/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __HEAD_32_H__
#define __HEAD_32_H__

#include <asm/ptrace.h> /* for STACK_FRAME_REGS_MARKER */

/*
 * Exception entry code.  This code runs with address translation
 * turned off, i.e. using physical addresses.
 * We assume sprg3 has the physical address of the current
 * task's thread_struct.
 */
.macro EXCEPTION_PROLOG         trapno name handle_dar_dsisr=0
        EXCEPTION_PROLOG_0      handle_dar_dsisr=\handle_dar_dsisr
        EXCEPTION_PROLOG_1
        EXCEPTION_PROLOG_2      \trapno \name handle_dar_dsisr=\handle_dar_dsisr
.endm

.macro EXCEPTION_PROLOG_0 handle_dar_dsisr=0
        mtspr   SPRN_SPRG_SCRATCH0,r10
        mtspr   SPRN_SPRG_SCRATCH1,r11
        mfspr   r10, SPRN_SPRG_THREAD
        .if     \handle_dar_dsisr
        mfspr   r11, SPRN_DAR
        stw     r11, DAR(r10)
        mfspr   r11, SPRN_DSISR
        stw     r11, DSISR(r10)
        .endif
        mfspr   r11, SPRN_SRR0
        stw     r11, SRR0(r10)
        mfspr   r11, SPRN_SRR1          /* check whether user or kernel */
        stw     r11, SRR1(r10)
        mfcr    r10
        andi.   r11, r11, MSR_PR
.endm

.macro EXCEPTION_PROLOG_1
        mtspr   SPRN_SPRG_SCRATCH2,r1
        subi    r1, r1, INT_FRAME_SIZE          /* use r1 if kernel */
        beq     1f
        mfspr   r1,SPRN_SPRG_THREAD
        lwz     r1,TASK_STACK-THREAD(r1)
        addi    r1, r1, THREAD_SIZE - INT_FRAME_SIZE
1:
#ifdef CONFIG_VMAP_STACK
        mtcrf   0x3f, r1
        bt      32 - THREAD_ALIGN_SHIFT, vmap_stack_overflow
#endif
.endm

.macro EXCEPTION_PROLOG_2 trapno name handle_dar_dsisr=0
#ifdef CONFIG_PPC_8xx
        .if     \handle_dar_dsisr
        li      r11, RPN_PATTERN
        mtspr   SPRN_DAR, r11   /* Tag DAR, to be used in DTLB Error */
        .endif
#endif
        LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~MSR_RI) /* re-enable MMU */
        mtspr   SPRN_SRR1, r11
        lis     r11, 1f@h
        ori     r11, r11, 1f@l
        mtspr   SPRN_SRR0, r11
        mfspr   r11, SPRN_SPRG_SCRATCH2
        rfi

        .text
\name\()_virt:
1:
        stw     r11,GPR1(r1)
        stw     r11,0(r1)
        mr      r11, r1
        stw     r10,_CCR(r11)           /* save registers */
        stw     r12,GPR12(r11)
        stw     r9,GPR9(r11)
        mfspr   r10,SPRN_SPRG_SCRATCH0
        mfspr   r12,SPRN_SPRG_SCRATCH1
        stw     r10,GPR10(r11)
        stw     r12,GPR11(r11)
        mflr    r10
        stw     r10,_LINK(r11)
        mfspr   r12, SPRN_SPRG_THREAD
        tovirt(r12, r12)
        .if     \handle_dar_dsisr
        lwz     r10, DAR(r12)
        stw     r10, _DAR(r11)
        lwz     r10, DSISR(r12)
        stw     r10, _DSISR(r11)
        .endif
        lwz     r9, SRR1(r12)
        lwz     r12, SRR0(r12)
#ifdef CONFIG_PPC_8xx
        mtspr   SPRN_EID, r2            /* Set MSR_RI */
#else
        li      r10, MSR_KERNEL         /* can take exceptions */
        mtmsr   r10                     /* (except for mach check in rtas) */
#endif
        COMMON_EXCEPTION_PROLOG_END \trapno
_ASM_NOKPROBE_SYMBOL(\name\()_virt)
.endm

.macro COMMON_EXCEPTION_PROLOG_END trapno
        stw     r0,GPR0(r1)
        lis     r10,STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
        addi    r10,r10,STACK_FRAME_REGS_MARKER@l
        stw     r10,STACK_INT_FRAME_MARKER(r1)
        li      r10, \trapno
        stw     r10,_TRAP(r1)
        SAVE_GPRS(3, 8, r1)
        SAVE_NVGPRS(r1)
        stw     r2,GPR2(r1)
        stw     r12,_NIP(r1)
        stw     r9,_MSR(r1)
        mfctr   r10
        mfspr   r2,SPRN_SPRG_THREAD
        stw     r10,_CTR(r1)
        tovirt(r2, r2)
        mfspr   r10,SPRN_XER
        addi    r2, r2, -THREAD
        stw     r10,_XER(r1)
        addi    r3,r1,STACK_INT_FRAME_REGS
.endm

.macro prepare_transfer_to_handler
#ifdef CONFIG_PPC_BOOK3S_32
        andi.   r12,r9,MSR_PR
        bne     777f
        bl      prepare_transfer_to_handler
#ifdef CONFIG_PPC_KUEP
        b       778f
777:
        bl      __kuep_lock
778:
#endif
777:
#endif
.endm

.macro SYSCALL_ENTRY trapno
        mfspr   r9, SPRN_SRR1
        mfspr   r12, SPRN_SRR0
        LOAD_REG_IMMEDIATE(r11, MSR_KERNEL)             /* can take exceptions */
        lis     r10, 1f@h
        ori     r10, r10, 1f@l
        mtspr   SPRN_SRR1, r11
        mtspr   SPRN_SRR0, r10
        mfspr   r10,SPRN_SPRG_THREAD
        mr      r11, r1
        lwz     r1,TASK_STACK-THREAD(r10)
        tovirt(r10, r10)
        addi    r1, r1, THREAD_SIZE - INT_FRAME_SIZE
        rfi
1:
        stw     r12,_NIP(r1)
        mfcr    r12
        rlwinm  r12,r12,0,4,2   /* Clear SO bit in CR */
        stw     r12,_CCR(r1)
        b       transfer_to_syscall             /* jump to handler */
.endm

/*
 * Note: code which follows this uses cr0.eq (set if from kernel),
 * r11, r12 (SRR0), and r9 (SRR1).
 *
 * Note2: once we have set r1 we are in a position to take exceptions
 * again, and we could thus set MSR:RI at that point.
 */

/*
 * Exception vectors.
 */
#ifdef CONFIG_PPC_BOOK3S
#define START_EXCEPTION(n, label)               \
        __HEAD;                                 \
        . = n;                                  \
        DO_KVM n;                               \
label:

#else
#define START_EXCEPTION(n, label)               \
        __HEAD;                                 \
        . = n;                                  \
label:

#endif

#define EXCEPTION(n, label, hdlr)               \
        START_EXCEPTION(n, label)               \
        EXCEPTION_PROLOG n label;               \
        prepare_transfer_to_handler;            \
        bl      hdlr;                           \
        b       interrupt_return

.macro vmap_stack_overflow_exception
        __HEAD
vmap_stack_overflow:
#ifdef CONFIG_SMP
        mfspr   r1, SPRN_SPRG_THREAD
        lwz     r1, TASK_CPU - THREAD(r1)
        slwi    r1, r1, 3
        addis   r1, r1, emergency_ctx-PAGE_OFFSET@ha
#else
        lis     r1, emergency_ctx-PAGE_OFFSET@ha
#endif
        lwz     r1, emergency_ctx-PAGE_OFFSET@l(r1)
        addi    r1, r1, THREAD_SIZE - INT_FRAME_SIZE
        EXCEPTION_PROLOG_2 0 vmap_stack_overflow
        prepare_transfer_to_handler
        bl      stack_overflow_exception
        b       interrupt_return
.endm

#endif /* __HEAD_32_H__ */