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 */
28 unsigned long
arch_get_unmapped_area(struct file * filp,unsigned long addr,unsigned long len,unsigned long pgoff,unsigned long flags)29 arch_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 }
77
78 static const pgprot_t protection_map[16] = {
79 [VM_NONE] = PAGE_U_NONE,
80 [VM_READ] = PAGE_U_R,
81 [VM_WRITE] = PAGE_U_R,
82 [VM_WRITE | VM_READ] = PAGE_U_R,
83 [VM_EXEC] = PAGE_U_X_R,
84 [VM_EXEC | VM_READ] = PAGE_U_X_R,
85 [VM_EXEC | VM_WRITE] = PAGE_U_X_R,
86 [VM_EXEC | VM_WRITE | VM_READ] = PAGE_U_X_R,
87 [VM_SHARED] = PAGE_U_NONE,
88 [VM_SHARED | VM_READ] = PAGE_U_R,
89 [VM_SHARED | VM_WRITE] = PAGE_U_W_R,
90 [VM_SHARED | VM_WRITE | VM_READ] = PAGE_U_W_R,
91 [VM_SHARED | VM_EXEC] = PAGE_U_X_R,
92 [VM_SHARED | VM_EXEC | VM_READ] = PAGE_U_X_R,
93 [VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_U_X_W_R,
94 [VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_U_X_W_R
95 };
96 DECLARE_VM_GET_PAGE_PROT
97