diff options
Diffstat (limited to 'mm/highmem.c')
| -rw-r--r-- | mm/highmem.c | 111 |
1 files changed, 30 insertions, 81 deletions
diff --git a/mm/highmem.c b/mm/highmem.c index 9c1e627f282..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> @@ -26,8 +26,14 @@ #include <linux/init.h> #include <linux/hash.h> #include <linux/highmem.h> +#include <linux/kgdb.h> #include <asm/tlbflush.h> + +#if defined(CONFIG_HIGHMEM) || defined(CONFIG_X86_32) +DEFINE_PER_CPU(int, __kmap_atomic_idx); +#endif + /* * Virtual_count is not a pure "count". * 0 means that it is not mapped, and has not been mapped @@ -41,6 +47,9 @@ unsigned long totalhigh_pages __read_mostly; EXPORT_SYMBOL(totalhigh_pages); + +EXPORT_PER_CPU_SYMBOL(__kmap_atomic_idx); + unsigned int nr_free_highpages (void) { pg_data_t *pgdat; @@ -85,6 +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; @@ -116,8 +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; @@ -220,7 +241,7 @@ EXPORT_SYMBOL(kmap_high); * @page: &struct page to pin * * Returns the page's current virtual memory address, or NULL if no mapping - * exists. When and only when a non null address is returned then a + * exists. If and only if a non null address is returned then a * matching call to kunmap_high() is necessary. * * This can be called from any context. @@ -241,7 +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 @@ -303,11 +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 @@ -317,7 +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)]; } @@ -328,7 +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; @@ -372,14 +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; @@ -392,9 +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; } } @@ -404,72 +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) */ - -#if defined(CONFIG_DEBUG_HIGHMEM) && defined(CONFIG_TRACE_IRQFLAGS_SUPPORT) - -void debug_kmap_atomic(enum km_type type) -{ - static int warn_count = 10; - - if (unlikely(warn_count < 0)) - return; - - if (unlikely(in_interrupt())) { - if (in_nmi()) { - if (type != KM_NMI && type != KM_NMI_PTE) { - WARN_ON(1); - warn_count--; - } - } else if (in_irq()) { - if (type != KM_IRQ0 && type != KM_IRQ1 && - type != KM_BIO_SRC_IRQ && type != KM_BIO_DST_IRQ && - type != KM_BOUNCE_READ && type != KM_IRQ_PTE) { - WARN_ON(1); - warn_count--; - } - } else if (!irqs_disabled()) { /* softirq */ - if (type != KM_IRQ0 && type != KM_IRQ1 && - type != KM_SOFTIRQ0 && type != KM_SOFTIRQ1 && - type != KM_SKB_SUNRPC_DATA && - type != KM_SKB_DATA_SOFTIRQ && - type != KM_BOUNCE_READ) { - WARN_ON(1); - warn_count--; - } - } - } - - if (type == KM_IRQ0 || type == KM_IRQ1 || type == KM_BOUNCE_READ || - type == KM_BIO_SRC_IRQ || type == KM_BIO_DST_IRQ || - type == KM_IRQ_PTE || type == KM_NMI || - type == KM_NMI_PTE ) { - if (!irqs_disabled()) { - WARN_ON(1); - warn_count--; - } - } else if (type == KM_SOFTIRQ0 || type == KM_SOFTIRQ1) { - if (irq_count() == 0 && !irqs_disabled()) { - WARN_ON(1); - warn_count--; - } - } -} - -#endif |