summaryrefslogtreecommitdiff
path: root/lib/ioremap.c
blob: 4bb30206b9426f1fcece4324cc0dfe76b8855c65 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
/*
 * Re-map IO memory to kernel address space so that we can access it.
 * This is needed for high PCI addresses that aren't mapped in the
 * 640k-1MB IO memory area on PC's
 *
 * (C) Copyright 1995 1996 Linus Torvalds
 */
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/io.h>
#include <linux/export.h>
#include <asm/cacheflush.h>
#include <asm/pgtable.h>

#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
static int __read_mostly ioremap_p4d_capable;
static int __read_mostly ioremap_pud_capable;
static int __read_mostly ioremap_pmd_capable;
static int __read_mostly ioremap_huge_disabled;

static int __init set_nohugeiomap(char *str)
{
	ioremap_huge_disabled = 1;
	return 0;
}
early_param("nohugeiomap", set_nohugeiomap);

void __init ioremap_huge_init(void)
{
	if (!ioremap_huge_disabled) {
		if (arch_ioremap_pud_supported())
			ioremap_pud_capable = 1;
		if (arch_ioremap_pmd_supported())
			ioremap_pmd_capable = 1;
	}
}

static inline int ioremap_p4d_enabled(void)
{
	return ioremap_p4d_capable;
}

static inline int ioremap_pud_enabled(void)
{
	return ioremap_pud_capable;
}

static inline int ioremap_pmd_enabled(void)
{
	return ioremap_pmd_capable;
}

#else	/* !CONFIG_HAVE_ARCH_HUGE_VMAP */
static inline int ioremap_p4d_enabled(void) { return 0; }
static inline int ioremap_pud_enabled(void) { return 0; }
static inline int ioremap_pmd_enabled(void) { return 0; }
#endif	/* CONFIG_HAVE_ARCH_HUGE_VMAP */

static int ioremap_pte_range(pmd_t *pmd, unsigned long addr,
		unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
{
	pte_t *pte;
	u64 pfn;

	pfn = phys_addr >> PAGE_SHIFT;
	pte = pte_alloc_kernel(pmd, addr);
	if (!pte)
		return -ENOMEM;
	do {
		BUG_ON(!pte_none(*pte));
		set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
		pfn++;
	} while (pte++, addr += PAGE_SIZE, addr != end);
	return 0;
}

static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr,
		unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
{
	pmd_t *pmd;
	unsigned long next;

	phys_addr -= addr;
	pmd = pmd_alloc(&init_mm, pud, addr);
	if (!pmd)
		return -ENOMEM;
	do {
		next = pmd_addr_end(addr, end);

		if (ioremap_pmd_enabled() &&
		    ((next - addr) == PMD_SIZE) &&
		    IS_ALIGNED(phys_addr + addr, PMD_SIZE)) {
			if (pmd_set_huge(pmd, phys_addr + addr, prot))
				continue;
		}

		if (ioremap_pte_range(pmd, addr, next, phys_addr + addr, prot))
			return -ENOMEM;
	} while (pmd++, addr = next, addr != end);
	return 0;
}

static inline int ioremap_pud_range(p4d_t *p4d, unsigned long addr,
		unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
{
	pud_t *pud;
	unsigned long next;

	phys_addr -= addr;
	pud = pud_alloc(&init_mm, p4d, addr);
	if (!pud)
		return -ENOMEM;
	do {
		next = pud_addr_end(addr, end);

		if (ioremap_pud_enabled() &&
		    ((next - addr) == PUD_SIZE) &&
		    IS_ALIGNED(phys_addr + addr, PUD_SIZE)) {
			if (pud_set_huge(pud, phys_addr + addr, prot))
				continue;
		}

		if (ioremap_pmd_range(pud, addr, next, phys_addr + addr, prot))
			return -ENOMEM;
	} while (pud++, addr = next, addr != end);
	return 0;
}

static inline int ioremap_p4d_range(pgd_t *pgd, unsigned long addr,
		unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
{
	p4d_t *p4d;
	unsigned long next;

	phys_addr -= addr;
	p4d = p4d_alloc(&init_mm, pgd, addr);
	if (!p4d)
		return -ENOMEM;
	do {
		next = p4d_addr_end(addr, end);

		if (ioremap_p4d_enabled() &&
		    ((next - addr) == P4D_SIZE) &&
		    IS_ALIGNED(phys_addr + addr, P4D_SIZE)) {
			if (p4d_set_huge(p4d, phys_addr + addr, prot))
				continue;
		}

		if (ioremap_pud_range(p4d, addr, next, phys_addr + addr, prot))
			return -ENOMEM;
	} while (p4d++, addr = next, addr != end);
	return 0;
}

int ioremap_page_range(unsigned long addr,
		       unsigned long end, phys_addr_t phys_addr, pgprot_t prot)
{
	pgd_t *pgd;
	unsigned long start;
	unsigned long next;
	int err;

	BUG_ON(addr >= end);

	start = addr;
	phys_addr -= addr;
	pgd = pgd_offset_k(addr);
	do {
		next = pgd_addr_end(addr, end);
		err = ioremap_p4d_range(pgd, addr, next, phys_addr+addr, prot);
		if (err)
			break;
	} while (pgd++, addr = next, addr != end);

	flush_cache_vmap(start, end);

	return err;
}