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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 | ||
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 KP |
61 | |
62 | pagefault_disable(); | |
63 | ||
3e4d3af5 | 64 | type = kmap_atomic_idx_push(); |
dd63fdcc IM |
65 | idx = type + KM_TYPE_NR * smp_processor_id(); |
66 | vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); | |
67 | set_pte(kmap_pte - idx, pfn_pte(pfn, prot)); | |
68 | arch_flush_lazy_mmu_mode(); | |
69 | ||
70 | return (void *)vaddr; | |
71 | } | |
72 | ||
73 | /* | |
3e4d3af5 | 74 | * Map 'pfn' using protections 'prot' |
fd940934 | 75 | */ |
cc1a8e52 | 76 | void __iomem * |
3e4d3af5 | 77 | iomap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot) |
fd940934 | 78 | { |
ef5fa0ab EA |
79 | /* |
80 | * For non-PAT systems, promote PAGE_KERNEL_WC to PAGE_KERNEL_UC_MINUS. | |
81 | * PAGE_KERNEL_WC maps to PWT, which translates to uncached if the | |
82 | * MTRR is UC or WC. UC_MINUS gets the real intention, of the | |
83 | * user, which is "WC if the MTRR is WC, UC if you can't do that." | |
84 | */ | |
85 | if (!pat_enabled && pgprot_val(prot) == pgprot_val(PAGE_KERNEL_WC)) | |
86 | prot = PAGE_KERNEL_UC_MINUS; | |
87 | ||
3e4d3af5 | 88 | return (void __force __iomem *) kmap_atomic_prot_pfn(pfn, prot); |
fd940934 KP |
89 | } |
90 | EXPORT_SYMBOL_GPL(iomap_atomic_prot_pfn); | |
91 | ||
92 | void | |
3e4d3af5 | 93 | iounmap_atomic(void __iomem *kvaddr) |
fd940934 KP |
94 | { |
95 | unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK; | |
fd940934 | 96 | |
3e4d3af5 PZ |
97 | if (vaddr >= __fix_to_virt(FIX_KMAP_END) && |
98 | vaddr <= __fix_to_virt(FIX_KMAP_BEGIN)) { | |
99 | int idx, type; | |
100 | ||
101 | type = kmap_atomic_idx_pop(); | |
102 | idx = type + KM_TYPE_NR * smp_processor_id(); | |
103 | ||
104 | #ifdef CONFIG_DEBUG_HIGHMEM | |
105 | WARN_ON_ONCE(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx)); | |
106 | #endif | |
107 | /* | |
108 | * Force other mappings to Oops if they'll try to access this | |
109 | * pte without first remap it. Keeping stale mappings around | |
110 | * is a bad idea also, in case the page changes cacheability | |
111 | * attributes or becomes a protected page in a hypervisor. | |
112 | */ | |
fd940934 | 113 | kpte_clear_flush(kmap_pte-idx, vaddr); |
3e4d3af5 | 114 | } |
fd940934 | 115 | |
fd940934 KP |
116 | pagefault_enable(); |
117 | } | |
118 | EXPORT_SYMBOL_GPL(iounmap_atomic); |