diff options
Diffstat (limited to 'mm/highmem.c')
| -rw-r--r-- | mm/highmem.c | 48 |
1 files changed, 20 insertions, 28 deletions
diff --git a/mm/highmem.c b/mm/highmem.c index 693394daa2e..b32b70cdaed 100644 --- a/mm/highmem.c +++ b/mm/highmem.c @@ -17,7 +17,7 @@ */ #include <linux/mm.h> -#include <linux/module.h> +#include <linux/export.h> #include <linux/swap.h> #include <linux/bio.h> #include <linux/pagemap.h> @@ -94,6 +94,19 @@ static DECLARE_WAIT_QUEUE_HEAD(pkmap_map_wait); do { spin_unlock(&kmap_lock); (void)(flags); } while (0) #endif +struct page *kmap_to_page(void *vaddr) +{ + unsigned long addr = (unsigned long)vaddr; + + if (addr >= PKMAP_ADDR(0) && addr < PKMAP_ADDR(LAST_PKMAP)) { + int i = PKMAP_NR(addr); + return pte_page(pkmap_page_table[i]); + } + + return virt_to_page(addr); +} +EXPORT_SYMBOL(kmap_to_page); + static void flush_all_zero_pkmaps(void) { int i; @@ -125,8 +138,7 @@ static void flush_all_zero_pkmaps(void) * So no dangers, even with speculative execution. */ page = pte_page(pkmap_page_table[i]); - pte_clear(&init_mm, (unsigned long)page_address(page), - &pkmap_page_table[i]); + pte_clear(&init_mm, PKMAP_ADDR(i), &pkmap_page_table[i]); set_page_address(page, NULL); need_flush = 1; @@ -250,7 +262,7 @@ void *kmap_high_get(struct page *page) #endif /** - * kunmap_high - map a highmem page into memory + * kunmap_high - unmap a highmem page into memory * @page: &struct page to unmap * * If ARCH_NEEDS_KMAP_HIGH_GET is not defined then this may be called @@ -312,11 +324,7 @@ struct page_address_map { struct list_head list; }; -/* - * page_address_map freelist, allocated from page_address_maps. - */ -static struct list_head page_address_pool; /* freelist */ -static spinlock_t pool_lock; /* protects page_address_pool */ +static struct page_address_map page_address_maps[LAST_PKMAP]; /* * Hash table bucket @@ -326,7 +334,7 @@ static struct page_address_slot { spinlock_t lock; /* Protect this bucket's list */ } ____cacheline_aligned_in_smp page_address_htable[1<<PA_HASH_ORDER]; -static struct page_address_slot *page_slot(struct page *page) +static struct page_address_slot *page_slot(const struct page *page) { return &page_address_htable[hash_ptr(page, PA_HASH_ORDER)]; } @@ -337,7 +345,7 @@ static struct page_address_slot *page_slot(struct page *page) * * Returns the page's virtual address. */ -void *page_address(struct page *page) +void *page_address(const struct page *page) { unsigned long flags; void *ret; @@ -381,14 +389,7 @@ void set_page_address(struct page *page, void *virtual) pas = page_slot(page); if (virtual) { /* Add */ - BUG_ON(list_empty(&page_address_pool)); - - spin_lock_irqsave(&pool_lock, flags); - pam = list_entry(page_address_pool.next, - struct page_address_map, list); - list_del(&pam->list); - spin_unlock_irqrestore(&pool_lock, flags); - + pam = &page_address_maps[PKMAP_NR((unsigned long)virtual)]; pam->page = page; pam->virtual = virtual; @@ -401,9 +402,6 @@ void set_page_address(struct page *page, void *virtual) if (pam->page == page) { list_del(&pam->list); spin_unlock_irqrestore(&pas->lock, flags); - spin_lock_irqsave(&pool_lock, flags); - list_add_tail(&pam->list, &page_address_pool); - spin_unlock_irqrestore(&pool_lock, flags); goto done; } } @@ -413,20 +411,14 @@ done: return; } -static struct page_address_map page_address_maps[LAST_PKMAP]; - void __init page_address_init(void) { int i; - INIT_LIST_HEAD(&page_address_pool); - for (i = 0; i < ARRAY_SIZE(page_address_maps); i++) - list_add(&page_address_maps[i].list, &page_address_pool); for (i = 0; i < ARRAY_SIZE(page_address_htable); i++) { INIT_LIST_HEAD(&page_address_htable[i].lh); spin_lock_init(&page_address_htable[i].lock); } - spin_lock_init(&pool_lock); } #endif /* defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL) */ |