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 */
8 #include <linux/vmalloc.h>
9 #include <linux/mm.h>
10 #include <linux/sched.h>
11 #include <linux/io.h>
12 #include <linux/export.h>
13 #include <asm/cacheflush.h>
14 #include <asm/pgtable.h>
15
16 #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
17 static int __read_mostly ioremap_pud_capable;
18 static int __read_mostly ioremap_pmd_capable;
19 static int __read_mostly ioremap_huge_disabled;
20
set_nohugeiomap(char * str)21 static int __init set_nohugeiomap(char *str)
22 {
23 ioremap_huge_disabled = 1;
24 return 0;
25 }
26 early_param("nohugeiomap", set_nohugeiomap);
27
ioremap_huge_init(void)28 void __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
ioremap_pud_enabled(void)38 static inline int ioremap_pud_enabled(void)
39 {
40 return ioremap_pud_capable;
41 }
42
ioremap_pmd_enabled(void)43 static inline int ioremap_pmd_enabled(void)
44 {
45 return ioremap_pmd_capable;
46 }
47
48 #else /* !CONFIG_HAVE_ARCH_HUGE_VMAP */
ioremap_pud_enabled(void)49 static inline int ioremap_pud_enabled(void) { return 0; }
ioremap_pmd_enabled(void)50 static inline int ioremap_pmd_enabled(void) { return 0; }
51 #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */
52
ioremap_pte_range(pmd_t * pmd,unsigned long addr,unsigned long end,phys_addr_t phys_addr,pgprot_t prot)53 static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
54 unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
55 {
56 pte_t *pte;
57 u64 pfn;
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
ioremap_pmd_range(pud_t * pud,unsigned long addr,unsigned long end,phys_addr_t phys_addr,pgprot_t prot)71 static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr,
72 unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
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
84 if (ioremap_pmd_enabled() &&
85 ((next - addr) == PMD_SIZE) &&
86 IS_ALIGNED(phys_addr + addr, PMD_SIZE)) {
87 if (pmd_set_huge(pmd, phys_addr + addr, prot))
88 continue;
89 }
90
91 if (ioremap_pte_range(pmd, addr, next, phys_addr + addr, prot))
92 return -ENOMEM;
93 } while (pmd++, addr = next, addr != end);
94 return 0;
95 }
96
ioremap_pud_range(pgd_t * pgd,unsigned long addr,unsigned long end,phys_addr_t phys_addr,pgprot_t prot)97 static inline int ioremap_pud_range(pgd_t *pgd, unsigned long addr,
98 unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
99 {
100 pud_t *pud;
101 unsigned long next;
102
103 phys_addr -= addr;
104 pud = pud_alloc(&init_mm, pgd, addr);
105 if (!pud)
106 return -ENOMEM;
107 do {
108 next = pud_addr_end(addr, end);
109
110 if (ioremap_pud_enabled() &&
111 ((next - addr) == PUD_SIZE) &&
112 IS_ALIGNED(phys_addr + addr, PUD_SIZE)) {
113 if (pud_set_huge(pud, phys_addr + addr, prot))
114 continue;
115 }
116
117 if (ioremap_pmd_range(pud, addr, next, phys_addr + addr, prot))
118 return -ENOMEM;
119 } while (pud++, addr = next, addr != end);
120 return 0;
121 }
122
ioremap_page_range(unsigned long addr,unsigned long end,phys_addr_t phys_addr,pgprot_t prot)123 int ioremap_page_range(unsigned long addr,
124 unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
125 {
126 pgd_t *pgd;
127 unsigned long start;
128 unsigned long next;
129 int err;
130
131 BUG_ON(addr >= end);
132
133 start = addr;
134 phys_addr -= addr;
135 pgd = pgd_offset_k(addr);
136 do {
137 next = pgd_addr_end(addr, end);
138 err = ioremap_pud_range(pgd, addr, next, phys_addr+addr, prot);
139 if (err)
140 break;
141 } while (pgd++, addr = next, addr != end);
142
143 flush_cache_vmap(start, end);
144
145 return err;
146 }
147 EXPORT_SYMBOL_GPL(ioremap_page_range);
148