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