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 #define EX_CFAR         80
  50
  51 /*
  52  * We're short on space and time in the exception prolog, so we can't
  53  * use the normal SET_REG_IMMEDIATE macro. Normally we just need the
  54  * low halfword of the address, but for Kdump we need the whole low
  55  * word.
  56  */
  57 #define LOAD_HANDLER(reg, label)                                        \
  58         addi    reg,reg,(label)-_stext; /* virt addr of handler ... */
  59
  60 /* Exception register prefixes */
  61 #define EXC_HV  H
  62 #define EXC_STD
  63
  64 #define __EXCEPTION_PROLOG_1(area, extra, vec)                          \
  65         GET_PACA(r13);                                                  \
  66         std     r9,area+EX_R9(r13);     /* save r9 - r12 */             \
  67         std     r10,area+EX_R10(r13);                                   \
  68         BEGIN_FTR_SECTION_NESTED(66);                                   \
  69         mfspr   r10,SPRN_CFAR;                                          \
  70         std     r10,area+EX_CFAR(r13);                                  \
  71         END_FTR_SECTION_NESTED(CPU_FTR_CFAR, CPU_FTR_CFAR, 66);         \
  72         mfcr    r9;                                                     \
  73         extra(vec);                                                     \
  74         std     r11,area+EX_R11(r13);                                   \
  75         std     r12,area+EX_R12(r13);                                   \
  76         GET_SCRATCH0(r10);                                              \
  77         std     r10,area+EX_R13(r13)
  78 #define EXCEPTION_PROLOG_1(area, extra, vec)                            \
  79         __EXCEPTION_PROLOG_1(area, extra, vec)
  80
  81 #define __EXCEPTION_PROLOG_PSERIES_1(label, h)                          \
  82         ld      r12,PACAKBASE(r13);     /* get high part of &label */   \
  83         ld      r10,PACAKMSR(r13);      /* get MSR value for kernel */  \
  84         mfspr   r11,SPRN_##h##SRR0;     /* save SRR0 */                 \
  85         LOAD_HANDLER(r12,label)                                         \
  86         mtspr   SPRN_##h##SRR0,r12;                                     \
  87         mfspr   r12,SPRN_##h##SRR1;     /* and SRR1 */                  \
  88         mtspr   SPRN_##h##SRR1,r10;                                     \
  89         h##rfid;                                                        \
  90         b       .       /* prevent speculative execution */
  91 #define EXCEPTION_PROLOG_PSERIES_1(label, h)                            \
  92         __EXCEPTION_PROLOG_PSERIES_1(label, h)
  93
  94 #define EXCEPTION_PROLOG_PSERIES(area, label, h, extra, vec)            \
  95         EXCEPTION_PROLOG_1(area, extra, vec);                           \
  96         EXCEPTION_PROLOG_PSERIES_1(label, h);
  97
  98 #define __KVMTEST(n)                                                    \
  99         lbz     r10,HSTATE_IN_GUEST(r13);                       \
 100         cmpwi   r10,0;                                                  \
 101         bne     do_kvm_##n
 102
 103 #define __KVM_HANDLER(area, h, n)                                       \
 104 do_kvm_##n:                                                             \
 105         ld      r10,area+EX_R10(r13);                                   \
 106         stw     r9,HSTATE_SCRATCH1(r13);                        \
 107         ld      r9,area+EX_R9(r13);                                     \
 108         std     r12,HSTATE_SCRATCH0(r13);                       \
 109         li      r12,n;                                                  \
 110         b       kvmppc_interrupt
 111
 112 #define __KVM_HANDLER_SKIP(area, h, n)                                  \
 113 do_kvm_##n:                                                             \
 114         cmpwi   r10,KVM_GUEST_MODE_SKIP;                                \
 115         ld      r10,area+EX_R10(r13);                                   \
 116         beq     89f;                                                    \
 117         stw     r9,HSTATE_SCRATCH1(r13);                        \
 118         ld      r9,area+EX_R9(r13);                                     \
 119         std     r12,HSTATE_SCRATCH0(r13);                       \
 120         li      r12,n;                                                  \
 121         b       kvmppc_interrupt;                                       \
 122 89:     mtocrf  0x80,r9;                                                \
 123         ld      r9,area+EX_R9(r13);                                     \
 124         b       kvmppc_skip_##h##interrupt
 125
 126 #ifdef CONFIG_KVM_BOOK3S_64_HANDLER
 127 #define KVMTEST(n)                      __KVMTEST(n)
 128 #define KVM_HANDLER(area, h, n)         __KVM_HANDLER(area, h, n)
 129 #define KVM_HANDLER_SKIP(area, h, n)    __KVM_HANDLER_SKIP(area, h, n)
 130
 131 #else
 132 #define KVMTEST(n)
 133 #define KVM_HANDLER(area, h, n)
 134 #define KVM_HANDLER_SKIP(area, h, n)
 135 #endif
 136
 137 #ifdef CONFIG_KVM_BOOK3S_PR
 138 #define KVMTEST_PR(n)                   __KVMTEST(n)
 139 #define KVM_HANDLER_PR(area, h, n)      __KVM_HANDLER(area, h, n)
 140 #define KVM_HANDLER_PR_SKIP(area, h, n) __KVM_HANDLER_SKIP(area, h, n)
 141
 142 #else
 143 #define KVMTEST_PR(n)
 144 #define KVM_HANDLER_PR(area, h, n)
 145 #define KVM_HANDLER_PR_SKIP(area, h, n)
 146 #endif
 147
 148 #define NOTEST(n)
 149
 150 /*
 151  * The common exception prolog is used for all except a few exceptions
 152  * such as a segment miss on a kernel address.  We have to be prepared
 153  * to take another exception from the point where we first touch the
 154  * kernel stack onwards.
 155  *
 156  * On entry r13 points to the paca, r9-r13 are saved in the paca,
 157  * r9 contains the saved CR, r11 and r12 contain the saved SRR0 and
 158  * SRR1, and relocation is on.
 159  */
 160 #define EXCEPTION_PROLOG_COMMON(n, area)                                   \
 161         andi.   r10,r12,MSR_PR;         /* See if coming from user      */ \
 162         mr      r10,r1;                 /* Save r1                      */ \
 163         subi    r1,r1,INT_FRAME_SIZE;   /* alloc frame on kernel stack  */ \
 164         beq-    1f;                                                        \
 165         ld      r1,PACAKSAVE(r13);      /* kernel stack to use          */ \
 166 1:      cmpdi   cr1,r1,0;               /* check if r1 is in userspace  */ \
 167         blt+    cr1,3f;                 /* abort if it is               */ \
 168         li      r1,(n);                 /* will be reloaded later       */ \
 169         sth     r1,PACA_TRAP_SAVE(r13);                                    \
 170         std     r3,area+EX_R3(r13);                                        \
 171         addi    r3,r13,area;            /* r3 -> where regs are saved*/    \
 172         b       bad_stack;                                                 \
 173 3:      std     r9,_CCR(r1);            /* save CR in stackframe        */ \
 174         std     r11,_NIP(r1);           /* save SRR0 in stackframe      */ \
 175         std     r12,_MSR(r1);           /* save SRR1 in stackframe      */ \
 176         std     r10,0(r1);              /* make stack chain pointer     */ \
 177         std     r0,GPR0(r1);            /* save r0 in stackframe        */ \
 178         std     r10,GPR1(r1);           /* save r1 in stackframe        */ \
 179         ACCOUNT_CPU_USER_ENTRY(r9, r10);                                   \
 180         std     r2,GPR2(r1);            /* save r2 in stackframe        */ \
 181         SAVE_4GPRS(3, r1);              /* save r3 - r6 in stackframe   */ \
 182         SAVE_2GPRS(7, r1);              /* save r7, r8 in stackframe    */ \
 183         ld      r9,area+EX_R9(r13);     /* move r9, r10 to stackframe   */ \
 184         ld      r10,area+EX_R10(r13);                                      \
 185         std     r9,GPR9(r1);                                               \
 186         std     r10,GPR10(r1);                                             \
 187         ld      r9,area+EX_R11(r13);    /* move r11 - r13 to stackframe */ \
 188         ld      r10,area+EX_R12(r13);                                      \
 189         ld      r11,area+EX_R13(r13);                                      \
 190         std     r9,GPR11(r1);                                              \
 191         std     r10,GPR12(r1);                                             \
 192         std     r11,GPR13(r1);                                             \
 193         BEGIN_FTR_SECTION_NESTED(66);                                      \
 194         ld      r10,area+EX_CFAR(r13);                                     \
 195         std     r10,ORIG_GPR3(r1);                                         \
 196         END_FTR_SECTION_NESTED(CPU_FTR_CFAR, CPU_FTR_CFAR, 66);            \
 197         ld      r2,PACATOC(r13);        /* get kernel TOC into r2       */ \
 198         mflr    r9;                     /* save LR in stackframe        */ \
 199         std     r9,_LINK(r1);                                              \
 200         mfctr   r10;                    /* save CTR in stackframe       */ \
 201         std     r10,_CTR(r1);                                              \
 202         lbz     r10,PACASOFTIRQEN(r13);                            \
 203         mfspr   r11,SPRN_XER;           /* save XER in stackframe       */ \
 204         std     r10,SOFTE(r1);                                             \
 205         std     r11,_XER(r1);                                              \
 206         li      r9,(n)+1;                                                  \
 207         std     r9,_TRAP(r1);           /* set trap number              */ \
 208         li      r10,0;                                                     \
 209         ld      r11,exception_marker@toc(r2);                              \
 210         std     r10,RESULT(r1);         /* clear regs->result           */ \
 211         std     r11,STACK_FRAME_OVERHEAD-16(r1); /* mark the frame      */ \
 212         ACCOUNT_STOLEN_TIME
 213
 214 /*
 215  * Exception vectors.
 216  */
 217 #define STD_EXCEPTION_PSERIES(loc, vec, label)          \
 218         . = loc;                                        \
 219         .globl label##_pSeries;                         \
 220 label##_pSeries:                                        \
 221         HMT_MEDIUM;                                     \
 222         SET_SCRATCH0(r13);              /* save r13 */          \
 223         EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common,    \
 224                                  EXC_STD, KVMTEST_PR, vec)
 225
 226 #define STD_EXCEPTION_HV(loc, vec, label)               \
 227         . = loc;                                        \
 228         .globl label##_hv;                              \
 229 label##_hv:                                             \
 230         HMT_MEDIUM;                                     \
 231         SET_SCRATCH0(r13);      /* save r13 */                  \
 232         EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common,    \
 233                                  EXC_HV, KVMTEST, vec)
 234
 235 #define __SOFTEN_TEST(h)                                                \
 236         lbz     r10,PACASOFTIRQEN(r13);                                 \
 237         cmpwi   r10,0;                                                  \
 238         beq     masked_##h##interrupt
 239 #define _SOFTEN_TEST(h) __SOFTEN_TEST(h)
 240
 241 #define SOFTEN_TEST_PR(vec)                                             \
 242         KVMTEST_PR(vec);                                                \
 243         _SOFTEN_TEST(EXC_STD)
 244
 245 #define SOFTEN_TEST_HV(vec)                                             \
 246         KVMTEST(vec);                                                   \
 247         _SOFTEN_TEST(EXC_HV)
 248
 249 #define SOFTEN_TEST_HV_201(vec)                                         \
 250         KVMTEST(vec);                                                   \
 251         _SOFTEN_TEST(EXC_STD)
 252
 253 #define __MASKABLE_EXCEPTION_PSERIES(vec, label, h, extra)              \
 254         HMT_MEDIUM;                                                     \
 255         SET_SCRATCH0(r13);    /* save r13 */                            \
 256         __EXCEPTION_PROLOG_1(PACA_EXGEN, extra, vec);           \
 257         EXCEPTION_PROLOG_PSERIES_1(label##_common, h);
 258 #define _MASKABLE_EXCEPTION_PSERIES(vec, label, h, extra)               \
 259         __MASKABLE_EXCEPTION_PSERIES(vec, label, h, extra)
 260
 261 #define MASKABLE_EXCEPTION_PSERIES(loc, vec, label)                     \
 262         . = loc;                                                        \
 263         .globl label##_pSeries;                                         \
 264 label##_pSeries:                                                        \
 265         _MASKABLE_EXCEPTION_PSERIES(vec, label,                         \
 266                                     EXC_STD, SOFTEN_TEST_PR)
 267
 268 #define MASKABLE_EXCEPTION_HV(loc, vec, label)                          \
 269         . = loc;                                                        \
 270         .globl label##_hv;                                              \
 271 label##_hv:                                                             \
 272         _MASKABLE_EXCEPTION_PSERIES(vec, label,                         \
 273                                     EXC_HV, SOFTEN_TEST_HV)
 274
 275 #define DISABLE_INTS                            \
 276         li      r11,0;                          \
 277         stb     r11,PACASOFTIRQEN(r13);         \
 278         stb     r11,PACAHARDIRQEN(r13);         \
 279         TRACE_DISABLE_INTS
 280
 281 #define ENABLE_INTS                             \
 282         ld      r12,_MSR(r1);                   \
 283         mfmsr   r11;                            \
 284         rlwimi  r11,r12,0,MSR_EE;               \
 285         mtmsrd  r11,1
 286
 287 #define ADD_NVGPRS                              \
 288         bl      .save_nvgprs
 289
 290 #define RUNLATCH_ON                             \
 291 BEGIN_FTR_SECTION                               \
 292         clrrdi  r3,r1,THREAD_SHIFT;             \
 293         ld      r4,TI_LOCAL_FLAGS(r3);          \
 294         andi.   r0,r4,_TLF_RUNLATCH;            \
 295         beql    ppc64_runlatch_on_trampoline;   \
 296 END_FTR_SECTION_IFSET(CPU_FTR_CTRL)
 297
 298 #define EXCEPTION_COMMON(trap, label, hdlr, ret, additions)     \
 299         .align  7;                                              \
 300         .globl label##_common;                                  \
 301 label##_common:                                                 \
 302         EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN);              \
 303         additions;                                              \
 304         addi    r3,r1,STACK_FRAME_OVERHEAD;                     \
 305         bl      hdlr;                                           \
 306         b       ret
 307
 308 #define STD_EXCEPTION_COMMON(trap, label, hdlr)                 \
 309         EXCEPTION_COMMON(trap, label, hdlr, ret_from_except,    \
 310                          ADD_NVGPRS;DISABLE_INTS)
 311
 312 /*
 313  * Like STD_EXCEPTION_COMMON, but for exceptions that can occur
 314  * in the idle task and therefore need the special idle handling
 315  * (finish nap and runlatch)
 316  */
 317 #define STD_EXCEPTION_COMMON_ASYNC(trap, label, hdlr)             \
 318         EXCEPTION_COMMON(trap, label, hdlr, ret_from_except_lite, \
 319                          FINISH_NAP;RUNLATCH_ON;DISABLE_INTS)
 320
 321 /*
 322  * When the idle code in power4_idle puts the CPU into NAP mode,
 323  * it has to do so in a loop, and relies on the external interrupt
 324  * and decrementer interrupt entry code to get it out of the loop.
 325  * It sets the _TLF_NAPPING bit in current_thread_info()->local_flags
 326  * to signal that it is in the loop and needs help to get out.
 327  */
 328 #ifdef CONFIG_PPC_970_NAP
 329 #define FINISH_NAP                              \
 330 BEGIN_FTR_SECTION                               \
 331         clrrdi  r11,r1,THREAD_SHIFT;            \
 332         ld      r9,TI_LOCAL_FLAGS(r11);         \
 333         andi.   r10,r9,_TLF_NAPPING;            \
 334         bnel    power4_fixup_nap;               \
 335 END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
 336 #else
 337 #define FINISH_NAP
 338 #endif
 339
 340 #endif  /* _ASM_POWERPC_EXCEPTION_H */