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fd940934 KP |
1 | /* |
2 | * Copyright © 2008 Ingo Molnar | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, but | |
10 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | * General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License along | |
15 | * with this program; if not, write to the Free Software Foundation, Inc., | |
16 | * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. | |
17 | */ | |
18 | ||
19 | #include <asm/iomap.h> | |
ef5fa0ab | 20 | #include <asm/pat.h> |
4b599fed | 21 | #include <linux/export.h> |
7ca43e75 | 22 | #include <linux/highmem.h> |
fd940934 | 23 | |
9e36fda0 | 24 | static int is_io_mapping_possible(resource_size_t base, unsigned long size) |
4ab0d47d | 25 | { |
6a491e2e | 26 | #if !defined(CONFIG_X86_PAE) && defined(CONFIG_PHYS_ADDR_T_64BIT) |
4ab0d47d VP |
27 | /* There is no way to map greater than 1 << 32 address without PAE */ |
28 | if (base + size > 0x100000000ULL) | |
29 | return 0; | |
92b9af9e | 30 | #endif |
4ab0d47d VP |
31 | return 1; |
32 | } | |
9e36fda0 VP |
33 | |
34 | int iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot) | |
35 | { | |
49a3b3cb | 36 | enum page_cache_mode pcm = _PAGE_CACHE_MODE_WC; |
9e36fda0 VP |
37 | int ret; |
38 | ||
39 | if (!is_io_mapping_possible(base, size)) | |
40 | return -EINVAL; | |
41 | ||
49a3b3cb | 42 | ret = io_reserve_memtype(base, base + size, &pcm); |
9e36fda0 VP |
43 | if (ret) |
44 | return ret; | |
45 | ||
49a3b3cb | 46 | *prot = __pgprot(__PAGE_KERNEL | cachemode2protval(pcm)); |
9e36fda0 VP |
47 | return 0; |
48 | } | |
49 | EXPORT_SYMBOL_GPL(iomap_create_wc); | |
50 | ||
3e4d3af5 | 51 | void iomap_free(resource_size_t base, unsigned long size) |
9e36fda0 VP |
52 | { |
53 | io_free_memtype(base, base + size); | |
54 | } | |
55 | EXPORT_SYMBOL_GPL(iomap_free); | |
4ab0d47d | 56 | |
3e4d3af5 | 57 | void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot) |
fd940934 | 58 | { |
fd940934 | 59 | unsigned long vaddr; |
3e4d3af5 | 60 | int idx, type; |
fd940934 | 61 | |
2cb7c9cb | 62 | preempt_disable(); |
fd940934 KP |
63 | pagefault_disable(); |
64 | ||
3e4d3af5 | 65 | type = kmap_atomic_idx_push(); |
dd63fdcc IM |
66 | idx = type + KM_TYPE_NR * smp_processor_id(); |
67 | vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); | |
68 | set_pte(kmap_pte - idx, pfn_pte(pfn, prot)); | |
69 | arch_flush_lazy_mmu_mode(); | |
70 | ||
71 | return (void *)vaddr; | |
72 | } | |
73 | ||
74 | /* | |
3e4d3af5 | 75 | * Map 'pfn' using protections 'prot' |
fd940934 | 76 | */ |
cc1a8e52 | 77 | void __iomem * |
3e4d3af5 | 78 | iomap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot) |
fd940934 | 79 | { |
ef5fa0ab | 80 | /* |
7202fdb1 BP |
81 | * For non-PAT systems, translate non-WB request to UC- just in |
82 | * case the caller set the PWT bit to prot directly without using | |
83 | * pgprot_writecombine(). UC- translates to uncached if the MTRR | |
84 | * is UC or WC. UC- gets the real intention, of the user, which is | |
85 | * "WC if the MTRR is WC, UC if you can't do that." | |
ef5fa0ab | 86 | */ |
7202fdb1 | 87 | if (!pat_enabled() && pgprot2cachemode(prot) != _PAGE_CACHE_MODE_WB) |
49a3b3cb JG |
88 | prot = __pgprot(__PAGE_KERNEL | |
89 | cachemode2protval(_PAGE_CACHE_MODE_UC_MINUS)); | |
ef5fa0ab | 90 | |
3e4d3af5 | 91 | return (void __force __iomem *) kmap_atomic_prot_pfn(pfn, prot); |
fd940934 KP |
92 | } |
93 | EXPORT_SYMBOL_GPL(iomap_atomic_prot_pfn); | |
94 | ||
95 | void | |
3e4d3af5 | 96 | iounmap_atomic(void __iomem *kvaddr) |
fd940934 KP |
97 | { |
98 | unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK; | |
fd940934 | 99 | |
3e4d3af5 PZ |
100 | if (vaddr >= __fix_to_virt(FIX_KMAP_END) && |
101 | vaddr <= __fix_to_virt(FIX_KMAP_BEGIN)) { | |
102 | int idx, type; | |
103 | ||
20273941 | 104 | type = kmap_atomic_idx(); |
3e4d3af5 PZ |
105 | idx = type + KM_TYPE_NR * smp_processor_id(); |
106 | ||
107 | #ifdef CONFIG_DEBUG_HIGHMEM | |
108 | WARN_ON_ONCE(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx)); | |
109 | #endif | |
110 | /* | |
111 | * Force other mappings to Oops if they'll try to access this | |
112 | * pte without first remap it. Keeping stale mappings around | |
113 | * is a bad idea also, in case the page changes cacheability | |
114 | * attributes or becomes a protected page in a hypervisor. | |
115 | */ | |
fd940934 | 116 | kpte_clear_flush(kmap_pte-idx, vaddr); |
20273941 | 117 | kmap_atomic_idx_pop(); |
3e4d3af5 | 118 | } |
fd940934 | 119 | |
fd940934 | 120 | pagefault_enable(); |
2cb7c9cb | 121 | preempt_enable(); |
fd940934 KP |
122 | } |
123 | EXPORT_SYMBOL_GPL(iounmap_atomic); |