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 #endif /* __ASSEMBLY__ */ 135 136 #endif /* _ASM_POWERPC_EXCEPTION_H */ 137