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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/pat.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 = io_reserve_memtype(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 io_free_memtype(base, base + size);
44}
45EXPORT_SYMBOL_GPL(iomap_free);
46
47void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
48{
49 unsigned long vaddr;
50 int idx, type;
51
52 preempt_disable();
53 pagefault_disable();
54
55 type = kmap_atomic_idx_push();
56 idx = type + KM_TYPE_NR * smp_processor_id();
57 vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
58 set_pte(kmap_pte - idx, pfn_pte(pfn, prot));
59 arch_flush_lazy_mmu_mode();
60
61 return (void *)vaddr;
62}
63
64/*
65 * Map 'pfn' using protections 'prot'
66 */
67void __iomem *
68iomap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
69{
70 /*
71 * For non-PAT systems, translate non-WB request to UC- just in
72 * case the caller set the PWT bit to prot directly without using
73 * pgprot_writecombine(). UC- translates to uncached if the MTRR
74 * is UC or WC. UC- gets the real intention, of the user, which is
75 * "WC if the MTRR is WC, UC if you can't do that."
76 */
77 if (!pat_enabled() && pgprot2cachemode(prot) != _PAGE_CACHE_MODE_WB)
78 prot = __pgprot(__PAGE_KERNEL |
79 cachemode2protval(_PAGE_CACHE_MODE_UC_MINUS));
80
81 /* Filter out unsupported __PAGE_KERNEL* bits: */
82 pgprot_val(prot) &= __default_kernel_pte_mask;
83
84 return (void __force __iomem *) kmap_atomic_prot_pfn(pfn, prot);
85}
86EXPORT_SYMBOL_GPL(iomap_atomic_prot_pfn);
87
88void
89iounmap_atomic(void __iomem *kvaddr)
90{
91 unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
92
93 if (vaddr >= __fix_to_virt(FIX_KMAP_END) &&
94 vaddr <= __fix_to_virt(FIX_KMAP_BEGIN)) {
95 int idx, type;
96
97 type = kmap_atomic_idx();
98 idx = type + KM_TYPE_NR * smp_processor_id();
99
100#ifdef CONFIG_DEBUG_HIGHMEM
101 WARN_ON_ONCE(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
102#endif
103 /*
104 * Force other mappings to Oops if they'll try to access this
105 * pte without first remap it. Keeping stale mappings around
106 * is a bad idea also, in case the page changes cacheability
107 * attributes or becomes a protected page in a hypervisor.
108 */
109 kpte_clear_flush(kmap_pte-idx, vaddr);
110 kmap_atomic_idx_pop();
111 }
112
113 pagefault_enable();
114 preempt_enable();
115}
116EXPORT_SYMBOL_GPL(iounmap_atomic);
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/module.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 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}
49EXPORT_SYMBOL_GPL(iomap_create_wc);
50
51void iomap_free(resource_size_t base, unsigned long size)
52{
53 io_free_memtype(base, base + size);
54}
55EXPORT_SYMBOL_GPL(iomap_free);
56
57void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
58{
59 unsigned long vaddr;
60 int idx, type;
61
62 pagefault_disable();
63
64 type = kmap_atomic_idx_push();
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/*
74 * Map 'pfn' using protections 'prot'
75 */
76void __iomem *
77iomap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot)
78{
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
88 return (void __force __iomem *) kmap_atomic_prot_pfn(pfn, prot);
89}
90EXPORT_SYMBOL_GPL(iomap_atomic_prot_pfn);
91
92void
93iounmap_atomic(void __iomem *kvaddr)
94{
95 unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
96
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();
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 */
113 kpte_clear_flush(kmap_pte-idx, vaddr);
114 kmap_atomic_idx_pop();
115 }
116
117 pagefault_enable();
118}
119EXPORT_SYMBOL_GPL(iounmap_atomic);