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
|
/*
* arch/sh/mm/ioremap.c
*
* 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
* (C) Copyright 2005, 2006 Paul Mundt
*
* 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/mm.h>
#include <linux/pci.h>
#include <linux/io.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <asm/addrspace.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
/*
* 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 *__ioremap(unsigned long phys_addr, unsigned long size,
unsigned long flags)
{
struct vm_struct * area;
unsigned long offset, last_addr, addr, orig_addr;
pgprot_t pgprot;
/* Don't allow wraparound or zero size */
last_addr = phys_addr + size - 1;
if (!size || last_addr < phys_addr)
return NULL;
/*
* If we're on an SH7751 or SH7780 PCI controller, PCI memory is
* mapped at the end of the address space (typically 0xfd000000)
* in a non-translatable area, so mapping through page tables for
* this area is not only pointless, but also fundamentally
* broken. Just return the physical address instead.
*
* For boards that map a small PCI memory aperture somewhere in
* P1/P2 space, ioremap() will already do the right thing,
* and we'll never get this far.
*/
if (is_pci_memaddr(phys_addr) && is_pci_memaddr(last_addr))
return (void __iomem *)phys_addr;
/*
* Don't allow anybody to remap normal RAM that we're using..
*/
if (phys_addr < virt_to_phys(high_memory))
return NULL;
/*
* 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(size, VM_IOREMAP);
if (!area)
return NULL;
area->phys_addr = phys_addr;
orig_addr = addr = (unsigned long)area->addr;
#ifdef CONFIG_32BIT
/*
* First try to remap through the PMB once a valid VMA has been
* established. Smaller allocations (or the rest of the size
* remaining after a PMB mapping due to the size not being
* perfectly aligned on a PMB size boundary) are then mapped
* through the UTLB using conventional page tables.
*
* PMB entries are all pre-faulted.
*/
if (unlikely(size >= 0x1000000)) {
unsigned long mapped = pmb_remap(addr, phys_addr, size, flags);
if (likely(mapped)) {
addr += mapped;
phys_addr += mapped;
size -= mapped;
}
}
#endif
pgprot = __pgprot(pgprot_val(PAGE_KERNEL_NOCACHE) | flags);
if (likely(size))
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);
void __iounmap(void __iomem *addr)
{
unsigned long vaddr = (unsigned long __force)addr;
struct vm_struct *p;
if (PXSEG(vaddr) < P3SEG || is_pci_memaddr(vaddr))
return;
#ifdef CONFIG_32BIT
/*
* Purge any PMB entries that may have been established for this
* mapping, then proceed with conventional VMA teardown.
*
* XXX: Note that due to the way that remove_vm_area() does
* matching of the resultant VMA, we aren't able to fast-forward
* the address past the PMB space until the end of the VMA where
* the page tables reside. As such, unmap_vm_area() will be
* forced to linearly scan over the area until it finds the page
* tables where PTEs that need to be unmapped actually reside,
* which is far from optimal. Perhaps we need to use a separate
* VMA for the PMB mappings?
* -- PFM.
*/
pmb_unmap(vaddr);
#endif
p = remove_vm_area((void *)(vaddr & PAGE_MASK));
if (!p) {
printk(KERN_ERR "%s: bad address %p\n", __FUNCTION__, addr);
return;
}
kfree(p);
}
EXPORT_SYMBOL(__iounmap);
|
