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	/* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
 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}
104EXPORT_SYMBOL(__kunmap_atomic);
105
106struct page *kmap_atomic_to_page(void *ptr)
107{
108	unsigned long idx, vaddr = (unsigned long)ptr;
109	pte_t *pte;
110
111	if (vaddr < FIXADDR_START)
112		return virt_to_page(ptr);
113
114	idx = virt_to_fix(vaddr);
115	pte = kmap_pte - (idx - FIX_KMAP_BEGIN);
116	return pte_page(*pte);
117}
118EXPORT_SYMBOL(kmap_atomic_to_page);
119
120void __init set_highmem_pages_init(void)
121{
122	struct zone *zone;
123	int nid;
124
125	/*
126	 * Explicitly reset zone->managed_pages because set_highmem_pages_init()
127	 * is invoked before free_all_bootmem()
128	 */
129	reset_all_zones_managed_pages();
130	for_each_zone(zone) {
131		unsigned long zone_start_pfn, zone_end_pfn;
132
133		if (!is_highmem(zone))
134			continue;
135
136		zone_start_pfn = zone->zone_start_pfn;
137		zone_end_pfn = zone_start_pfn + zone->spanned_pages;
138
139		nid = zone_to_nid(zone);
140		printk(KERN_INFO "Initializing %s for node %d (%08lx:%08lx)\n",
141				zone->name, nid, zone_start_pfn, zone_end_pfn);
142
143		add_highpages_with_active_regions(nid, zone_start_pfn,
144				 zone_end_pfn);
145	}
146}

 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}