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

 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}