Merge branch 'akpm' (Andrew's patchbomb)
[linux-3.10.git] / arch / sh / mm / mmap.c
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  */
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
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 <= vma->vm_start))
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
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 <= vma->vm_start))
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  */
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
160 int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
161 {
162         return 1;
163 }