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 pmd_free_pte_page(pmd, addr)) {
88 if (pmd_set_huge(pmd, phys_addr + addr, prot))
89 continue;
90 }
91
92 if (ioremap_pte_range(pmd, addr, next, phys_addr + addr, prot))
93 return -ENOMEM;
94 } while (pmd++, addr = next, addr != end);
95 return 0;
96 }
97
ioremap_pud_range(pgd_t * pgd,unsigned long addr,unsigned long end,phys_addr_t phys_addr,pgprot_t prot)98 static inline int ioremap_pud_range(pgd_t *pgd, unsigned long addr,
99 unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
100 {
101 pud_t *pud;
102 unsigned long next;
103
104 phys_addr -= addr;
105 pud = pud_alloc(&init_mm, pgd, addr);
106 if (!pud)
107 return -ENOMEM;
108 do {
109 next = pud_addr_end(addr, end);
110
111 if (ioremap_pud_enabled() &&
112 ((next - addr) == PUD_SIZE) &&
113 IS_ALIGNED(phys_addr + addr, PUD_SIZE) &&
114 pud_free_pmd_page(pud, addr)) {
115 if (pud_set_huge(pud, phys_addr + addr, prot))
116 continue;
117 }
118
119 if (ioremap_pmd_range(pud, addr, next, phys_addr + addr, prot))
120 return -ENOMEM;
121 } while (pud++, addr = next, addr != end);
122 return 0;
123 }
124
ioremap_page_range(unsigned long addr,unsigned long end,phys_addr_t phys_addr,pgprot_t prot)125 int ioremap_page_range(unsigned long addr,
126 unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
127 {
128 pgd_t *pgd;
129 unsigned long start;
130 unsigned long next;
131 int err;
132
133 BUG_ON(addr >= end);
134
135 start = addr;
136 phys_addr -= addr;
137 pgd = pgd_offset_k(addr);
138 do {
139 next = pgd_addr_end(addr, end);
140 err = ioremap_pud_range(pgd, addr, next, phys_addr+addr, prot);
141 if (err)
142 break;
143 } while (pgd++, addr = next, addr != end);
144
145 flush_cache_vmap(start, end);
146
147 return err;
148 }
149 EXPORT_SYMBOL_GPL(ioremap_page_range);
150