blob: 58f621e8191955c2e02016df1d8e99bec8e1ed8f [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001#include <linux/highmem.h>
Alexey Dobriyan129f6942005-06-23 00:08:33 -07002#include <linux/module.h>
Pekka Enberg867c5b522009-03-03 14:10:12 +02003#include <linux/swap.h> /* for totalram_pages */
Linus Torvalds1da177e2005-04-16 15:20:36 -07004
5void *kmap(struct page *page)
6{
7 might_sleep();
8 if (!PageHighMem(page))
9 return page_address(page);
10 return kmap_high(page);
11}
12
13void kunmap(struct page *page)
14{
15 if (in_interrupt())
16 BUG();
17 if (!PageHighMem(page))
18 return;
19 kunmap_high(page);
20}
21
22/*
23 * kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because
24 * no global lock is needed and because the kmap code must perform a global TLB
25 * invalidation when the kmap pool wraps.
26 *
27 * However when holding an atomic kmap is is not legal to sleep, so atomic
28 * kmaps are appropriate for short, tight code paths only.
29 */
Jeremy Fitzhardingece6234b2007-05-02 19:27:15 +020030void *kmap_atomic_prot(struct page *page, enum km_type type, pgprot_t prot)
Linus Torvalds1da177e2005-04-16 15:20:36 -070031{
32 enum fixed_addresses idx;
33 unsigned long vaddr;
Andrew Morton9c312052008-03-28 11:47:34 -070034
Linus Torvalds1da177e2005-04-16 15:20:36 -070035 /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
Peter Zijlstraa8663742006-12-06 20:32:20 -080036 pagefault_disable();
Ingo Molnar656dad32007-02-10 01:46:36 -080037
Linus Torvalds1da177e2005-04-16 15:20:36 -070038 if (!PageHighMem(page))
39 return page_address(page);
40
Akinobu Mitaf4112de2009-03-31 15:23:25 -070041 debug_kmap_atomic(type);
Andrew Morton9c312052008-03-28 11:47:34 -070042
Andrew Morton4150d3f2007-09-11 15:24:10 -070043 idx = type + KM_TYPE_NR*smp_processor_id();
Linus Torvalds1da177e2005-04-16 15:20:36 -070044 vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
Andrew Morton4150d3f2007-09-11 15:24:10 -070045 BUG_ON(!pte_none(*(kmap_pte-idx)));
Jeremy Fitzhardingece6234b2007-05-02 19:27:15 +020046 set_pte(kmap_pte-idx, mk_pte(page, prot));
Linus Torvalds1da177e2005-04-16 15:20:36 -070047
Andrew Morton4150d3f2007-09-11 15:24:10 -070048 return (void *)vaddr;
Linus Torvalds1da177e2005-04-16 15:20:36 -070049}
50
Jeremy Fitzhardingece6234b2007-05-02 19:27:15 +020051void *kmap_atomic(struct page *page, enum km_type type)
52{
53 return kmap_atomic_prot(page, type, kmap_prot);
54}
55
Linus Torvalds1da177e2005-04-16 15:20:36 -070056void kunmap_atomic(void *kvaddr, enum km_type type)
57{
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
59 enum fixed_addresses idx = type + KM_TYPE_NR*smp_processor_id();
60
Zachary Amsden23002d82006-09-30 23:29:35 -070061 /*
62 * Force other mappings to Oops if they'll try to access this pte
63 * without first remap it. Keeping stale mappings around is a bad idea
64 * also, in case the page changes cacheability attributes or becomes
65 * a protected page in a hypervisor.
66 */
Jeremy Fitzhardinge3b179792006-12-06 20:32:22 -080067 if (vaddr == __fix_to_virt(FIX_KMAP_BEGIN+idx))
68 kpte_clear_flush(kmap_pte-idx, vaddr);
69 else {
70#ifdef CONFIG_DEBUG_HIGHMEM
71 BUG_ON(vaddr < PAGE_OFFSET);
72 BUG_ON(vaddr >= (unsigned long)high_memory);
73#endif
74 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070075
Peter Zijlstraa8663742006-12-06 20:32:20 -080076 pagefault_enable();
Linus Torvalds1da177e2005-04-16 15:20:36 -070077}
78
Ingo Molnardd63fdc2009-03-13 03:20:49 +010079/*
80 * This is the same as kmap_atomic() but can map memory that doesn't
Vivek Goyal60e64d42005-06-25 14:58:19 -070081 * have a struct page associated with it.
82 */
83void *kmap_atomic_pfn(unsigned long pfn, enum km_type type)
84{
Akinobu Mitabb6d59c2009-03-11 23:33:18 +090085 return kmap_atomic_prot_pfn(pfn, type, kmap_prot);
Vivek Goyal60e64d42005-06-25 14:58:19 -070086}
Eric Anholtd1d8c922008-08-21 12:53:33 -070087EXPORT_SYMBOL_GPL(kmap_atomic_pfn); /* temporarily in use by i915 GEM until vmap */
Vivek Goyal60e64d42005-06-25 14:58:19 -070088
Linus Torvalds1da177e2005-04-16 15:20:36 -070089struct page *kmap_atomic_to_page(void *ptr)
90{
91 unsigned long idx, vaddr = (unsigned long)ptr;
92 pte_t *pte;
93
94 if (vaddr < FIXADDR_START)
95 return virt_to_page(ptr);
96
97 idx = virt_to_fix(vaddr);
98 pte = kmap_pte - (idx - FIX_KMAP_BEGIN);
99 return pte_page(*pte);
100}
101
Alexey Dobriyan129f6942005-06-23 00:08:33 -0700102EXPORT_SYMBOL(kmap);
103EXPORT_SYMBOL(kunmap);
104EXPORT_SYMBOL(kmap_atomic);
105EXPORT_SYMBOL(kunmap_atomic);
Pekka Enberg867c5b522009-03-03 14:10:12 +0200106
Pekka Enberg867c5b522009-03-03 14:10:12 +0200107void __init set_highmem_pages_init(void)
108{
109 struct zone *zone;
110 int nid;
111
112 for_each_zone(zone) {
113 unsigned long zone_start_pfn, zone_end_pfn;
114
115 if (!is_highmem(zone))
116 continue;
117
118 zone_start_pfn = zone->zone_start_pfn;
119 zone_end_pfn = zone_start_pfn + zone->spanned_pages;
120
121 nid = zone_to_nid(zone);
122 printk(KERN_INFO "Initializing %s for node %d (%08lx:%08lx)\n",
123 zone->name, nid, zone_start_pfn, zone_end_pfn);
124
125 add_highpages_with_active_regions(nid, zone_start_pfn,
126 zone_end_pfn);
127 }
128 totalram_pages += totalhigh_pages;
129}