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		(_PROT_DEFAULT | PTE_MAYBE_NG)
34 #define PROT_SECT_DEFAULT	(_PROT_SECT_DEFAULT | PMD_MAYBE_NG)
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 #ifdef __ASSEMBLY__
61 #define PTE_MAYBE_NG	0
62 #endif
63 
64 #ifndef __ASSEMBLY__
65 
66 #include <asm/cpufeature.h>
67 #include <asm/pgtable-types.h>
68 
69 extern bool arm64_use_ng_mappings;
70 
71 #define PTE_MAYBE_NG		(arm64_use_ng_mappings ? PTE_NG : 0)
72 #define PMD_MAYBE_NG		(arm64_use_ng_mappings ? PMD_SECT_NG : 0)
73 
74 /*
75  * If we have userspace only BTI we don't want to mark kernel pages
76  * guarded even if the system does support BTI.
77  */
78 #ifdef CONFIG_ARM64_BTI_KERNEL
79 #define PTE_MAYBE_GP		(system_supports_bti() ? PTE_GP : 0)
80 #else
81 #define PTE_MAYBE_GP		0
82 #endif
83 
84 #define PAGE_KERNEL		__pgprot(_PAGE_KERNEL)
85 #define PAGE_KERNEL_RO		__pgprot(_PAGE_KERNEL_RO)
86 #define PAGE_KERNEL_ROX		__pgprot(_PAGE_KERNEL_ROX)
87 #define PAGE_KERNEL_EXEC	__pgprot(_PAGE_KERNEL_EXEC)
88 #define PAGE_KERNEL_EXEC_CONT	__pgprot(_PAGE_KERNEL_EXEC_CONT)
89 
90 #define PAGE_S2_MEMATTR(attr, has_fwb)					\
91 	({								\
92 		u64 __val;						\
93 		if (has_fwb)						\
94 			__val = PTE_S2_MEMATTR(MT_S2_FWB_ ## attr);	\
95 		else							\
96 			__val = PTE_S2_MEMATTR(MT_S2_ ## attr);		\
97 		__val;							\
98 	 })
99 
100 #define PAGE_NONE		__pgprot(((_PAGE_DEFAULT) & ~PTE_VALID) | PTE_PROT_NONE | PTE_RDONLY | PTE_NG | PTE_PXN | PTE_UXN)
101 /* shared+writable pages are clean by default, hence PTE_RDONLY|PTE_WRITE */
102 #define PAGE_SHARED		__pgprot(_PAGE_SHARED)
103 #define PAGE_SHARED_EXEC	__pgprot(_PAGE_SHARED_EXEC)
104 #define PAGE_READONLY		__pgprot(_PAGE_READONLY)
105 #define PAGE_READONLY_EXEC	__pgprot(_PAGE_READONLY_EXEC)
106 #define PAGE_EXECONLY		__pgprot(_PAGE_EXECONLY)
107 
108 #endif /* __ASSEMBLY__ */
109 
110 #define pte_pi_index(pte) ( \
111 	((pte & BIT(PTE_PI_IDX_3)) >> (PTE_PI_IDX_3 - 3)) | \
112 	((pte & BIT(PTE_PI_IDX_2)) >> (PTE_PI_IDX_2 - 2)) | \
113 	((pte & BIT(PTE_PI_IDX_1)) >> (PTE_PI_IDX_1 - 1)) | \
114 	((pte & BIT(PTE_PI_IDX_0)) >> (PTE_PI_IDX_0 - 0)))
115 
116 /*
117  * Page types used via Permission Indirection Extension (PIE). PIE uses
118  * the USER, DBM, PXN and UXN bits to to generate an index which is used
119  * to look up the actual permission in PIR_ELx and PIRE0_EL1. We define
120  * combinations we use on non-PIE systems with the same encoding, for
121  * convenience these are listed here as comments as are the unallocated
122  * encodings.
123  */
124 
125 /* 0: PAGE_DEFAULT                                                  */
126 /* 1:                                                      PTE_USER */
127 /* 2:                                          PTE_WRITE            */
128 /* 3:                                          PTE_WRITE | PTE_USER */
129 /* 4: PAGE_EXECONLY                  PTE_PXN                        */
130 /* 5: PAGE_READONLY_EXEC             PTE_PXN |             PTE_USER */
131 /* 6:                                PTE_PXN | PTE_WRITE            */
132 /* 7: PAGE_SHARED_EXEC               PTE_PXN | PTE_WRITE | PTE_USER */
133 /* 8: PAGE_KERNEL_ROX      PTE_UXN                                  */
134 /* 9:                      PTE_UXN |                       PTE_USER */
135 /* a: PAGE_KERNEL_EXEC     PTE_UXN |           PTE_WRITE            */
136 /* b:                      PTE_UXN |           PTE_WRITE | PTE_USER */
137 /* c: PAGE_KERNEL_RO       PTE_UXN | PTE_PXN                        */
138 /* d: PAGE_READONLY        PTE_UXN | PTE_PXN |             PTE_USER */
139 /* e: PAGE_KERNEL          PTE_UXN | PTE_PXN | PTE_WRITE            */
140 /* f: PAGE_SHARED          PTE_UXN | PTE_PXN | PTE_WRITE | PTE_USER */
141 
142 #define PIE_E0	( \
143 	PIRx_ELx_PERM(pte_pi_index(_PAGE_EXECONLY),      PIE_X_O) | \
144 	PIRx_ELx_PERM(pte_pi_index(_PAGE_READONLY_EXEC), PIE_RX)  | \
145 	PIRx_ELx_PERM(pte_pi_index(_PAGE_SHARED_EXEC),   PIE_RWX) | \
146 	PIRx_ELx_PERM(pte_pi_index(_PAGE_READONLY),      PIE_R)   | \
147 	PIRx_ELx_PERM(pte_pi_index(_PAGE_SHARED),        PIE_RW))
148 
149 #define PIE_E1	( \
150 	PIRx_ELx_PERM(pte_pi_index(_PAGE_EXECONLY),      PIE_NONE_O) | \
151 	PIRx_ELx_PERM(pte_pi_index(_PAGE_READONLY_EXEC), PIE_R)      | \
152 	PIRx_ELx_PERM(pte_pi_index(_PAGE_SHARED_EXEC),   PIE_RW)     | \
153 	PIRx_ELx_PERM(pte_pi_index(_PAGE_READONLY),      PIE_R)      | \
154 	PIRx_ELx_PERM(pte_pi_index(_PAGE_SHARED),        PIE_RW)     | \
155 	PIRx_ELx_PERM(pte_pi_index(_PAGE_KERNEL_ROX),    PIE_RX)     | \
156 	PIRx_ELx_PERM(pte_pi_index(_PAGE_KERNEL_EXEC),   PIE_RWX)    | \
157 	PIRx_ELx_PERM(pte_pi_index(_PAGE_KERNEL_RO),     PIE_R)      | \
158 	PIRx_ELx_PERM(pte_pi_index(_PAGE_KERNEL),        PIE_RW))
159 
160 #endif /* __ASM_PGTABLE_PROT_H */
161