arch/powerpc/include/asm/exception-64s.h

   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 */