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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright © 2008 Ingo Molnar
4 */
5
6#include <asm/iomap.h>
7#include <asm/memtype.h>
8#include <linux/export.h>
9#include <linux/highmem.h>
10
11static int is_io_mapping_possible(resource_size_t base, unsigned long size)
12{
13#if !defined(CONFIG_X86_PAE) && defined(CONFIG_PHYS_ADDR_T_64BIT)
14 /* There is no way to map greater than 1 << 32 address without PAE */
15 if (base + size > 0x100000000ULL)
16 return 0;
17#endif
18 return 1;
19}
20
21int iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot)
22{
23 enum page_cache_mode pcm = _PAGE_CACHE_MODE_WC;
24 int ret;
25
26 if (!is_io_mapping_possible(base, size))
27 return -EINVAL;
28
29 ret = memtype_reserve_io(base, base + size, &pcm);
30 if (ret)
31 return ret;
32
33 *prot = __pgprot(__PAGE_KERNEL | cachemode2protval(pcm));
34 /* Filter out unsupported __PAGE_KERNEL* bits: */
35 pgprot_val(*prot) &= __default_kernel_pte_mask;
36
37 return 0;
38}
39EXPORT_SYMBOL_GPL(iomap_create_wc);
40
41void iomap_free(resource_size_t base, unsigned long size)
42{
43 memtype_free_io(base, base + size);
44}
45EXPORT_SYMBOL_GPL(iomap_free);
46
47void __iomem *__iomap_local_pfn_prot(unsigned long pfn, pgprot_t prot)
48{
49 /*
50 * For non-PAT systems, translate non-WB request to UC- just in
51 * case the caller set the PWT bit to prot directly without using
52 * pgprot_writecombine(). UC- translates to uncached if the MTRR
53 * is UC or WC. UC- gets the real intention, of the user, which is
54 * "WC if the MTRR is WC, UC if you can't do that."
55 */
56 if (!pat_enabled() && pgprot2cachemode(prot) != _PAGE_CACHE_MODE_WB)
57 prot = __pgprot(__PAGE_KERNEL |
58 cachemode2protval(_PAGE_CACHE_MODE_UC_MINUS));
59
60 /* Filter out unsupported __PAGE_KERNEL* bits: */
61 pgprot_val(prot) &= __default_kernel_pte_mask;
62
63 return (void __force __iomem *)__kmap_local_pfn_prot(pfn, prot);
64}
65EXPORT_SYMBOL_GPL(__iomap_local_pfn_prot);
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>
20#include <asm/pat.h>
21#include <linux/export.h>
22#include <linux/highmem.h>
23
24static int is_io_mapping_possible(resource_size_t base, unsigned long size)
25{
26#if !defined(CONFIG_X86_PAE) && defined(CONFIG_PHYS_ADDR_T_64BIT)
27 /* There is no way to map greater than 1 << 32 address without PAE */
28 if (base + size > 0x100000000ULL)
29 return 0;
30#endif
31 return 1;
32}
33
34int iomap_create_wc(resource_size_t base, unsigned long size, pgprot_t *prot)
35{
36 enum page_cache_mode pcm = _PAGE_CACHE_MODE_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, &pcm);
43 if (ret)
44 return ret;
45
46 *prot = __pgprot(__PAGE_KERNEL | cachemode2protval(pcm));
47 /* Filter out unsupported __PAGE_KERNEL* bits: */
48 pgprot_val(*prot) &= __default_kernel_pte_mask;
49
50 return 0;
51}
52EXPORT_SYMBOL_GPL(iomap_create_wc);
53
54void iomap_free(resource_size_t base, unsigned long size)
55{
56 io_free_memtype(base, base + size);
57}
58EXPORT_SYMBOL_GPL(iomap_free);
59
60void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
61{
62 unsigned long vaddr;
63 int idx, type;
64
65 preempt_disable();
66 pagefault_disable();
67
68 type = kmap_atomic_idx_push();
69 idx = type + KM_TYPE_NR * smp_processor_id();
70 vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
71 set_pte(kmap_pte - idx, pfn_pte(pfn, prot));
72 arch_flush_lazy_mmu_mode();
73
74 return (void *)vaddr;
75}
76
77/*
78 * Map 'pfn' using protections 'prot'
79 */
80void __iomem *
81iomap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
82{
83 /*
84 * For non-PAT systems, translate non-WB request to UC- just in
85 * case the caller set the PWT bit to prot directly without using
86 * pgprot_writecombine(). UC- translates to uncached if the MTRR
87 * is UC or WC. UC- gets the real intention, of the user, which is
88 * "WC if the MTRR is WC, UC if you can't do that."
89 */
90 if (!pat_enabled() && pgprot2cachemode(prot) != _PAGE_CACHE_MODE_WB)
91 prot = __pgprot(__PAGE_KERNEL |
92 cachemode2protval(_PAGE_CACHE_MODE_UC_MINUS));
93
94 /* Filter out unsupported __PAGE_KERNEL* bits: */
95 pgprot_val(prot) &= __default_kernel_pte_mask;
96
97 return (void __force __iomem *) kmap_atomic_prot_pfn(pfn, prot);
98}
99EXPORT_SYMBOL_GPL(iomap_atomic_prot_pfn);
100
101void
102iounmap_atomic(void __iomem *kvaddr)
103{
104 unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
105
106 if (vaddr >= __fix_to_virt(FIX_KMAP_END) &&
107 vaddr <= __fix_to_virt(FIX_KMAP_BEGIN)) {
108 int idx, type;
109
110 type = kmap_atomic_idx();
111 idx = type + KM_TYPE_NR * smp_processor_id();
112
113#ifdef CONFIG_DEBUG_HIGHMEM
114 WARN_ON_ONCE(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
115#endif
116 /*
117 * Force other mappings to Oops if they'll try to access this
118 * pte without first remap it. Keeping stale mappings around
119 * is a bad idea also, in case the page changes cacheability
120 * attributes or becomes a protected page in a hypervisor.
121 */
122 kpte_clear_flush(kmap_pte-idx, vaddr);
123 kmap_atomic_idx_pop();
124 }
125
126 pagefault_enable();
127 preempt_enable();
128}
129EXPORT_SYMBOL_GPL(iounmap_atomic);