));
-}
+ pgprot_t ref_prot = pte_pgprot(pte_clrhuge(*kpte));
+ unsigned long flags;
+ unsigned long addr;
+ pte_t *pbase, *tmp;
+ struct page *base;
+ int i, level;
-static inline void save_page(struct page *kpte_page)
-{
- if (!test_and_set_bit(PG_arch_1, &kpte_page->flags))
- list_add(&kpte_page->lru, &df_list);
+ base = alloc_pages(GFP_KERNEL, 0);
+ if (!base)
+ return -ENOMEM;
+
+ spin_lock_irqsave(&pgd_lock, flags);
+ /*
+ * Check for races, another CPU might have split this page
+ * up for us already:
+ */
+ tmp = lookup_address(address, &level);
+ if (tmp != kpte) {
+ WARN_ON_ONCE(1);
+ goto out_unlock;
+ }
+
+ address = __pa(address);
+ addr = address & LARGE_PAGE_MASK;
+ pbase = (pte_t *)page_address(base);
+ paravirt_alloc_pt(&init_mm, page_to_pfn(base));
+
+ for (i = 0; i < PTRS_PER_PTE; i++, addr += PAGE_SIZE)
+ set_pte(&pbase[i], pfn_pte(addr >> PAGE_SHIFT, ref_prot));
+
+ /*
+ * Install the new, split up pagetable:
+ */
+ __set_pmd_pte(kpte, address, mk_pte(base, ref_prot));
+ base = NULL;
+
+out_unlock:
+ spin_unlock_irqrestore(&pgd_lock, flags);
+
+ if (base)
+ __free_pages(base, 0);
+
+ return 0;
}
-static int
-__change_page_attr(struct page *page, pgprot_t prot)
-{
- pte_t *kpte;
- unsigned long address;
+static int __change_page_attr(struct page *page, pgprot_t prot)
+{
struct page *kpte_page;
+ unsigned long address;
+ int level, err = 0;
+ pte_t *kpte;
BUG_ON(PageHighMem(page));
address = (unsigned long)page_address(page);
- kpte = lookup_address(address);
+repeat:
+ kpte = lookup_address(address, &level);
if (!kpte)
return -EINVAL;
+
kpte_page = virt_to_page(kpte);
BUG_ON(PageLRU(kpte_page));
BUG_ON(PageCompound(kpte_page));
- if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL)) {
- if (!pte_huge(*kpte)) {
- set_pte_atomic(kpte, mk_pte(page, prot));
- } else {
- pgprot_t ref_prot;
- struct page *split;
-
- ref_prot =
- ((address & LARGE_PAGE_MASK) < (unsigned long)&_etext)
- ? PAGE_KERNEL_EXEC : PAGE_KERNEL;
- split = split_large_page(address, prot, ref_prot);
- if (!split)
- return -ENOMEM;
- set_pmd_pte(kpte,address,mk_pte(split, ref_prot));
- kpte_page = split;
- }
- page_private(kpte_page)++;
- } else if (!pte_huge(*kpte)) {
- set_pte_atomic(kpte, mk_pte(page, PAGE_KERNEL));
- BUG_ON(page_private(kpte_page) == 0);
- page_private(kpte_page)--;
- } else
- BUG();
-
/*
- * If the pte was reserved, it means it was created at boot
- * time (not via split_large_page) and in turn we must not
- * replace it with a largepage.
+ * Better fail early if someone sets the kernel text to NX.
+ * Does not cover __inittext
*/
-
- save_page(kpte_page);
- if (!PageReserved(kpte_page)) {
- if (cpu_has_pse && (page_private(kpte_page) == 0)) {
- paravirt_release_pt(page_to_pfn(kpte_page));
- revert_page(kpte_page, address);
- }
+ BUG_ON(address >= (unsigned long)&_text &&
+ address < (unsigned long)&_etext &&
+ (pgprot_val(prot) & _PAGE_NX));
+
+ if (level == 3) {
+ set_pte_atomic(kpte, mk_pte(page, canon_pgprot(prot)));
+ } else {
+ err = split_large_page(kpte, address);
+ if (!err)
+ goto repeat;
}
- return 0;
-}
-
-static inline void flush_map(struct list_head *l)
-{
- on_each_cpu(flush_kernel_map, l, 1, 1);
+ return err;
}
/*
* than write-back somewhere - some CPUs do not like it when mappings with
* different caching policies exist. This changes the page attributes of the
* in kernel linear mapping too.
- *
+ *
* The caller needs to ensure that there are no conflicting mappings elsewhere.
* This function only deals with the kernel linear map.
- *
+ *
* Caller must call global_flush_tlb() after this.
*/
int change_page_attr(struct page *page, int numpages, pgprot_t prot)
{
- int err = 0;
- int i;
- unsigned long flags;
+ int err = 0, i;
- spin_lock_irqsave(&cpa_lock, flags);
- for (i = 0; i < numpages; i++, page++) {
+ for (i = 0; i < numpages; i++, page++) {
err = __change_page_attr(page, prot);
- if (err)
- break;
- }
- spin_unlock_irqrestore(&cpa_lock, flags);
+ if (err)
+ break;
+ }
+
return err;
}
+EXPORT_SYMBOL(change_page_attr);
+
+int change_page_attr_addr(unsigned long addr, int numpages, pgprot_t prot)
+{
+ int i;
+ unsigned long pfn = (__pa(addr) >> PAGE_SHIFT);
+
+ for (i = 0; i < numpages; i++) {
+ if (!pfn_valid(pfn + i)) {
+ WARN_ON_ONCE(1);
+ break;
+ } else {
+ int level;
+ pte_t *pte = lookup_address(addr + i*PAGE_SIZE, &level);
+ BUG_ON(pte && pte_none(*pte));
+ }
+ }
+
+ return change_page_attr(virt_to_page(addr), i, prot);
+}
-void global_flush_tlb(void)
+static void flush_kernel_map(void *arg)
{
- struct list_head l;
- struct page *pg, *next;
+ /*
+ * Flush all to work around Errata in early athlons regarding
+ * large page flushing.
+ */
+ __flush_tlb_all();
+ if (boot_cpu_data.x86_model >= 4)
+ wbinvd();
+}
+
+void global_flush_tlb(void)
+{
BUG_ON(irqs_disabled());
- spin_lock_irq(&cpa_lock);
- list_replace_init(&df_list, &l);
- spin_unlock_irq(&cpa_lock);
- flush_map(&l);
- list_for_each_entry_safe(pg, next, &l, lru) {
- list_del(&pg->lru);
- clear_bit(PG_arch_1, &pg->flags);
- if (PageReserved(pg) || !cpu_has_pse || page_private(pg) != 0)
- continue;
- ClearPagePrivate(pg);
- __free_page(pg);
- }
+ on_each_cpu(flush_kernel_map, NULL, 1, 1);
}
+EXPORT_SYMBOL(global_flush_tlb);
#ifdef CONFIG_DEBUG_PAGEALLOC
void kernel_map_pages(struct page *page, int numpages, int enable)
{
if (PageHighMem(page))
return;
- if (!enable)
+ if (!enable) {
debug_check_no_locks_freed(page_address(page),
numpages * PAGE_SIZE);
+ }
- /* the return value is ignored - the calls cannot fail,
+ /*
+ * the return value is ignored - the calls cannot fail,
* large pages are disabled at boot time.
*/
change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0));
- /* we should perform an IPI and flush all tlbs,
+
+ /*
+ * we should perform an IPI and flush all tlbs,
* but that can deadlock->flush only current cpu.
*/
__flush_tlb_all();
}
#endif
-
-EXPORT_SYMBOL(change_page_attr);
-EXPORT_SYMBOL(global_flush_tlb);
git.samba.org / sfrench / cifs-2.6.git / blobdiff