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Diffstat (limited to 'arch/x86_64/mm/pageattr.c')
-rw-r--r--arch/x86_64/mm/pageattr.c63
1 files changed, 27 insertions, 36 deletions
diff --git a/arch/x86_64/mm/pageattr.c b/arch/x86_64/mm/pageattr.c
index 35f1f1aab06..531ad21447b 100644
--- a/arch/x86_64/mm/pageattr.c
+++ b/arch/x86_64/mm/pageattr.c
@@ -45,6 +45,13 @@ static struct page *split_large_page(unsigned long address, pgprot_t prot,
pte_t *pbase;
if (!base)
return NULL;
+ /*
+ * page_private is used to track the number of entries in
+ * the page table page have non standard attributes.
+ */
+ SetPagePrivate(base);
+ page_private(base) = 0;
+
address = __pa(address);
addr = address & LARGE_PAGE_MASK;
pbase = (pte_t *)page_address(base);
@@ -77,26 +84,12 @@ static inline void flush_map(unsigned long address)
on_each_cpu(flush_kernel_map, (void *)address, 1, 1);
}
-struct deferred_page {
- struct deferred_page *next;
- struct page *fpage;
- unsigned long address;
-};
-static struct deferred_page *df_list; /* protected by init_mm.mmap_sem */
+static struct page *deferred_pages; /* protected by init_mm.mmap_sem */
-static inline void save_page(unsigned long address, struct page *fpage)
+static inline void save_page(struct page *fpage)
{
- struct deferred_page *df;
- df = kmalloc(sizeof(struct deferred_page), GFP_KERNEL);
- if (!df) {
- flush_map(address);
- __free_page(fpage);
- } else {
- df->next = df_list;
- df->fpage = fpage;
- df->address = address;
- df_list = df;
- }
+ fpage->lru.next = (struct list_head *)deferred_pages;
+ deferred_pages = fpage;
}
/*
@@ -138,8 +131,8 @@ __change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot,
set_pte(kpte, pfn_pte(pfn, prot));
} else {
/*
- * split_large_page will take the reference for this change_page_attr
- * on the split page.
+ * split_large_page will take the reference for this
+ * change_page_attr on the split page.
*/
struct page *split;
@@ -151,23 +144,20 @@ __change_page_attr(unsigned long address, unsigned long pfn, pgprot_t prot,
set_pte(kpte,mk_pte(split, ref_prot2));
kpte_page = split;
}
- get_page(kpte_page);
+ page_private(kpte_page)++;
} else if ((kpte_flags & _PAGE_PSE) == 0) {
set_pte(kpte, pfn_pte(pfn, ref_prot));
- __put_page(kpte_page);
+ BUG_ON(page_private(kpte_page) == 0);
+ page_private(kpte_page)--;
} else
BUG();
/* on x86-64 the direct mapping set at boot is not using 4k pages */
BUG_ON(PageReserved(kpte_page));
- switch (page_count(kpte_page)) {
- case 1:
- save_page(address, kpte_page);
+ if (page_private(kpte_page) == 0) {
+ save_page(kpte_page);
revert_page(address, ref_prot);
- break;
- case 0:
- BUG(); /* memleak and failed 2M page regeneration */
}
return 0;
}
@@ -220,17 +210,18 @@ int change_page_attr(struct page *page, int numpages, pgprot_t prot)
void global_flush_tlb(void)
{
- struct deferred_page *df, *next_df;
+ struct page *dpage;
down_read(&init_mm.mmap_sem);
- df = xchg(&df_list, NULL);
+ dpage = xchg(&deferred_pages, NULL);
up_read(&init_mm.mmap_sem);
- flush_map((df && !df->next) ? df->address : 0);
- for (; df; df = next_df) {
- next_df = df->next;
- if (df->fpage)
- __free_page(df->fpage);
- kfree(df);
+
+ flush_map((dpage && !dpage->lru.next) ? (unsigned long)page_address(dpage) : 0);
+ while (dpage) {
+ struct page *tmp = dpage;
+ dpage = (struct page *)dpage->lru.next;
+ ClearPagePrivate(tmp);
+ __free_page(tmp);
}
}