LXR linux/arch/x86/mm/highmem

   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_atomic_high_prot(struct page *page, pgprot_t prot)
   8{
   9        unsigned long vaddr;
  10        int idx, type;
  11
  12        type = kmap_atomic_idx_push();
  13        idx = type + KM_TYPE_NR*smp_processor_id();
  14        vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
  15        BUG_ON(!pte_none(*(kmap_pte-idx)));
  16        set_pte(kmap_pte-idx, mk_pte(page, prot));
  17        arch_flush_lazy_mmu_mode();
  18
  19        return (void *)vaddr;
  20}
  21EXPORT_SYMBOL(kmap_atomic_high_prot);
  22
  23/*
  24 * This is the same as kmap_atomic() but can map memory that doesn't
  25 * have a struct page associated with it.
  26 */
  27void *kmap_atomic_pfn(unsigned long pfn)
  28{
  29        return kmap_atomic_prot_pfn(pfn, kmap_prot);
  30}
  31EXPORT_SYMBOL_GPL(kmap_atomic_pfn);
  32
  33void kunmap_atomic_high(void *kvaddr)
  34{
  35        unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
  36
  37        if (vaddr >= __fix_to_virt(FIX_KMAP_END) &&
  38            vaddr <= __fix_to_virt(FIX_KMAP_BEGIN)) {
  39                int idx, type;
  40
  41                type = kmap_atomic_idx();
  42                idx = type + KM_TYPE_NR * smp_processor_id();
  43
  44#ifdef CONFIG_DEBUG_HIGHMEM
  45                WARN_ON_ONCE(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
  46#endif
  47                /*
  48                 * Force other mappings to Oops if they'll try to access this
  49                 * pte without first remap it.  Keeping stale mappings around
  50                 * is a bad idea also, in case the page changes cacheability
  51                 * attributes or becomes a protected page in a hypervisor.
  52                 */
  53                kpte_clear_flush(kmap_pte-idx, vaddr);
  54                kmap_atomic_idx_pop();
  55                arch_flush_lazy_mmu_mode();
  56        }
  57#ifdef CONFIG_DEBUG_HIGHMEM
  58        else {
  59                BUG_ON(vaddr < PAGE_OFFSET);
  60                BUG_ON(vaddr >= (unsigned long)high_memory);
  61        }
  62#endif
  63}
  64EXPORT_SYMBOL(kunmap_atomic_high);
  65
  66void __init set_highmem_pages_init(void)
  67{
  68        struct zone *zone;
  69        int nid;
  70
  71        /*
  72         * Explicitly reset zone->managed_pages because set_highmem_pages_init()
  73         * is invoked before memblock_free_all()
  74         */
  75        reset_all_zones_managed_pages();
  76        for_each_zone(zone) {
  77                unsigned long zone_start_pfn, zone_end_pfn;
  78
  79                if (!is_highmem(zone))
  80                        continue;
  81
  82                zone_start_pfn = zone->zone_start_pfn;
  83                zone_end_pfn = zone_start_pfn + zone->spanned_pages;
  84
  85                nid = zone_to_nid(zone);
  86                printk(KERN_INFO "Initializing %s for node %d (%08lx:%08lx)\n",
  87                                zone->name, nid, zone_start_pfn, zone_end_pfn);
  88
  89                add_highpages_with_active_regions(nid, zone_start_pfn,
  90                                 zone_end_pfn);
  91        }
  92}
  93