Commit | Line | Data |
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5bba49f5 VG |
1 | /* |
2 | * ARC700 mmap | |
3 | * | |
4 | * (started from arm version - for VIPT alias handling) | |
5 | * | |
6 | * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com) | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License version 2 as | |
10 | * published by the Free Software Foundation. | |
11 | */ | |
12 | ||
13 | #include <linux/fs.h> | |
14 | #include <linux/mm.h> | |
15 | #include <linux/mman.h> | |
16 | #include <linux/sched.h> | |
17 | #include <asm/cacheflush.h> | |
18 | ||
19 | #define COLOUR_ALIGN(addr, pgoff) \ | |
20 | ((((addr) + SHMLBA - 1) & ~(SHMLBA - 1)) + \ | |
21 | (((pgoff) << PAGE_SHIFT) & (SHMLBA - 1))) | |
22 | ||
23 | /* | |
24 | * Ensure that shared mappings are correctly aligned to | |
25 | * avoid aliasing issues with VIPT caches. | |
26 | * We need to ensure that | |
27 | * a specific page of an object is always mapped at a multiple of | |
28 | * SHMLBA bytes. | |
29 | */ | |
30 | unsigned long | |
31 | arch_get_unmapped_area(struct file *filp, unsigned long addr, | |
32 | unsigned long len, unsigned long pgoff, unsigned long flags) | |
33 | { | |
34 | struct mm_struct *mm = current->mm; | |
35 | struct vm_area_struct *vma; | |
36 | int do_align = 0; | |
37 | int aliasing = cache_is_vipt_aliasing(); | |
38 | struct vm_unmapped_area_info info; | |
39 | ||
40 | /* | |
41 | * We only need to do colour alignment if D cache aliases. | |
42 | */ | |
43 | if (aliasing) | |
44 | do_align = filp || (flags & MAP_SHARED); | |
45 | ||
46 | /* | |
47 | * We enforce the MAP_FIXED case. | |
48 | */ | |
49 | if (flags & MAP_FIXED) { | |
50 | if (aliasing && flags & MAP_SHARED && | |
51 | (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)) | |
52 | return -EINVAL; | |
53 | return addr; | |
54 | } | |
55 | ||
56 | if (len > TASK_SIZE) | |
57 | return -ENOMEM; | |
58 | ||
59 | if (addr) { | |
60 | if (do_align) | |
61 | addr = COLOUR_ALIGN(addr, pgoff); | |
62 | else | |
63 | addr = PAGE_ALIGN(addr); | |
64 | ||
65 | vma = find_vma(mm, addr); | |
66 | if (TASK_SIZE - len >= addr && | |
67 | (!vma || addr + len <= vma->vm_start)) | |
68 | return addr; | |
69 | } | |
70 | ||
71 | info.flags = 0; | |
72 | info.length = len; | |
73 | info.low_limit = mm->mmap_base; | |
74 | info.high_limit = TASK_SIZE; | |
75 | info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 0; | |
76 | info.align_offset = pgoff << PAGE_SHIFT; | |
77 | return vm_unmapped_area(&info); | |
78 | } |