blob: 722d26b943072572133101c6379b1c4c73d5561b [file] [log] [blame]
Thomas Gleixnerd2912cb2019-06-04 10:11:33 +02001// SPDX-License-Identifier: GPL-2.0-only
Vineet Gupta5bba49f2013-05-09 19:20:43 +05302/*
3 * ARC700 mmap
4 *
5 * (started from arm version - for VIPT alias handling)
6 *
7 * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
Vineet Gupta5bba49f2013-05-09 19:20:43 +05308 */
9
10#include <linux/fs.h>
11#include <linux/mm.h>
12#include <linux/mman.h>
Ingo Molnar01042602017-02-08 18:51:31 +010013#include <linux/sched/mm.h>
14
Vineet Gupta5bba49f2013-05-09 19:20:43 +053015#include <asm/cacheflush.h>
16
17#define COLOUR_ALIGN(addr, pgoff) \
18 ((((addr) + SHMLBA - 1) & ~(SHMLBA - 1)) + \
19 (((pgoff) << PAGE_SHIFT) & (SHMLBA - 1)))
20
21/*
22 * Ensure that shared mappings are correctly aligned to
23 * avoid aliasing issues with VIPT caches.
24 * We need to ensure that
25 * a specific page of an object is always mapped at a multiple of
26 * SHMLBA bytes.
27 */
28unsigned long
29arch_get_unmapped_area(struct file *filp, unsigned long addr,
30 unsigned long len, unsigned long pgoff, unsigned long flags)
31{
32 struct mm_struct *mm = current->mm;
33 struct vm_area_struct *vma;
34 int do_align = 0;
35 int aliasing = cache_is_vipt_aliasing();
36 struct vm_unmapped_area_info info;
37
38 /*
39 * We only need to do colour alignment if D cache aliases.
40 */
41 if (aliasing)
42 do_align = filp || (flags & MAP_SHARED);
43
44 /*
45 * We enforce the MAP_FIXED case.
46 */
47 if (flags & MAP_FIXED) {
48 if (aliasing && flags & MAP_SHARED &&
49 (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
50 return -EINVAL;
51 return addr;
52 }
53
54 if (len > TASK_SIZE)
55 return -ENOMEM;
56
57 if (addr) {
58 if (do_align)
59 addr = COLOUR_ALIGN(addr, pgoff);
60 else
61 addr = PAGE_ALIGN(addr);
62
63 vma = find_vma(mm, addr);
64 if (TASK_SIZE - len >= addr &&
Hugh Dickins1be71072017-06-19 04:03:24 -070065 (!vma || addr + len <= vm_start_gap(vma)))
Vineet Gupta5bba49f2013-05-09 19:20:43 +053066 return addr;
67 }
68
69 info.flags = 0;
70 info.length = len;
71 info.low_limit = mm->mmap_base;
72 info.high_limit = TASK_SIZE;
73 info.align_mask = do_align ? (PAGE_MASK & (SHMLBA - 1)) : 0;
74 info.align_offset = pgoff << PAGE_SHIFT;
75 return vm_unmapped_area(&info);
76}