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

   1 #ifndef _ASM_POWERPC_EXCEPTION_H
   2 #define _ASM_POWERPC_EXCEPTION_H
   3 /*
   4  * Extracted from head_64.S
   5  *
   6  *  PowerPC version
   7  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   8  *
   9  *  Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP
  10  *    Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu>
  11  *  Adapted for Power Macintosh by Paul Mackerras.
  12  *  Low-level exception handlers and MMU support
  13  *  rewritten by Paul Mackerras.
  14  *    Copyright (C) 1996 Paul Mackerras.
  15  *
  16  *  Adapted for 64bit PowerPC by Dave Engebretsen, Peter Bergner, and
  17  *    Mike Corrigan {engebret|bergner|mikejc}@us.ibm.com
  18  *
  19  *  This file contains the low-level support and setup for the
  20  *  PowerPC-64 platform, including trap and interrupt dispatch.
  21  *
  22  *  This program is free software; you can redistribute it and/or
  23  *  modify it under the terms of the GNU General Public License
  24  *  as published by the Free Software Foundation; either version
  25  *  2 of the License, or (at your option) any later version.
  26  */
  27 /*
  28  * The following macros define the code that appears as
  29  * the prologue to each of the exception handlers.  They
  30  * are split into two parts to allow a single kernel binary
  31  * to be used for pSeries and iSeries.
  32  *
  33  * We make as much of the exception code common between native
  34  * exception handlers (including pSeries LPAR) and iSeries LPAR
  35  * implementations as possible.
  36  */
  37
  38 #define EX_R9           0
  39 #define EX_R10          8
  40 #define EX_R11          16
  41 #define EX_R12          24
  42 #define EX_R13          32
  43 #define EX_SRR0         40
  44 #define EX_DAR          48
  45 #define EX_DSISR        56
  46 #define EX_CCR          60
  47 #define EX_R3           64
  48 #define EX_LR           72
  49
  50 /*
  51  * We're short on space and time in the exception prolog, so we can't
  52  * use the normal SET_REG_IMMEDIATE macro. Normally we just need the
  53  * low halfword of the address, but for Kdump we need the whole low
  54  * word.
  55  */
  56 #define LOAD_HANDLER(reg, label)                                        \
  57         addi    reg,reg,(label)-_stext; /* virt addr of handler ... */
  58
  59 /* Exception register prefixes */
  60 #define EXC_HV  H
  61 #define EXC_STD
  62
  63 #define EXCEPTION_PROLOG_1(area)                                        \
  64         GET_PACA(r13);                                                  \
  65         std     r9,area+EX_R9(r13);     /* save r9 - r12 */             \
  66         std     r10,area+EX_R10(r13);                                   \
  67         std     r11,area+EX_R11(r13);                                   \
  68         std     r12,area+EX_R12(r13);                                   \
  69         GET_SCRATCH0(r9);                                               \
  70         std     r9,area+EX_R13(r13);                                    \
  71         mfcr    r9
  72
  73 #define __EXCEPTION_PROLOG_PSERIES_1(label, h)                          \
  74         ld      r12,PACAKBASE(r13);     /* get high part of &label */   \
  75         ld      r10,PACAKMSR(r13);      /* get MSR value for kernel */  \
  76         mfspr   r11,SPRN_##h##SRR0;     /* save SRR0 */                 \
  77         LOAD_HANDLER(r12,label)                                         \
  78         mtspr   SPRN_##h##SRR0,r12;                                     \
  79         mfspr   r12,SPRN_##h##SRR1;     /* and SRR1 */                  \
  80         mtspr   SPRN_##h##SRR1,r10;                                     \
  81         h##rfid;                                                        \
  82         b       .       /* prevent speculative execution */
  83 #define EXCEPTION_PROLOG_PSERIES_1(label, h) \
  84         __EXCEPTION_PROLOG_PSERIES_1(label, h)
  85
  86 #define EXCEPTION_PROLOG_PSERIES(area, label, h)                        \
  87         EXCEPTION_PROLOG_1(area);                                       \
  88         EXCEPTION_PROLOG_PSERIES_1(label, h);
  89
  90 /*
  91  * The common exception prolog is used for all except a few exceptions
  92  * such as a segment miss on a kernel address.  We have to be prepared
  93  * to take another exception from the point where we first touch the
  94  * kernel stack onwards.
  95  *
  96  * On entry r13 points to the paca, r9-r13 are saved in the paca,
  97  * r9 contains the saved CR, r11 and r12 contain the saved SRR0 and
  98  * SRR1, and relocation is on.
  99  */
 100 #define EXCEPTION_PROLOG_COMMON(n, area)                                   \
 101         andi.   r10,r12,MSR_PR;         /* See if coming from user      */ \
 102         mr      r10,r1;                 /* Save r1                      */ \
 103         subi    r1,r1,INT_FRAME_SIZE;   /* alloc frame on kernel stack  */ \
 104         beq-    1f;                                                        \
 105         ld      r1,PACAKSAVE(r13);      /* kernel stack to use          */ \
 106 1:      cmpdi   cr1,r1,0;               /* check if r1 is in userspace  */ \
 107         blt+    cr1,3f;                 /* abort if it is               */ \
 108         li      r1,(n);                 /* will be reloaded later       */ \
 109         sth     r1,PACA_TRAP_SAVE(r13);                                    \
 110         std     r3,area+EX_R3(r13);                                        \
 111         addi    r3,r13,area;            /* r3 -> where regs are saved*/    \
 112         b       bad_stack;                                                 \
 113 3:      std     r9,_CCR(r1);            /* save CR in stackframe        */ \
 114         std     r11,_NIP(r1);           /* save SRR0 in stackframe      */ \
 115         std     r12,_MSR(r1);           /* save SRR1 in stackframe      */ \
 116         std     r10,0(r1);              /* make stack chain pointer     */ \
 117         std     r0,GPR0(r1);            /* save r0 in stackframe        */ \
 118         std     r10,GPR1(r1);           /* save r1 in stackframe        */ \
 119         ACCOUNT_CPU_USER_ENTRY(r9, r10);                                   \
 120         std     r2,GPR2(r1);            /* save r2 in stackframe        */ \
 121         SAVE_4GPRS(3, r1);              /* save r3 - r6 in stackframe   */ \
 122         SAVE_2GPRS(7, r1);              /* save r7, r8 in stackframe    */ \
 123         ld      r9,area+EX_R9(r13);     /* move r9, r10 to stackframe   */ \
 124         ld      r10,area+EX_R10(r13);                                      \
 125         std     r9,GPR9(r1);                                               \
 126         std     r10,GPR10(r1);                                             \
 127         ld      r9,area+EX_R11(r13);    /* move r11 - r13 to stackframe */ \
 128         ld      r10,area+EX_R12(r13);                                      \
 129         ld      r11,area+EX_R13(r13);                                      \
 130         std     r9,GPR11(r1);                                              \
 131         std     r10,GPR12(r1);                                             \
 132         std     r11,GPR13(r1);                                             \
 133         ld      r2,PACATOC(r13);        /* get kernel TOC into r2       */ \
 134         mflr    r9;                     /* save LR in stackframe        */ \
 135         std     r9,_LINK(r1);                                              \
 136         mfctr   r10;                    /* save CTR in stackframe       */ \
 137         std     r10,_CTR(r1);                                              \
 138         lbz     r10,PACASOFTIRQEN(r13);                            \
 139         mfspr   r11,SPRN_XER;           /* save XER in stackframe       */ \
 140         std     r10,SOFTE(r1);                                             \
 141         std     r11,_XER(r1);                                              \
 142         li      r9,(n)+1;                                                  \
 143         std     r9,_TRAP(r1);           /* set trap number              */ \
 144         li      r10,0;                                                     \
 145         ld      r11,exception_marker@toc(r2);                              \
 146         std     r10,RESULT(r1);         /* clear regs->result           */ \
 147         std     r11,STACK_FRAME_OVERHEAD-16(r1); /* mark the frame      */ \
 148         ACCOUNT_STOLEN_TIME
 149
 150 /*
 151  * Exception vectors.
 152  */
 153 #define STD_EXCEPTION_PSERIES(loc, vec, label)          \
 154         . = loc;                                        \
 155         .globl label##_pSeries;                         \
 156 label##_pSeries:                                        \
 157         HMT_MEDIUM;                                     \
 158         DO_KVM  vec;                                    \
 159         SET_SCRATCH0(r13);              /* save r13 */          \
 160         EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common, EXC_STD)
 161
 162 #define STD_EXCEPTION_HV(loc, vec, label)               \
 163         . = loc;                                        \
 164         .globl label##_hv;                              \
 165 label##_hv:                                             \
 166         HMT_MEDIUM;                                     \
 167         DO_KVM  vec;                                    \
 168         SET_SCRATCH0(r13);      /* save r13 */          \
 169         EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common, EXC_HV)
 170
 171 #define __MASKABLE_EXCEPTION_PSERIES(vec, label, h)                     \
 172         HMT_MEDIUM;                                                     \
 173         DO_KVM  vec;                                                    \
 174         SET_SCRATCH0(r13);    /* save r13 */                            \
 175         GET_PACA(r13);                                                  \
 176         std     r9,PACA_EXGEN+EX_R9(r13);       /* save r9, r10 */      \
 177         std     r10,PACA_EXGEN+EX_R10(r13);                             \
 178         lbz     r10,PACASOFTIRQEN(r13);                                 \
 179         mfcr    r9;                                                     \
 180         cmpwi   r10,0;                                                  \
 181         beq     masked_##h##interrupt;                                  \
 182         GET_SCRATCH0(r10);                                              \
 183         std     r10,PACA_EXGEN+EX_R13(r13);                             \
 184         std     r11,PACA_EXGEN+EX_R11(r13);                             \
 185         std     r12,PACA_EXGEN+EX_R12(r13);                             \
 186         ld      r12,PACAKBASE(r13);     /* get high part of &label */   \
 187         ld      r10,PACAKMSR(r13);      /* get MSR value for kernel */  \
 188         mfspr   r11,SPRN_##h##SRR0;     /* save SRR0 */                 \
 189         LOAD_HANDLER(r12,label##_common)                                \
 190         mtspr   SPRN_##h##SRR0,r12;                                     \
 191         mfspr   r12,SPRN_##h##SRR1;     /* and SRR1 */                  \
 192         mtspr   SPRN_##h##SRR1,r10;                                     \
 193         h##rfid;                                                        \
 194         b       .       /* prevent speculative execution */
 195 #define _MASKABLE_EXCEPTION_PSERIES(vec, label, h)                      \
 196         __MASKABLE_EXCEPTION_PSERIES(vec, label, h)
 197
 198 #define MASKABLE_EXCEPTION_PSERIES(loc, vec, label)                     \
 199         . = loc;                                                        \
 200         .globl label##_pSeries;                                         \
 201 label##_pSeries:                                                        \
 202         _MASKABLE_EXCEPTION_PSERIES(vec, label, EXC_STD)
 203
 204 #define MASKABLE_EXCEPTION_HV(loc, vec, label)                          \
 205         . = loc;                                                        \
 206         .globl label##_hv;                                              \
 207 label##_hv:                                                             \
 208         _MASKABLE_EXCEPTION_PSERIES(vec, label, EXC_HV)
 209
 210 #ifdef CONFIG_PPC_ISERIES
 211 #define DISABLE_INTS                            \
 212         li      r11,0;                          \
 213         stb     r11,PACASOFTIRQEN(r13);         \
 214 BEGIN_FW_FTR_SECTION;                           \
 215         stb     r11,PACAHARDIRQEN(r13);         \
 216 END_FW_FTR_SECTION_IFCLR(FW_FEATURE_ISERIES);   \
 217         TRACE_DISABLE_INTS;                     \
 218 BEGIN_FW_FTR_SECTION;                           \
 219         mfmsr   r10;                            \
 220         ori     r10,r10,MSR_EE;                 \
 221         mtmsrd  r10,1;                          \
 222 END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
 223 #else
 224 #define DISABLE_INTS                            \
 225         li      r11,0;                          \
 226         stb     r11,PACASOFTIRQEN(r13);         \
 227         stb     r11,PACAHARDIRQEN(r13);         \
 228         TRACE_DISABLE_INTS
 229 #endif /* CONFIG_PPC_ISERIES */
 230
 231 #define ENABLE_INTS                             \
 232         ld      r12,_MSR(r1);                   \
 233         mfmsr   r11;                            \
 234         rlwimi  r11,r12,0,MSR_EE;               \
 235         mtmsrd  r11,1
 236
 237 #define STD_EXCEPTION_COMMON(trap, label, hdlr)         \
 238         .align  7;                                      \
 239         .globl label##_common;                          \
 240 label##_common:                                         \
 241         EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN);      \
 242         DISABLE_INTS;                                   \
 243         bl      .save_nvgprs;                           \
 244         addi    r3,r1,STACK_FRAME_OVERHEAD;             \
 245         bl      hdlr;                                   \
 246         b       .ret_from_except
 247
 248 /*
 249  * Like STD_EXCEPTION_COMMON, but for exceptions that can occur
 250  * in the idle task and therefore need the special idle handling.
 251  */
 252 #define STD_EXCEPTION_COMMON_IDLE(trap, label, hdlr)    \
 253         .align  7;                                      \
 254         .globl label##_common;                          \
 255 label##_common:                                         \
 256         EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN);      \
 257         FINISH_NAP;                                     \
 258         DISABLE_INTS;                                   \
 259         bl      .save_nvgprs;                           \
 260         addi    r3,r1,STACK_FRAME_OVERHEAD;             \
 261         bl      hdlr;                                   \
 262         b       .ret_from_except
 263
 264 #define STD_EXCEPTION_COMMON_LITE(trap, label, hdlr)    \
 265         .align  7;                                      \
 266         .globl label##_common;                          \
 267 label##_common:                                         \
 268         EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN);      \
 269         FINISH_NAP;                                     \
 270         DISABLE_INTS;                                   \
 271 BEGIN_FTR_SECTION                                       \
 272         bl      .ppc64_runlatch_on;                     \
 273 END_FTR_SECTION_IFSET(CPU_FTR_CTRL)                     \
 274         addi    r3,r1,STACK_FRAME_OVERHEAD;             \
 275         bl      hdlr;                                   \
 276         b       .ret_from_except_lite
 277
 278 /*
 279  * When the idle code in power4_idle puts the CPU into NAP mode,
 280  * it has to do so in a loop, and relies on the external interrupt
 281  * and decrementer interrupt entry code to get it out of the loop.
 282  * It sets the _TLF_NAPPING bit in current_thread_info()->local_flags
 283  * to signal that it is in the loop and needs help to get out.
 284  */
 285 #ifdef CONFIG_PPC_970_NAP
 286 #define FINISH_NAP                              \
 287 BEGIN_FTR_SECTION                               \
 288         clrrdi  r11,r1,THREAD_SHIFT;            \
 289         ld      r9,TI_LOCAL_FLAGS(r11);         \
 290         andi.   r10,r9,_TLF_NAPPING;            \
 291         bnel    power4_fixup_nap;               \
 292 END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
 293 #else
 294 #define FINISH_NAP
 295 #endif
 296
 297 #endif  /* _ASM_POWERPC_EXCEPTION_H */