drivers: power: report battery voltage in AOSP compatible format
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / sparc / mm / highmem.c
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1da177e4
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1/*
2 * highmem.c: virtual kernel memory mappings for high memory
3 *
4 * Provides kernel-static versions of atomic kmap functions originally
5 * found as inlines in include/asm-sparc/highmem.h. These became
6 * needed as kmap_atomic() and kunmap_atomic() started getting
7 * called from within modules.
8 * -- Tomas Szepe <szepe@pinerecords.com>, September 2002
9 *
10 * But kmap_atomic() and kunmap_atomic() cannot be inlined in
11 * modules because they are loaded with btfixup-ped functions.
12 */
13
14/*
15 * The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap
16 * gives a more generic (and caching) interface. But kmap_atomic can
17 * be used in IRQ contexts, so in some (very limited) cases we need it.
18 *
19 * XXX This is an old text. Actually, it's good to use atomic kmaps,
20 * provided you remember that they are atomic and not try to sleep
21 * with a kmap taken, much like a spinlock. Non-atomic kmaps are
22 * shared by CPUs, and so precious, and establishing them requires IPI.
23 * Atomic kmaps are lightweight and we may have NCPUS more of them.
24 */
1da177e4 25#include <linux/highmem.h>
7b64db60 26#include <linux/export.h>
1b6d06d8
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27#include <linux/mm.h>
28
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29#include <asm/cacheflush.h>
30#include <asm/tlbflush.h>
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31#include <asm/pgalloc.h>
32#include <asm/vaddrs.h>
1da177e4 33
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34pgprot_t kmap_prot;
35
36static pte_t *kmap_pte;
37
38void __init kmap_init(void)
39{
40 unsigned long address;
41 pmd_t *dir;
42
43 address = __fix_to_virt(FIX_KMAP_BEGIN);
44 dir = pmd_offset(pgd_offset_k(address), address);
45
46 /* cache the first kmap pte */
47 kmap_pte = pte_offset_kernel(dir, address);
48 kmap_prot = __pgprot(SRMMU_ET_PTE | SRMMU_PRIV | SRMMU_CACHE);
49}
50
a24401bc 51void *kmap_atomic(struct page *page)
1da177e4 52{
1da177e4 53 unsigned long vaddr;
3e4d3af5 54 long idx, type;
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55
56 /* even !CONFIG_PREEMPT needs this, for in_atomic in do_page_fault */
a866374a 57 pagefault_disable();
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58 if (!PageHighMem(page))
59 return page_address(page);
60
3e4d3af5 61 type = kmap_atomic_idx_push();
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62 idx = type + KM_TYPE_NR*smp_processor_id();
63 vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
64
65/* XXX Fix - Anton */
66#if 0
67 __flush_cache_one(vaddr);
68#else
69 flush_cache_all();
70#endif
71
72#ifdef CONFIG_DEBUG_HIGHMEM
73 BUG_ON(!pte_none(*(kmap_pte-idx)));
74#endif
75 set_pte(kmap_pte-idx, mk_pte(page, kmap_prot));
76/* XXX Fix - Anton */
77#if 0
78 __flush_tlb_one(vaddr);
79#else
80 flush_tlb_all();
81#endif
82
83 return (void*) vaddr;
84}
a24401bc 85EXPORT_SYMBOL(kmap_atomic);
1da177e4 86
3e4d3af5 87void __kunmap_atomic(void *kvaddr)
1da177e4 88{
1da177e4 89 unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
3e4d3af5 90 int type;
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91
92 if (vaddr < FIXADDR_START) { // FIXME
a866374a 93 pagefault_enable();
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94 return;
95 }
96
20273941 97 type = kmap_atomic_idx();
1da177e4 98
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99#ifdef CONFIG_DEBUG_HIGHMEM
100 {
101 unsigned long idx;
102
103 idx = type + KM_TYPE_NR * smp_processor_id();
104 BUG_ON(vaddr != __fix_to_virt(FIX_KMAP_BEGIN+idx));
105
106 /* XXX Fix - Anton */
1da177e4 107#if 0
3e4d3af5 108 __flush_cache_one(vaddr);
1da177e4 109#else
3e4d3af5 110 flush_cache_all();
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111#endif
112
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113 /*
114 * force other mappings to Oops if they'll try to access
115 * this pte without first remap it
116 */
117 pte_clear(&init_mm, vaddr, kmap_pte-idx);
118 /* XXX Fix - Anton */
1da177e4 119#if 0
3e4d3af5 120 __flush_tlb_one(vaddr);
1da177e4 121#else
3e4d3af5 122 flush_tlb_all();
1da177e4 123#endif
3e4d3af5 124 }
1da177e4 125#endif
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126
127 kmap_atomic_idx_pop();
a866374a 128 pagefault_enable();
1da177e4 129}
3e4d3af5 130EXPORT_SYMBOL(__kunmap_atomic);