1/*- 2 * Copyright (c) 2015-2018 Ruslan Bukin <br@bsdpad.com> 3 * All rights reserved. 4 * 5 * Portions of this software were developed by SRI International and the 6 * University of Cambridge Computer Laboratory under DARPA/AFRL contract 7 * FA8750-10-C-0237 ("CTSRD"), as part of the DARPA CRASH research programme. 8 * 9 * Portions of this software were developed by the University of Cambridge 10 * Computer Laboratory as part of the CTSRD Project, with support from the 11 * UK Higher Education Innovation Fund (HEIF). 12 * 13 * Redistribution and use in source and binary forms, with or without 14 * modification, are permitted provided that the following conditions 15 * are met: 16 * 1. Redistributions of source code must retain the above copyright 17 * notice, this list of conditions and the following disclaimer. 18 * 2. Redistributions in binary form must reproduce the above copyright 19 * notice, this list of conditions and the following disclaimer in the 20 * documentation and/or other materials provided with the distribution. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 */ 34 35#include <machine/asm.h> 36#include "assym.inc" 37 38#include <machine/trap.h> 39#include <machine/riscvreg.h> 40 41.macro save_registers mode 42 addi sp, sp, -(TF_SIZE) 43 44 sd ra, (TF_RA)(sp) 45 sd tp, (TF_TP)(sp) 46 sd gp, (TF_GP)(sp) 47 48.if \mode == 0 /* We came from userspace. */ 49.option push 50.option norelax 51 /* Load the kernel's global pointer */ 52 la gp, __global_pointer$ 53.option pop 54 55 /* Load our pcpu */ 56 ld tp, (TF_SIZE)(sp) 57.endif 58 59 sd t0, (TF_T + 0 * 8)(sp) 60 sd t1, (TF_T + 1 * 8)(sp) 61 sd t2, (TF_T + 2 * 8)(sp) 62 sd t3, (TF_T + 3 * 8)(sp) 63 sd t4, (TF_T + 4 * 8)(sp) 64 sd t5, (TF_T + 5 * 8)(sp) 65 sd t6, (TF_T + 6 * 8)(sp) 66 67 sd s0, (TF_S + 0 * 8)(sp) 68 sd s1, (TF_S + 1 * 8)(sp) 69 sd s2, (TF_S + 2 * 8)(sp) 70 sd s3, (TF_S + 3 * 8)(sp) 71 sd s4, (TF_S + 4 * 8)(sp) 72 sd s5, (TF_S + 5 * 8)(sp) 73 sd s6, (TF_S + 6 * 8)(sp) 74 sd s7, (TF_S + 7 * 8)(sp) 75 sd s8, (TF_S + 8 * 8)(sp) 76 sd s9, (TF_S + 9 * 8)(sp) 77 sd s10, (TF_S + 10 * 8)(sp) 78 sd s11, (TF_S + 11 * 8)(sp) 79 80 sd a0, (TF_A + 0 * 8)(sp) 81 sd a1, (TF_A + 1 * 8)(sp) 82 sd a2, (TF_A + 2 * 8)(sp) 83 sd a3, (TF_A + 3 * 8)(sp) 84 sd a4, (TF_A + 4 * 8)(sp) 85 sd a5, (TF_A + 5 * 8)(sp) 86 sd a6, (TF_A + 6 * 8)(sp) 87 sd a7, (TF_A + 7 * 8)(sp) 88 89.if \mode == 1 90 /* Store kernel sp */ 91 li t1, TF_SIZE 92 add t0, sp, t1 93 sd t0, (TF_SP)(sp) 94.else 95 /* Store user sp */ 96 csrr t0, sscratch 97 sd t0, (TF_SP)(sp) 98.endif 99 li t0, 0 100 csrw sscratch, t0 101 csrr t0, sepc 102 sd t0, (TF_SEPC)(sp) 103 csrr t0, sstatus 104 sd t0, (TF_SSTATUS)(sp) 105.if \mode == 1 106 /* Disable user address access for supervisor mode exceptions. */ 107 li t0, SSTATUS_SUM 108 csrc sstatus, t0 109.endif 110 csrr t0, stval 111 sd t0, (TF_STVAL)(sp) 112 csrr t0, scause 113 sd t0, (TF_SCAUSE)(sp) 114.endm 115 116.macro load_registers mode 117 ld t0, (TF_SSTATUS)(sp) 118.if \mode == 0 119 /* Ensure user interrupts will be enabled on eret */ 120 li t1, SSTATUS_SPIE 121 or t0, t0, t1 122.else 123 /* 124 * Disable interrupts for supervisor mode exceptions. 125 * For user mode exceptions we have already done this 126 * in do_ast. 127 */ 128 li t1, ~SSTATUS_SIE 129 and t0, t0, t1 130.endif 131 csrw sstatus, t0 132 133 ld t0, (TF_SEPC)(sp) 134 csrw sepc, t0 135 136.if \mode == 0 137 /* We go to userspace. Load user sp */ 138 ld t0, (TF_SP)(sp) 139 csrw sscratch, t0 140 141 /* Store our pcpu */ 142 sd tp, (TF_SIZE)(sp) 143 ld tp, (TF_TP)(sp) 144 145 /* And restore the user's global pointer */ 146 ld gp, (TF_GP)(sp) 147.endif 148 149 ld ra, (TF_RA)(sp) 150 151 ld t0, (TF_T + 0 * 8)(sp) 152 ld t1, (TF_T + 1 * 8)(sp) 153 ld t2, (TF_T + 2 * 8)(sp) 154 ld t3, (TF_T + 3 * 8)(sp) 155 ld t4, (TF_T + 4 * 8)(sp) 156 ld t5, (TF_T + 5 * 8)(sp) 157 ld t6, (TF_T + 6 * 8)(sp) 158 159 ld s0, (TF_S + 0 * 8)(sp) 160 ld s1, (TF_S + 1 * 8)(sp) 161 ld s2, (TF_S + 2 * 8)(sp) 162 ld s3, (TF_S + 3 * 8)(sp) 163 ld s4, (TF_S + 4 * 8)(sp) 164 ld s5, (TF_S + 5 * 8)(sp) 165 ld s6, (TF_S + 6 * 8)(sp) 166 ld s7, (TF_S + 7 * 8)(sp) 167 ld s8, (TF_S + 8 * 8)(sp) 168 ld s9, (TF_S + 9 * 8)(sp) 169 ld s10, (TF_S + 10 * 8)(sp) 170 ld s11, (TF_S + 11 * 8)(sp) 171 172 ld a0, (TF_A + 0 * 8)(sp) 173 ld a1, (TF_A + 1 * 8)(sp) 174 ld a2, (TF_A + 2 * 8)(sp) 175 ld a3, (TF_A + 3 * 8)(sp) 176 ld a4, (TF_A + 4 * 8)(sp) 177 ld a5, (TF_A + 5 * 8)(sp) 178 ld a6, (TF_A + 6 * 8)(sp) 179 ld a7, (TF_A + 7 * 8)(sp) 180 181 addi sp, sp, (TF_SIZE) 182.endm 183 184.macro do_ast 185 /* Disable interrupts */ 186 csrr a4, sstatus 1871: 188 csrci sstatus, (SSTATUS_SIE) 189 190 ld a1, PC_CURTHREAD(tp) 191 lw a2, TD_AST(a1) 192 193 beqz a2, 2f 194 195 /* Restore interrupts */ 196 andi a4, a4, (SSTATUS_SIE) 197 csrs sstatus, a4 198 199 /* Handle the ast */ 200 mv a0, sp 201 call _C_LABEL(ast) 202 203 /* Re-check for new ast scheduled */ 204 j 1b 2052: 206.endm 207 208ENTRY(cpu_exception_handler) 209 csrrw sp, sscratch, sp 210 beqz sp, 1f 211 /* User mode detected */ 212 j cpu_exception_handler_user 2131: 214 /* Supervisor mode detected */ 215 csrrw sp, sscratch, sp 216 j cpu_exception_handler_supervisor 217END(cpu_exception_handler) 218 219ENTRY(cpu_exception_handler_supervisor) 220 save_registers 1 221 mv a0, sp 222 call _C_LABEL(do_trap_supervisor) 223 load_registers 1 224 sret 225END(cpu_exception_handler_supervisor) 226 227ENTRY(cpu_exception_handler_user) 228 save_registers 0 229 mv a0, sp 230 call _C_LABEL(do_trap_user) 231 do_ast 232 load_registers 0 233 csrrw sp, sscratch, sp 234 sret 235END(cpu_exception_handler_user) 236