1#include <linux/highmem.h>
  2#include <linux/module.h>
  3#include <linux/swap.h> /* for totalram_pages */
  4
  5void *kmap(struct page *page)
  6{
  7	might_sleep();
  8	if (!PageHighMem(page))
  9		return page_address(page);
 10	return kmap_high(page);
 11}
 12EXPORT_SYMBOL(kmap);
 13
 14void kunmap(struct page *page)
 15{
 16	if (in_interrupt())
 17		BUG();
 18	if (!PageHighMem(page))
 19		return;
 20	kunmap_high(page);
 21}
 22EXPORT_SYMBOL(kunmap);
 23
 24/*
 25 * kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because
 26 * no global lock is needed and because the kmap code must perform a global TLB
 27 * invalidation when the kmap pool wraps.
 28 *
 29 * However when holding an atomic kmap it is not legal to sleep, so atomic
 30 * kmaps are appropriate for short, tight code paths only.
 31 */
 32void *kmap_atomic_prot(struct page *page, pgprot_t prot)
 33{
 34	unsigned long vaddr;
 35	int idx, type;
 36
 37	/* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
 38	pagefault_disable();
 39
 40	if (!PageHighMem(page))
 41		return page_address(page);
 42
 43	type = kmap_atomic_idx_push();
 44	idx = type + KM_TYPE_NR*smp_processor_id();
 45	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
 46	BUG_ON(!pte_none(*(kmap_pte-idx)));
 47	set_pte(kmap_pte-idx, mk_pte(page, prot));
 48
 49	return (void *)vaddr;
 50}
 51EXPORT_SYMBOL(kmap_atomic_prot);
 52
 53void *__kmap_atomic(struct page *page)
 54{
 55	return kmap_atomic_prot(page, kmap_prot);
 56}
 57EXPORT_SYMBOL(__kmap_atomic);
 58
 59/*
 60 * This is the same as kmap_atomic() but can map memory that doesn't
 61 * have a struct page associated with it.
 62 */
 63void *kmap_atomic_pfn(unsigned long pfn)
 64{
 65	return kmap_atomic_prot_pfn(pfn, kmap_prot);
 66}
 67EXPORT_SYMBOL_GPL(kmap_atomic_pfn);
 68
 69void __kunmap_atomic(void *kvaddr)
 70{
 71	unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
 72
 73	if (vaddr >= __fix_to_virt(FIX_KMAP_END) &&
 74	    vaddr <= __fix_to_virt(FIX_KMAP_BEGIN)) {
 75		int idx, type;
 76
 77		type = kmap_atomic_idx();
 78		idx = type + KM_TYPE_NR * smp_processor_id();
 79
 80#ifdef CONFIG_DEBUG_HIGHMEM
 81		WARN_ON_ONCE(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
 82#endif
 83		/*
 84		 * Force other mappings to Oops if they'll try to access this
 85		 * pte without first remap it.  Keeping stale mappings around
 86		 * is a bad idea also, in case the page changes cacheability
 87		 * attributes or becomes a protected page in a hypervisor.
 88		 */
 89		kpte_clear_flush(kmap_pte-idx, vaddr);
 90		kmap_atomic_idx_pop();
 91	}
 92#ifdef CONFIG_DEBUG_HIGHMEM
 93	else {
 94		BUG_ON(vaddr < PAGE_OFFSET);
 95		BUG_ON(vaddr >= (unsigned long)high_memory);
 96	}
 97#endif
 98
 99	pagefault_enable();
100}
101EXPORT_SYMBOL(__kunmap_atomic);
102
103struct page *kmap_atomic_to_page(void *ptr)
104{
105	unsigned long idx, vaddr = (unsigned long)ptr;
106	pte_t *pte;
107
108	if (vaddr < FIXADDR_START)
109		return virt_to_page(ptr);
110
111	idx = virt_to_fix(vaddr);
112	pte = kmap_pte - (idx - FIX_KMAP_BEGIN);
113	return pte_page(*pte);
114}
115EXPORT_SYMBOL(kmap_atomic_to_page);
116
117void __init set_highmem_pages_init(void)
118{
119	struct zone *zone;
120	int nid;
121
 
 
 
 
 
122	for_each_zone(zone) {
123		unsigned long zone_start_pfn, zone_end_pfn;
124
125		if (!is_highmem(zone))
126			continue;
127
128		zone_start_pfn = zone->zone_start_pfn;
129		zone_end_pfn = zone_start_pfn + zone->spanned_pages;
130
131		nid = zone_to_nid(zone);
132		printk(KERN_INFO "Initializing %s for node %d (%08lx:%08lx)\n",
133				zone->name, nid, zone_start_pfn, zone_end_pfn);
134
135		add_highpages_with_active_regions(nid, zone_start_pfn,
136				 zone_end_pfn);
137	}
138	totalram_pages += totalhigh_pages;
139}

 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#include <asm/numa.h>
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 7
 8void __init set_highmem_pages_init(void)
 9{
10	struct zone *zone;
11	int nid;
12
13	/*
14	 * Explicitly reset zone->managed_pages because set_highmem_pages_init()
15	 * is invoked before memblock_free_all()
16	 */
17	reset_all_zones_managed_pages();
18	for_each_zone(zone) {
19		unsigned long zone_start_pfn, zone_end_pfn;
20
21		if (!is_highmem(zone))
22			continue;
23
24		zone_start_pfn = zone->zone_start_pfn;
25		zone_end_pfn = zone_start_pfn + zone->spanned_pages;
26
27		nid = zone_to_nid(zone);
28		printk(KERN_INFO "Initializing %s for node %d (%08lx:%08lx)\n",
29				zone->name, nid, zone_start_pfn, zone_end_pfn);
30
31		add_highpages_with_active_regions(nid, zone_start_pfn,
32				 zone_end_pfn);
33	}
 
34}