1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * ARC700 mmap
 4 *
 5 * (started from arm version - for VIPT alias handling)
 6 *
 7 * Copyright (C) 2013 Synopsys, Inc. (www.synopsys.com)
 8 */
 9
10#include <linux/fs.h>
11#include <linux/mm.h>
12#include <linux/mman.h>
13#include <linux/sched/mm.h>
14
15#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 &&
65		    (!vma || addr + len <= vm_start_gap(vma)))
66			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}