xref: /linux/arch/arm64/include/asm/pgtable-prot.h (revision 45d8b572fac3aa8b49d53c946b3685eaf78a2824)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Copyright (C) 2016 ARM Ltd.
4  */
5 #ifndef __ASM_PGTABLE_PROT_H
6 #define __ASM_PGTABLE_PROT_H
7 
8 #include <asm/memory.h>
9 #include <asm/pgtable-hwdef.h>
10 
11 #include <linux/const.h>
12 
13 /*
14  * Software defined PTE bits definition.
15  */
16 #define PTE_WRITE		(PTE_DBM)		 /* same as DBM (51) */
17 #define PTE_SWP_EXCLUSIVE	(_AT(pteval_t, 1) << 2)	 /* only for swp ptes */
18 #define PTE_DIRTY		(_AT(pteval_t, 1) << 55)
19 #define PTE_SPECIAL		(_AT(pteval_t, 1) << 56)
20 #define PTE_DEVMAP		(_AT(pteval_t, 1) << 57)
21 #define PTE_PROT_NONE		(_AT(pteval_t, 1) << 58) /* only when !PTE_VALID */
22 
23 /*
24  * This bit indicates that the entry is present i.e. pmd_page()
25  * still points to a valid huge page in memory even if the pmd
26  * has been invalidated.
27  */
28 #define PMD_PRESENT_INVALID	(_AT(pteval_t, 1) << 59) /* only when !PMD_SECT_VALID */
29 
30 #define _PROT_DEFAULT		(PTE_TYPE_PAGE | PTE_AF | PTE_SHARED)
31 #define _PROT_SECT_DEFAULT	(PMD_TYPE_SECT | PMD_SECT_AF | PMD_SECT_S)
32 
33 #define PROT_DEFAULT		(PTE_TYPE_PAGE | PTE_MAYBE_NG | PTE_MAYBE_SHARED | PTE_AF)
34 #define PROT_SECT_DEFAULT	(PMD_TYPE_SECT | PMD_MAYBE_NG | PMD_MAYBE_SHARED | PMD_SECT_AF)
35 
36 #define PROT_DEVICE_nGnRnE	(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_WRITE | PTE_ATTRINDX(MT_DEVICE_nGnRnE))
37 #define PROT_DEVICE_nGnRE	(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_WRITE | PTE_ATTRINDX(MT_DEVICE_nGnRE))
38 #define PROT_NORMAL_NC		(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_WRITE | PTE_ATTRINDX(MT_NORMAL_NC))
39 #define PROT_NORMAL		(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_WRITE | PTE_ATTRINDX(MT_NORMAL))
40 #define PROT_NORMAL_TAGGED	(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_WRITE | PTE_ATTRINDX(MT_NORMAL_TAGGED))
41 
42 #define PROT_SECT_DEVICE_nGnRE	(PROT_SECT_DEFAULT | PMD_SECT_PXN | PMD_SECT_UXN | PMD_ATTRINDX(MT_DEVICE_nGnRE))
43 #define PROT_SECT_NORMAL	(PROT_SECT_DEFAULT | PMD_SECT_PXN | PMD_SECT_UXN | PTE_WRITE | PMD_ATTRINDX(MT_NORMAL))
44 #define PROT_SECT_NORMAL_EXEC	(PROT_SECT_DEFAULT | PMD_SECT_UXN | PMD_ATTRINDX(MT_NORMAL))
45 
46 #define _PAGE_DEFAULT		(_PROT_DEFAULT | PTE_ATTRINDX(MT_NORMAL))
47 
48 #define _PAGE_KERNEL		(PROT_NORMAL)
49 #define _PAGE_KERNEL_RO		((PROT_NORMAL & ~PTE_WRITE) | PTE_RDONLY)
50 #define _PAGE_KERNEL_ROX	((PROT_NORMAL & ~(PTE_WRITE | PTE_PXN)) | PTE_RDONLY)
51 #define _PAGE_KERNEL_EXEC	(PROT_NORMAL & ~PTE_PXN)
52 #define _PAGE_KERNEL_EXEC_CONT	((PROT_NORMAL & ~PTE_PXN) | PTE_CONT)
53 
54 #define _PAGE_SHARED		(_PAGE_DEFAULT | PTE_USER | PTE_RDONLY | PTE_NG | PTE_PXN | PTE_UXN | PTE_WRITE)
55 #define _PAGE_SHARED_EXEC	(_PAGE_DEFAULT | PTE_USER | PTE_RDONLY | PTE_NG | PTE_PXN | PTE_WRITE)
56 #define _PAGE_READONLY		(_PAGE_DEFAULT | PTE_USER | PTE_RDONLY | PTE_NG | PTE_PXN | PTE_UXN)
57 #define _PAGE_READONLY_EXEC	(_PAGE_DEFAULT | PTE_USER | PTE_RDONLY | PTE_NG | PTE_PXN)
58 #define _PAGE_EXECONLY		(_PAGE_DEFAULT | PTE_RDONLY | PTE_NG | PTE_PXN)
59 
60 #ifndef __ASSEMBLY__
61 
62 #include <asm/cpufeature.h>
63 #include <asm/pgtable-types.h>
64 
65 extern bool arm64_use_ng_mappings;
66 
67 #define PTE_MAYBE_NG		(arm64_use_ng_mappings ? PTE_NG : 0)
68 #define PMD_MAYBE_NG		(arm64_use_ng_mappings ? PMD_SECT_NG : 0)
69 
70 #ifndef CONFIG_ARM64_LPA2
71 #define lpa2_is_enabled()	false
72 #define PTE_MAYBE_SHARED	PTE_SHARED
73 #define PMD_MAYBE_SHARED	PMD_SECT_S
74 #else
75 static inline bool __pure lpa2_is_enabled(void)
76 {
77 	return read_tcr() & TCR_DS;
78 }
79 
80 #define PTE_MAYBE_SHARED	(lpa2_is_enabled() ? 0 : PTE_SHARED)
81 #define PMD_MAYBE_SHARED	(lpa2_is_enabled() ? 0 : PMD_SECT_S)
82 #endif
83 
84 /*
85  * If we have userspace only BTI we don't want to mark kernel pages
86  * guarded even if the system does support BTI.
87  */
88 #define PTE_MAYBE_GP		(system_supports_bti_kernel() ? PTE_GP : 0)
89 
90 #define PAGE_KERNEL		__pgprot(_PAGE_KERNEL)
91 #define PAGE_KERNEL_RO		__pgprot(_PAGE_KERNEL_RO)
92 #define PAGE_KERNEL_ROX		__pgprot(_PAGE_KERNEL_ROX)
93 #define PAGE_KERNEL_EXEC	__pgprot(_PAGE_KERNEL_EXEC)
94 #define PAGE_KERNEL_EXEC_CONT	__pgprot(_PAGE_KERNEL_EXEC_CONT)
95 
96 #define PAGE_S2_MEMATTR(attr, has_fwb)					\
97 	({								\
98 		u64 __val;						\
99 		if (has_fwb)						\
100 			__val = PTE_S2_MEMATTR(MT_S2_FWB_ ## attr);	\
101 		else							\
102 			__val = PTE_S2_MEMATTR(MT_S2_ ## attr);		\
103 		__val;							\
104 	 })
105 
106 #define PAGE_NONE		__pgprot(((_PAGE_DEFAULT) & ~PTE_VALID) | PTE_PROT_NONE | PTE_RDONLY | PTE_NG | PTE_PXN | PTE_UXN)
107 /* shared+writable pages are clean by default, hence PTE_RDONLY|PTE_WRITE */
108 #define PAGE_SHARED		__pgprot(_PAGE_SHARED)
109 #define PAGE_SHARED_EXEC	__pgprot(_PAGE_SHARED_EXEC)
110 #define PAGE_READONLY		__pgprot(_PAGE_READONLY)
111 #define PAGE_READONLY_EXEC	__pgprot(_PAGE_READONLY_EXEC)
112 #define PAGE_EXECONLY		__pgprot(_PAGE_EXECONLY)
113 
114 #endif /* __ASSEMBLY__ */
115 
116 #define pte_pi_index(pte) ( \
117 	((pte & BIT(PTE_PI_IDX_3)) >> (PTE_PI_IDX_3 - 3)) | \
118 	((pte & BIT(PTE_PI_IDX_2)) >> (PTE_PI_IDX_2 - 2)) | \
119 	((pte & BIT(PTE_PI_IDX_1)) >> (PTE_PI_IDX_1 - 1)) | \
120 	((pte & BIT(PTE_PI_IDX_0)) >> (PTE_PI_IDX_0 - 0)))
121 
122 /*
123  * Page types used via Permission Indirection Extension (PIE). PIE uses
124  * the USER, DBM, PXN and UXN bits to to generate an index which is used
125  * to look up the actual permission in PIR_ELx and PIRE0_EL1. We define
126  * combinations we use on non-PIE systems with the same encoding, for
127  * convenience these are listed here as comments as are the unallocated
128  * encodings.
129  */
130 
131 /* 0: PAGE_DEFAULT                                                  */
132 /* 1:                                                      PTE_USER */
133 /* 2:                                          PTE_WRITE            */
134 /* 3:                                          PTE_WRITE | PTE_USER */
135 /* 4: PAGE_EXECONLY                  PTE_PXN                        */
136 /* 5: PAGE_READONLY_EXEC             PTE_PXN |             PTE_USER */
137 /* 6:                                PTE_PXN | PTE_WRITE            */
138 /* 7: PAGE_SHARED_EXEC               PTE_PXN | PTE_WRITE | PTE_USER */
139 /* 8: PAGE_KERNEL_ROX      PTE_UXN                                  */
140 /* 9:                      PTE_UXN |                       PTE_USER */
141 /* a: PAGE_KERNEL_EXEC     PTE_UXN |           PTE_WRITE            */
142 /* b:                      PTE_UXN |           PTE_WRITE | PTE_USER */
143 /* c: PAGE_KERNEL_RO       PTE_UXN | PTE_PXN                        */
144 /* d: PAGE_READONLY        PTE_UXN | PTE_PXN |             PTE_USER */
145 /* e: PAGE_KERNEL          PTE_UXN | PTE_PXN | PTE_WRITE            */
146 /* f: PAGE_SHARED          PTE_UXN | PTE_PXN | PTE_WRITE | PTE_USER */
147 
148 #define PIE_E0	( \
149 	PIRx_ELx_PERM(pte_pi_index(_PAGE_EXECONLY),      PIE_X_O) | \
150 	PIRx_ELx_PERM(pte_pi_index(_PAGE_READONLY_EXEC), PIE_RX)  | \
151 	PIRx_ELx_PERM(pte_pi_index(_PAGE_SHARED_EXEC),   PIE_RWX) | \
152 	PIRx_ELx_PERM(pte_pi_index(_PAGE_READONLY),      PIE_R)   | \
153 	PIRx_ELx_PERM(pte_pi_index(_PAGE_SHARED),        PIE_RW))
154 
155 #define PIE_E1	( \
156 	PIRx_ELx_PERM(pte_pi_index(_PAGE_EXECONLY),      PIE_NONE_O) | \
157 	PIRx_ELx_PERM(pte_pi_index(_PAGE_READONLY_EXEC), PIE_R)      | \
158 	PIRx_ELx_PERM(pte_pi_index(_PAGE_SHARED_EXEC),   PIE_RW)     | \
159 	PIRx_ELx_PERM(pte_pi_index(_PAGE_READONLY),      PIE_R)      | \
160 	PIRx_ELx_PERM(pte_pi_index(_PAGE_SHARED),        PIE_RW)     | \
161 	PIRx_ELx_PERM(pte_pi_index(_PAGE_KERNEL_ROX),    PIE_RX)     | \
162 	PIRx_ELx_PERM(pte_pi_index(_PAGE_KERNEL_EXEC),   PIE_RWX)    | \
163 	PIRx_ELx_PERM(pte_pi_index(_PAGE_KERNEL_RO),     PIE_R)      | \
164 	PIRx_ELx_PERM(pte_pi_index(_PAGE_KERNEL),        PIE_RW))
165 
166 #endif /* __ASM_PGTABLE_PROT_H */
167