diff options
Diffstat (limited to 'arch/x86_64/mm/pageattr.c')
-rw-r--r-- | arch/x86_64/mm/pageattr.c | 63 |
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); } } |