aboutsummaryrefslogtreecommitdiff
path: root/arch/arm64/mm/ioremap.c
blob: 4a07630a66165e9948ccffaaf888cdd21ddb2a8c (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
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
/*
 * Based on arch/arm/mm/ioremap.c
 *
 * (C) Copyright 1995 1996 Linus Torvalds
 * Hacked for ARM by Phil Blundell <philb@gnu.org>
 * Hacked to allow all architectures to build, and various cleanups
 * by Russell King
 * Copyright (C) 2012 ARM Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/export.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/io.h>

#include <asm/fixmap.h>
#include <asm/tlbflush.h>
#include <asm/pgalloc.h>

static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size,
				      pgprot_t prot, void *caller)
{
	unsigned long last_addr;
	unsigned long offset = phys_addr & ~PAGE_MASK;
	int err;
	unsigned long addr;
	struct vm_struct *area;

	/*
	 * Page align the mapping address and size, taking account of any
	 * offset.
	 */
	phys_addr &= PAGE_MASK;
	size = PAGE_ALIGN(size + offset);

	/*
	 * Don't allow wraparound, zero size or outside PHYS_MASK.
	 */
	last_addr = phys_addr + size - 1;
	if (!size || last_addr < phys_addr || (last_addr & ~PHYS_MASK))
		return NULL;

	/*
	 * Don't allow RAM to be mapped.
	 */
	if (WARN_ON(pfn_valid(__phys_to_pfn(phys_addr))))
		return NULL;

	area = get_vm_area_caller(size, VM_IOREMAP, caller);
	if (!area)
		return NULL;
	addr = (unsigned long)area->addr;

	err = ioremap_page_range(addr, addr + size, phys_addr, prot);
	if (err) {
		vunmap((void *)addr);
		return NULL;
	}

	return (void __iomem *)(offset + addr);
}

void __iomem *__ioremap(phys_addr_t phys_addr, size_t size, pgprot_t prot)
{
	return __ioremap_caller(phys_addr, size, prot,
				__builtin_return_address(0));
}
EXPORT_SYMBOL(__ioremap);

void __iounmap(volatile void __iomem *io_addr)
{
	unsigned long addr = (unsigned long)io_addr & PAGE_MASK;

	/*
	 * We could get an address outside vmalloc range in case
	 * of ioremap_cache() reusing a RAM mapping.
	 */
	if (VMALLOC_START <= addr && addr < VMALLOC_END)
		vunmap((void *)addr);
}
EXPORT_SYMBOL(__iounmap);

void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size)
{
	/* For normal memory we already have a cacheable mapping. */
	if (pfn_valid(__phys_to_pfn(phys_addr)))
		return (void __iomem *)__phys_to_virt(phys_addr);

	return __ioremap_caller(phys_addr, size, __pgprot(PROT_NORMAL),
				__builtin_return_address(0));
}
EXPORT_SYMBOL(ioremap_cache);

static pte_t bm_pte[PTRS_PER_PTE] __page_aligned_bss;
#if CONFIG_ARM64_PGTABLE_LEVELS > 2
static pmd_t bm_pmd[PTRS_PER_PMD] __page_aligned_bss;
#endif
#if CONFIG_ARM64_PGTABLE_LEVELS > 3
static pud_t bm_pud[PTRS_PER_PUD] __page_aligned_bss;
#endif

static inline pud_t * __init early_ioremap_pud(unsigned long addr)
{
	pgd_t *pgd;

	pgd = pgd_offset_k(addr);
	BUG_ON(pgd_none(*pgd) || pgd_bad(*pgd));

	return pud_offset(pgd, addr);
}

static inline pmd_t * __init early_ioremap_pmd(unsigned long addr)
{
	pud_t *pud = early_ioremap_pud(addr);

	BUG_ON(pud_none(*pud) || pud_bad(*pud));

	return pmd_offset(pud, addr);
}

static inline pte_t * __init early_ioremap_pte(unsigned long addr)
{
	pmd_t *pmd = early_ioremap_pmd(addr);

	BUG_ON(pmd_none(*pmd) || pmd_bad(*pmd));

	return pte_offset_kernel(pmd, addr);
}

void __init early_ioremap_init(void)
{
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd;
	unsigned long addr = fix_to_virt(FIX_BTMAP_BEGIN);

	pgd = pgd_offset_k(addr);
	pgd_populate(&init_mm, pgd, bm_pud);
	pud = pud_offset(pgd, addr);
	pud_populate(&init_mm, pud, bm_pmd);
	pmd = pmd_offset(pud, addr);
	pmd_populate_kernel(&init_mm, pmd, bm_pte);

	/*
	 * The boot-ioremap range spans multiple pmds, for which
	 * we are not prepared:
	 */
	BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
		     != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));

	if (pmd != early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))) {
		WARN_ON(1);
		pr_warn("pmd %p != %p\n",
			pmd, early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END)));
		pr_warn("fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
			fix_to_virt(FIX_BTMAP_BEGIN));
		pr_warn("fix_to_virt(FIX_BTMAP_END):   %08lx\n",
			fix_to_virt(FIX_BTMAP_END));

		pr_warn("FIX_BTMAP_END:       %d\n", FIX_BTMAP_END);
		pr_warn("FIX_BTMAP_BEGIN:     %d\n",
			FIX_BTMAP_BEGIN);
	}

	early_ioremap_setup();
}

void __init __early_set_fixmap(enum fixed_addresses idx,
			       phys_addr_t phys, pgprot_t flags)
{
	unsigned long addr = __fix_to_virt(idx);
	pte_t *pte;

	if (idx >= __end_of_fixed_addresses) {
		BUG();
		return;
	}

	pte = early_ioremap_pte(addr);

	if (pgprot_val(flags))
		set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
	else {
		pte_clear(&init_mm, addr, pte);
		flush_tlb_kernel_range(addr, addr+PAGE_SIZE);
	}
}