1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __ASM_MMAN_H__
3#define __ASM_MMAN_H__
4
5#include <linux/compiler.h>
6#include <linux/types.h>
7#include <uapi/asm/mman.h>
8
9static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot,
10	unsigned long pkey __always_unused)
11{
12	unsigned long ret = 0;
13
14	if (system_supports_bti() && (prot & PROT_BTI))
15		ret |= VM_ARM64_BTI;
16
17	if (system_supports_mte() && (prot & PROT_MTE))
18		ret |= VM_MTE;
19
20	return ret;
21}
22#define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey)
23
24static inline unsigned long arch_calc_vm_flag_bits(unsigned long flags)
25{
26	/*
27	 * Only allow MTE on anonymous mappings as these are guaranteed to be
28	 * backed by tags-capable memory. The vm_flags may be overridden by a
29	 * filesystem supporting MTE (RAM-based).
30	 */
31	if (system_supports_mte() && (flags & MAP_ANONYMOUS))
32		return VM_MTE_ALLOWED;
33
34	return 0;
35}
36#define arch_calc_vm_flag_bits(flags) arch_calc_vm_flag_bits(flags)
37
38static inline bool arch_validate_prot(unsigned long prot,
39	unsigned long addr __always_unused)
40{
41	unsigned long supported = PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM;
42
43	if (system_supports_bti())
44		supported |= PROT_BTI;
45
46	if (system_supports_mte())
47		supported |= PROT_MTE;
48
49	return (prot & ~supported) == 0;
50}
51#define arch_validate_prot(prot, addr) arch_validate_prot(prot, addr)
52
53static inline bool arch_validate_flags(unsigned long vm_flags)
54{
55	if (!system_supports_mte())
56		return true;
57
58	/* only allow VM_MTE if VM_MTE_ALLOWED has been set previously */
59	return !(vm_flags & VM_MTE) || (vm_flags & VM_MTE_ALLOWED);
60}
61#define arch_validate_flags(vm_flags) arch_validate_flags(vm_flags)
62
63#endif /* ! __ASM_MMAN_H__ */
64