diff options
Diffstat (limited to 'arch/i386/mm/highmem.c')
-rw-r--r-- | arch/i386/mm/highmem.c | 113 |
1 files changed, 0 insertions, 113 deletions
diff --git a/arch/i386/mm/highmem.c b/arch/i386/mm/highmem.c deleted file mode 100644 index 1c3bf95f735..00000000000 --- a/arch/i386/mm/highmem.c +++ /dev/null @@ -1,113 +0,0 @@ -#include <linux/highmem.h> -#include <linux/module.h> - -void *kmap(struct page *page) -{ - might_sleep(); - if (!PageHighMem(page)) - return page_address(page); - return kmap_high(page); -} - -void kunmap(struct page *page) -{ - if (in_interrupt()) - BUG(); - if (!PageHighMem(page)) - return; - kunmap_high(page); -} - -/* - * kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because - * no global lock is needed and because the kmap code must perform a global TLB - * invalidation when the kmap pool wraps. - * - * However when holding an atomic kmap is is not legal to sleep, so atomic - * kmaps are appropriate for short, tight code paths only. - */ -void *kmap_atomic_prot(struct page *page, enum km_type type, pgprot_t prot) -{ - enum fixed_addresses idx; - unsigned long vaddr; - - /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */ - pagefault_disable(); - - if (!PageHighMem(page)) - return page_address(page); - - idx = type + KM_TYPE_NR*smp_processor_id(); - vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); - BUG_ON(!pte_none(*(kmap_pte-idx))); - set_pte(kmap_pte-idx, mk_pte(page, prot)); - arch_flush_lazy_mmu_mode(); - - return (void *)vaddr; -} - -void *kmap_atomic(struct page *page, enum km_type type) -{ - return kmap_atomic_prot(page, type, kmap_prot); -} - -void kunmap_atomic(void *kvaddr, enum km_type type) -{ - unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK; - enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id(); - - /* - * Force other mappings to Oops if they'll try to access this pte - * without first remap it. Keeping stale mappings around is a bad idea - * also, in case the page changes cacheability attributes or becomes - * a protected page in a hypervisor. - */ - if (vaddr == __fix_to_virt(FIX_KMAP_BEGIN+idx)) - kpte_clear_flush(kmap_pte-idx, vaddr); - else { -#ifdef CONFIG_DEBUG_HIGHMEM - BUG_ON(vaddr < PAGE_OFFSET); - BUG_ON(vaddr >= (unsigned long)high_memory); -#endif - } - - arch_flush_lazy_mmu_mode(); - pagefault_enable(); -} - -/* This is the same as kmap_atomic() but can map memory that doesn't - * have a struct page associated with it. - */ -void *kmap_atomic_pfn(unsigned long pfn, enum km_type type) -{ - enum fixed_addresses idx; - unsigned long vaddr; - - pagefault_disable(); - - idx = type + KM_TYPE_NR*smp_processor_id(); - vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); - set_pte(kmap_pte-idx, pfn_pte(pfn, kmap_prot)); - arch_flush_lazy_mmu_mode(); - - return (void*) vaddr; -} - -struct page *kmap_atomic_to_page(void *ptr) -{ - unsigned long idx, vaddr = (unsigned long)ptr; - pte_t *pte; - - if (vaddr < FIXADDR_START) - return virt_to_page(ptr); - - idx = virt_to_fix(vaddr); - pte = kmap_pte - (idx - FIX_KMAP_BEGIN); - return pte_page(*pte); -} - -EXPORT_SYMBOL(kmap); -EXPORT_SYMBOL(kunmap); -EXPORT_SYMBOL(kmap_atomic); -EXPORT_SYMBOL(kunmap_atomic); -EXPORT_SYMBOL(kmap_atomic_to_page); |