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lib/ioremap.c: add huge I/O map capability interfaces
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1/*
2 * Re-map IO memory to kernel address space so that we can access it.
3 * This is needed for high PCI addresses that aren't mapped in the
4 * 640k-1MB IO memory area on PC's
5 *
6 * (C) Copyright 1995 1996 Linus Torvalds
7 */
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8#include <linux/vmalloc.h>
9#include <linux/mm.h>
e8edc6e0 10#include <linux/sched.h>
53fa6645 11#include <linux/io.h>
8bc3bcc9 12#include <linux/export.h>
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13#include <asm/cacheflush.h>
14#include <asm/pgtable.h>
15
0ddab1d2
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16#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
17int __read_mostly ioremap_pud_capable;
18int __read_mostly ioremap_pmd_capable;
19int __read_mostly ioremap_huge_disabled;
20
21static int __init set_nohugeiomap(char *str)
22{
23 ioremap_huge_disabled = 1;
24 return 0;
25}
26early_param("nohugeiomap", set_nohugeiomap);
27
28void __init ioremap_huge_init(void)
29{
30 if (!ioremap_huge_disabled) {
31 if (arch_ioremap_pud_supported())
32 ioremap_pud_capable = 1;
33 if (arch_ioremap_pmd_supported())
34 ioremap_pmd_capable = 1;
35 }
36}
37
38static inline int ioremap_pud_enabled(void)
39{
40 return ioremap_pud_capable;
41}
42
43static inline int ioremap_pmd_enabled(void)
44{
45 return ioremap_pmd_capable;
46}
47
48#else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
49static inline int ioremap_pud_enabled(void) { return 0; }
50static inline int ioremap_pmd_enabled(void) { return 0; }
51#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
52
74588d8b 53static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
ffa71f33 54 unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
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55{
56 pte_t *pte;
ffa71f33 57 u64 pfn;
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58
59 pfn = phys_addr >> PAGE_SHIFT;
60 pte = pte_alloc_kernel(pmd, addr);
61 if (!pte)
62 return -ENOMEM;
63 do {
64 BUG_ON(!pte_none(*pte));
65 set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
66 pfn++;
67 } while (pte++, addr += PAGE_SIZE, addr != end);
68 return 0;
69}
70
71static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr,
ffa71f33 72 unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
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73{
74 pmd_t *pmd;
75 unsigned long next;
76
77 phys_addr -= addr;
78 pmd = pmd_alloc(&init_mm, pud, addr);
79 if (!pmd)
80 return -ENOMEM;
81 do {
82 next = pmd_addr_end(addr, end);
83 if (ioremap_pte_range(pmd, addr, next, phys_addr + addr, prot))
84 return -ENOMEM;
85 } while (pmd++, addr = next, addr != end);
86 return 0;
87}
88
89static inline int ioremap_pud_range(pgd_t *pgd, unsigned long addr,
ffa71f33 90 unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
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91{
92 pud_t *pud;
93 unsigned long next;
94
95 phys_addr -= addr;
96 pud = pud_alloc(&init_mm, pgd, addr);
97 if (!pud)
98 return -ENOMEM;
99 do {
100 next = pud_addr_end(addr, end);
101 if (ioremap_pmd_range(pud, addr, next, phys_addr + addr, prot))
102 return -ENOMEM;
103 } while (pud++, addr = next, addr != end);
104 return 0;
105}
106
107int ioremap_page_range(unsigned long addr,
ffa71f33 108 unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
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109{
110 pgd_t *pgd;
111 unsigned long start;
112 unsigned long next;
113 int err;
114
115 BUG_ON(addr >= end);
116
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117 start = addr;
118 phys_addr -= addr;
119 pgd = pgd_offset_k(addr);
120 do {
121 next = pgd_addr_end(addr, end);
122 err = ioremap_pud_range(pgd, addr, next, phys_addr+addr, prot);
123 if (err)
124 break;
125 } while (pgd++, addr = next, addr != end);
126
db71daab 127 flush_cache_vmap(start, end);
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128
129 return err;
130}
81e88fdc 131EXPORT_SYMBOL_GPL(ioremap_page_range);