linux/arch/powerpc/include/asm/exception.h
<<
>>
Prefs 
   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#define EXCEPTION_PROLOG_1(area)                                \
  60        mfspr   r13,SPRN_SPRG3;         /* get paca address into r13 */ \
  61        std     r9,area+EX_R9(r13);     /* save r9 - r12 */             \
  62        std     r10,area+EX_R10(r13);                                   \
  63        std     r11,area+EX_R11(r13);                                   \
  64        std     r12,area+EX_R12(r13);                                   \
  65        mfspr   r9,SPRN_SPRG1;                                          \
  66        std     r9,area+EX_R13(r13);                                    \
  67        mfcr    r9
  68
  69#define EXCEPTION_PROLOG_PSERIES(area, label)                           \
  70        EXCEPTION_PROLOG_1(area);                                       \
  71        ld      r12,PACAKBASE(r13);     /* get high part of &label */   \
  72        ld      r10,PACAKMSR(r13);      /* get MSR value for kernel */  \
  73        mfspr   r11,SPRN_SRR0;          /* save SRR0 */                 \
  74        LOAD_HANDLER(r12,label)                                         \
  75        mtspr   SPRN_SRR0,r12;                                          \
  76        mfspr   r12,SPRN_SRR1;          /* and SRR1 */                  \
  77        mtspr   SPRN_SRR1,r10;                                          \
  78        rfid;                                                           \
  79        b       .       /* prevent speculative execution */
  80
  81/*
  82 * The common exception prolog is used for all except a few exceptions
  83 * such as a segment miss on a kernel address.  We have to be prepared
  84 * to take another exception from the point where we first touch the
  85 * kernel stack onwards.
  86 *
  87 * On entry r13 points to the paca, r9-r13 are saved in the paca,
  88 * r9 contains the saved CR, r11 and r12 contain the saved SRR0 and
  89 * SRR1, and relocation is on.
  90 */
  91#define EXCEPTION_PROLOG_COMMON(n, area)                                   \
  92        andi.   r10,r12,MSR_PR;         /* See if coming from user      */ \
  93        mr      r10,r1;                 /* Save r1                      */ \
  94        subi    r1,r1,INT_FRAME_SIZE;   /* alloc frame on kernel stack  */ \
  95        beq-    1f;                                                        \
  96        ld      r1,PACAKSAVE(r13);      /* kernel stack to use          */ \
  971:      cmpdi   cr1,r1,0;               /* check if r1 is in userspace  */ \
  98        bge-    cr1,2f;                 /* abort if it is               */ \
  99        b       3f;                                                        \
 1002:      li      r1,(n);                 /* will be reloaded later       */ \
 101        sth     r1,PACA_TRAP_SAVE(r13);                                    \
 102        b       bad_stack;                                                 \
 1033:      std     r9,_CCR(r1);            /* save CR in stackframe        */ \
 104        std     r11,_NIP(r1);           /* save SRR0 in stackframe      */ \
 105        std     r12,_MSR(r1);           /* save SRR1 in stackframe      */ \
 106        std     r10,0(r1);              /* make stack chain pointer     */ \
 107        std     r0,GPR0(r1);            /* save r0 in stackframe        */ \
 108        std     r10,GPR1(r1);           /* save r1 in stackframe        */ \
 109        ACCOUNT_CPU_USER_ENTRY(r9, r10);                                   \
 110        std     r2,GPR2(r1);            /* save r2 in stackframe        */ \
 111        SAVE_4GPRS(3, r1);              /* save r3 - r6 in stackframe   */ \
 112        SAVE_2GPRS(7, r1);              /* save r7, r8 in stackframe    */ \
 113        ld      r9,area+EX_R9(r13);     /* move r9, r10 to stackframe   */ \
 114        ld      r10,area+EX_R10(r13);                                      \
 115        std     r9,GPR9(r1);                                               \
 116        std     r10,GPR10(r1);                                             \
 117        ld      r9,area+EX_R11(r13);    /* move r11 - r13 to stackframe */ \
 118        ld      r10,area+EX_R12(r13);                                      \
 119        ld      r11,area+EX_R13(r13);                                      \
 120        std     r9,GPR11(r1);                                              \
 121        std     r10,GPR12(r1);                                             \
 122        std     r11,GPR13(r1);                                             \
 123        ld      r2,PACATOC(r13);        /* get kernel TOC into r2       */ \
 124        mflr    r9;                     /* save LR in stackframe        */ \
 125        std     r9,_LINK(r1);                                              \
 126        mfctr   r10;                    /* save CTR in stackframe       */ \
 127        std     r10,_CTR(r1);                                              \
 128        lbz     r10,PACASOFTIRQEN(r13);                            \
 129        mfspr   r11,SPRN_XER;           /* save XER in stackframe       */ \
 130        std     r10,SOFTE(r1);                                             \
 131        std     r11,_XER(r1);                                              \
 132        li      r9,(n)+1;                                                  \
 133        std     r9,_TRAP(r1);           /* set trap number              */ \
 134        li      r10,0;                                                     \
 135        ld      r11,exception_marker@toc(r2);                              \
 136        std     r10,RESULT(r1);         /* clear regs->result           */ \
 137        std     r11,STACK_FRAME_OVERHEAD-16(r1); /* mark the frame      */
 138
 139/*
 140 * Exception vectors.
 141 */
 142#define STD_EXCEPTION_PSERIES(n, label)                 \
 143        . = n;                                          \
 144        .globl label##_pSeries;                         \
 145label##_pSeries:                                        \
 146        HMT_MEDIUM;                                     \
 147        mtspr   SPRN_SPRG1,r13;         /* save r13 */  \
 148        EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common)
 149
 150#define HSTD_EXCEPTION_PSERIES(n, label)                \
 151        . = n;                                          \
 152        .globl label##_pSeries;                         \
 153label##_pSeries:                                        \
 154        HMT_MEDIUM;                                     \
 155        mtspr   SPRN_SPRG1,r20;         /* save r20 */  \
 156        mfspr   r20,SPRN_HSRR0;         /* copy HSRR0 to SRR0 */ \
 157        mtspr   SPRN_SRR0,r20;                          \
 158        mfspr   r20,SPRN_HSRR1;         /* copy HSRR0 to SRR0 */ \
 159        mtspr   SPRN_SRR1,r20;                          \
 160        mfspr   r20,SPRN_SPRG1;         /* restore r20 */ \
 161        mtspr   SPRN_SPRG1,r13;         /* save r13 */  \
 162        EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common)
 163
 164
 165#define MASKABLE_EXCEPTION_PSERIES(n, label)                            \
 166        . = n;                                                          \
 167        .globl label##_pSeries;                                         \
 168label##_pSeries:                                                        \
 169        HMT_MEDIUM;                                                     \
 170        mtspr   SPRN_SPRG1,r13;         /* save r13 */                  \
 171        mfspr   r13,SPRN_SPRG3;         /* get paca address into r13 */ \
 172        std     r9,PACA_EXGEN+EX_R9(r13);       /* save r9, r10 */      \
 173        std     r10,PACA_EXGEN+EX_R10(r13);                             \
 174        lbz     r10,PACASOFTIRQEN(r13);                                 \
 175        mfcr    r9;                                                     \
 176        cmpwi   r10,0;                                                  \
 177        beq     masked_interrupt;                                       \
 178        mfspr   r10,SPRN_SPRG1;                                         \
 179        std     r10,PACA_EXGEN+EX_R13(r13);                             \
 180        std     r11,PACA_EXGEN+EX_R11(r13);                             \
 181        std     r12,PACA_EXGEN+EX_R12(r13);                             \
 182        ld      r12,PACAKBASE(r13);     /* get high part of &label */   \
 183        ld      r10,PACAKMSR(r13);      /* get MSR value for kernel */  \
 184        mfspr   r11,SPRN_SRR0;          /* save SRR0 */                 \
 185        LOAD_HANDLER(r12,label##_common)                                \
 186        mtspr   SPRN_SRR0,r12;                                          \
 187        mfspr   r12,SPRN_SRR1;          /* and SRR1 */                  \
 188        mtspr   SPRN_SRR1,r10;                                          \
 189        rfid;                                                           \
 190        b       .       /* prevent speculative execution */
 191
 192#ifdef CONFIG_PPC_ISERIES
 193#define DISABLE_INTS                            \
 194        li      r11,0;                          \
 195        stb     r11,PACASOFTIRQEN(r13);         \
 196BEGIN_FW_FTR_SECTION;                           \
 197        stb     r11,PACAHARDIRQEN(r13);         \
 198END_FW_FTR_SECTION_IFCLR(FW_FEATURE_ISERIES);   \
 199        TRACE_DISABLE_INTS;                     \
 200BEGIN_FW_FTR_SECTION;                           \
 201        mfmsr   r10;                            \
 202        ori     r10,r10,MSR_EE;                 \
 203        mtmsrd  r10,1;                          \
 204END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
 205#else
 206#define DISABLE_INTS                            \
 207        li      r11,0;                          \
 208        stb     r11,PACASOFTIRQEN(r13);         \
 209        stb     r11,PACAHARDIRQEN(r13);         \
 210        TRACE_DISABLE_INTS
 211#endif /* CONFIG_PPC_ISERIES */
 212
 213#define ENABLE_INTS                             \
 214        ld      r12,_MSR(r1);                   \
 215        mfmsr   r11;                            \
 216        rlwimi  r11,r12,0,MSR_EE;               \
 217        mtmsrd  r11,1
 218
 219#define STD_EXCEPTION_COMMON(trap, label, hdlr)         \
 220        .align  7;                                      \
 221        .globl label##_common;                          \
 222label##_common:                                         \
 223        EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN);      \
 224        DISABLE_INTS;                                   \
 225        bl      .save_nvgprs;                           \
 226        addi    r3,r1,STACK_FRAME_OVERHEAD;             \
 227        bl      hdlr;                                   \
 228        b       .ret_from_except
 229
 230/*
 231 * Like STD_EXCEPTION_COMMON, but for exceptions that can occur
 232 * in the idle task and therefore need the special idle handling.
 233 */
 234#define STD_EXCEPTION_COMMON_IDLE(trap, label, hdlr)    \
 235        .align  7;                                      \
 236        .globl label##_common;                          \
 237label##_common:                                         \
 238        EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN);      \
 239        FINISH_NAP;                                     \
 240        DISABLE_INTS;                                   \
 241        bl      .save_nvgprs;                           \
 242        addi    r3,r1,STACK_FRAME_OVERHEAD;             \
 243        bl      hdlr;                                   \
 244        b       .ret_from_except
 245
 246#define STD_EXCEPTION_COMMON_LITE(trap, label, hdlr)    \
 247        .align  7;                                      \
 248        .globl label##_common;                          \
 249label##_common:                                         \
 250        EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN);      \
 251        FINISH_NAP;                                     \
 252        DISABLE_INTS;                                   \
 253BEGIN_FTR_SECTION                                       \
 254        bl      .ppc64_runlatch_on;                     \
 255END_FTR_SECTION_IFSET(CPU_FTR_CTRL)                     \
 256        addi    r3,r1,STACK_FRAME_OVERHEAD;             \
 257        bl      hdlr;                                   \
 258        b       .ret_from_except_lite
 259
 260/*
 261 * When the idle code in power4_idle puts the CPU into NAP mode,
 262 * it has to do so in a loop, and relies on the external interrupt
 263 * and decrementer interrupt entry code to get it out of the loop.
 264 * It sets the _TLF_NAPPING bit in current_thread_info()->local_flags
 265 * to signal that it is in the loop and needs help to get out.
 266 */
 267#ifdef CONFIG_PPC_970_NAP
 268#define FINISH_NAP                              \
 269BEGIN_FTR_SECTION                               \
 270        clrrdi  r11,r1,THREAD_SHIFT;            \
 271        ld      r9,TI_LOCAL_FLAGS(r11);         \
 272        andi.   r10,r9,_TLF_NAPPING;            \
 273        bnel    power4_fixup_nap;               \
 274END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
 275#else
 276#define FINISH_NAP
 277#endif
 278
 279#endif  /* _ASM_POWERPC_EXCEPTION_H */
 280
The original LXR software by the LXR community, this experimental version by lxr@linux.no.