summaryrefslogtreecommitdiff
path: root/arch/sh/mm/ioremap.c
blob: 21342581144dee0643237a833084e6c01e568c29 (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
/*
 * arch/sh/mm/ioremap.c
 *
 * (C) Copyright 1995 1996 Linus Torvalds
 * (C) Copyright 2005 - 2010  Paul Mundt
 *
 * 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
 *
 * This file is subject to the terms and conditions of the GNU General
 * Public License. See the file "COPYING" in the main directory of this
 * archive for more details.
 */
#include <linux/vmalloc.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/pci.h>
#include <linux/io.h>
#include <asm/io_trapped.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/addrspace.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
#include <asm/mmu.h>
#include "ioremap.h"

/*
 * On 32-bit SH, we traditionally have the whole physical address space mapped
 * at all times (as MIPS does), so "ioremap()" and "iounmap()" do not need to do
 * anything but place the address in the proper segment.  This is true for P1
 * and P2 addresses, as well as some P3 ones.  However, most of the P3 addresses
 * and newer cores using extended addressing need to map through page tables, so
 * the ioremap() implementation becomes a bit more complicated.
 */
#ifdef CONFIG_29BIT
static void __iomem *
__ioremap_29bit(phys_addr_t offset, unsigned long size, pgprot_t prot)
{
	phys_addr_t last_addr = offset + size - 1;

	/*
	 * For P1 and P2 space this is trivial, as everything is already
	 * mapped. Uncached access for P1 addresses are done through P2.
	 * In the P3 case or for addresses outside of the 29-bit space,
	 * mapping must be done by the PMB or by using page tables.
	 */
	if (likely(PXSEG(offset) < P3SEG && PXSEG(last_addr) < P3SEG)) {
		u64 flags = pgprot_val(prot);

		/*
		 * Anything using the legacy PTEA space attributes needs
		 * to be kicked down to page table mappings.
		 */
		if (unlikely(flags & _PAGE_PCC_MASK))
			return NULL;
		if (unlikely(flags & _PAGE_CACHABLE))
			return (void __iomem *)P1SEGADDR(offset);

		return (void __iomem *)P2SEGADDR(offset);
	}

	/* P4 above the store queues are always mapped. */
	if (unlikely(offset >= P3_ADDR_MAX))
		return (void __iomem *)P4SEGADDR(offset);

	return NULL;
}
#else
#define __ioremap_29bit(offset, size, prot)		NULL
#endif /* CONFIG_29BIT */

/*
 * Remap an arbitrary physical address space into the kernel virtual
 * address space. Needed when the kernel wants to access high addresses
 * directly.
 *
 * NOTE! We need to allow non-page-aligned mappings too: we will obviously
 * have to convert them into an offset in a page-aligned mapping, but the
 * caller shouldn't need to know that small detail.
 */
void __iomem * __ref
__ioremap_caller(phys_addr_t phys_addr, unsigned long size,
		 pgprot_t pgprot, void *caller)
{
	struct vm_struct *area;
	unsigned long offset, last_addr, addr, orig_addr;
	void __iomem *mapped;

	mapped = __ioremap_trapped(phys_addr, size);
	if (mapped)
		return mapped;

	mapped = __ioremap_29bit(phys_addr, size, pgprot);
	if (mapped)
		return mapped;

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

	/*
	 * If we can't yet use the regular approach, go the fixmap route.
	 */
	if (!mem_init_done)
		return ioremap_fixed(phys_addr, size, pgprot);

	/*
	 * First try to remap through the PMB.
	 * PMB entries are all pre-faulted.
	 */
	mapped = pmb_remap_caller(phys_addr, size, pgprot, caller);
	if (mapped && !IS_ERR(mapped))
		return mapped;

	/*
	 * Mappings have to be page-aligned
	 */
	offset = phys_addr & ~PAGE_MASK;
	phys_addr &= PAGE_MASK;
	size = PAGE_ALIGN(last_addr+1) - phys_addr;

	/*
	 * Ok, go for it..
	 */
	area = get_vm_area_caller(size, VM_IOREMAP, caller);
	if (!area)
		return NULL;
	area->phys_addr = phys_addr;
	orig_addr = addr = (unsigned long)area->addr;

	if (ioremap_page_range(addr, addr + size, phys_addr, pgprot)) {
		vunmap((void *)orig_addr);
		return NULL;
	}

	return (void __iomem *)(offset + (char *)orig_addr);
}
EXPORT_SYMBOL(__ioremap_caller);

/*
 * Simple checks for non-translatable mappings.
 */
static inline int iomapping_nontranslatable(unsigned long offset)
{
#ifdef CONFIG_29BIT
	/*
	 * In 29-bit mode this includes the fixed P1/P2 areas, as well as
	 * parts of P3.
	 */
	if (PXSEG(offset) < P3SEG || offset >= P3_ADDR_MAX)
		return 1;
#endif

	return 0;
}

void iounmap(void __iomem *addr)
{
	unsigned long vaddr = (unsigned long __force)addr;
	struct vm_struct *p;

	/*
	 * Nothing to do if there is no translatable mapping.
	 */
	if (iomapping_nontranslatable(vaddr))
		return;

	/*
	 * There's no VMA if it's from an early fixed mapping.
	 */
	if (iounmap_fixed(addr) == 0)
		return;

	/*
	 * If the PMB handled it, there's nothing else to do.
	 */
	if (pmb_unmap(addr) == 0)
		return;

	p = remove_vm_area((void *)(vaddr & PAGE_MASK));
	if (!p) {
		printk(KERN_ERR "%s: bad address %p\n", __func__, addr);
		return;
	}

	kfree(p);
}
EXPORT_SYMBOL(iounmap);