1 /*- 2 * SPDX-License-Identifier: BSD-4-Clause 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 * 41 * from: @(#)vm_machdep.c 7.3 (Berkeley) 5/13/91 42 * Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$ 43 */ 44 45 #include <sys/cdefs.h> 46 #include <sys/param.h> 47 #include <sys/systm.h> 48 #include <sys/kernel.h> 49 #include <sys/malloc.h> 50 #include <sys/mbuf.h> 51 #include <sys/proc.h> 52 #include <sys/socketvar.h> 53 #include <sys/syscall.h> 54 #include <sys/sysctl.h> 55 #include <sys/sysent.h> 56 #include <sys/unistd.h> 57 58 #include <machine/cpu.h> 59 #include <machine/frame.h> 60 #include <machine/pcb.h> 61 #include <machine/sysarch.h> 62 #include <sys/lock.h> 63 #include <sys/mutex.h> 64 65 #include <vm/vm.h> 66 #include <vm/pmap.h> 67 #include <vm/vm_extern.h> 68 #include <vm/vm_kern.h> 69 #include <vm/vm_page.h> 70 #include <vm/vm_map.h> 71 #include <vm/vm_param.h> 72 #include <vm/vm_pageout.h> 73 #include <vm/uma.h> 74 #include <vm/uma_int.h> 75 76 #include <machine/md_var.h> 77 #include <machine/vfp.h> 78 79 /* 80 * struct switchframe and trapframe must both be a multiple of 8 81 * for correct stack alignment. 82 */ 83 _Static_assert((sizeof(struct switchframe) % 8) == 0, "Bad alignment"); 84 _Static_assert((sizeof(struct trapframe) % 8) == 0, "Bad alignment"); 85 86 uint32_t initial_fpscr = VFPSCR_DN | VFPSCR_FZ; 87 88 /* 89 * Finish a fork operation, with process p2 nearly set up. 90 * Copy and update the pcb, set up the stack so that the child 91 * ready to run and return to user mode. 92 */ 93 void 94 cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags) 95 { 96 struct pcb *pcb2; 97 struct trapframe *tf; 98 struct mdproc *mdp2; 99 100 if ((flags & RFPROC) == 0) 101 return; 102 103 /* Point the pcb to the top of the stack */ 104 pcb2 = (struct pcb *) 105 (td2->td_kstack + td2->td_kstack_pages * PAGE_SIZE) - 1; 106 #ifdef VFP 107 /* Store actual state of VFP */ 108 if (curthread == td1) { 109 if ((td1->td_pcb->pcb_fpflags & PCB_FP_STARTED) != 0) 110 vfp_save_state(td1, td1->td_pcb); 111 } 112 #endif 113 td2->td_pcb = pcb2; 114 115 /* Clone td1's pcb */ 116 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2)); 117 118 /* Point to mdproc and then copy over td1's contents */ 119 mdp2 = &p2->p_md; 120 bcopy(&td1->td_proc->p_md, mdp2, sizeof(*mdp2)); 121 122 /* Point the frame to the stack in front of pcb and copy td1's frame */ 123 td2->td_frame = (struct trapframe *)pcb2 - 1; 124 *td2->td_frame = *td1->td_frame; 125 126 /* 127 * Create a new fresh stack for the new process. 128 * Copy the trap frame for the return to user mode as if from a 129 * syscall. This copies most of the user mode register values. 130 */ 131 pmap_set_pcb_pagedir(vmspace_pmap(p2->p_vmspace), pcb2); 132 pcb2->pcb_regs.sf_r4 = (register_t)fork_return; 133 pcb2->pcb_regs.sf_r5 = (register_t)td2; 134 pcb2->pcb_regs.sf_lr = (register_t)fork_trampoline; 135 pcb2->pcb_regs.sf_sp = STACKALIGN(td2->td_frame); 136 pcb2->pcb_regs.sf_tpidrurw = (register_t)get_tls(); 137 138 #ifdef VFP 139 vfp_new_thread(td2, td1, true); 140 #endif 141 142 tf = td2->td_frame; 143 tf->tf_spsr &= ~PSR_C; 144 tf->tf_r0 = 0; 145 tf->tf_r1 = 0; 146 147 /* Setup to release spin count in fork_exit(). */ 148 td2->td_md.md_spinlock_count = 1; 149 td2->td_md.md_saved_cspr = PSR_SVC32_MODE; 150 } 151 152 void 153 cpu_thread_swapin(struct thread *td) 154 { 155 } 156 157 void 158 cpu_thread_swapout(struct thread *td) 159 { 160 } 161 162 void 163 cpu_set_syscall_retval(struct thread *td, int error) 164 { 165 struct trapframe *frame; 166 167 frame = td->td_frame; 168 switch (error) { 169 case 0: 170 frame->tf_r0 = td->td_retval[0]; 171 frame->tf_r1 = td->td_retval[1]; 172 frame->tf_spsr &= ~PSR_C; /* carry bit */ 173 break; 174 case ERESTART: 175 /* 176 * Reconstruct the pc to point at the swi. 177 */ 178 #if __ARM_ARCH >= 7 179 if ((frame->tf_spsr & PSR_T) != 0) 180 frame->tf_pc -= THUMB_INSN_SIZE; 181 else 182 #endif 183 frame->tf_pc -= INSN_SIZE; 184 break; 185 case EJUSTRETURN: 186 /* nothing to do */ 187 break; 188 default: 189 frame->tf_r0 = error; 190 frame->tf_spsr |= PSR_C; /* carry bit */ 191 break; 192 } 193 } 194 195 /* 196 * Initialize machine state, mostly pcb and trap frame for a new 197 * thread, about to return to userspace. Put enough state in the new 198 * thread's PCB to get it to go back to the fork_return(), which 199 * finalizes the thread state and handles peculiarities of the first 200 * return to userspace for the new thread. 201 */ 202 void 203 cpu_copy_thread(struct thread *td, struct thread *td0) 204 { 205 206 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe)); 207 bcopy(td0->td_pcb, td->td_pcb, sizeof(struct pcb)); 208 209 td->td_pcb->pcb_regs.sf_r4 = (register_t)fork_return; 210 td->td_pcb->pcb_regs.sf_r5 = (register_t)td; 211 td->td_pcb->pcb_regs.sf_lr = (register_t)fork_trampoline; 212 td->td_pcb->pcb_regs.sf_sp = STACKALIGN(td->td_frame); 213 214 td->td_frame->tf_spsr &= ~PSR_C; 215 td->td_frame->tf_r0 = 0; 216 217 #ifdef VFP 218 vfp_new_thread(td, td0, false); 219 #endif 220 221 /* Setup to release spin count in fork_exit(). */ 222 td->td_md.md_spinlock_count = 1; 223 td->td_md.md_saved_cspr = PSR_SVC32_MODE; 224 } 225 226 /* 227 * Set that machine state for performing an upcall that starts 228 * the entry function with the given argument. 229 */ 230 void 231 cpu_set_upcall(struct thread *td, void (*entry)(void *), void *arg, 232 stack_t *stack) 233 { 234 struct trapframe *tf = td->td_frame; 235 236 tf->tf_usr_sp = STACKALIGN((int)stack->ss_sp + stack->ss_size); 237 tf->tf_pc = (int)entry; 238 tf->tf_r0 = (int)arg; 239 tf->tf_spsr = PSR_USR32_MODE; 240 if ((register_t)entry & 1) 241 tf->tf_spsr |= PSR_T; 242 } 243 244 int 245 cpu_set_user_tls(struct thread *td, void *tls_base) 246 { 247 248 td->td_pcb->pcb_regs.sf_tpidrurw = (register_t)tls_base; 249 if (td == curthread) 250 set_tls(tls_base); 251 return (0); 252 } 253 254 void 255 cpu_thread_exit(struct thread *td) 256 { 257 } 258 259 void 260 cpu_thread_alloc(struct thread *td) 261 { 262 td->td_pcb = (struct pcb *)(td->td_kstack + td->td_kstack_pages * 263 PAGE_SIZE) - 1; 264 /* 265 * Ensure td_frame is aligned to an 8 byte boundary as it will be 266 * placed into the stack pointer which must be 8 byte aligned in 267 * the ARM EABI. 268 */ 269 td->td_frame = (struct trapframe *)((caddr_t)td->td_pcb) - 1; 270 } 271 272 void 273 cpu_thread_free(struct thread *td) 274 { 275 } 276 277 void 278 cpu_thread_clean(struct thread *td) 279 { 280 } 281 282 /* 283 * Intercept the return address from a freshly forked process that has NOT 284 * been scheduled yet. 285 * 286 * This is needed to make kernel threads stay in kernel mode. 287 */ 288 void 289 cpu_fork_kthread_handler(struct thread *td, void (*func)(void *), void *arg) 290 { 291 td->td_pcb->pcb_regs.sf_r4 = (register_t)func; /* function */ 292 td->td_pcb->pcb_regs.sf_r5 = (register_t)arg; /* first arg */ 293 } 294 295 void 296 cpu_exit(struct thread *td) 297 { 298 } 299 300 bool 301 cpu_exec_vmspace_reuse(struct proc *p __unused, vm_map_t map __unused) 302 { 303 304 return (true); 305 } 306 307 int 308 cpu_procctl(struct thread *td __unused, int idtype __unused, id_t id __unused, 309 int com __unused, void *data __unused) 310 { 311 312 return (EINVAL); 313 } 314