LXR linux/arch/powerpc/kernel/head

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef __HEAD_32_H__
   3#define __HEAD_32_H__
   4
   5#include <asm/ptrace.h> /* for STACK_FRAME_REGS_MARKER */
   6
   7/*
   8 * Exception entry code.  This code runs with address translation
   9 * turned off, i.e. using physical addresses.
  10 * We assume sprg3 has the physical address of the current
  11 * task's thread_struct.
  12 */
  13.macro EXCEPTION_PROLOG         trapno name handle_dar_dsisr=0
  14        EXCEPTION_PROLOG_0      handle_dar_dsisr=\handle_dar_dsisr
  15        EXCEPTION_PROLOG_1
  16        EXCEPTION_PROLOG_2      \trapno \name handle_dar_dsisr=\handle_dar_dsisr
  17.endm
  18
  19.macro EXCEPTION_PROLOG_0 handle_dar_dsisr=0
  20        mtspr   SPRN_SPRG_SCRATCH0,r10
  21        mtspr   SPRN_SPRG_SCRATCH1,r11
  22        mfspr   r10, SPRN_SPRG_THREAD
  23        .if     \handle_dar_dsisr
  24#ifdef CONFIG_40x
  25        mfspr   r11, SPRN_DEAR
  26#else
  27        mfspr   r11, SPRN_DAR
  28#endif
  29        stw     r11, DAR(r10)
  30#ifdef CONFIG_40x
  31        mfspr   r11, SPRN_ESR
  32#else
  33        mfspr   r11, SPRN_DSISR
  34#endif
  35        stw     r11, DSISR(r10)
  36        .endif
  37        mfspr   r11, SPRN_SRR0
  38        stw     r11, SRR0(r10)
  39        mfspr   r11, SPRN_SRR1          /* check whether user or kernel */
  40        stw     r11, SRR1(r10)
  41        mfcr    r10
  42        andi.   r11, r11, MSR_PR
  43.endm
  44
  45.macro EXCEPTION_PROLOG_1
  46        mtspr   SPRN_SPRG_SCRATCH2,r1
  47        subi    r1, r1, INT_FRAME_SIZE          /* use r1 if kernel */
  48        beq     1f
  49        mfspr   r1,SPRN_SPRG_THREAD
  50        lwz     r1,TASK_STACK-THREAD(r1)
  51        addi    r1, r1, THREAD_SIZE - INT_FRAME_SIZE
  521:
  53#ifdef CONFIG_VMAP_STACK
  54        mtcrf   0x3f, r1
  55        bt      32 - THREAD_ALIGN_SHIFT, vmap_stack_overflow
  56#endif
  57.endm
  58
  59.macro EXCEPTION_PROLOG_2 trapno name handle_dar_dsisr=0
  60#ifdef CONFIG_PPC_8xx
  61        .if     \handle_dar_dsisr
  62        li      r11, RPN_PATTERN
  63        mtspr   SPRN_DAR, r11   /* Tag DAR, to be used in DTLB Error */
  64        .endif
  65#endif
  66        LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~MSR_RI) /* re-enable MMU */
  67        mtspr   SPRN_SRR1, r11
  68        lis     r11, 1f@h
  69        ori     r11, r11, 1f@l
  70        mtspr   SPRN_SRR0, r11
  71        mfspr   r11, SPRN_SPRG_SCRATCH2
  72        rfi
  73
  74        .text
  75\name\()_virt:
  761:
  77        stw     r11,GPR1(r1)
  78        stw     r11,0(r1)
  79        mr      r11, r1
  80        stw     r10,_CCR(r11)           /* save registers */
  81        stw     r12,GPR12(r11)
  82        stw     r9,GPR9(r11)
  83        mfspr   r10,SPRN_SPRG_SCRATCH0
  84        mfspr   r12,SPRN_SPRG_SCRATCH1
  85        stw     r10,GPR10(r11)
  86        stw     r12,GPR11(r11)
  87        mflr    r10
  88        stw     r10,_LINK(r11)
  89        mfspr   r12, SPRN_SPRG_THREAD
  90        tovirt(r12, r12)
  91        .if     \handle_dar_dsisr
  92        lwz     r10, DAR(r12)
  93        stw     r10, _DAR(r11)
  94        lwz     r10, DSISR(r12)
  95        stw     r10, _DSISR(r11)
  96        .endif
  97        lwz     r9, SRR1(r12)
  98        lwz     r12, SRR0(r12)
  99#ifdef CONFIG_40x
 100        rlwinm  r9,r9,0,14,12           /* clear MSR_WE (necessary?) */
 101#elif defined(CONFIG_PPC_8xx)
 102        mtspr   SPRN_EID, r2            /* Set MSR_RI */
 103#else
 104        li      r10, MSR_KERNEL         /* can take exceptions */
 105        mtmsr   r10                     /* (except for mach check in rtas) */
 106#endif
 107        COMMON_EXCEPTION_PROLOG_END \trapno
 108_ASM_NOKPROBE_SYMBOL(\name\()_virt)
 109.endm
 110
 111.macro COMMON_EXCEPTION_PROLOG_END trapno
 112        stw     r0,GPR0(r1)
 113        lis     r10,STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
 114        addi    r10,r10,STACK_FRAME_REGS_MARKER@l
 115        stw     r10,8(r1)
 116        li      r10, \trapno
 117        stw     r10,_TRAP(r1)
 118        SAVE_4GPRS(3, r1)
 119        SAVE_2GPRS(7, r1)
 120        SAVE_NVGPRS(r1)
 121        stw     r2,GPR2(r1)
 122        stw     r12,_NIP(r1)
 123        stw     r9,_MSR(r1)
 124        mfctr   r10
 125        mfspr   r2,SPRN_SPRG_THREAD
 126        stw     r10,_CTR(r1)
 127        tovirt(r2, r2)
 128        mfspr   r10,SPRN_XER
 129        addi    r2, r2, -THREAD
 130        stw     r10,_XER(r1)
 131        addi    r3,r1,STACK_FRAME_OVERHEAD
 132.endm
 133
 134.macro prepare_transfer_to_handler
 135#ifdef CONFIG_PPC_BOOK3S_32
 136        andi.   r12,r9,MSR_PR
 137        bne     777f
 138        bl      prepare_transfer_to_handler
 139777:
 140#endif
 141.endm
 142
 143.macro SYSCALL_ENTRY trapno
 144        mfspr   r9, SPRN_SRR1
 145        mfspr   r12, SPRN_SRR0
 146        LOAD_REG_IMMEDIATE(r11, MSR_KERNEL)             /* can take exceptions */
 147        lis     r10, 1f@h
 148        ori     r10, r10, 1f@l
 149        mtspr   SPRN_SRR1, r11
 150        mtspr   SPRN_SRR0, r10
 151        mfspr   r10,SPRN_SPRG_THREAD
 152        mr      r11, r1
 153        lwz     r1,TASK_STACK-THREAD(r10)
 154        tovirt(r10, r10)
 155        addi    r1, r1, THREAD_SIZE - INT_FRAME_SIZE
 156        rfi
 1571:
 158        stw     r12,_NIP(r1)
 159        mfcr    r12
 160        rlwinm  r12,r12,0,4,2   /* Clear SO bit in CR */
 161        stw     r12,_CCR(r1)
 162        b       transfer_to_syscall             /* jump to handler */
 163.endm
 164
 165/*
 166 * Note: code which follows this uses cr0.eq (set if from kernel),
 167 * r11, r12 (SRR0), and r9 (SRR1).
 168 *
 169 * Note2: once we have set r1 we are in a position to take exceptions
 170 * again, and we could thus set MSR:RI at that point.
 171 */
 172
 173/*
 174 * Exception vectors.
 175 */
 176#ifdef CONFIG_PPC_BOOK3S
 177#define START_EXCEPTION(n, label)               \
 178        __HEAD;                                 \
 179        . = n;                                  \
 180        DO_KVM n;                               \
 181label:
 182
 183#else
 184#define START_EXCEPTION(n, label)               \
 185        __HEAD;                                 \
 186        . = n;                                  \
 187label:
 188
 189#endif
 190
 191#define EXCEPTION(n, label, hdlr)               \
 192        START_EXCEPTION(n, label)               \
 193        EXCEPTION_PROLOG n label;               \
 194        prepare_transfer_to_handler;            \
 195        bl      hdlr;                           \
 196        b       interrupt_return
 197
 198.macro vmap_stack_overflow_exception
 199        __HEAD
 200vmap_stack_overflow:
 201#ifdef CONFIG_SMP
 202        mfspr   r1, SPRN_SPRG_THREAD
 203        lwz     r1, TASK_CPU - THREAD(r1)
 204        slwi    r1, r1, 3
 205        addis   r1, r1, emergency_ctx@ha
 206#else
 207        lis     r1, emergency_ctx@ha
 208#endif
 209        lwz     r1, emergency_ctx@l(r1)
 210        addi    r1, r1, THREAD_SIZE - INT_FRAME_SIZE
 211        EXCEPTION_PROLOG_2 0 vmap_stack_overflow
 212        prepare_transfer_to_handler
 213        bl      stack_overflow_exception
 214        b       interrupt_return
 215.endm
 216
 217#endif /* __HEAD_32_H__ */
 218