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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> | |
01042607 IM |
16 | #include <linux/sched/mm.h> |
17 | ||
5bba49f5 VG |
18 | #include <asm/cacheflush.h> |
19 | ||
20 | #define COLOUR_ALIGN(addr, pgoff) \ | |
21 | ((((addr) + SHMLBA - 1) & ~(SHMLBA - 1)) + \ | |
22 | (((pgoff) << PAGE_SHIFT) & (SHMLBA - 1))) | |
23 | ||
24 | /* | |
25 | * Ensure that shared mappings are correctly aligned to | |
26 | * avoid aliasing issues with VIPT caches. | |
27 | * We need to ensure that | |
28 | * a specific page of an object is always mapped at a multiple of | |
29 | * SHMLBA bytes. | |
30 | */ | |
31 | unsigned long | |
32 | arch_get_unmapped_area(struct file *filp, unsigned long addr, | |
33 | unsigned long len, unsigned long pgoff, unsigned long flags) | |
34 | { | |
35 | struct mm_struct *mm = current->mm; | |
36 | struct vm_area_struct *vma; | |
37 | int do_align = 0; | |
38 | int aliasing = cache_is_vipt_aliasing(); | |
39 | struct vm_unmapped_area_info info; | |
40 | ||
41 | /* | |
42 | * We only need to do colour alignment if D cache aliases. | |
43 | */ | |
44 | if (aliasing) | |
45 | do_align = filp || (flags & MAP_SHARED); | |
46 | ||
47 | /* | |
48 | * We enforce the MAP_FIXED case. | |
49 | */ | |
50 | if (flags & MAP_FIXED) { | |
51 | if (aliasing && flags & MAP_SHARED && | |
52 | (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1)) | |
53 | return -EINVAL; | |
54 | return addr; | |
55 | } | |
56 | ||
57 | if (len > TASK_SIZE) | |
58 | return -ENOMEM; | |
59 | ||
60 | if (addr) { | |
61 | if (do_align) | |
62 | addr = COLOUR_ALIGN(addr, pgoff); | |
63 | else | |
64 | addr = PAGE_ALIGN(addr); | |
65 | ||
66 | vma = find_vma(mm, addr); | |
67 | if (TASK_SIZE - len >= addr && | |
68 | (!vma || addr + len <= vma->vm_start)) | |
69 | return addr; | |
70 | } | |
71 | ||
72 | info.flags = 0; | |
73 | info.length = len; | |
74 | info.low_limit = mm->mmap_base; | |
75 | info.high_limit = TASK_SIZE; | |
76 | info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 0; | |
77 | info.align_offset = pgoff << PAGE_SHIFT; | |
78 | return vm_unmapped_area(&info); | |
79 | } |