1 /*- 2 * SPDX-License-Identifier: (BSD-4-Clause AND MIT-CMU) 3 * 4 * Copyright (c) 1982, 1986 The Regents of the University of California. 5 * Copyright (c) 1989, 1990 William Jolitz 6 * Copyright (c) 1994 John Dyson 7 * All rights reserved. 8 * 9 * This code is derived from software contributed to Berkeley by 10 * the Systems Programming Group of the University of Utah Computer 11 * Science Department, and William Jolitz. 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 * 3. All advertising materials mentioning features or use of this software 22 * must display the following acknowledgement: 23 * This product includes software developed by the University of 24 * California, Berkeley and its contributors. 25 * 4. Neither the name of the University nor the names of its contributors 26 * may be used to endorse or promote products derived from this software 27 * without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 39 * SUCH DAMAGE. 40 * Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$ 41 */ 42 /*- 43 * Copyright (c) 1994, 1995, 1996 Carnegie-Mellon University. 44 * All rights reserved. 45 * 46 * Author: Chris G. Demetriou 47 * 48 * Permission to use, copy, modify and distribute this software and 49 * its documentation is hereby granted, provided that both the copyright 50 * notice and this permission notice appear in all copies of the 51 * software, derivative works or modified versions, and any portions 52 * thereof, and that both notices appear in supporting documentation. 53 * 54 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 55 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 56 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 57 * 58 * Carnegie Mellon requests users of this software to return to 59 * 60 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 61 * School of Computer Science 62 * Carnegie Mellon University 63 * Pittsburgh PA 15213-3890 64 * 65 * any improvements or extensions that they make and grant Carnegie the 66 * rights to redistribute these changes. 67 */ 68 69 #include <sys/param.h> 70 #include <sys/systm.h> 71 #include <sys/proc.h> 72 #include <sys/malloc.h> 73 #include <sys/bio.h> 74 #include <sys/buf.h> 75 #include <sys/ktr.h> 76 #include <sys/lock.h> 77 #include <sys/mutex.h> 78 #include <sys/vnode.h> 79 #include <sys/vmmeter.h> 80 #include <sys/kernel.h> 81 #include <sys/mbuf.h> 82 #include <sys/sysctl.h> 83 #include <sys/sysent.h> 84 #include <sys/unistd.h> 85 86 #include <machine/cpu.h> 87 #include <machine/fpu.h> 88 #include <machine/frame.h> 89 #include <machine/md_var.h> 90 #include <machine/pcb.h> 91 #include <machine/reg.h> 92 93 #include <dev/ofw/openfirm.h> 94 95 #include <vm/vm.h> 96 #include <vm/vm_param.h> 97 #include <vm/vm_kern.h> 98 #include <vm/vm_page.h> 99 #include <vm/vm_map.h> 100 #include <vm/vm_extern.h> 101 102 /* 103 * Finish a fork operation, with process p2 nearly set up. 104 * Copy and update the pcb, set up the stack so that the child 105 * ready to run and return to user mode. 106 */ 107 void 108 cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags) 109 { 110 struct trapframe *tf; 111 struct callframe *cf; 112 struct pcb *pcb; 113 114 KASSERT(td1 == curthread || td1 == &thread0, 115 ("cpu_fork: p1 not curproc and not proc0")); 116 CTR3(KTR_PROC, "cpu_fork: called td1=%p p2=%p flags=%x", 117 td1, p2, flags); 118 119 if ((flags & RFPROC) == 0) 120 return; 121 122 /* Ensure td1 is up to date before copy. */ 123 if (td1 == curthread) 124 cpu_save_thread_regs(td1); 125 126 pcb = (struct pcb *)((td2->td_kstack + 127 td2->td_kstack_pages * PAGE_SIZE - sizeof(struct pcb)) & ~0x2fUL); 128 td2->td_pcb = pcb; 129 130 /* Copy the pcb */ 131 bcopy(td1->td_pcb, pcb, sizeof(struct pcb)); 132 133 /* 134 * Create a fresh stack for the new process. 135 * Copy the trap frame for the return to user mode as if from a 136 * syscall. This copies most of the user mode register values. 137 */ 138 tf = (struct trapframe *)pcb - 1; 139 bcopy(td1->td_frame, tf, sizeof(*tf)); 140 141 /* Set up trap frame. */ 142 tf->fixreg[FIRSTARG] = 0; 143 tf->fixreg[FIRSTARG + 1] = 0; 144 tf->cr &= ~0x10000000; 145 146 td2->td_frame = tf; 147 148 cf = (struct callframe *)tf - 1; 149 memset(cf, 0, sizeof(struct callframe)); 150 #if defined(__powerpc64__) && (!defined(_CALL_ELF) || _CALL_ELF == 1) 151 cf->cf_toc = ((register_t *)fork_return)[1]; 152 #endif 153 cf->cf_func = (register_t)fork_return; 154 cf->cf_arg0 = (register_t)td2; 155 cf->cf_arg1 = (register_t)tf; 156 157 pcb->pcb_sp = (register_t)cf; 158 KASSERT(pcb->pcb_sp % 16 == 0, ("stack misaligned")); 159 #if defined(__powerpc64__) && (!defined(_CALL_ELF) || _CALL_ELF == 1) 160 pcb->pcb_lr = ((register_t *)fork_trampoline)[0]; 161 pcb->pcb_toc = ((register_t *)fork_trampoline)[1]; 162 #else 163 pcb->pcb_lr = (register_t)fork_trampoline; 164 pcb->pcb_context[0] = pcb->pcb_lr; 165 #endif 166 #ifdef AIM 167 pcb->pcb_cpu.aim.usr_vsid = 0; 168 #endif 169 170 /* Setup to release spin count in fork_exit(). */ 171 td2->td_md.md_spinlock_count = 1; 172 td2->td_md.md_saved_msr = psl_kernset; 173 174 /* 175 * Now cpu_switch() can schedule the new process. 176 */ 177 } 178 179 /* 180 * Intercept the return address from a freshly forked process that has NOT 181 * been scheduled yet. 182 * 183 * This is needed to make kernel threads stay in kernel mode. 184 */ 185 void 186 cpu_fork_kthread_handler(struct thread *td, void (*func)(void *), void *arg) 187 { 188 struct callframe *cf; 189 190 CTR4(KTR_PROC, "%s called with td=%p func=%p arg=%p", 191 __func__, td, func, arg); 192 193 cf = (struct callframe *)td->td_pcb->pcb_sp; 194 195 #if defined(__powerpc64__) && (!defined(_CALL_ELF) || _CALL_ELF == 1) 196 cf->cf_toc = ((register_t *)func)[1]; 197 #endif 198 cf->cf_func = (register_t)func; 199 cf->cf_arg0 = (register_t)arg; 200 } 201 202 void 203 cpu_exit(struct thread *td) 204 { 205 206 } 207 208 /* 209 * CPU threading functions related to the VM layer. These could be used 210 * to map the SLB bits required for the kernel stack instead of forcing a 211 * fixed-size KVA. 212 */ 213 214 void 215 cpu_thread_swapin(struct thread *td) 216 { 217 218 } 219 220 void 221 cpu_thread_swapout(struct thread *td) 222 { 223 224 } 225 226 bool 227 cpu_exec_vmspace_reuse(struct proc *p __unused, vm_map_t map __unused) 228 { 229 230 return (true); 231 } 232 233 int 234 cpu_procctl(struct thread *td __unused, int idtype __unused, id_t id __unused, 235 int com __unused, void *data __unused) 236 { 237 238 return (EINVAL); 239 } 240 241 void 242 cpu_sync_core(void) 243 { 244 /* 245 * Linux performs "rfi" there. Our rendezvous IPI handler on 246 * the target cpu does "rfi" before and lwsync/sync after the 247 * action, which is stronger than required. 248 */ 249 } 250