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23#include <linux/highmem.h>
24#include <linux/module.h>
25
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31
32void *kmap_atomic_prot(struct page *page, pgprot_t prot)
33{
34 unsigned long vaddr;
35 int idx, type;
36
37 preempt_disable();
38 pagefault_disable();
39 if (!PageHighMem(page))
40 return page_address(page);
41
42 type = kmap_atomic_idx_push();
43 idx = type + KM_TYPE_NR*smp_processor_id();
44 vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
45#ifdef CONFIG_DEBUG_HIGHMEM
46 BUG_ON(!pte_none(*(kmap_pte-idx)));
47#endif
48 __set_pte_at(&init_mm, vaddr, kmap_pte-idx, mk_pte(page, prot), 1);
49 local_flush_tlb_page(NULL, vaddr);
50
51 return (void*) vaddr;
52}
53EXPORT_SYMBOL(kmap_atomic_prot);
54
55void __kunmap_atomic(void *kvaddr)
56{
57 unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
58 int type;
59
60 if (vaddr < __fix_to_virt(FIX_KMAP_END)) {
61 pagefault_enable();
62 preempt_enable();
63 return;
64 }
65
66 type = kmap_atomic_idx();
67
68#ifdef CONFIG_DEBUG_HIGHMEM
69 {
70 unsigned int idx;
71
72 idx = type + KM_TYPE_NR * smp_processor_id();
73 BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN + idx));
74
75
76
77
78
79 pte_clear(&init_mm, vaddr, kmap_pte-idx);
80 local_flush_tlb_page(NULL, vaddr);
81 }
82#endif
83
84 kmap_atomic_idx_pop();
85 pagefault_enable();
86 preempt_enable();
87}
88EXPORT_SYMBOL(__kunmap_atomic);
89