| David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 1 | /* MN10300 Virtual kernel memory mappings for high memory |
| 2 | * |
| 3 | * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. |
| 4 | * Written by David Howells (dhowells@redhat.com) |
| 5 | * - Derived from include/asm-i386/highmem.h |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU General Public Licence |
| 9 | * as published by the Free Software Foundation; either version |
| 10 | * 2 of the Licence, or (at your option) any later version. |
| 11 | */ |
| 12 | #ifndef _ASM_HIGHMEM_H |
| 13 | #define _ASM_HIGHMEM_H |
| 14 | |
| 15 | #ifdef __KERNEL__ |
| 16 | |
| 17 | #include <linux/init.h> |
| 18 | #include <linux/interrupt.h> |
| 19 | #include <asm/kmap_types.h> |
| 20 | #include <asm/pgtable.h> |
| 21 | |
| 22 | /* undef for production */ |
| 23 | #undef HIGHMEM_DEBUG |
| 24 | |
| 25 | /* declarations for highmem.c */ |
| 26 | extern unsigned long highstart_pfn, highend_pfn; |
| 27 | |
| 28 | extern pte_t *kmap_pte; |
| 29 | extern pgprot_t kmap_prot; |
| 30 | extern pte_t *pkmap_page_table; |
| 31 | |
| 32 | extern void __init kmap_init(void); |
| 33 | |
| 34 | /* |
| 35 | * Right now we initialize only a single pte table. It can be extended |
| 36 | * easily, subsequent pte tables have to be allocated in one physical |
| 37 | * chunk of RAM. |
| 38 | */ |
| 39 | #define PKMAP_BASE 0xfe000000UL |
| 40 | #define LAST_PKMAP 1024 |
| 41 | #define LAST_PKMAP_MASK (LAST_PKMAP - 1) |
| 42 | #define PKMAP_NR(virt) ((virt - PKMAP_BASE) >> PAGE_SHIFT) |
| 43 | #define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) |
| 44 | |
| Harvey Harrison | 2153430 | 2008-02-13 15:03:17 -0800 | [diff] [blame] | 45 | extern unsigned long kmap_high(struct page *page); |
| 46 | extern void kunmap_high(struct page *page); |
| David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 47 | |
| 48 | static inline unsigned long kmap(struct page *page) |
| 49 | { |
| 50 | if (in_interrupt()) |
| 51 | BUG(); |
| 52 | if (page < highmem_start_page) |
| 53 | return page_address(page); |
| 54 | return kmap_high(page); |
| 55 | } |
| 56 | |
| 57 | static inline void kunmap(struct page *page) |
| 58 | { |
| 59 | if (in_interrupt()) |
| 60 | BUG(); |
| 61 | if (page < highmem_start_page) |
| 62 | return; |
| 63 | kunmap_high(page); |
| 64 | } |
| 65 | |
| 66 | /* |
| 67 | * The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap |
| 68 | * gives a more generic (and caching) interface. But kmap_atomic can |
| 69 | * be used in IRQ contexts, so in some (very limited) cases we need |
| 70 | * it. |
| 71 | */ |
| 72 | static inline unsigned long kmap_atomic(struct page *page, enum km_type type) |
| 73 | { |
| 74 | enum fixed_addresses idx; |
| 75 | unsigned long vaddr; |
| 76 | |
| 77 | if (page < highmem_start_page) |
| 78 | return page_address(page); |
| 79 | |
| 80 | idx = type + KM_TYPE_NR * smp_processor_id(); |
| 81 | vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); |
| 82 | #if HIGHMEM_DEBUG |
| 83 | if (!pte_none(*(kmap_pte - idx))) |
| 84 | BUG(); |
| 85 | #endif |
| 86 | set_pte(kmap_pte - idx, mk_pte(page, kmap_prot)); |
| 87 | __flush_tlb_one(vaddr); |
| 88 | |
| 89 | return vaddr; |
| 90 | } |
| 91 | |
| 92 | static inline void kunmap_atomic(unsigned long vaddr, enum km_type type) |
| 93 | { |
| 94 | #if HIGHMEM_DEBUG |
| 95 | enum fixed_addresses idx = type + KM_TYPE_NR * smp_processor_id(); |
| 96 | |
| 97 | if (vaddr < FIXADDR_START) /* FIXME */ |
| 98 | return; |
| 99 | |
| 100 | if (vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx)) |
| 101 | BUG(); |
| 102 | |
| 103 | /* |
| 104 | * force other mappings to Oops if they'll try to access |
| 105 | * this pte without first remap it |
| 106 | */ |
| 107 | pte_clear(kmap_pte - idx); |
| 108 | __flush_tlb_one(vaddr); |
| 109 | #endif |
| 110 | } |
| 111 | |
| 112 | #endif /* __KERNEL__ */ |
| 113 | |
| 114 | #endif /* _ASM_HIGHMEM_H */ |