| /* highmem.c: arch-specific highmem stuff |
| * |
| * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. |
| * Written by David Howells (dhowells@redhat.com) |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| */ |
| #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); |
| } |
| |
| EXPORT_SYMBOL(kmap); |
| |
| void kunmap(struct page *page) |
| { |
| if (in_interrupt()) |
| BUG(); |
| if (!PageHighMem(page)) |
| return; |
| kunmap_high(page); |
| } |
| |
| EXPORT_SYMBOL(kunmap); |
| |
| struct page *kmap_atomic_to_page(void *ptr) |
| { |
| return virt_to_page(ptr); |
| } |
| |
| void *kmap_atomic(struct page *page) |
| { |
| unsigned long paddr; |
| int type; |
| |
| preempt_disable(); |
| pagefault_disable(); |
| type = kmap_atomic_idx_push(); |
| paddr = page_to_phys(page); |
| |
| switch (type) { |
| /* |
| * The first 4 primary maps are reserved for architecture code |
| */ |
| case 0: return __kmap_atomic_primary(0, paddr, 6); |
| case 1: return __kmap_atomic_primary(0, paddr, 7); |
| case 2: return __kmap_atomic_primary(0, paddr, 8); |
| case 3: return __kmap_atomic_primary(0, paddr, 9); |
| case 4: return __kmap_atomic_primary(0, paddr, 10); |
| |
| case 5 ... 5 + NR_TLB_LINES - 1: |
| return __kmap_atomic_secondary(type - 5, paddr); |
| |
| default: |
| BUG(); |
| return NULL; |
| } |
| } |
| EXPORT_SYMBOL(kmap_atomic); |
| |
| void __kunmap_atomic(void *kvaddr) |
| { |
| int type = kmap_atomic_idx(); |
| switch (type) { |
| case 0: __kunmap_atomic_primary(0, 6); break; |
| case 1: __kunmap_atomic_primary(0, 7); break; |
| case 2: __kunmap_atomic_primary(0, 8); break; |
| case 3: __kunmap_atomic_primary(0, 9); break; |
| case 4: __kunmap_atomic_primary(0, 10); break; |
| |
| case 5 ... 5 + NR_TLB_LINES - 1: |
| __kunmap_atomic_secondary(type - 5, kvaddr); |
| break; |
| |
| default: |
| BUG(); |
| } |
| kmap_atomic_idx_pop(); |
| pagefault_enable(); |
| preempt_enable(); |
| } |
| EXPORT_SYMBOL(__kunmap_atomic); |