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 <sys/cdefs.h> 36 __FBSDID("$FreeBSD$"); 37 38 #include <sys/param.h> 39 #include <sys/systm.h> 40 #include <sys/limits.h> 41 #include <sys/proc.h> 42 #include <sys/sf_buf.h> 43 #include <sys/signal.h> 44 #include <sys/unistd.h> 45 46 #include <vm/vm.h> 47 #include <vm/vm_page.h> 48 #include <vm/vm_map.h> 49 #include <vm/uma.h> 50 #include <vm/uma_int.h> 51 52 #include <machine/riscvreg.h> 53 #include <machine/cpu.h> 54 #include <machine/pcb.h> 55 #include <machine/frame.h> 56 #include <machine/sbi.h> 57 58 #if __riscv_xlen == 64 59 #define TP_OFFSET 16 /* sizeof(struct tcb) */ 60 #endif 61 62 /* 63 * Finish a fork operation, with process p2 nearly set up. 64 * Copy and update the pcb, set up the stack so that the child 65 * ready to run and return to user mode. 66 */ 67 void 68 cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags) 69 { 70 struct pcb *pcb2; 71 struct trapframe *tf; 72 73 if ((flags & RFPROC) == 0) 74 return; 75 76 /* RISCVTODO: save the FPU state here */ 77 78 pcb2 = (struct pcb *)(td2->td_kstack + 79 td2->td_kstack_pages * PAGE_SIZE) - 1; 80 81 td2->td_pcb = pcb2; 82 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2)); 83 84 tf = (struct trapframe *)STACKALIGN((struct trapframe *)pcb2 - 1); 85 bcopy(td1->td_frame, tf, sizeof(*tf)); 86 87 /* Clear syscall error flag */ 88 tf->tf_t[0] = 0; 89 90 /* Arguments for child */ 91 tf->tf_a[0] = 0; 92 tf->tf_a[1] = 0; 93 tf->tf_sstatus |= (SSTATUS_SPIE); /* Enable interrupts. */ 94 tf->tf_sstatus &= ~(SSTATUS_SPP); /* User mode. */ 95 96 td2->td_frame = tf; 97 98 /* Set the return value registers for fork() */ 99 td2->td_pcb->pcb_s[0] = (uintptr_t)fork_return; 100 td2->td_pcb->pcb_s[1] = (uintptr_t)td2; 101 td2->td_pcb->pcb_ra = (uintptr_t)fork_trampoline; 102 td2->td_pcb->pcb_sp = (uintptr_t)td2->td_frame; 103 104 /* Setup to release spin count in fork_exit(). */ 105 td2->td_md.md_spinlock_count = 1; 106 td2->td_md.md_saved_sstatus_ie = (SSTATUS_SIE); 107 } 108 109 void 110 cpu_reset(void) 111 { 112 113 sbi_system_reset(SBI_SRST_TYPE_COLD_REBOOT, SBI_SRST_REASON_NONE); 114 115 while(1); 116 } 117 118 void 119 cpu_thread_swapin(struct thread *td) 120 { 121 } 122 123 void 124 cpu_thread_swapout(struct thread *td) 125 { 126 } 127 128 void 129 cpu_set_syscall_retval(struct thread *td, int error) 130 { 131 struct trapframe *frame; 132 133 frame = td->td_frame; 134 135 if (__predict_true(error == 0)) { 136 frame->tf_a[0] = td->td_retval[0]; 137 frame->tf_a[1] = td->td_retval[1]; 138 frame->tf_t[0] = 0; /* syscall succeeded */ 139 return; 140 } 141 142 switch (error) { 143 case ERESTART: 144 frame->tf_sepc -= 4; /* prev instruction */ 145 break; 146 case EJUSTRETURN: 147 break; 148 default: 149 frame->tf_a[0] = error; 150 frame->tf_t[0] = 1; /* syscall error */ 151 break; 152 } 153 } 154 155 /* 156 * Initialize machine state, mostly pcb and trap frame for a new 157 * thread, about to return to userspace. Put enough state in the new 158 * thread's PCB to get it to go back to the fork_return(), which 159 * finalizes the thread state and handles peculiarities of the first 160 * return to userspace for the new thread. 161 */ 162 void 163 cpu_copy_thread(struct thread *td, struct thread *td0) 164 { 165 166 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe)); 167 bcopy(td0->td_pcb, td->td_pcb, sizeof(struct pcb)); 168 169 td->td_pcb->pcb_s[0] = (uintptr_t)fork_return; 170 td->td_pcb->pcb_s[1] = (uintptr_t)td; 171 td->td_pcb->pcb_ra = (uintptr_t)fork_trampoline; 172 td->td_pcb->pcb_sp = (uintptr_t)td->td_frame; 173 174 /* Setup to release spin count in fork_exit(). */ 175 td->td_md.md_spinlock_count = 1; 176 td->td_md.md_saved_sstatus_ie = (SSTATUS_SIE); 177 } 178 179 /* 180 * Set that machine state for performing an upcall that starts 181 * the entry function with the given argument. 182 */ 183 void 184 cpu_set_upcall(struct thread *td, void (*entry)(void *), void *arg, 185 stack_t *stack) 186 { 187 struct trapframe *tf; 188 189 tf = td->td_frame; 190 191 tf->tf_sp = STACKALIGN((uintptr_t)stack->ss_sp + stack->ss_size); 192 tf->tf_sepc = (register_t)entry; 193 tf->tf_a[0] = (register_t)arg; 194 } 195 196 int 197 cpu_set_user_tls(struct thread *td, void *tls_base) 198 { 199 200 if ((uintptr_t)tls_base >= VM_MAXUSER_ADDRESS) 201 return (EINVAL); 202 203 /* 204 * The user TLS is set by modifying the trapframe's tp value, which 205 * will be restored when returning to userspace. 206 */ 207 td->td_frame->tf_tp = (register_t)tls_base + TP_OFFSET; 208 209 return (0); 210 } 211 212 void 213 cpu_thread_exit(struct thread *td) 214 { 215 } 216 217 void 218 cpu_thread_alloc(struct thread *td) 219 { 220 221 td->td_pcb = (struct pcb *)(td->td_kstack + 222 td->td_kstack_pages * PAGE_SIZE) - 1; 223 td->td_frame = (struct trapframe *)STACKALIGN( 224 (caddr_t)td->td_pcb - 8 - sizeof(struct trapframe)); 225 } 226 227 void 228 cpu_thread_free(struct thread *td) 229 { 230 } 231 232 void 233 cpu_thread_clean(struct thread *td) 234 { 235 } 236 237 /* 238 * Intercept the return address from a freshly forked process that has NOT 239 * been scheduled yet. 240 * 241 * This is needed to make kernel threads stay in kernel mode. 242 */ 243 void 244 cpu_fork_kthread_handler(struct thread *td, void (*func)(void *), void *arg) 245 { 246 247 td->td_pcb->pcb_s[0] = (uintptr_t)func; 248 td->td_pcb->pcb_s[1] = (uintptr_t)arg; 249 td->td_pcb->pcb_ra = (uintptr_t)fork_trampoline; 250 td->td_pcb->pcb_sp = (uintptr_t)td->td_frame; 251 } 252 253 void 254 cpu_exit(struct thread *td) 255 { 256 } 257 258 bool 259 cpu_exec_vmspace_reuse(struct proc *p __unused, vm_map_t map __unused) 260 { 261 262 return (true); 263 } 264 265 int 266 cpu_procctl(struct thread *td __unused, int idtype __unused, id_t id __unused, 267 int com __unused, void *data __unused) 268 { 269 270 return (EINVAL); 271 } 272