blob: a136a435fdaad0555a32ab9b4addcd57af7a7084 (
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
|
/*
* Re-map IO memory to kernel address space so that we can access it.
* Needed for memory-mapped I/O devices mapped outside our normal DRAM
* window (that is, all memory-mapped I/O devices).
*
* Copyright (C) 1995,1996 Linus Torvalds
*
* Meta port based on CRIS-port by Axis Communications AB
*/
#include <linux/vmalloc.h>
#include <linux/io.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <asm/pgtable.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, size_t size,
unsigned long flags)
{
unsigned long addr;
struct vm_struct *area;
unsigned long offset, last_addr;
pgprot_t prot;
/* Don't allow wraparound or zero size */
last_addr = phys_addr + size - 1;
if (!size || last_addr < phys_addr)
return NULL;
/* Custom region addresses are accessible and uncached by default. */
if (phys_addr >= LINSYSCUSTOM_BASE &&
phys_addr < (LINSYSCUSTOM_BASE + LINSYSCUSTOM_LIMIT))
return (__force void __iomem *) phys_addr;
/*
* Mappings have to be page-aligned
*/
offset = phys_addr & ~PAGE_MASK;
phys_addr &= PAGE_MASK;
size = PAGE_ALIGN(last_addr+1) - phys_addr;
prot = __pgprot(_PAGE_PRESENT | _PAGE_WRITE | _PAGE_DIRTY |
_PAGE_ACCESSED | _PAGE_KERNEL | _PAGE_CACHE_WIN0 |
flags);
/*
* Ok, go for it..
*/
area = get_vm_area(size, VM_IOREMAP);
if (!area)
return NULL;
area->phys_addr = phys_addr;
addr = (unsigned long) area->addr;
if (ioremap_page_range(addr, addr + size, phys_addr, prot)) {
vunmap((void *) addr);
return NULL;
}
return (__force void __iomem *) (offset + (char *)addr);
}
EXPORT_SYMBOL(__ioremap);
void __iounmap(void __iomem *addr)
{
struct vm_struct *p;
if ((__force unsigned long)addr >= LINSYSCUSTOM_BASE &&
(__force unsigned long)addr < (LINSYSCUSTOM_BASE +
LINSYSCUSTOM_LIMIT))
return;
p = remove_vm_area((void *)(PAGE_MASK & (unsigned long __force)addr));
if (unlikely(!p)) {
pr_err("iounmap: bad address %p\n", addr);
return;
}
kfree(p);
}
EXPORT_SYMBOL(__iounmap);
|