xref: /openbmc/linux/arch/arm64/include/asm/traps.h (revision feac8c8b)
1 /*
2  * Based on arch/arm/include/asm/traps.h
3  *
4  * Copyright (C) 2012 ARM Ltd.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License version 2 as
8  * published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
17  */
18 #ifndef __ASM_TRAP_H
19 #define __ASM_TRAP_H
20 
21 #include <linux/list.h>
22 #include <asm/esr.h>
23 #include <asm/sections.h>
24 
25 struct pt_regs;
26 
27 struct undef_hook {
28 	struct list_head node;
29 	u32 instr_mask;
30 	u32 instr_val;
31 	u64 pstate_mask;
32 	u64 pstate_val;
33 	int (*fn)(struct pt_regs *regs, u32 instr);
34 };
35 
36 void register_undef_hook(struct undef_hook *hook);
37 void unregister_undef_hook(struct undef_hook *hook);
38 void force_signal_inject(int signal, int code, struct pt_regs *regs,
39 			 unsigned long address);
40 
41 void arm64_notify_segfault(struct pt_regs *regs, unsigned long addr);
42 
43 /*
44  * Move regs->pc to next instruction and do necessary setup before it
45  * is executed.
46  */
47 void arm64_skip_faulting_instruction(struct pt_regs *regs, unsigned long size);
48 
49 static inline int __in_irqentry_text(unsigned long ptr)
50 {
51 	return ptr >= (unsigned long)&__irqentry_text_start &&
52 	       ptr < (unsigned long)&__irqentry_text_end;
53 }
54 
55 static inline int in_exception_text(unsigned long ptr)
56 {
57 	int in;
58 
59 	in = ptr >= (unsigned long)&__exception_text_start &&
60 	     ptr < (unsigned long)&__exception_text_end;
61 
62 	return in ? : __in_irqentry_text(ptr);
63 }
64 
65 static inline int in_entry_text(unsigned long ptr)
66 {
67 	return ptr >= (unsigned long)&__entry_text_start &&
68 	       ptr < (unsigned long)&__entry_text_end;
69 }
70 
71 /*
72  * CPUs with the RAS extensions have an Implementation-Defined-Syndrome bit
73  * to indicate whether this ESR has a RAS encoding. CPUs without this feature
74  * have a ISS-Valid bit in the same position.
75  * If this bit is set, we know its not a RAS SError.
76  * If its clear, we need to know if the CPU supports RAS. Uncategorized RAS
77  * errors share the same encoding as an all-zeros encoding from a CPU that
78  * doesn't support RAS.
79  */
80 static inline bool arm64_is_ras_serror(u32 esr)
81 {
82 	WARN_ON(preemptible());
83 
84 	if (esr & ESR_ELx_IDS)
85 		return false;
86 
87 	if (this_cpu_has_cap(ARM64_HAS_RAS_EXTN))
88 		return true;
89 	else
90 		return false;
91 }
92 
93 /*
94  * Return the AET bits from a RAS SError's ESR.
95  *
96  * It is implementation defined whether Uncategorized errors are containable.
97  * We treat them as Uncontainable.
98  * Non-RAS SError's are reported as Uncontained/Uncategorized.
99  */
100 static inline u32 arm64_ras_serror_get_severity(u32 esr)
101 {
102 	u32 aet = esr & ESR_ELx_AET;
103 
104 	if (!arm64_is_ras_serror(esr)) {
105 		/* Not a RAS error, we can't interpret the ESR. */
106 		return ESR_ELx_AET_UC;
107 	}
108 
109 	/*
110 	 * AET is RES0 if 'the value returned in the DFSC field is not
111 	 * [ESR_ELx_FSC_SERROR]'
112 	 */
113 	if ((esr & ESR_ELx_FSC) != ESR_ELx_FSC_SERROR) {
114 		/* No severity information : Uncategorized */
115 		return ESR_ELx_AET_UC;
116 	}
117 
118 	return aet;
119 }
120 
121 bool arm64_is_fatal_ras_serror(struct pt_regs *regs, unsigned int esr);
122 void __noreturn arm64_serror_panic(struct pt_regs *regs, u32 esr);
123 #endif
124