1 /*
2 * arch/sh/mm/mmap.c
3 *
4 * Copyright (C) 2008 - 2009 Paul Mundt
5 *
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License. See the file "COPYING" in the main directory of this archive
8 * for more details.
9 */
10 #include <linux/io.h>
11 #include <linux/mm.h>
12 #include <linux/mman.h>
13 #include <linux/module.h>
14 #include <asm/page.h>
15 #include <asm/processor.h>
16
17 unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */
18 EXPORT_SYMBOL(shm_align_mask);
19
20 #ifdef CONFIG_MMU
21 /*
22 * To avoid cache aliases, we map the shared page with same color.
23 */
COLOUR_ALIGN(unsigned long addr,unsigned long pgoff)24 static inline unsigned long COLOUR_ALIGN(unsigned long addr,
25 unsigned long pgoff)
26 {
27 unsigned long base = (addr + shm_align_mask) & ~shm_align_mask;
28 unsigned long off = (pgoff << PAGE_SHIFT) & shm_align_mask;
29
30 return base + off;
31 }
32
arch_get_unmapped_area(struct file * filp,unsigned long addr,unsigned long len,unsigned long pgoff,unsigned long flags)33 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
34 unsigned long len, unsigned long pgoff, unsigned long flags)
35 {
36 struct mm_struct *mm = current->mm;
37 struct vm_area_struct *vma;
38 int do_colour_align;
39 struct vm_unmapped_area_info info;
40
41 if (flags & MAP_FIXED) {
42 /* We do not accept a shared mapping if it would violate
43 * cache aliasing constraints.
44 */
45 if ((flags & MAP_SHARED) &&
46 ((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask))
47 return -EINVAL;
48 return addr;
49 }
50
51 if (unlikely(len > TASK_SIZE))
52 return -ENOMEM;
53
54 do_colour_align = 0;
55 if (filp || (flags & MAP_SHARED))
56 do_colour_align = 1;
57
58 if (addr) {
59 if (do_colour_align)
60 addr = COLOUR_ALIGN(addr, pgoff);
61 else
62 addr = PAGE_ALIGN(addr);
63
64 vma = find_vma(mm, addr);
65 if (TASK_SIZE - len >= addr &&
66 (!vma || addr + len <= vm_start_gap(vma)))
67 return addr;
68 }
69
70 info.flags = 0;
71 info.length = len;
72 info.low_limit = TASK_UNMAPPED_BASE;
73 info.high_limit = TASK_SIZE;
74 info.align_mask = do_colour_align ? (PAGE_MASK & shm_align_mask) : 0;
75 info.align_offset = pgoff << PAGE_SHIFT;
76 return vm_unmapped_area(&info);
77 }
78
79 unsigned long
arch_get_unmapped_area_topdown(struct file * filp,const unsigned long addr0,const unsigned long len,const unsigned long pgoff,const unsigned long flags)80 arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
81 const unsigned long len, const unsigned long pgoff,
82 const unsigned long flags)
83 {
84 struct vm_area_struct *vma;
85 struct mm_struct *mm = current->mm;
86 unsigned long addr = addr0;
87 int do_colour_align;
88 struct vm_unmapped_area_info info;
89
90 if (flags & MAP_FIXED) {
91 /* We do not accept a shared mapping if it would violate
92 * cache aliasing constraints.
93 */
94 if ((flags & MAP_SHARED) &&
95 ((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask))
96 return -EINVAL;
97 return addr;
98 }
99
100 if (unlikely(len > TASK_SIZE))
101 return -ENOMEM;
102
103 do_colour_align = 0;
104 if (filp || (flags & MAP_SHARED))
105 do_colour_align = 1;
106
107 /* requesting a specific address */
108 if (addr) {
109 if (do_colour_align)
110 addr = COLOUR_ALIGN(addr, pgoff);
111 else
112 addr = PAGE_ALIGN(addr);
113
114 vma = find_vma(mm, addr);
115 if (TASK_SIZE - len >= addr &&
116 (!vma || addr + len <= vm_start_gap(vma)))
117 return addr;
118 }
119
120 info.flags = VM_UNMAPPED_AREA_TOPDOWN;
121 info.length = len;
122 info.low_limit = PAGE_SIZE;
123 info.high_limit = mm->mmap_base;
124 info.align_mask = do_colour_align ? (PAGE_MASK & shm_align_mask) : 0;
125 info.align_offset = pgoff << PAGE_SHIFT;
126 addr = vm_unmapped_area(&info);
127
128 /*
129 * A failed mmap() very likely causes application failure,
130 * so fall back to the bottom-up function here. This scenario
131 * can happen with large stack limits and large mmap()
132 * allocations.
133 */
134 if (addr & ~PAGE_MASK) {
135 VM_BUG_ON(addr != -ENOMEM);
136 info.flags = 0;
137 info.low_limit = TASK_UNMAPPED_BASE;
138 info.high_limit = TASK_SIZE;
139 addr = vm_unmapped_area(&info);
140 }
141
142 return addr;
143 }
144 #endif /* CONFIG_MMU */
145
146 /*
147 * You really shouldn't be using read() or write() on /dev/mem. This
148 * might go away in the future.
149 */
valid_phys_addr_range(phys_addr_t addr,size_t count)150 int valid_phys_addr_range(phys_addr_t addr, size_t count)
151 {
152 if (addr < __MEMORY_START)
153 return 0;
154 if (addr + count > __pa(high_memory))
155 return 0;
156
157 return 1;
158 }
159
valid_mmap_phys_addr_range(unsigned long pfn,size_t size)160 int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
161 {
162 return 1;
163 }
164