arch/powerpc/platforms/iseries/exception.S

   1 /*
   2  *  Low level routines for legacy iSeries support.
   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 #include <asm/reg.h>
  29 #include <asm/ppc_asm.h>
  30 #include <asm/asm-offsets.h>
  31 #include <asm/thread_info.h>
  32 #include <asm/ptrace.h>
  33 #include <asm/cputable.h>
  34
  35 #include "exception.h"
  36
  37         .text
  38
  39         .globl system_reset_iSeries
  40 system_reset_iSeries:
  41         bl      .relative_toc
  42         mfspr   r13,SPRN_SPRG3          /* Get alpaca address */
  43         LOAD_REG_ADDR(r23, alpaca)
  44         li      r0,ALPACA_SIZE
  45         sub     r23,r13,r23
  46         divdu   r23,r23,r0              /* r23 has cpu number */
  47         LOAD_REG_ADDR(r13, paca)
  48         mulli   r0,r23,PACA_SIZE
  49         add     r13,r13,r0
  50         mtspr   SPRN_SPRG3,r13          /* Save it away for the future */
  51         mfmsr   r24
  52         ori     r24,r24,MSR_RI
  53         mtmsrd  r24                     /* RI on */
  54         mr      r24,r23
  55         cmpwi   0,r24,0                 /* Are we processor 0? */
  56         bne     1f
  57         b       .__start_initialization_iSeries /* Start up the first processor */
  58 1:      mfspr   r4,SPRN_CTRLF
  59         li      r5,CTRL_RUNLATCH        /* Turn off the run light */
  60         andc    r4,r4,r5
  61         mtspr   SPRN_CTRLT,r4
  62
  63 /* Spin on __secondary_hold_spinloop until it is updated by the boot cpu. */
  64 /* In the UP case we'll yield() later, and we will not access the paca anyway */
  65 #ifdef CONFIG_SMP
  66 1:
  67         HMT_LOW
  68         LOAD_REG_ADDR(r23, __secondary_hold_spinloop)
  69         ld      r23,0(r23)
  70         sync
  71         LOAD_REG_ADDR(r3,current_set)
  72         sldi    r28,r24,3               /* get current_set[cpu#] */
  73         ldx     r3,r3,r28
  74         addi    r1,r3,THREAD_SIZE
  75         subi    r1,r1,STACK_FRAME_OVERHEAD
  76
  77         cmpwi   0,r23,0                 /* Keep poking the Hypervisor until */
  78         bne     2f                      /* we're released */
  79         /* Let the Hypervisor know we are alive */
  80         /* 8002 is a call to HvCallCfg::getLps, a harmless Hypervisor function */
  81         lis     r3,0x8002
  82         rldicr  r3,r3,32,15             /* r0 = (r3 << 32) & 0xffff000000000000 */
  83         li      r0,-1                   /* r0=-1 indicates a Hypervisor call */
  84         sc                              /* Invoke the hypervisor via a system call */
  85         b       1b
  86 #endif
  87
  88 2:
  89         HMT_LOW
  90 #ifdef CONFIG_SMP
  91         lbz     r23,PACAPROCSTART(r13)  /* Test if this processor
  92                                          * should start */
  93         sync
  94         LOAD_REG_ADDR(r3,current_set)
  95         sldi    r28,r24,3               /* get current_set[cpu#] */
  96         ldx     r3,r3,r28
  97         addi    r1,r3,THREAD_SIZE
  98         subi    r1,r1,STACK_FRAME_OVERHEAD
  99
 100         cmpwi   0,r23,0
 101         beq     iSeries_secondary_smp_loop      /* Loop until told to go */
 102         b       __secondary_start               /* Loop until told to go */
 103 iSeries_secondary_smp_loop:
 104         /* Let the Hypervisor know we are alive */
 105         /* 8002 is a call to HvCallCfg::getLps, a harmless Hypervisor function */
 106         lis     r3,0x8002
 107         rldicr  r3,r3,32,15             /* r0 = (r3 << 32) & 0xffff000000000000 */
 108 #else /* CONFIG_SMP */
 109         /* Yield the processor.  This is required for non-SMP kernels
 110                 which are running on multi-threaded machines. */
 111         lis     r3,0x8000
 112         rldicr  r3,r3,32,15             /* r3 = (r3 << 32) & 0xffff000000000000 */
 113         addi    r3,r3,18                /* r3 = 0x8000000000000012 which is "yield" */
 114         li      r4,0                    /* "yield timed" */
 115         li      r5,-1                   /* "yield forever" */
 116 #endif /* CONFIG_SMP */
 117         li      r0,-1                   /* r0=-1 indicates a Hypervisor call */
 118         sc                              /* Invoke the hypervisor via a system call */
 119         mfspr   r13,SPRN_SPRG3          /* Put r13 back ???? */
 120         b       2b                      /* If SMP not configured, secondaries
 121                                          * loop forever */
 122
 123 /***  ISeries-LPAR interrupt handlers ***/
 124
 125         STD_EXCEPTION_ISERIES(machine_check, PACA_EXMC)
 126
 127         .globl data_access_iSeries
 128 data_access_iSeries:
 129         mtspr   SPRN_SPRG1,r13
 130 BEGIN_FTR_SECTION
 131         mtspr   SPRN_SPRG2,r12
 132         mfspr   r13,SPRN_DAR
 133         mfspr   r12,SPRN_DSISR
 134         srdi    r13,r13,60
 135         rlwimi  r13,r12,16,0x20
 136         mfcr    r12
 137         cmpwi   r13,0x2c
 138         beq     .do_stab_bolted_iSeries
 139         mtcrf   0x80,r12
 140         mfspr   r12,SPRN_SPRG2
 141 END_FTR_SECTION_IFCLR(CPU_FTR_SLB)
 142         EXCEPTION_PROLOG_1(PACA_EXGEN)
 143         EXCEPTION_PROLOG_ISERIES_1
 144         b       data_access_common
 145
 146 .do_stab_bolted_iSeries:
 147         mtcrf   0x80,r12
 148         mfspr   r12,SPRN_SPRG2
 149         EXCEPTION_PROLOG_1(PACA_EXSLB)
 150         EXCEPTION_PROLOG_ISERIES_1
 151         b       .do_stab_bolted
 152
 153         .globl  data_access_slb_iSeries
 154 data_access_slb_iSeries:
 155         mtspr   SPRN_SPRG1,r13          /* save r13 */
 156         mfspr   r13,SPRN_SPRG3          /* get paca address into r13 */
 157         std     r3,PACA_EXSLB+EX_R3(r13)
 158         mfspr   r3,SPRN_DAR
 159         std     r9,PACA_EXSLB+EX_R9(r13)
 160         mfcr    r9
 161 #ifdef __DISABLED__
 162         cmpdi   r3,0
 163         bge     slb_miss_user_iseries
 164 #endif
 165         std     r10,PACA_EXSLB+EX_R10(r13)
 166         std     r11,PACA_EXSLB+EX_R11(r13)
 167         std     r12,PACA_EXSLB+EX_R12(r13)
 168         mfspr   r10,SPRN_SPRG1
 169         std     r10,PACA_EXSLB+EX_R13(r13)
 170         ld      r12,PACALPPACAPTR(r13)
 171         ld      r12,LPPACASRR1(r12)
 172         b       .slb_miss_realmode
 173
 174         STD_EXCEPTION_ISERIES(instruction_access, PACA_EXGEN)
 175
 176         .globl  instruction_access_slb_iSeries
 177 instruction_access_slb_iSeries:
 178         mtspr   SPRN_SPRG1,r13          /* save r13 */
 179         mfspr   r13,SPRN_SPRG3          /* get paca address into r13 */
 180         std     r3,PACA_EXSLB+EX_R3(r13)
 181         ld      r3,PACALPPACAPTR(r13)
 182         ld      r3,LPPACASRR0(r3)       /* get SRR0 value */
 183         std     r9,PACA_EXSLB+EX_R9(r13)
 184         mfcr    r9
 185 #ifdef __DISABLED__
 186         cmpdi   r3,0
 187         bge     slb_miss_user_iseries
 188 #endif
 189         std     r10,PACA_EXSLB+EX_R10(r13)
 190         std     r11,PACA_EXSLB+EX_R11(r13)
 191         std     r12,PACA_EXSLB+EX_R12(r13)
 192         mfspr   r10,SPRN_SPRG1
 193         std     r10,PACA_EXSLB+EX_R13(r13)
 194         ld      r12,PACALPPACAPTR(r13)
 195         ld      r12,LPPACASRR1(r12)
 196         b       .slb_miss_realmode
 197
 198 #ifdef __DISABLED__
 199 slb_miss_user_iseries:
 200         std     r10,PACA_EXGEN+EX_R10(r13)
 201         std     r11,PACA_EXGEN+EX_R11(r13)
 202         std     r12,PACA_EXGEN+EX_R12(r13)
 203         mfspr   r10,SPRG1
 204         ld      r11,PACA_EXSLB+EX_R9(r13)
 205         ld      r12,PACA_EXSLB+EX_R3(r13)
 206         std     r10,PACA_EXGEN+EX_R13(r13)
 207         std     r11,PACA_EXGEN+EX_R9(r13)
 208         std     r12,PACA_EXGEN+EX_R3(r13)
 209         EXCEPTION_PROLOG_ISERIES_1
 210         b       slb_miss_user_common
 211 #endif
 212
 213         MASKABLE_EXCEPTION_ISERIES(hardware_interrupt)
 214         STD_EXCEPTION_ISERIES(alignment, PACA_EXGEN)
 215         STD_EXCEPTION_ISERIES(program_check, PACA_EXGEN)
 216         STD_EXCEPTION_ISERIES(fp_unavailable, PACA_EXGEN)
 217         MASKABLE_EXCEPTION_ISERIES(decrementer)
 218         STD_EXCEPTION_ISERIES(trap_0a, PACA_EXGEN)
 219         STD_EXCEPTION_ISERIES(trap_0b, PACA_EXGEN)
 220
 221         .globl  system_call_iSeries
 222 system_call_iSeries:
 223         mr      r9,r13
 224         mfspr   r13,SPRN_SPRG3
 225         EXCEPTION_PROLOG_ISERIES_1
 226         b       system_call_common
 227
 228         STD_EXCEPTION_ISERIES(single_step, PACA_EXGEN)
 229         STD_EXCEPTION_ISERIES(trap_0e, PACA_EXGEN)
 230         STD_EXCEPTION_ISERIES(performance_monitor, PACA_EXGEN)
 231
 232 decrementer_iSeries_masked:
 233         /* We may not have a valid TOC pointer in here. */
 234         li      r11,1
 235         ld      r12,PACALPPACAPTR(r13)
 236         stb     r11,LPPACADECRINT(r12)
 237         LOAD_REG_IMMEDIATE(r12, tb_ticks_per_jiffy)
 238         lwz     r12,0(r12)
 239         mtspr   SPRN_DEC,r12
 240         /* fall through */
 241
 242 hardware_interrupt_iSeries_masked:
 243         mtcrf   0x80,r9         /* Restore regs */
 244         ld      r12,PACALPPACAPTR(r13)
 245         ld      r11,LPPACASRR0(r12)
 246         ld      r12,LPPACASRR1(r12)
 247         mtspr   SPRN_SRR0,r11
 248         mtspr   SPRN_SRR1,r12
 249         ld      r9,PACA_EXGEN+EX_R9(r13)
 250         ld      r10,PACA_EXGEN+EX_R10(r13)
 251         ld      r11,PACA_EXGEN+EX_R11(r13)
 252         ld      r12,PACA_EXGEN+EX_R12(r13)
 253         ld      r13,PACA_EXGEN+EX_R13(r13)
 254         rfid
 255         b       .       /* prevent speculative execution */
 256
 257 _INIT_STATIC(__start_initialization_iSeries)
 258         /* Clear out the BSS */
 259         LOAD_REG_ADDR(r11,__bss_stop)
 260         LOAD_REG_ADDR(r8,__bss_start)
 261         sub     r11,r11,r8              /* bss size                     */
 262         addi    r11,r11,7               /* round up to an even double word */
 263         rldicl. r11,r11,61,3            /* shift right by 3             */
 264         beq     4f
 265         addi    r8,r8,-8
 266         li      r0,0
 267         mtctr   r11                     /* zero this many doublewords   */
 268 3:      stdu    r0,8(r8)
 269         bdnz    3b
 270 4:
 271         LOAD_REG_ADDR(r1,init_thread_union)
 272         addi    r1,r1,THREAD_SIZE
 273         li      r0,0
 274         stdu    r0,-STACK_FRAME_OVERHEAD(r1)
 275
 276         bl      .iSeries_early_setup
 277         bl      .early_setup
 278
 279         /* relocation is on at this point */
 280
 281         b       .start_here_common