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#define ENTRY_FLUSH_SLOT						\
61	ENTRY_FLUSH_FIXUP_SECTION;					\
62	nop;								\
63	nop;								\
64	nop;
65
66#define SCV_ENTRY_FLUSH_SLOT						\
67	SCV_ENTRY_FLUSH_FIXUP_SECTION;					\
68	nop;								\
69	nop;								\
70	nop;
71
72/*
73 * r10 must be free to use, r13 must be paca
74 */
75#define INTERRUPT_TO_KERNEL						\
76	STF_ENTRY_BARRIER_SLOT;						\
77	ENTRY_FLUSH_SLOT
78
79/*
80 * r10, ctr must be free to use, r13 must be paca
81 */
82#define SCV_INTERRUPT_TO_KERNEL						\
83	STF_ENTRY_BARRIER_SLOT;						\
84	SCV_ENTRY_FLUSH_SLOT
85
86/*
87 * Macros for annotating the expected destination of (h)rfid
88 *
89 * The nop instructions allow us to insert one or more instructions to flush the
90 * L1-D cache when returning to userspace or a guest.
91 *
92 * powerpc relies on return from interrupt/syscall being context synchronising
93 * (which hrfid, rfid, and rfscv are) to support ARCH_HAS_MEMBARRIER_SYNC_CORE
94 * without additional synchronisation instructions.
95 *
96 * soft-masked interrupt replay does not include a context-synchronising rfid,
97 * but those always return to kernel, the sync is only required when returning
98 * to user.
99 */
100#define RFI_FLUSH_SLOT							\
101	RFI_FLUSH_FIXUP_SECTION;					\
102	nop;								\
103	nop;								\
104	nop
105
106#define RFI_TO_KERNEL							\
107	rfid
108
109#define RFI_TO_USER							\
110	STF_EXIT_BARRIER_SLOT;						\
111	RFI_FLUSH_SLOT;							\
112	rfid;								\
113	b	rfi_flush_fallback
114
115#define RFI_TO_USER_OR_KERNEL						\
116	STF_EXIT_BARRIER_SLOT;						\
117	RFI_FLUSH_SLOT;							\
118	rfid;								\
119	b	rfi_flush_fallback
120
121#define RFI_TO_GUEST							\
122	STF_EXIT_BARRIER_SLOT;						\
123	RFI_FLUSH_SLOT;							\
124	rfid;								\
125	b	rfi_flush_fallback
126
127#define HRFI_TO_KERNEL							\
128	hrfid
129
130#define HRFI_TO_USER							\
131	STF_EXIT_BARRIER_SLOT;						\
132	RFI_FLUSH_SLOT;							\
133	hrfid;								\
134	b	hrfi_flush_fallback
135
136#define HRFI_TO_USER_OR_KERNEL						\
137	STF_EXIT_BARRIER_SLOT;						\
138	RFI_FLUSH_SLOT;							\
139	hrfid;								\
140	b	hrfi_flush_fallback
141
142#define HRFI_TO_GUEST							\
143	STF_EXIT_BARRIER_SLOT;						\
144	RFI_FLUSH_SLOT;							\
145	hrfid;								\
146	b	hrfi_flush_fallback
147
148#define HRFI_TO_UNKNOWN							\
149	STF_EXIT_BARRIER_SLOT;						\
150	RFI_FLUSH_SLOT;							\
151	hrfid;								\
152	b	hrfi_flush_fallback
153
154#define RFSCV_TO_USER							\
155	STF_EXIT_BARRIER_SLOT;						\
156	RFI_FLUSH_SLOT;							\
157	RFSCV;								\
158	b	rfscv_flush_fallback
159
160#else /* __ASSEMBLY__ */
161/* Prototype for function defined in exceptions-64s.S */
162void do_uaccess_flush(void);
163#endif /* __ASSEMBLY__ */
164
165#endif	/* _ASM_POWERPC_EXCEPTION_H */
166