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 #define RFI_FLUSH_SLOT							\
73 	RFI_FLUSH_FIXUP_SECTION;					\
74 	nop;								\
75 	nop;								\
76 	nop
77 
78 #define RFI_TO_KERNEL							\
79 	rfid
80 
81 #define RFI_TO_USER							\
82 	STF_EXIT_BARRIER_SLOT;						\
83 	RFI_FLUSH_SLOT;							\
84 	rfid;								\
85 	b	rfi_flush_fallback
86 
87 #define RFI_TO_USER_OR_KERNEL						\
88 	STF_EXIT_BARRIER_SLOT;						\
89 	RFI_FLUSH_SLOT;							\
90 	rfid;								\
91 	b	rfi_flush_fallback
92 
93 #define RFI_TO_GUEST							\
94 	STF_EXIT_BARRIER_SLOT;						\
95 	RFI_FLUSH_SLOT;							\
96 	rfid;								\
97 	b	rfi_flush_fallback
98 
99 #define HRFI_TO_KERNEL							\
100 	hrfid
101 
102 #define HRFI_TO_USER							\
103 	STF_EXIT_BARRIER_SLOT;						\
104 	RFI_FLUSH_SLOT;							\
105 	hrfid;								\
106 	b	hrfi_flush_fallback
107 
108 #define HRFI_TO_USER_OR_KERNEL						\
109 	STF_EXIT_BARRIER_SLOT;						\
110 	RFI_FLUSH_SLOT;							\
111 	hrfid;								\
112 	b	hrfi_flush_fallback
113 
114 #define HRFI_TO_GUEST							\
115 	STF_EXIT_BARRIER_SLOT;						\
116 	RFI_FLUSH_SLOT;							\
117 	hrfid;								\
118 	b	hrfi_flush_fallback
119 
120 #define HRFI_TO_UNKNOWN							\
121 	STF_EXIT_BARRIER_SLOT;						\
122 	RFI_FLUSH_SLOT;							\
123 	hrfid;								\
124 	b	hrfi_flush_fallback
125 
126 #endif /* __ASSEMBLY__ */
127 
128 #endif	/* _ASM_POWERPC_EXCEPTION_H */
129