| /* |
| * (C) Copyright 2004, Psyent Corporation <www.psyent.com> |
| * Scott McNutt <smcnutt@psyent.com> |
| * |
| * SPDX-License-Identifier: GPL-2.0+ |
| */ |
| |
| #include <config.h> |
| #include <asm/opcodes.h> |
| |
| |
| .text |
| .align 4 |
| |
| .global _exception |
| |
| .set noat |
| .set nobreak |
| |
| _exception: |
| /* SAVE ALL REGS -- this allows trap and unimplemented |
| * instruction handlers to be coded conveniently in C |
| */ |
| addi sp, sp, -(33*4) |
| stw r0, 0(sp) |
| stw r1, 4(sp) |
| stw r2, 8(sp) |
| stw r3, 12(sp) |
| stw r4, 16(sp) |
| stw r5, 20(sp) |
| stw r6, 24(sp) |
| stw r7, 28(sp) |
| stw r8, 32(sp) |
| stw r9, 36(sp) |
| stw r10, 40(sp) |
| stw r11, 44(sp) |
| stw r12, 48(sp) |
| stw r13, 52(sp) |
| stw r14, 56(sp) |
| stw r15, 60(sp) |
| stw r16, 64(sp) |
| stw r17, 68(sp) |
| stw r19, 72(sp) |
| stw r19, 76(sp) |
| stw r20, 80(sp) |
| stw r21, 84(sp) |
| stw r22, 88(sp) |
| stw r23, 92(sp) |
| stw r24, 96(sp) |
| stw r25, 100(sp) |
| stw r26, 104(sp) |
| stw r27, 108(sp) |
| stw r28, 112(sp) |
| stw r29, 116(sp) |
| stw r30, 120(sp) |
| stw r31, 124(sp) |
| rdctl et, estatus |
| stw et, 128(sp) |
| |
| /* If interrupts are disabled -- software interrupt */ |
| rdctl et, estatus |
| andi et, et, 1 |
| beq et, r0, 0f |
| |
| /* If no interrupts are pending -- software interrupt */ |
| rdctl et, ipending |
| beq et, r0, 0f |
| |
| /* HARDWARE INTERRUPT: Call interrupt handler */ |
| movhi r3, %hi(external_interrupt) |
| ori r3, r3, %lo(external_interrupt) |
| mov r4, sp /* ptr to regs */ |
| callr r3 |
| |
| /* Return address fixup: execution resumes by re-issue of |
| * interrupted instruction at ea-4 (ea == r29). Here we do |
| * simple fixup to allow common exception return. |
| */ |
| ldw r3, 116(sp) |
| addi r3, r3, -4 |
| stw r3, 116(sp) |
| br _exception_return |
| |
| 0: |
| /* TRAP EXCEPTION */ |
| movhi r3, %hi(OPC_TRAP) |
| ori r3, r3, %lo(OPC_TRAP) |
| addi r1, ea, -4 |
| ldw r1, 0(r1) |
| bne r1, r3, 1f |
| movhi r3, %hi(trap_handler) |
| ori r3, r3, %lo(trap_handler) |
| mov r4, sp /* ptr to regs */ |
| callr r3 |
| br _exception_return |
| |
| 1: |
| /* UNIMPLEMENTED INSTRUCTION EXCEPTION */ |
| movhi r3, %hi(soft_emulation) |
| ori r3, r3, %lo(soft_emulation) |
| mov r4, sp /* ptr to regs */ |
| callr r3 |
| |
| /* Restore regsisters and return from exception*/ |
| _exception_return: |
| ldw r1, 4(sp) |
| ldw r2, 8(sp) |
| ldw r3, 12(sp) |
| ldw r4, 16(sp) |
| ldw r5, 20(sp) |
| ldw r6, 24(sp) |
| ldw r7, 28(sp) |
| ldw r8, 32(sp) |
| ldw r9, 36(sp) |
| ldw r10, 40(sp) |
| ldw r11, 44(sp) |
| ldw r12, 48(sp) |
| ldw r13, 52(sp) |
| ldw r14, 56(sp) |
| ldw r15, 60(sp) |
| ldw r16, 64(sp) |
| ldw r17, 68(sp) |
| ldw r19, 72(sp) |
| ldw r19, 76(sp) |
| ldw r20, 80(sp) |
| ldw r21, 84(sp) |
| ldw r22, 88(sp) |
| ldw r23, 92(sp) |
| ldw r24, 96(sp) |
| ldw r25, 100(sp) |
| ldw r26, 104(sp) |
| ldw r27, 108(sp) |
| ldw r28, 112(sp) |
| ldw r29, 116(sp) |
| ldw r30, 120(sp) |
| ldw r31, 124(sp) |
| addi sp, sp, (33*4) |
| eret |
| /*-------------------------------------------------------------*/ |