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1#include <linux/highmem.h>
2#include <linux/module.h>
3#include <linux/swap.h> /* for totalram_pages */
4#include <linux/bootmem.h>
5
6void *kmap(struct page *page)
7{
8 might_sleep();
9 if (!PageHighMem(page))
10 return page_address(page);
11 return kmap_high(page);
12}
13EXPORT_SYMBOL(kmap);
14
15void kunmap(struct page *page)
16{
17 if (in_interrupt())
18 BUG();
19 if (!PageHighMem(page))
20 return;
21 kunmap_high(page);
22}
23EXPORT_SYMBOL(kunmap);
24
25/*
26 * kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because
27 * no global lock is needed and because the kmap code must perform a global TLB
28 * invalidation when the kmap pool wraps.
29 *
30 * However when holding an atomic kmap it is not legal to sleep, so atomic
31 * kmaps are appropriate for short, tight code paths only.
32 */
33void *kmap_atomic_prot(struct page *page, pgprot_t prot)
34{
35 unsigned long vaddr;
36 int idx, type;
37
38 preempt_disable();
39 pagefault_disable();
40
41 if (!PageHighMem(page))
42 return page_address(page);
43
44 type = kmap_atomic_idx_push();
45 idx = type + KM_TYPE_NR*smp_processor_id();
46 vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
47 BUG_ON(!pte_none(*(kmap_pte-idx)));
48 set_pte(kmap_pte-idx, mk_pte(page, prot));
49 arch_flush_lazy_mmu_mode();
50
51 return (void *)vaddr;
52}
53EXPORT_SYMBOL(kmap_atomic_prot);
54
55void *kmap_atomic(struct page *page)
56{
57 return kmap_atomic_prot(page, kmap_prot);
58}
59EXPORT_SYMBOL(kmap_atomic);
60
61/*
62 * This is the same as kmap_atomic() but can map memory that doesn't
63 * have a struct page associated with it.
64 */
65void *kmap_atomic_pfn(unsigned long pfn)
66{
67 return kmap_atomic_prot_pfn(pfn, kmap_prot);
68}
69EXPORT_SYMBOL_GPL(kmap_atomic_pfn);
70
71void __kunmap_atomic(void *kvaddr)
72{
73 unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
74
75 if (vaddr >= __fix_to_virt(FIX_KMAP_END) &&
76 vaddr <= __fix_to_virt(FIX_KMAP_BEGIN)) {
77 int idx, type;
78
79 type = kmap_atomic_idx();
80 idx = type + KM_TYPE_NR * smp_processor_id();
81
82#ifdef CONFIG_DEBUG_HIGHMEM
83 WARN_ON_ONCE(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
84#endif
85 /*
86 * Force other mappings to Oops if they'll try to access this
87 * pte without first remap it. Keeping stale mappings around
88 * is a bad idea also, in case the page changes cacheability
89 * attributes or becomes a protected page in a hypervisor.
90 */
91 kpte_clear_flush(kmap_pte-idx, vaddr);
92 kmap_atomic_idx_pop();
93 arch_flush_lazy_mmu_mode();
94 }
95#ifdef CONFIG_DEBUG_HIGHMEM
96 else {
97 BUG_ON(vaddr < PAGE_OFFSET);
98 BUG_ON(vaddr >= (unsigned long)high_memory);
99 }
100#endif
101
102 pagefault_enable();
103 preempt_enable();
104}
105EXPORT_SYMBOL(__kunmap_atomic);
106
107void __init set_highmem_pages_init(void)
108{
109 struct zone *zone;
110 int nid;
111
112 /*
113 * Explicitly reset zone->managed_pages because set_highmem_pages_init()
114 * is invoked before free_all_bootmem()
115 */
116 reset_all_zones_managed_pages();
117 for_each_zone(zone) {
118 unsigned long zone_start_pfn, zone_end_pfn;
119
120 if (!is_highmem(zone))
121 continue;
122
123 zone_start_pfn = zone->zone_start_pfn;
124 zone_end_pfn = zone_start_pfn + zone->spanned_pages;
125
126 nid = zone_to_nid(zone);
127 printk(KERN_INFO "Initializing %s for node %d (%08lx:%08lx)\n",
128 zone->name, nid, zone_start_pfn, zone_end_pfn);
129
130 add_highpages_with_active_regions(nid, zone_start_pfn,
131 zone_end_pfn);
132 }
133}
1// SPDX-License-Identifier: GPL-2.0-only
2#include <linux/highmem.h>
3#include <linux/export.h>
4#include <linux/swap.h> /* for totalram_pages */
5#include <linux/memblock.h>
6
7void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
8{
9 unsigned long vaddr;
10 int idx, type;
11
12 type = kmap_atomic_idx_push();
13 idx = type + KM_TYPE_NR*smp_processor_id();
14 vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
15 BUG_ON(!pte_none(*(kmap_pte-idx)));
16 set_pte(kmap_pte-idx, mk_pte(page, prot));
17 arch_flush_lazy_mmu_mode();
18
19 return (void *)vaddr;
20}
21EXPORT_SYMBOL(kmap_atomic_high_prot);
22
23/*
24 * This is the same as kmap_atomic() but can map memory that doesn't
25 * have a struct page associated with it.
26 */
27void *kmap_atomic_pfn(unsigned long pfn)
28{
29 return kmap_atomic_prot_pfn(pfn, kmap_prot);
30}
31EXPORT_SYMBOL_GPL(kmap_atomic_pfn);
32
33void kunmap_atomic_high(void *kvaddr)
34{
35 unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
36
37 if (vaddr >= __fix_to_virt(FIX_KMAP_END) &&
38 vaddr <= __fix_to_virt(FIX_KMAP_BEGIN)) {
39 int idx, type;
40
41 type = kmap_atomic_idx();
42 idx = type + KM_TYPE_NR * smp_processor_id();
43
44#ifdef CONFIG_DEBUG_HIGHMEM
45 WARN_ON_ONCE(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
46#endif
47 /*
48 * Force other mappings to Oops if they'll try to access this
49 * pte without first remap it. Keeping stale mappings around
50 * is a bad idea also, in case the page changes cacheability
51 * attributes or becomes a protected page in a hypervisor.
52 */
53 kpte_clear_flush(kmap_pte-idx, vaddr);
54 kmap_atomic_idx_pop();
55 arch_flush_lazy_mmu_mode();
56 }
57#ifdef CONFIG_DEBUG_HIGHMEM
58 else {
59 BUG_ON(vaddr < PAGE_OFFSET);
60 BUG_ON(vaddr >= (unsigned long)high_memory);
61 }
62#endif
63}
64EXPORT_SYMBOL(kunmap_atomic_high);
65
66void __init set_highmem_pages_init(void)
67{
68 struct zone *zone;
69 int nid;
70
71 /*
72 * Explicitly reset zone->managed_pages because set_highmem_pages_init()
73 * is invoked before memblock_free_all()
74 */
75 reset_all_zones_managed_pages();
76 for_each_zone(zone) {
77 unsigned long zone_start_pfn, zone_end_pfn;
78
79 if (!is_highmem(zone))
80 continue;
81
82 zone_start_pfn = zone->zone_start_pfn;
83 zone_end_pfn = zone_start_pfn + zone->spanned_pages;
84
85 nid = zone_to_nid(zone);
86 printk(KERN_INFO "Initializing %s for node %d (%08lx:%08lx)\n",
87 zone->name, nid, zone_start_pfn, zone_end_pfn);
88
89 add_highpages_with_active_regions(nid, zone_start_pfn,
90 zone_end_pfn);
91 }
92}