xref: /linux/arch/arm64/include/asm/mman.h (revision 288cb34ead03c0d09932317b239f1f4d38fc9d4f)
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 
9 static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot,
10 	unsigned long pkey)
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 #ifdef CONFIG_ARCH_HAS_PKEYS
21 	if (system_supports_poe()) {
22 		ret |= pkey & BIT(0) ? VM_PKEY_BIT0 : 0;
23 		ret |= pkey & BIT(1) ? VM_PKEY_BIT1 : 0;
24 		ret |= pkey & BIT(2) ? VM_PKEY_BIT2 : 0;
25 	}
26 #endif
27 
28 	return ret;
29 }
30 #define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey)
31 
32 static inline unsigned long arch_calc_vm_flag_bits(unsigned long flags)
33 {
34 	/*
35 	 * Only allow MTE on anonymous mappings as these are guaranteed to be
36 	 * backed by tags-capable memory. The vm_flags may be overridden by a
37 	 * filesystem supporting MTE (RAM-based).
38 	 */
39 	if (system_supports_mte() && (flags & MAP_ANONYMOUS))
40 		return VM_MTE_ALLOWED;
41 
42 	return 0;
43 }
44 #define arch_calc_vm_flag_bits(flags) arch_calc_vm_flag_bits(flags)
45 
46 static inline bool arch_validate_prot(unsigned long prot,
47 	unsigned long addr __always_unused)
48 {
49 	unsigned long supported = PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM;
50 
51 	if (system_supports_bti())
52 		supported |= PROT_BTI;
53 
54 	if (system_supports_mte())
55 		supported |= PROT_MTE;
56 
57 	return (prot & ~supported) == 0;
58 }
59 #define arch_validate_prot(prot, addr) arch_validate_prot(prot, addr)
60 
61 static inline bool arch_validate_flags(unsigned long vm_flags)
62 {
63 	if (!system_supports_mte())
64 		return true;
65 
66 	/* only allow VM_MTE if VM_MTE_ALLOWED has been set previously */
67 	return !(vm_flags & VM_MTE) || (vm_flags & VM_MTE_ALLOWED);
68 }
69 #define arch_validate_flags(vm_flags) arch_validate_flags(vm_flags)
70 
71 #endif /* ! __ASM_MMAN_H__ */
72