arch/powerpc/include/asm/exception.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 #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          */ \
  97 1:      cmpdi   cr1,r1,0;               /* check if r1 is in userspace  */ \
  98         bge-    cr1,2f;                 /* abort if it is               */ \
  99         b       3f;                                                        \
 100 2:      li      r1,(n);                 /* will be reloaded later       */ \
 101         sth     r1,PACA_TRAP_SAVE(r13);                                    \
 102         b       bad_stack;                                                 \
 103 3:      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;                         \
 145 label##_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;                         \
 153 label##_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;                                         \
 168 label##_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);         \
 196 BEGIN_FW_FTR_SECTION;                           \
 197         stb     r11,PACAHARDIRQEN(r13);         \
 198 END_FW_FTR_SECTION_IFCLR(FW_FEATURE_ISERIES);   \
 199         TRACE_DISABLE_INTS;                     \
 200 BEGIN_FW_FTR_SECTION;                           \
 201         mfmsr   r10;                            \
 202         ori     r10,r10,MSR_EE;                 \
 203         mtmsrd  r10,1;                          \
 204 END_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;                          \
 222 label##_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;                          \
 237 label##_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;                          \
 249 label##_common:                                         \
 250         EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN);      \
 251         FINISH_NAP;                                     \
 252         DISABLE_INTS;                                   \
 253 BEGIN_FTR_SECTION                                       \
 254         bl      .ppc64_runlatch_on;                     \
 255 END_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                              \
 269 BEGIN_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;               \
 274 END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
 275 #else
 276 #define FINISH_NAP
 277 #endif
 278
 279 #endif  /* _ASM_POWERPC_EXCEPTION_H */