Blame view

kernel/linux-rt-4.4.41/arch/arc/mm/ioremap.c 2.29 KB
5113f6f70   김현기   kernel add
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
  /*
   * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
   *
   * 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.
   */
  
  #include <linux/vmalloc.h>
  #include <linux/init.h>
  #include <linux/module.h>
  #include <linux/io.h>
  #include <linux/mm.h>
  #include <linux/slab.h>
  #include <linux/cache.h>
  
  void __iomem *ioremap(unsigned long paddr, unsigned long size)
  {
  	unsigned long end;
  
  	/* Don't allow wraparound or zero size */
  	end = paddr + size - 1;
  	if (!size || (end < paddr))
  		return NULL;
  
  	/* If the region is h/w uncached, avoid MMU mappings */
  	if (paddr >= ARC_UNCACHED_ADDR_SPACE)
  		return (void __iomem *)paddr;
  
  	return ioremap_prot(paddr, size, PAGE_KERNEL_NO_CACHE);
  }
  EXPORT_SYMBOL(ioremap);
  
  /*
   * ioremap with access flags
   * Cache semantics wise it is same as ioremap - "forced" uncached.
   * However unline vanilla ioremap which bypasses ARC MMU for addresses in
   * ARC hardware uncached region, this one still goes thru the MMU as caller
   * might need finer access control (R/W/X)
   */
  void __iomem *ioremap_prot(phys_addr_t paddr, unsigned long size,
  			   unsigned long flags)
  {
  	void __iomem *vaddr;
  	struct vm_struct *area;
  	unsigned long off, end;
  	pgprot_t prot = __pgprot(flags);
  
  	/* Don't allow wraparound, zero size */
  	end = paddr + size - 1;
  	if ((!size) || (end < paddr))
  		return NULL;
  
  	/* An early platform driver might end up here */
  	if (!slab_is_available())
  		return NULL;
  
  	/* force uncached */
  	prot = pgprot_noncached(prot);
  
  	/* Mappings have to be page-aligned */
  	off = paddr & ~PAGE_MASK;
  	paddr &= PAGE_MASK;
  	size = PAGE_ALIGN(end + 1) - paddr;
  
  	/*
  	 * Ok, go for it..
  	 */
  	area = get_vm_area(size, VM_IOREMAP);
  	if (!area)
  		return NULL;
  	area->phys_addr = paddr;
  	vaddr = (void __iomem *)area->addr;
  	if (ioremap_page_range((unsigned long)vaddr,
  			       (unsigned long)vaddr + size, paddr, prot)) {
  		vunmap((void __force *)vaddr);
  		return NULL;
  	}
  	return (void __iomem *)(off + (char __iomem *)vaddr);
  }
  EXPORT_SYMBOL(ioremap_prot);
  
  
  void iounmap(const void __iomem *addr)
  {
  	if (addr >= (void __force __iomem *)ARC_UNCACHED_ADDR_SPACE)
  		return;
  
  	vfree((void *)(PAGE_MASK & (unsigned long __force)addr));
  }
  EXPORT_SYMBOL(iounmap);