arch/ppc/kernel/head_booke.h

   1 #ifndef __HEAD_BOOKE_H__
   2 #define __HEAD_BOOKE_H__
   3
   4 /*
   5  * Macros used for common Book-e exception handling
   6  */
   7
   8 #define SET_IVOR(vector_number, vector_label)           \
   9                 li      r26,vector_label@l;             \
  10                 mtspr   SPRN_IVOR##vector_number,r26;   \
  11                 sync
  12
  13 #define NORMAL_EXCEPTION_PROLOG                                              \
  14         mtspr   SPRN_SPRG0,r10;         /* save two registers to work with */\
  15         mtspr   SPRN_SPRG1,r11;                                              \
  16         mtspr   SPRN_SPRG4W,r1;                                              \
  17         mfcr    r10;                    /* save CR in r10 for now          */\
  18         mfspr   r11,SPRN_SRR1;          /* check whether user or kernel    */\
  19         andi.   r11,r11,MSR_PR;                                              \
  20         beq     1f;                                                          \
  21         mfspr   r1,SPRN_SPRG3;          /* if from user, start at top of   */\
  22         lwz     r1,THREAD_INFO-THREAD(r1); /* this thread's kernel stack   */\
  23         addi    r1,r1,THREAD_SIZE;                                           \
  24 1:      subi    r1,r1,INT_FRAME_SIZE;   /* Allocate an exception frame     */\
  25         mr      r11,r1;                                                      \
  26         stw     r10,_CCR(r11);          /* save various registers          */\
  27         stw     r12,GPR12(r11);                                              \
  28         stw     r9,GPR9(r11);                                                \
  29         mfspr   r10,SPRN_SPRG0;                                              \
  30         stw     r10,GPR10(r11);                                              \
  31         mfspr   r12,SPRN_SPRG1;                                              \
  32         stw     r12,GPR11(r11);                                              \
  33         mflr    r10;                                                         \
  34         stw     r10,_LINK(r11);                                              \
  35         mfspr   r10,SPRN_SPRG4R;                                             \
  36         mfspr   r12,SPRN_SRR0;                                               \
  37         stw     r10,GPR1(r11);                                               \
  38         mfspr   r9,SPRN_SRR1;                                                \
  39         stw     r10,0(r11);                                                  \
  40         rlwinm  r9,r9,0,14,12;          /* clear MSR_WE (necessary?)       */\
  41         stw     r0,GPR0(r11);                                                \
  42         SAVE_4GPRS(3, r11);                                                  \
  43         SAVE_2GPRS(7, r11)
  44
  45 /* To handle the additional exception priority levels on 40x and Book-E
  46  * processors we allocate a 4k stack per additional priority level. The various
  47  * head_xxx.S files allocate space (exception_stack_top) for each priority's
  48  * stack times the number of CPUs
  49  *
  50  * On 40x critical is the only additional level
  51  * On 44x/e500 we have critical and machine check
  52  *
  53  * Additionally we reserve a SPRG for each priority level so we can free up a
  54  * GPR to use as the base for indirect access to the exception stacks.  This
  55  * is necessary since the MMU is always on, for Book-E parts, and the stacks
  56  * are offset from KERNELBASE.
  57  *
  58  */
  59 #define BOOKE_EXCEPTION_STACK_SIZE      (8192)
  60
  61 /* CRIT_SPRG only used in critical exception handling */
  62 #define CRIT_SPRG       SPRN_SPRG2
  63 /* MCHECK_SPRG only used in critical exception handling */
  64 #define MCHECK_SPRG     SPRN_SPRG6W
  65
  66 #define MCHECK_STACK_TOP        (exception_stack_top - 4096)
  67 #define CRIT_STACK_TOP          (exception_stack_top)
  68
  69 #ifdef CONFIG_SMP
  70 #define BOOKE_LOAD_CRIT_STACK                           \
  71         mfspr   r8,SPRN_PIR;                            \
  72         mulli   r8,r8,BOOKE_EXCEPTION_STACK_SIZE;       \
  73         neg     r8,r8;                                  \
  74         addis   r8,r8,CRIT_STACK_TOP@ha;                \
  75         addi    r8,r8,CRIT_STACK_TOP@l
  76 #define BOOKE_LOAD_MCHECK_STACK                         \
  77         mfspr   r8,SPRN_PIR;                            \
  78         mulli   r8,r8,BOOKE_EXCEPTION_STACK_SIZE;       \
  79         neg     r8,r8;                                  \
  80         addis   r8,r8,MCHECK_STACK_TOP@ha;              \
  81         addi    r8,r8,MCHECK_STACK_TOP@l
  82 #else
  83 #define BOOKE_LOAD_CRIT_STACK                           \
  84         lis     r8,CRIT_STACK_TOP@h;                    \
  85         ori     r8,r8,CRIT_STACK_TOP@l
  86 #define BOOKE_LOAD_MCHECK_STACK                         \
  87         lis     r8,MCHECK_STACK_TOP@h;                  \
  88         ori     r8,r8,MCHECK_STACK_TOP@l
  89 #endif
  90
  91 /*
  92  * Exception prolog for critical exceptions.  This is a little different
  93  * from the normal exception prolog above since a critical exception
  94  * can potentially occur at any point during normal exception processing.
  95  * Thus we cannot use the same SPRG registers as the normal prolog above.
  96  * Instead we use a portion of the critical exception stack at low physical
  97  * addresses.
  98  */
  99
 100 #define CRITICAL_EXCEPTION_PROLOG                                            \
 101         mtspr   CRIT_SPRG,r8;                                                \
 102         BOOKE_LOAD_CRIT_STACK;          /* r8 points to the crit stack */    \
 103         stw     r10,GPR10-INT_FRAME_SIZE(r8);                                \
 104         stw     r11,GPR11-INT_FRAME_SIZE(r8);                                \
 105         mfcr    r10;                    /* save CR in r10 for now          */\
 106         mfspr   r11,SPRN_CSRR1;         /* check whether user or kernel    */\
 107         andi.   r11,r11,MSR_PR;                                              \
 108         mr      r11,r8;                                                      \
 109         mfspr   r8,CRIT_SPRG;                                                \
 110         beq     1f;                                                          \
 111         /* COMING FROM USER MODE */                                          \
 112         mfspr   r11,SPRN_SPRG3;         /* if from user, start at top of   */\
 113         lwz     r11,THREAD_INFO-THREAD(r11); /* this thread's kernel stack */\
 114         addi    r11,r11,THREAD_SIZE;                                         \
 115 1:      subi    r11,r11,INT_FRAME_SIZE; /* Allocate an exception frame     */\
 116         stw     r10,_CCR(r11);          /* save various registers          */\
 117         stw     r12,GPR12(r11);                                              \
 118         stw     r9,GPR9(r11);                                                \
 119         mflr    r10;                                                         \
 120         stw     r10,_LINK(r11);                                              \
 121         mfspr   r12,SPRN_DEAR;          /* save DEAR and ESR in the frame  */\
 122         stw     r12,_DEAR(r11);         /* since they may have had stuff   */\
 123         mfspr   r9,SPRN_ESR;            /* in them at the point where the  */\
 124         stw     r9,_ESR(r11);           /* exception was taken             */\
 125         mfspr   r12,SPRN_CSRR0;                                              \
 126         stw     r1,GPR1(r11);                                                \
 127         mfspr   r9,SPRN_CSRR1;                                               \
 128         stw     r1,0(r11);                                                   \
 129         mr      r1,r11;                                                      \
 130         rlwinm  r9,r9,0,14,12;          /* clear MSR_WE (necessary?)       */\
 131         stw     r0,GPR0(r11);                                                \
 132         SAVE_4GPRS(3, r11);                                                  \
 133         SAVE_2GPRS(7, r11)
 134
 135 /*
 136  * Exception prolog for machine check exceptions.  This is similar to
 137  * the critical exception prolog, except that machine check exceptions
 138  * have their stack.
 139  */
 140 #define MCHECK_EXCEPTION_PROLOG                                      \
 141         mtspr   MCHECK_SPRG,r8;                                              \
 142         BOOKE_LOAD_MCHECK_STACK;        /* r8 points to the mcheck stack   */\
 143         stw     r10,GPR10-INT_FRAME_SIZE(r8);                                \
 144         stw     r11,GPR11-INT_FRAME_SIZE(r8);                                \
 145         mfcr    r10;                    /* save CR in r10 for now          */\
 146         mfspr   r11,SPRN_MCSRR1;        /* check whether user or kernel    */\
 147         andi.   r11,r11,MSR_PR;                                              \
 148         mr      r11,r8;                                                      \
 149         mfspr   r8,MCHECK_SPRG;                                              \
 150         beq     1f;                                                          \
 151         /* COMING FROM USER MODE */                                          \
 152         mfspr   r11,SPRN_SPRG3;         /* if from user, start at top of   */\
 153         lwz     r11,THREAD_INFO-THREAD(r11); /* this thread's kernel stack */\
 154         addi    r11,r11,THREAD_SIZE;                                         \
 155 1:      subi    r11,r11,INT_FRAME_SIZE; /* Allocate an exception frame     */\
 156         stw     r10,_CCR(r11);          /* save various registers          */\
 157         stw     r12,GPR12(r11);                                              \
 158         stw     r9,GPR9(r11);                                                \
 159         mflr    r10;                                                         \
 160         stw     r10,_LINK(r11);                                              \
 161         mfspr   r12,SPRN_DEAR;          /* save DEAR and ESR in the frame  */\
 162         stw     r12,_DEAR(r11);         /* since they may have had stuff   */\
 163         mfspr   r9,SPRN_ESR;            /* in them at the point where the  */\
 164         stw     r9,_ESR(r11);           /* exception was taken             */\
 165         mfspr   r12,SPRN_MCSRR0;                                             \
 166         stw     r1,GPR1(r11);                                                \
 167         mfspr   r9,SPRN_MCSRR1;                                              \
 168         stw     r1,0(r11);                                                   \
 169         mr      r1,r11;                                                      \
 170         rlwinm  r9,r9,0,14,12;          /* clear MSR_WE (necessary?)       */\
 171         stw     r0,GPR0(r11);                                                \
 172         SAVE_4GPRS(3, r11);                                                  \
 173         SAVE_2GPRS(7, r11)
 174
 175 /*
 176  * Exception vectors.
 177  */
 178 #define START_EXCEPTION(label)                                               \
 179         .align 5;                                                            \
 180 label:
 181
 182 #define FINISH_EXCEPTION(func)                                  \
 183         bl      transfer_to_handler_full;                       \
 184         .long   func;                                           \
 185         .long   ret_from_except_full
 186
 187 #define EXCEPTION(n, label, hdlr, xfer)                         \
 188         START_EXCEPTION(label);                                 \
 189         NORMAL_EXCEPTION_PROLOG;                                \
 190         addi    r3,r1,STACK_FRAME_OVERHEAD;                     \
 191         xfer(n, hdlr)
 192
 193 #define CRITICAL_EXCEPTION(n, label, hdlr)                      \
 194         START_EXCEPTION(label);                                 \
 195         CRITICAL_EXCEPTION_PROLOG;                              \
 196         addi    r3,r1,STACK_FRAME_OVERHEAD;                     \
 197         EXC_XFER_TEMPLATE(hdlr, n+2, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), \
 198                           NOCOPY, crit_transfer_to_handler, \
 199                           ret_from_crit_exc)
 200
 201 #define MCHECK_EXCEPTION(n, label, hdlr)                        \
 202         START_EXCEPTION(label);                                 \
 203         MCHECK_EXCEPTION_PROLOG;                                \
 204         mfspr   r5,SPRN_ESR;                                    \
 205         stw     r5,_ESR(r11);                                   \
 206         addi    r3,r1,STACK_FRAME_OVERHEAD;                     \
 207         EXC_XFER_TEMPLATE(hdlr, n+2, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), \
 208                           NOCOPY, mcheck_transfer_to_handler,   \
 209                           ret_from_mcheck_exc)
 210
 211 #define EXC_XFER_TEMPLATE(hdlr, trap, msr, copyee, tfer, ret)   \
 212         li      r10,trap;                                       \
 213         stw     r10,TRAP(r11);                                  \
 214         lis     r10,msr@h;                                      \
 215         ori     r10,r10,msr@l;                                  \
 216         copyee(r10, r9);                                        \
 217         bl      tfer;                                           \
 218         .long   hdlr;                                           \
 219         .long   ret
 220
 221 #define COPY_EE(d, s)           rlwimi d,s,0,16,16
 222 #define NOCOPY(d, s)
 223
 224 #define EXC_XFER_STD(n, hdlr)           \
 225         EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, NOCOPY, transfer_to_handler_full, \
 226                           ret_from_except_full)
 227
 228 #define EXC_XFER_LITE(n, hdlr)          \
 229         EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, NOCOPY, transfer_to_handler, \
 230                           ret_from_except)
 231
 232 #define EXC_XFER_EE(n, hdlr)            \
 233         EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, COPY_EE, transfer_to_handler_full, \
 234                           ret_from_except_full)
 235
 236 #define EXC_XFER_EE_LITE(n, hdlr)       \
 237         EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, COPY_EE, transfer_to_handler, \
 238                           ret_from_except)
 239
 240
 241 /* Check for a single step debug exception while in an exception
 242  * handler before state has been saved.  This is to catch the case
 243  * where an instruction that we are trying to single step causes
 244  * an exception (eg ITLB/DTLB miss) and thus the first instruction of
 245  * the exception handler generates a single step debug exception.
 246  *
 247  * If we get a debug trap on the first instruction of an exception handler,
 248  * we reset the MSR_DE in the _exception handler's_ MSR (the debug trap is
 249  * a critical exception, so we are using SPRN_CSRR1 to manipulate the MSR).
 250  * The exception handler was handling a non-critical interrupt, so it will
 251  * save (and later restore) the MSR via SPRN_CSRR1, which will still have
 252  * the MSR_DE bit set.
 253  */
 254 #define DEBUG_EXCEPTION                                                       \
 255         START_EXCEPTION(Debug);                                               \
 256         CRITICAL_EXCEPTION_PROLOG;                                            \
 257                                                                               \
 258         /*                                                                    \
 259          * If there is a single step or branch-taken exception in an          \
 260          * exception entry sequence, it was probably meant to apply to        \
 261          * the code where the exception occurred (since exception entry       \
 262          * doesn't turn off DE automatically).  We simulate the effect        \
 263          * of turning off DE on entry to an exception handler by turning      \
 264          * off DE in the CSRR1 value and clearing the debug status.           \
 265          */                                                                   \
 266         mfspr   r10,SPRN_DBSR;          /* check single-step/branch taken */  \
 267         andis.  r10,r10,DBSR_IC@h;                                            \
 268         beq+    2f;                                                           \
 269                                                                               \
 270         lis     r10,KERNELBASE@h;       /* check if exception in vectors */   \
 271         ori     r10,r10,KERNELBASE@l;                                         \
 272         cmplw   r12,r10;                                                      \
 273         blt+    2f;                     /* addr below exception vectors */    \
 274                                                                               \
 275         lis     r10,Debug@h;                                                  \
 276         ori     r10,r10,Debug@l;                                              \
 277         cmplw   r12,r10;                                                      \
 278         bgt+    2f;                     /* addr above exception vectors */    \
 279                                                                               \
 280         /* here it looks like we got an inappropriate debug exception. */     \
 281 1:      rlwinm  r9,r9,0,~MSR_DE;        /* clear DE in the CSRR1 value */     \
 282         lis     r10,DBSR_IC@h;          /* clear the IC event */              \
 283         mtspr   SPRN_DBSR,r10;                                                \
 284         /* restore state and get out */                                       \
 285         lwz     r10,_CCR(r11);                                                \
 286         lwz     r0,GPR0(r11);                                                 \
 287         lwz     r1,GPR1(r11);                                                 \
 288         mtcrf   0x80,r10;                                                     \
 289         mtspr   SPRN_CSRR0,r12;                                               \
 290         mtspr   SPRN_CSRR1,r9;                                                \
 291         lwz     r9,GPR9(r11);                                                 \
 292         lwz     r12,GPR12(r11);                                               \
 293         mtspr   CRIT_SPRG,r8;                                                 \
 294         BOOKE_LOAD_CRIT_STACK;          /* r8 points to the crit stack */     \
 295         lwz     r10,GPR10-INT_FRAME_SIZE(r8);                                 \
 296         lwz     r11,GPR11-INT_FRAME_SIZE(r8);                                 \
 297         mfspr   r8,CRIT_SPRG;                                                 \
 298                                                                               \
 299         rfci;                                                                 \
 300         b       .;                                                            \
 301                                                                               \
 302         /* continue normal handling for a critical exception... */            \
 303 2:      mfspr   r4,SPRN_DBSR;                                                 \
 304         addi    r3,r1,STACK_FRAME_OVERHEAD;                                   \
 305         EXC_XFER_TEMPLATE(DebugException, 0x2002, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), NOCOPY, crit_transfer_to_handler, ret_from_crit_exc)
 306
 307 #define INSTRUCTION_STORAGE_EXCEPTION                                         \
 308         START_EXCEPTION(InstructionStorage)                                   \
 309         NORMAL_EXCEPTION_PROLOG;                                              \
 310         mfspr   r5,SPRN_ESR;            /* Grab the ESR and save it */        \
 311         stw     r5,_ESR(r11);                                                 \
 312         mr      r4,r12;                 /* Pass SRR0 as arg2 */               \
 313         li      r5,0;                   /* Pass zero as arg3 */               \
 314         EXC_XFER_EE_LITE(0x0400, handle_page_fault)
 315
 316 #define ALIGNMENT_EXCEPTION                                                   \
 317         START_EXCEPTION(Alignment)                                            \
 318         NORMAL_EXCEPTION_PROLOG;                                              \
 319         mfspr   r4,SPRN_DEAR;           /* Grab the DEAR and save it */       \
 320         stw     r4,_DEAR(r11);                                                \
 321         addi    r3,r1,STACK_FRAME_OVERHEAD;                                   \
 322         EXC_XFER_EE(0x0600, AlignmentException)
 323
 324 #define PROGRAM_EXCEPTION                                                     \
 325         START_EXCEPTION(Program)                                              \
 326         NORMAL_EXCEPTION_PROLOG;                                              \
 327         mfspr   r4,SPRN_ESR;            /* Grab the ESR and save it */        \
 328         stw     r4,_ESR(r11);                                                 \
 329         addi    r3,r1,STACK_FRAME_OVERHEAD;                                   \
 330         EXC_XFER_STD(0x0700, ProgramCheckException)
 331
 332 #define DECREMENTER_EXCEPTION                                                 \
 333         START_EXCEPTION(Decrementer)                                          \
 334         NORMAL_EXCEPTION_PROLOG;                                              \
 335         lis     r0,TSR_DIS@h;           /* Setup the DEC interrupt mask */    \
 336         mtspr   SPRN_TSR,r0;            /* Clear the DEC interrupt */         \
 337         addi    r3,r1,STACK_FRAME_OVERHEAD;                                   \
 338         EXC_XFER_LITE(0x0900, timer_interrupt)
 339
 340 #define FP_UNAVAILABLE_EXCEPTION                                              \
 341         START_EXCEPTION(FloatingPointUnavailable)                             \
 342         NORMAL_EXCEPTION_PROLOG;                                              \
 343         bne     load_up_fpu;            /* if from user, just load it up */   \
 344         addi    r3,r1,STACK_FRAME_OVERHEAD;                                   \
 345         EXC_XFER_EE_LITE(0x800, KernelFP)
 346
 347 #endif /* __HEAD_BOOKE_H__ */