Nicolas Pitre | d73cd42 | 2008-09-15 16:44:55 -0400 | [diff] [blame] | 1 | /* |
| 2 | * arch/arm/mm/highmem.c -- ARM highmem support |
| 3 | * |
| 4 | * Author: Nicolas Pitre |
| 5 | * Created: september 8, 2008 |
| 6 | * Copyright: Marvell Semiconductors Inc. |
| 7 | * |
| 8 | * This program is free software; you can redistribute it and/or modify |
| 9 | * it under the terms of the GNU General Public License version 2 as |
| 10 | * published by the Free Software Foundation. |
| 11 | */ |
| 12 | |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/highmem.h> |
| 15 | #include <linux/interrupt.h> |
| 16 | #include <asm/fixmap.h> |
| 17 | #include <asm/cacheflush.h> |
| 18 | #include <asm/tlbflush.h> |
| 19 | #include "mm.h" |
| 20 | |
Liu Hua | a05e54c | 2014-04-18 09:43:32 +0100 | [diff] [blame] | 21 | pte_t *fixmap_page_table; |
| 22 | |
| 23 | static inline void set_fixmap_pte(int idx, pte_t pte) |
| 24 | { |
| 25 | unsigned long vaddr = __fix_to_virt(idx); |
| 26 | set_pte_ext(fixmap_page_table + idx, pte, 0); |
| 27 | local_flush_tlb_kernel_page(vaddr); |
| 28 | } |
| 29 | |
| 30 | static inline pte_t get_fixmap_pte(unsigned long vaddr) |
| 31 | { |
| 32 | unsigned long idx = __virt_to_fix(vaddr); |
| 33 | return *(fixmap_page_table + idx); |
| 34 | } |
| 35 | |
Nicolas Pitre | d73cd42 | 2008-09-15 16:44:55 -0400 | [diff] [blame] | 36 | void *kmap(struct page *page) |
| 37 | { |
| 38 | might_sleep(); |
| 39 | if (!PageHighMem(page)) |
| 40 | return page_address(page); |
| 41 | return kmap_high(page); |
| 42 | } |
| 43 | EXPORT_SYMBOL(kmap); |
| 44 | |
| 45 | void kunmap(struct page *page) |
| 46 | { |
| 47 | BUG_ON(in_interrupt()); |
| 48 | if (!PageHighMem(page)) |
| 49 | return; |
| 50 | kunmap_high(page); |
| 51 | } |
| 52 | EXPORT_SYMBOL(kunmap); |
| 53 | |
Cong Wang | a24401b | 2011-11-26 10:53:39 +0800 | [diff] [blame] | 54 | void *kmap_atomic(struct page *page) |
Nicolas Pitre | d73cd42 | 2008-09-15 16:44:55 -0400 | [diff] [blame] | 55 | { |
| 56 | unsigned int idx; |
| 57 | unsigned long vaddr; |
Nicolas Pitre | 7929eb9 | 2009-09-03 21:45:59 +0100 | [diff] [blame] | 58 | void *kmap; |
Peter Zijlstra | 3e4d3af | 2010-10-26 14:21:51 -0700 | [diff] [blame] | 59 | int type; |
Nicolas Pitre | d73cd42 | 2008-09-15 16:44:55 -0400 | [diff] [blame] | 60 | |
| 61 | pagefault_disable(); |
| 62 | if (!PageHighMem(page)) |
| 63 | return page_address(page); |
| 64 | |
Nicolas Pitre | 17ebba1 | 2010-06-07 21:28:55 +0100 | [diff] [blame] | 65 | #ifdef CONFIG_DEBUG_HIGHMEM |
| 66 | /* |
| 67 | * There is no cache coherency issue when non VIVT, so force the |
| 68 | * dedicated kmap usage for better debugging purposes in that case. |
| 69 | */ |
| 70 | if (!cache_is_vivt()) |
| 71 | kmap = NULL; |
| 72 | else |
| 73 | #endif |
| 74 | kmap = kmap_high_get(page); |
Nicolas Pitre | 7929eb9 | 2009-09-03 21:45:59 +0100 | [diff] [blame] | 75 | if (kmap) |
| 76 | return kmap; |
| 77 | |
Peter Zijlstra | 3e4d3af | 2010-10-26 14:21:51 -0700 | [diff] [blame] | 78 | type = kmap_atomic_idx_push(); |
| 79 | |
Nicolas Pitre | d73cd42 | 2008-09-15 16:44:55 -0400 | [diff] [blame] | 80 | idx = type + KM_TYPE_NR * smp_processor_id(); |
Liu Hua | 4221e2e | 2014-04-18 09:27:01 +0100 | [diff] [blame] | 81 | vaddr = __fix_to_virt(idx); |
Nicolas Pitre | d73cd42 | 2008-09-15 16:44:55 -0400 | [diff] [blame] | 82 | #ifdef CONFIG_DEBUG_HIGHMEM |
| 83 | /* |
| 84 | * With debugging enabled, kunmap_atomic forces that entry to 0. |
| 85 | * Make sure it was indeed properly unmapped. |
| 86 | */ |
Liu Hua | a05e54c | 2014-04-18 09:43:32 +0100 | [diff] [blame] | 87 | BUG_ON(!pte_none(*(fixmap_page_table + idx))); |
Nicolas Pitre | d73cd42 | 2008-09-15 16:44:55 -0400 | [diff] [blame] | 88 | #endif |
Nicolas Pitre | d73cd42 | 2008-09-15 16:44:55 -0400 | [diff] [blame] | 89 | /* |
| 90 | * When debugging is off, kunmap_atomic leaves the previous mapping |
Russell King | 67ece14 | 2011-07-02 15:20:44 +0100 | [diff] [blame] | 91 | * in place, so the contained TLB flush ensures the TLB is updated |
| 92 | * with the new mapping. |
Nicolas Pitre | d73cd42 | 2008-09-15 16:44:55 -0400 | [diff] [blame] | 93 | */ |
Liu Hua | a05e54c | 2014-04-18 09:43:32 +0100 | [diff] [blame] | 94 | set_fixmap_pte(idx, mk_pte(page, kmap_prot)); |
Nicolas Pitre | d73cd42 | 2008-09-15 16:44:55 -0400 | [diff] [blame] | 95 | |
| 96 | return (void *)vaddr; |
| 97 | } |
Cong Wang | a24401b | 2011-11-26 10:53:39 +0800 | [diff] [blame] | 98 | EXPORT_SYMBOL(kmap_atomic); |
Nicolas Pitre | d73cd42 | 2008-09-15 16:44:55 -0400 | [diff] [blame] | 99 | |
Peter Zijlstra | 3e4d3af | 2010-10-26 14:21:51 -0700 | [diff] [blame] | 100 | void __kunmap_atomic(void *kvaddr) |
Nicolas Pitre | d73cd42 | 2008-09-15 16:44:55 -0400 | [diff] [blame] | 101 | { |
| 102 | unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK; |
Peter Zijlstra | 3e4d3af | 2010-10-26 14:21:51 -0700 | [diff] [blame] | 103 | int idx, type; |
Nicolas Pitre | d73cd42 | 2008-09-15 16:44:55 -0400 | [diff] [blame] | 104 | |
| 105 | if (kvaddr >= (void *)FIXADDR_START) { |
Peter Zijlstra | 2027394 | 2010-10-27 15:32:58 -0700 | [diff] [blame] | 106 | type = kmap_atomic_idx(); |
Peter Zijlstra | 3e4d3af | 2010-10-26 14:21:51 -0700 | [diff] [blame] | 107 | idx = type + KM_TYPE_NR * smp_processor_id(); |
| 108 | |
Nicolas Pitre | 7e5a69e | 2010-03-29 21:46:02 +0100 | [diff] [blame] | 109 | if (cache_is_vivt()) |
| 110 | __cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE); |
Nicolas Pitre | d73cd42 | 2008-09-15 16:44:55 -0400 | [diff] [blame] | 111 | #ifdef CONFIG_DEBUG_HIGHMEM |
Liu Hua | 4221e2e | 2014-04-18 09:27:01 +0100 | [diff] [blame] | 112 | BUG_ON(vaddr != __fix_to_virt(idx)); |
Liu Hua | a05e54c | 2014-04-18 09:43:32 +0100 | [diff] [blame] | 113 | set_fixmap_pte(idx, __pte(0)); |
Nicolas Pitre | d73cd42 | 2008-09-15 16:44:55 -0400 | [diff] [blame] | 114 | #else |
| 115 | (void) idx; /* to kill a warning */ |
| 116 | #endif |
Peter Zijlstra | 2027394 | 2010-10-27 15:32:58 -0700 | [diff] [blame] | 117 | kmap_atomic_idx_pop(); |
Nicolas Pitre | 7929eb9 | 2009-09-03 21:45:59 +0100 | [diff] [blame] | 118 | } else if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) { |
| 119 | /* this address was obtained through kmap_high_get() */ |
| 120 | kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)])); |
Nicolas Pitre | d73cd42 | 2008-09-15 16:44:55 -0400 | [diff] [blame] | 121 | } |
| 122 | pagefault_enable(); |
| 123 | } |
Peter Zijlstra | 3e4d3af | 2010-10-26 14:21:51 -0700 | [diff] [blame] | 124 | EXPORT_SYMBOL(__kunmap_atomic); |
Nicolas Pitre | d73cd42 | 2008-09-15 16:44:55 -0400 | [diff] [blame] | 125 | |
Peter Zijlstra | 3e4d3af | 2010-10-26 14:21:51 -0700 | [diff] [blame] | 126 | void *kmap_atomic_pfn(unsigned long pfn) |
Nicolas Pitre | d73cd42 | 2008-09-15 16:44:55 -0400 | [diff] [blame] | 127 | { |
Nicolas Pitre | d73cd42 | 2008-09-15 16:44:55 -0400 | [diff] [blame] | 128 | unsigned long vaddr; |
Peter Zijlstra | 3e4d3af | 2010-10-26 14:21:51 -0700 | [diff] [blame] | 129 | int idx, type; |
Nicolas Pitre | d73cd42 | 2008-09-15 16:44:55 -0400 | [diff] [blame] | 130 | |
| 131 | pagefault_disable(); |
| 132 | |
Peter Zijlstra | 3e4d3af | 2010-10-26 14:21:51 -0700 | [diff] [blame] | 133 | type = kmap_atomic_idx_push(); |
Nicolas Pitre | d73cd42 | 2008-09-15 16:44:55 -0400 | [diff] [blame] | 134 | idx = type + KM_TYPE_NR * smp_processor_id(); |
Liu Hua | 4221e2e | 2014-04-18 09:27:01 +0100 | [diff] [blame] | 135 | vaddr = __fix_to_virt(idx); |
Nicolas Pitre | d73cd42 | 2008-09-15 16:44:55 -0400 | [diff] [blame] | 136 | #ifdef CONFIG_DEBUG_HIGHMEM |
Liu Hua | a05e54c | 2014-04-18 09:43:32 +0100 | [diff] [blame] | 137 | BUG_ON(!pte_none(*(fixmap_page_table + idx))); |
Nicolas Pitre | d73cd42 | 2008-09-15 16:44:55 -0400 | [diff] [blame] | 138 | #endif |
Liu Hua | a05e54c | 2014-04-18 09:43:32 +0100 | [diff] [blame] | 139 | set_fixmap_pte(idx, pfn_pte(pfn, kmap_prot)); |
Nicolas Pitre | d73cd42 | 2008-09-15 16:44:55 -0400 | [diff] [blame] | 140 | |
| 141 | return (void *)vaddr; |
| 142 | } |
| 143 | |
| 144 | struct page *kmap_atomic_to_page(const void *ptr) |
| 145 | { |
| 146 | unsigned long vaddr = (unsigned long)ptr; |
Nicolas Pitre | d73cd42 | 2008-09-15 16:44:55 -0400 | [diff] [blame] | 147 | |
| 148 | if (vaddr < FIXADDR_START) |
| 149 | return virt_to_page(ptr); |
| 150 | |
Liu Hua | a05e54c | 2014-04-18 09:43:32 +0100 | [diff] [blame] | 151 | return pte_page(get_fixmap_pte(vaddr)); |
Nicolas Pitre | d73cd42 | 2008-09-15 16:44:55 -0400 | [diff] [blame] | 152 | } |