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/Ethereal-msm8939-beta9/arch/metag/mm/ioremap.c

https://bitbucket.org/MilosStamenkovic95/etherealos
C | 89 lines | 52 code | 11 blank | 26 comment | 7 complexity | c2e4aab6076c9fea1723f5ec2f88f77a MD5 | raw file
 1/*
 2 * Re-map IO memory to kernel address space so that we can access it.
 3 * Needed for memory-mapped I/O devices mapped outside our normal DRAM
 4 * window (that is, all memory-mapped I/O devices).
 5 *
 6 * Copyright (C) 1995,1996 Linus Torvalds
 7 *
 8 * Meta port based on CRIS-port by Axis Communications AB
 9 */
10
11#include <linux/vmalloc.h>
12#include <linux/io.h>
13#include <linux/export.h>
14#include <linux/slab.h>
15#include <linux/mm.h>
16
17#include <asm/pgtable.h>
18
19/*
20 * Remap an arbitrary physical address space into the kernel virtual
21 * address space. Needed when the kernel wants to access high addresses
22 * directly.
23 *
24 * NOTE! We need to allow non-page-aligned mappings too: we will obviously
25 * have to convert them into an offset in a page-aligned mapping, but the
26 * caller shouldn't need to know that small detail.
27 */
28void __iomem *__ioremap(unsigned long phys_addr, size_t size,
29			unsigned long flags)
30{
31	unsigned long addr;
32	struct vm_struct *area;
33	unsigned long offset, last_addr;
34	pgprot_t prot;
35
36	/* Don't allow wraparound or zero size */
37	last_addr = phys_addr + size - 1;
38	if (!size || last_addr < phys_addr)
39		return NULL;
40
41	/* Custom region addresses are accessible and uncached by default. */
42	if (phys_addr >= LINSYSCUSTOM_BASE &&
43	    phys_addr < (LINSYSCUSTOM_BASE + LINSYSCUSTOM_LIMIT))
44		return (__force void __iomem *) phys_addr;
45
46	/*
47	 * Mappings have to be page-aligned
48	 */
49	offset = phys_addr & ~PAGE_MASK;
50	phys_addr &= PAGE_MASK;
51	size = PAGE_ALIGN(last_addr+1) - phys_addr;
52	prot = __pgprot(_PAGE_PRESENT | _PAGE_WRITE | _PAGE_DIRTY |
53			_PAGE_ACCESSED | _PAGE_KERNEL | _PAGE_CACHE_WIN0 |
54			flags);
55
56	/*
57	 * Ok, go for it..
58	 */
59	area = get_vm_area(size, VM_IOREMAP);
60	if (!area)
61		return NULL;
62	area->phys_addr = phys_addr;
63	addr = (unsigned long) area->addr;
64	if (ioremap_page_range(addr, addr + size, phys_addr, prot)) {
65		vunmap((void *) addr);
66		return NULL;
67	}
68	return (__force void __iomem *) (offset + (char *)addr);
69}
70EXPORT_SYMBOL(__ioremap);
71
72void __iounmap(void __iomem *addr)
73{
74	struct vm_struct *p;
75
76	if ((__force unsigned long)addr >= LINSYSCUSTOM_BASE &&
77	    (__force unsigned long)addr < (LINSYSCUSTOM_BASE +
78					   LINSYSCUSTOM_LIMIT))
79		return;
80
81	p = remove_vm_area((void *)(PAGE_MASK & (unsigned long __force)addr));
82	if (unlikely(!p)) {
83		pr_err("iounmap: bad address %p\n", addr);
84		return;
85	}
86
87	kfree(p);
88}
89EXPORT_SYMBOL(__iounmap);