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/*
18 * Ensure that shared mappings are correctly aligned to
19 * avoid aliasing issues with VIPT caches.
20 * We need to ensure that
21 * a specific page of an object is always mapped at a multiple of
22 * SHMLBA bytes.
23 */
24unsigned long
25arch_get_unmapped_area(struct file *filp, unsigned long addr,
26 unsigned long len, unsigned long pgoff,
27 unsigned long flags, vm_flags_t vm_flags)
28{
29 struct mm_struct *mm = current->mm;
30 struct vm_area_struct *vma;
31 struct vm_unmapped_area_info info = {};
32
33 /*
34 * We enforce the MAP_FIXED case.
35 */
36 if (flags & MAP_FIXED) {
37 if (flags & MAP_SHARED &&
38 (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
39 return -EINVAL;
40 return addr;
41 }
42
43 if (len > TASK_SIZE)
44 return -ENOMEM;
45
46 if (addr) {
47 addr = PAGE_ALIGN(addr);
48
49 vma = find_vma(mm, addr);
50 if (TASK_SIZE - len >= addr &&
51 (!vma || addr + len <= vm_start_gap(vma)))
52 return addr;
53 }
54
55 info.length = len;
56 info.low_limit = mm->mmap_base;
57 info.high_limit = TASK_SIZE;
58 info.align_offset = pgoff << PAGE_SHIFT;
59 return vm_unmapped_area(info: &info);
60}
61
62static const pgprot_t protection_map[16] = {
63 [VM_NONE] = PAGE_U_NONE,
64 [VM_READ] = PAGE_U_R,
65 [VM_WRITE] = PAGE_U_R,
66 [VM_WRITE | VM_READ] = PAGE_U_R,
67 [VM_EXEC] = PAGE_U_X_R,
68 [VM_EXEC | VM_READ] = PAGE_U_X_R,
69 [VM_EXEC | VM_WRITE] = PAGE_U_X_R,
70 [VM_EXEC | VM_WRITE | VM_READ] = PAGE_U_X_R,
71 [VM_SHARED] = PAGE_U_NONE,
72 [VM_SHARED | VM_READ] = PAGE_U_R,
73 [VM_SHARED | VM_WRITE] = PAGE_U_W_R,
74 [VM_SHARED | VM_WRITE | VM_READ] = PAGE_U_W_R,
75 [VM_SHARED | VM_EXEC] = PAGE_U_X_R,
76 [VM_SHARED | VM_EXEC | VM_READ] = PAGE_U_X_R,
77 [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_U_X_W_R,
78 [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_U_X_W_R
79};
80DECLARE_VM_GET_PAGE_PROT
81

source code of linux/arch/arc/mm/mmap.c