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> |
Akinobu Mita | 7ca43e7 | 2009-03-31 15:23:25 -0700 | [diff] [blame] | 19 | #include <linux/highmem.h> |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 20 | #include <asm/kmap_types.h> |
| 21 | #include <asm/pgtable.h> |
| 22 | |
| 23 | /* undef for production */ |
| 24 | #undef HIGHMEM_DEBUG |
| 25 | |
| 26 | /* declarations for highmem.c */ |
| 27 | extern unsigned long highstart_pfn, highend_pfn; |
| 28 | |
| 29 | extern pte_t *kmap_pte; |
| 30 | extern pgprot_t kmap_prot; |
| 31 | extern pte_t *pkmap_page_table; |
| 32 | |
| 33 | extern void __init kmap_init(void); |
| 34 | |
| 35 | /* |
| 36 | * Right now we initialize only a single pte table. It can be extended |
| 37 | * easily, subsequent pte tables have to be allocated in one physical |
| 38 | * chunk of RAM. |
| 39 | */ |
| 40 | #define PKMAP_BASE 0xfe000000UL |
| 41 | #define LAST_PKMAP 1024 |
| 42 | #define LAST_PKMAP_MASK (LAST_PKMAP - 1) |
| 43 | #define PKMAP_NR(virt) ((virt - PKMAP_BASE) >> PAGE_SHIFT) |
| 44 | #define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) |
| 45 | |
Harvey Harrison | 2153430 | 2008-02-13 15:03:17 -0800 | [diff] [blame] | 46 | extern unsigned long kmap_high(struct page *page); |
| 47 | extern void kunmap_high(struct page *page); |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 48 | |
| 49 | static inline unsigned long kmap(struct page *page) |
| 50 | { |
| 51 | if (in_interrupt()) |
| 52 | BUG(); |
| 53 | if (page < highmem_start_page) |
| 54 | return page_address(page); |
| 55 | return kmap_high(page); |
| 56 | } |
| 57 | |
| 58 | static inline void kunmap(struct page *page) |
| 59 | { |
| 60 | if (in_interrupt()) |
| 61 | BUG(); |
| 62 | if (page < highmem_start_page) |
| 63 | return; |
| 64 | kunmap_high(page); |
| 65 | } |
| 66 | |
| 67 | /* |
| 68 | * The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap |
| 69 | * gives a more generic (and caching) interface. But kmap_atomic can |
| 70 | * be used in IRQ contexts, so in some (very limited) cases we need |
| 71 | * it. |
| 72 | */ |
Peter Zijlstra | 3e4d3af | 2010-10-26 14:21:51 -0700 | [diff] [blame] | 73 | static inline unsigned long __kmap_atomic(struct page *page) |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 74 | { |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 75 | unsigned long vaddr; |
Peter Zijlstra | 3e4d3af | 2010-10-26 14:21:51 -0700 | [diff] [blame] | 76 | int idx, type; |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 77 | |
Peter Zijlstra | 3e4d3af | 2010-10-26 14:21:51 -0700 | [diff] [blame] | 78 | pagefault_disable(); |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 79 | if (page < highmem_start_page) |
| 80 | return page_address(page); |
| 81 | |
Peter Zijlstra | 3e4d3af | 2010-10-26 14:21:51 -0700 | [diff] [blame] | 82 | type = kmap_atomic_idx_push(); |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 83 | idx = type + KM_TYPE_NR * smp_processor_id(); |
| 84 | vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); |
| 85 | #if HIGHMEM_DEBUG |
| 86 | if (!pte_none(*(kmap_pte - idx))) |
| 87 | BUG(); |
| 88 | #endif |
| 89 | set_pte(kmap_pte - idx, mk_pte(page, kmap_prot)); |
David Howells | 492e675 | 2010-10-27 17:28:49 +0100 | [diff] [blame] | 90 | local_flush_tlb_one(vaddr); |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 91 | |
| 92 | return vaddr; |
| 93 | } |
| 94 | |
Peter Zijlstra | 3e4d3af | 2010-10-26 14:21:51 -0700 | [diff] [blame] | 95 | static inline void __kunmap_atomic(unsigned long vaddr) |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 96 | { |
Peter Zijlstra | 3e4d3af | 2010-10-26 14:21:51 -0700 | [diff] [blame] | 97 | int type; |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 98 | |
Peter Zijlstra | 3e4d3af | 2010-10-26 14:21:51 -0700 | [diff] [blame] | 99 | if (vaddr < FIXADDR_START) { /* FIXME */ |
| 100 | pagefault_enable(); |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 101 | return; |
Peter Zijlstra | 3e4d3af | 2010-10-26 14:21:51 -0700 | [diff] [blame] | 102 | } |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 103 | |
Peter Zijlstra | 2027394 | 2010-10-27 15:32:58 -0700 | [diff] [blame] | 104 | type = kmap_atomic_idx(); |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 105 | |
Peter Zijlstra | 3e4d3af | 2010-10-26 14:21:51 -0700 | [diff] [blame] | 106 | #if HIGHMEM_DEBUG |
| 107 | { |
| 108 | unsigned int idx; |
| 109 | idx = type + KM_TYPE_NR * smp_processor_id(); |
| 110 | |
| 111 | if (vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx)) |
| 112 | BUG(); |
| 113 | |
| 114 | /* |
| 115 | * force other mappings to Oops if they'll try to access |
| 116 | * this pte without first remap it |
| 117 | */ |
| 118 | pte_clear(kmap_pte - idx); |
David Howells | 492e675 | 2010-10-27 17:28:49 +0100 | [diff] [blame] | 119 | local_flush_tlb_one(vaddr); |
Peter Zijlstra | 3e4d3af | 2010-10-26 14:21:51 -0700 | [diff] [blame] | 120 | } |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 121 | #endif |
Peter Zijlstra | 2027394 | 2010-10-27 15:32:58 -0700 | [diff] [blame] | 122 | |
| 123 | kmap_atomic_idx_pop(); |
Peter Zijlstra | 3e4d3af | 2010-10-26 14:21:51 -0700 | [diff] [blame] | 124 | pagefault_enable(); |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 125 | } |
David Howells | b920de1 | 2008-02-08 04:19:31 -0800 | [diff] [blame] | 126 | #endif /* __KERNEL__ */ |
| 127 | |
| 128 | #endif /* _ASM_HIGHMEM_H */ |