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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> |
fd940934 | 21 | #include <linux/module.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 | { | |
36 | unsigned long flag = _PAGE_CACHE_WC; | |
37 | int ret; | |
38 | ||
39 | if (!is_io_mapping_possible(base, size)) | |
40 | return -EINVAL; | |
41 | ||
42 | ret = io_reserve_memtype(base, base + size, &flag); | |
43 | if (ret) | |
44 | return ret; | |
45 | ||
46 | *prot = __pgprot(__PAGE_KERNEL | flag); | |
47 | return 0; | |
48 | } | |
49 | EXPORT_SYMBOL_GPL(iomap_create_wc); | |
50 | ||
51 | void | |
52 | iomap_free(resource_size_t base, unsigned long size) | |
53 | { | |
54 | io_free_memtype(base, base + size); | |
55 | } | |
56 | EXPORT_SYMBOL_GPL(iomap_free); | |
4ab0d47d | 57 | |
dd63fdcc | 58 | void *kmap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot) |
fd940934 KP |
59 | { |
60 | enum fixed_addresses idx; | |
61 | unsigned long vaddr; | |
62 | ||
63 | pagefault_disable(); | |
64 | ||
a7f8c50d | 65 | debug_kmap_atomic(type); |
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 | /* | |
75 | * Map 'pfn' using fixed map 'type' and protections 'prot' | |
fd940934 KP |
76 | */ |
77 | void * | |
78 | iomap_atomic_prot_pfn(unsigned long pfn, enum km_type type, pgprot_t prot) | |
79 | { | |
ef5fa0ab EA |
80 | /* |
81 | * For non-PAT systems, promote PAGE_KERNEL_WC to PAGE_KERNEL_UC_MINUS. | |
82 | * PAGE_KERNEL_WC maps to PWT, which translates to uncached if the | |
83 | * MTRR is UC or WC. UC_MINUS gets the real intention, of the | |
84 | * user, which is "WC if the MTRR is WC, UC if you can't do that." | |
85 | */ | |
86 | if (!pat_enabled && pgprot_val(prot) == pgprot_val(PAGE_KERNEL_WC)) | |
87 | prot = PAGE_KERNEL_UC_MINUS; | |
88 | ||
bb6d59ca | 89 | return kmap_atomic_prot_pfn(pfn, type, prot); |
fd940934 KP |
90 | } |
91 | EXPORT_SYMBOL_GPL(iomap_atomic_prot_pfn); | |
92 | ||
93 | void | |
94 | iounmap_atomic(void *kvaddr, enum km_type type) | |
95 | { | |
96 | unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK; | |
97 | enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id(); | |
98 | ||
99 | /* | |
100 | * Force other mappings to Oops if they'll try to access this pte | |
101 | * without first remap it. Keeping stale mappings around is a bad idea | |
102 | * also, in case the page changes cacheability attributes or becomes | |
103 | * a protected page in a hypervisor. | |
104 | */ | |
105 | if (vaddr == __fix_to_virt(FIX_KMAP_BEGIN+idx)) | |
106 | kpte_clear_flush(kmap_pte-idx, vaddr); | |
107 | ||
fd940934 KP |
108 | pagefault_enable(); |
109 | } | |
110 | EXPORT_SYMBOL_GPL(iounmap_atomic); |