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__FBSDID("$FreeBSD$"); 37 38#include "assym.inc" 39 40#include <machine/trap.h> 41#include <machine/riscvreg.h> 42 43.macro save_registers el 44 addi sp, sp, -(TF_SIZE) 45 46 sd ra, (TF_RA)(sp) 47 48.if \el == 0 /* We came from userspace. */ 49 sd gp, (TF_GP)(sp) 50.option push 51.option norelax 52 /* Load the kernel's global pointer */ 53 la gp, __global_pointer$ 54.option pop 55 56 /* Load our pcpu */ 57 sd tp, (TF_TP)(sp) 58 ld tp, (TF_SIZE)(sp) 59.endif 60 61 sd t0, (TF_T + 0 * 8)(sp) 62 sd t1, (TF_T + 1 * 8)(sp) 63 sd t2, (TF_T + 2 * 8)(sp) 64 sd t3, (TF_T + 3 * 8)(sp) 65 sd t4, (TF_T + 4 * 8)(sp) 66 sd t5, (TF_T + 5 * 8)(sp) 67 sd t6, (TF_T + 6 * 8)(sp) 68 69 sd s0, (TF_S + 0 * 8)(sp) 70 sd s1, (TF_S + 1 * 8)(sp) 71 sd s2, (TF_S + 2 * 8)(sp) 72 sd s3, (TF_S + 3 * 8)(sp) 73 sd s4, (TF_S + 4 * 8)(sp) 74 sd s5, (TF_S + 5 * 8)(sp) 75 sd s6, (TF_S + 6 * 8)(sp) 76 sd s7, (TF_S + 7 * 8)(sp) 77 sd s8, (TF_S + 8 * 8)(sp) 78 sd s9, (TF_S + 9 * 8)(sp) 79 sd s10, (TF_S + 10 * 8)(sp) 80 sd s11, (TF_S + 11 * 8)(sp) 81 82 sd a0, (TF_A + 0 * 8)(sp) 83 sd a1, (TF_A + 1 * 8)(sp) 84 sd a2, (TF_A + 2 * 8)(sp) 85 sd a3, (TF_A + 3 * 8)(sp) 86 sd a4, (TF_A + 4 * 8)(sp) 87 sd a5, (TF_A + 5 * 8)(sp) 88 sd a6, (TF_A + 6 * 8)(sp) 89 sd a7, (TF_A + 7 * 8)(sp) 90 91.if \el == 1 92 /* Store kernel sp */ 93 li t1, TF_SIZE 94 add t0, sp, t1 95 sd t0, (TF_SP)(sp) 96.else 97 /* Store user sp */ 98 csrr t0, sscratch 99 sd t0, (TF_SP)(sp) 100.endif 101 li t0, 0 102 csrw sscratch, t0 103 csrr t0, sepc 104 sd t0, (TF_SEPC)(sp) 105 csrr t0, sstatus 106 sd t0, (TF_SSTATUS)(sp) 107 csrr t0, stval 108 sd t0, (TF_STVAL)(sp) 109 csrr t0, scause 110 sd t0, (TF_SCAUSE)(sp) 111.endm 112 113.macro load_registers el 114 ld t0, (TF_SSTATUS)(sp) 115.if \el == 0 116 /* Ensure user interrupts will be enabled on eret */ 117 li t1, SSTATUS_SPIE 118 or t0, t0, t1 119.else 120 /* 121 * Disable interrupts for supervisor mode exceptions. 122 * For user mode exceptions we have already done this 123 * in do_ast. 124 */ 125 li t1, ~SSTATUS_SIE 126 and t0, t0, t1 127.endif 128 csrw sstatus, t0 129 130 ld t0, (TF_SEPC)(sp) 131 csrw sepc, t0 132 133.if \el == 0 134 /* We go to userspace. Load user sp */ 135 ld t0, (TF_SP)(sp) 136 csrw sscratch, t0 137 138 /* Store our pcpu */ 139 sd tp, (TF_SIZE)(sp) 140 ld tp, (TF_TP)(sp) 141 142 /* And restore the user's global pointer */ 143 ld gp, (TF_GP)(sp) 144.endif 145 146 ld ra, (TF_RA)(sp) 147 148 ld t0, (TF_T + 0 * 8)(sp) 149 ld t1, (TF_T + 1 * 8)(sp) 150 ld t2, (TF_T + 2 * 8)(sp) 151 ld t3, (TF_T + 3 * 8)(sp) 152 ld t4, (TF_T + 4 * 8)(sp) 153 ld t5, (TF_T + 5 * 8)(sp) 154 ld t6, (TF_T + 6 * 8)(sp) 155 156 ld s0, (TF_S + 0 * 8)(sp) 157 ld s1, (TF_S + 1 * 8)(sp) 158 ld s2, (TF_S + 2 * 8)(sp) 159 ld s3, (TF_S + 3 * 8)(sp) 160 ld s4, (TF_S + 4 * 8)(sp) 161 ld s5, (TF_S + 5 * 8)(sp) 162 ld s6, (TF_S + 6 * 8)(sp) 163 ld s7, (TF_S + 7 * 8)(sp) 164 ld s8, (TF_S + 8 * 8)(sp) 165 ld s9, (TF_S + 9 * 8)(sp) 166 ld s10, (TF_S + 10 * 8)(sp) 167 ld s11, (TF_S + 11 * 8)(sp) 168 169 ld a0, (TF_A + 0 * 8)(sp) 170 ld a1, (TF_A + 1 * 8)(sp) 171 ld a2, (TF_A + 2 * 8)(sp) 172 ld a3, (TF_A + 3 * 8)(sp) 173 ld a4, (TF_A + 4 * 8)(sp) 174 ld a5, (TF_A + 5 * 8)(sp) 175 ld a6, (TF_A + 6 * 8)(sp) 176 ld a7, (TF_A + 7 * 8)(sp) 177 178 addi sp, sp, (TF_SIZE) 179.endm 180 181.macro do_ast 182 /* Disable interrupts */ 183 csrr a4, sstatus 1841: 185 csrci sstatus, (SSTATUS_SIE) 186 187 ld a1, PC_CURTHREAD(tp) 188 lw a2, TD_FLAGS(a1) 189 190 li a3, (TDF_ASTPENDING|TDF_NEEDRESCHED) 191 and a2, a2, a3 192 beqz a2, 2f 193 194 /* Restore interrupts */ 195 andi a4, a4, (SSTATUS_SIE) 196 csrs sstatus, a4 197 198 /* Handle the ast */ 199 mv a0, sp 200 call _C_LABEL(ast) 201 202 /* Re-check for new ast scheduled */ 203 j 1b 2042: 205.endm 206 207ENTRY(cpu_exception_handler) 208 csrrw sp, sscratch, sp 209 beqz sp, 1f 210 /* User mode detected */ 211 j cpu_exception_handler_user 2121: 213 /* Supervisor mode detected */ 214 csrrw sp, sscratch, sp 215 j cpu_exception_handler_supervisor 216END(cpu_exception_handler) 217 218ENTRY(cpu_exception_handler_supervisor) 219 save_registers 1 220 mv a0, sp 221 call _C_LABEL(do_trap_supervisor) 222 load_registers 1 223 sret 224END(cpu_exception_handler_supervisor) 225 226ENTRY(cpu_exception_handler_user) 227 save_registers 0 228 mv a0, sp 229 call _C_LABEL(do_trap_user) 230 do_ast 231 load_registers 0 232 csrrw sp, sscratch, sp 233 sret 234END(cpu_exception_handler_user) 235