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1/*
2 * arch/arm/mm/highmem.c -- ARM highmem support
3 *
4 * Author: Nicolas Pitre
5 * Created: september 8, 2008
6 * Copyright: Marvell Semiconductors Inc.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13#include <linux/module.h>
14#include <linux/highmem.h>
15#include <linux/interrupt.h>
16#include <asm/fixmap.h>
17#include <asm/cacheflush.h>
18#include <asm/tlbflush.h>
19#include "mm.h"
20
21void *kmap(struct page *page)
22{
23 might_sleep();
24 if (!PageHighMem(page))
25 return page_address(page);
26 return kmap_high(page);
27}
28EXPORT_SYMBOL(kmap);
29
30void kunmap(struct page *page)
31{
32 BUG_ON(in_interrupt());
33 if (!PageHighMem(page))
34 return;
35 kunmap_high(page);
36}
37EXPORT_SYMBOL(kunmap);
38
39void *kmap_atomic(struct page *page)
40{
41 unsigned int idx;
42 unsigned long vaddr;
43 void *kmap;
44 int type;
45
46 pagefault_disable();
47 if (!PageHighMem(page))
48 return page_address(page);
49
50#ifdef CONFIG_DEBUG_HIGHMEM
51 /*
52 * There is no cache coherency issue when non VIVT, so force the
53 * dedicated kmap usage for better debugging purposes in that case.
54 */
55 if (!cache_is_vivt())
56 kmap = NULL;
57 else
58#endif
59 kmap = kmap_high_get(page);
60 if (kmap)
61 return kmap;
62
63 type = kmap_atomic_idx_push();
64
65 idx = type + KM_TYPE_NR * smp_processor_id();
66 vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
67#ifdef CONFIG_DEBUG_HIGHMEM
68 /*
69 * With debugging enabled, kunmap_atomic forces that entry to 0.
70 * Make sure it was indeed properly unmapped.
71 */
72 BUG_ON(!pte_none(get_top_pte(vaddr)));
73#endif
74 /*
75 * When debugging is off, kunmap_atomic leaves the previous mapping
76 * in place, so the contained TLB flush ensures the TLB is updated
77 * with the new mapping.
78 */
79 set_top_pte(vaddr, mk_pte(page, kmap_prot));
80
81 return (void *)vaddr;
82}
83EXPORT_SYMBOL(kmap_atomic);
84
85void __kunmap_atomic(void *kvaddr)
86{
87 unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
88 int idx, type;
89
90 if (kvaddr >= (void *)FIXADDR_START) {
91 type = kmap_atomic_idx();
92 idx = type + KM_TYPE_NR * smp_processor_id();
93
94 if (cache_is_vivt())
95 __cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE);
96#ifdef CONFIG_DEBUG_HIGHMEM
97 BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
98 set_top_pte(vaddr, __pte(0));
99#else
100 (void) idx; /* to kill a warning */
101#endif
102 kmap_atomic_idx_pop();
103 } else if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) {
104 /* this address was obtained through kmap_high_get() */
105 kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)]));
106 }
107 pagefault_enable();
108}
109EXPORT_SYMBOL(__kunmap_atomic);
110
111void *kmap_atomic_pfn(unsigned long pfn)
112{
113 unsigned long vaddr;
114 int idx, type;
115
116 pagefault_disable();
117
118 type = kmap_atomic_idx_push();
119 idx = type + KM_TYPE_NR * smp_processor_id();
120 vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
121#ifdef CONFIG_DEBUG_HIGHMEM
122 BUG_ON(!pte_none(get_top_pte(vaddr)));
123#endif
124 set_top_pte(vaddr, pfn_pte(pfn, kmap_prot));
125
126 return (void *)vaddr;
127}
128
129struct page *kmap_atomic_to_page(const void *ptr)
130{
131 unsigned long vaddr = (unsigned long)ptr;
132
133 if (vaddr < FIXADDR_START)
134 return virt_to_page(ptr);
135
136 return pte_page(get_top_pte(vaddr));
137}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * arch/arm/mm/highmem.c -- ARM highmem support
4 *
5 * Author: Nicolas Pitre
6 * Created: september 8, 2008
7 * Copyright: Marvell Semiconductors Inc.
8 */
9
10#include <linux/module.h>
11#include <linux/highmem.h>
12#include <linux/interrupt.h>
13#include <asm/fixmap.h>
14#include <asm/cacheflush.h>
15#include <asm/tlbflush.h>
16#include "mm.h"
17
18static inline void set_fixmap_pte(int idx, pte_t pte)
19{
20 unsigned long vaddr = __fix_to_virt(idx);
21 pte_t *ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
22
23 set_pte_ext(ptep, pte, 0);
24 local_flush_tlb_kernel_page(vaddr);
25}
26
27static inline pte_t get_fixmap_pte(unsigned long vaddr)
28{
29 pte_t *ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
30
31 return *ptep;
32}
33
34void *kmap(struct page *page)
35{
36 might_sleep();
37 if (!PageHighMem(page))
38 return page_address(page);
39 return kmap_high(page);
40}
41EXPORT_SYMBOL(kmap);
42
43void kunmap(struct page *page)
44{
45 BUG_ON(in_interrupt());
46 if (!PageHighMem(page))
47 return;
48 kunmap_high(page);
49}
50EXPORT_SYMBOL(kunmap);
51
52void *kmap_atomic(struct page *page)
53{
54 unsigned int idx;
55 unsigned long vaddr;
56 void *kmap;
57 int type;
58
59 preempt_disable();
60 pagefault_disable();
61 if (!PageHighMem(page))
62 return page_address(page);
63
64#ifdef CONFIG_DEBUG_HIGHMEM
65 /*
66 * There is no cache coherency issue when non VIVT, so force the
67 * dedicated kmap usage for better debugging purposes in that case.
68 */
69 if (!cache_is_vivt())
70 kmap = NULL;
71 else
72#endif
73 kmap = kmap_high_get(page);
74 if (kmap)
75 return kmap;
76
77 type = kmap_atomic_idx_push();
78
79 idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id();
80 vaddr = __fix_to_virt(idx);
81#ifdef CONFIG_DEBUG_HIGHMEM
82 /*
83 * With debugging enabled, kunmap_atomic forces that entry to 0.
84 * Make sure it was indeed properly unmapped.
85 */
86 BUG_ON(!pte_none(get_fixmap_pte(vaddr)));
87#endif
88 /*
89 * When debugging is off, kunmap_atomic leaves the previous mapping
90 * in place, so the contained TLB flush ensures the TLB is updated
91 * with the new mapping.
92 */
93 set_fixmap_pte(idx, mk_pte(page, kmap_prot));
94
95 return (void *)vaddr;
96}
97EXPORT_SYMBOL(kmap_atomic);
98
99void __kunmap_atomic(void *kvaddr)
100{
101 unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
102 int idx, type;
103
104 if (kvaddr >= (void *)FIXADDR_START) {
105 type = kmap_atomic_idx();
106 idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id();
107
108 if (cache_is_vivt())
109 __cpuc_flush_dcache_area((void *)vaddr, PAGE_SIZE);
110#ifdef CONFIG_DEBUG_HIGHMEM
111 BUG_ON(vaddr != __fix_to_virt(idx));
112 set_fixmap_pte(idx, __pte(0));
113#else
114 (void) idx; /* to kill a warning */
115#endif
116 kmap_atomic_idx_pop();
117 } else if (vaddr >= PKMAP_ADDR(0) && vaddr < PKMAP_ADDR(LAST_PKMAP)) {
118 /* this address was obtained through kmap_high_get() */
119 kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)]));
120 }
121 pagefault_enable();
122 preempt_enable();
123}
124EXPORT_SYMBOL(__kunmap_atomic);
125
126void *kmap_atomic_pfn(unsigned long pfn)
127{
128 unsigned long vaddr;
129 int idx, type;
130 struct page *page = pfn_to_page(pfn);
131
132 preempt_disable();
133 pagefault_disable();
134 if (!PageHighMem(page))
135 return page_address(page);
136
137 type = kmap_atomic_idx_push();
138 idx = FIX_KMAP_BEGIN + type + KM_TYPE_NR * smp_processor_id();
139 vaddr = __fix_to_virt(idx);
140#ifdef CONFIG_DEBUG_HIGHMEM
141 BUG_ON(!pte_none(get_fixmap_pte(vaddr)));
142#endif
143 set_fixmap_pte(idx, pfn_pte(pfn, kmap_prot));
144
145 return (void *)vaddr;
146}