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1/* SPDX-License-Identifier: GPL-2.0-or-later */
2#ifndef _ASM_POWERPC_EXCEPTION_H
3#define _ASM_POWERPC_EXCEPTION_H
4/*
5 * Extracted from head_64.S
6 *
7 * PowerPC version
8 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
9 *
10 * Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP
11 * Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu>
12 * Adapted for Power Macintosh by Paul Mackerras.
13 * Low-level exception handlers and MMU support
14 * rewritten by Paul Mackerras.
15 * Copyright (C) 1996 Paul Mackerras.
16 *
17 * Adapted for 64bit PowerPC by Dave Engebretsen, Peter Bergner, and
18 * Mike Corrigan {engebret|bergner|mikejc}@us.ibm.com
19 *
20 * This file contains the low-level support and setup for the
21 * PowerPC-64 platform, including trap and interrupt dispatch.
22 */
23/*
24 * The following macros define the code that appears as
25 * the prologue to each of the exception handlers. They
26 * are split into two parts to allow a single kernel binary
27 * to be used for pSeries and iSeries.
28 *
29 * We make as much of the exception code common between native
30 * exception handlers (including pSeries LPAR) and iSeries LPAR
31 * implementations as possible.
32 */
33#include <asm/feature-fixups.h>
34
35/* PACA save area size in u64 units (exgen, exmc, etc) */
36#define EX_SIZE 10
37
38/*
39 * maximum recursive depth of MCE exceptions
40 */
41#define MAX_MCE_DEPTH 4
42
43#ifdef __ASSEMBLY__
44
45#define STF_ENTRY_BARRIER_SLOT \
46 STF_ENTRY_BARRIER_FIXUP_SECTION; \
47 nop; \
48 nop; \
49 nop
50
51#define STF_EXIT_BARRIER_SLOT \
52 STF_EXIT_BARRIER_FIXUP_SECTION; \
53 nop; \
54 nop; \
55 nop; \
56 nop; \
57 nop; \
58 nop
59
60/*
61 * r10 must be free to use, r13 must be paca
62 */
63#define INTERRUPT_TO_KERNEL \
64 STF_ENTRY_BARRIER_SLOT
65
66/*
67 * Macros for annotating the expected destination of (h)rfid
68 *
69 * The nop instructions allow us to insert one or more instructions to flush the
70 * L1-D cache when returning to userspace or a guest.
71 *
72 * powerpc relies on return from interrupt/syscall being context synchronising
73 * (which hrfid, rfid, and rfscv are) to support ARCH_HAS_MEMBARRIER_SYNC_CORE
74 * without additional synchronisation instructions.
75 *
76 * soft-masked interrupt replay does not include a context-synchronising rfid,
77 * but those always return to kernel, the sync is only required when returning
78 * to user.
79 */
80#define RFI_FLUSH_SLOT \
81 RFI_FLUSH_FIXUP_SECTION; \
82 nop; \
83 nop; \
84 nop
85
86#define RFI_TO_KERNEL \
87 rfid
88
89#define RFI_TO_USER \
90 STF_EXIT_BARRIER_SLOT; \
91 RFI_FLUSH_SLOT; \
92 rfid; \
93 b rfi_flush_fallback
94
95#define RFI_TO_USER_OR_KERNEL \
96 STF_EXIT_BARRIER_SLOT; \
97 RFI_FLUSH_SLOT; \
98 rfid; \
99 b rfi_flush_fallback
100
101#define RFI_TO_GUEST \
102 STF_EXIT_BARRIER_SLOT; \
103 RFI_FLUSH_SLOT; \
104 rfid; \
105 b rfi_flush_fallback
106
107#define HRFI_TO_KERNEL \
108 hrfid
109
110#define HRFI_TO_USER \
111 STF_EXIT_BARRIER_SLOT; \
112 RFI_FLUSH_SLOT; \
113 hrfid; \
114 b hrfi_flush_fallback
115
116#define HRFI_TO_USER_OR_KERNEL \
117 STF_EXIT_BARRIER_SLOT; \
118 RFI_FLUSH_SLOT; \
119 hrfid; \
120 b hrfi_flush_fallback
121
122#define HRFI_TO_GUEST \
123 STF_EXIT_BARRIER_SLOT; \
124 RFI_FLUSH_SLOT; \
125 hrfid; \
126 b hrfi_flush_fallback
127
128#define HRFI_TO_UNKNOWN \
129 STF_EXIT_BARRIER_SLOT; \
130 RFI_FLUSH_SLOT; \
131 hrfid; \
132 b hrfi_flush_fallback
133
134#define RFSCV_TO_USER \
135 STF_EXIT_BARRIER_SLOT; \
136 RFI_FLUSH_SLOT; \
137 RFSCV; \
138 b rfscv_flush_fallback
139
140#endif /* __ASSEMBLY__ */
141
142#endif /* _ASM_POWERPC_EXCEPTION_H */