Merge tag 'for-5.8-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave...
[linux-2.6-microblaze.git] / arch / x86 / mm / highmem_32.c
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
7 void *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 }
21 EXPORT_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  */
27 void *kmap_atomic_pfn(unsigned long pfn)
28 {
29         return kmap_atomic_prot_pfn(pfn, kmap_prot);
30 }
31 EXPORT_SYMBOL_GPL(kmap_atomic_pfn);
32
33 void 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 }
64 EXPORT_SYMBOL(kunmap_atomic_high);
65
66 void __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 }