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}
134