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 __FBSDID("$FreeBSD$"); 47 48 #include <sys/param.h> 49 #include <sys/systm.h> 50 #include <sys/kernel.h> 51 #include <sys/malloc.h> 52 #include <sys/mbuf.h> 53 #include <sys/proc.h> 54 #include <sys/socketvar.h> 55 #include <sys/syscall.h> 56 #include <sys/sysctl.h> 57 #include <sys/sysent.h> 58 #include <sys/unistd.h> 59 60 #include <machine/cpu.h> 61 #include <machine/frame.h> 62 #include <machine/pcb.h> 63 #include <machine/sysarch.h> 64 #include <sys/lock.h> 65 #include <sys/mutex.h> 66 67 #include <vm/vm.h> 68 #include <vm/pmap.h> 69 #include <vm/vm_extern.h> 70 #include <vm/vm_kern.h> 71 #include <vm/vm_page.h> 72 #include <vm/vm_map.h> 73 #include <vm/vm_param.h> 74 #include <vm/vm_pageout.h> 75 #include <vm/uma.h> 76 #include <vm/uma_int.h> 77 78 #include <machine/md_var.h> 79 #include <machine/vfp.h> 80 81 /* 82 * struct switchframe and trapframe must both be a multiple of 8 83 * for correct stack alignment. 84 */ 85 _Static_assert((sizeof(struct switchframe) % 8) == 0, "Bad alignment"); 86 _Static_assert((sizeof(struct trapframe) % 8) == 0, "Bad alignment"); 87 88 uint32_t initial_fpscr = VFPSCR_DN | VFPSCR_FZ; 89 90 /* 91 * Finish a fork operation, with process p2 nearly set up. 92 * Copy and update the pcb, set up the stack so that the child 93 * ready to run and return to user mode. 94 */ 95 void 96 cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags) 97 { 98 struct pcb *pcb2; 99 struct trapframe *tf; 100 struct mdproc *mdp2; 101 102 if ((flags & RFPROC) == 0) 103 return; 104 105 /* Point the pcb to the top of the stack */ 106 pcb2 = (struct pcb *) 107 (td2->td_kstack + td2->td_kstack_pages * PAGE_SIZE) - 1; 108 #ifdef VFP 109 /* Store actual state of VFP */ 110 if (curthread == td1) { 111 critical_enter(); 112 vfp_store(&td1->td_pcb->pcb_vfpstate, false); 113 critical_exit(); 114 } 115 #endif 116 td2->td_pcb = pcb2; 117 118 /* Clone td1's pcb */ 119 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2)); 120 121 /* Point to mdproc and then copy over td1's contents */ 122 mdp2 = &p2->p_md; 123 bcopy(&td1->td_proc->p_md, mdp2, sizeof(*mdp2)); 124 125 /* Point the frame to the stack in front of pcb and copy td1's frame */ 126 td2->td_frame = (struct trapframe *)pcb2 - 1; 127 *td2->td_frame = *td1->td_frame; 128 129 /* 130 * Create a new fresh stack for the new process. 131 * Copy the trap frame for the return to user mode as if from a 132 * syscall. This copies most of the user mode register values. 133 */ 134 pmap_set_pcb_pagedir(vmspace_pmap(p2->p_vmspace), pcb2); 135 pcb2->pcb_regs.sf_r4 = (register_t)fork_return; 136 pcb2->pcb_regs.sf_r5 = (register_t)td2; 137 pcb2->pcb_regs.sf_lr = (register_t)fork_trampoline; 138 pcb2->pcb_regs.sf_sp = STACKALIGN(td2->td_frame); 139 pcb2->pcb_regs.sf_tpidrurw = (register_t)get_tls(); 140 141 pcb2->pcb_vfpcpu = -1; 142 pcb2->pcb_vfpstate.fpscr = initial_fpscr; 143 144 tf = td2->td_frame; 145 tf->tf_spsr &= ~PSR_C; 146 tf->tf_r0 = 0; 147 tf->tf_r1 = 0; 148 149 /* Setup to release spin count in fork_exit(). */ 150 td2->td_md.md_spinlock_count = 1; 151 td2->td_md.md_saved_cspr = PSR_SVC32_MODE; 152 } 153 154 void 155 cpu_thread_swapin(struct thread *td) 156 { 157 } 158 159 void 160 cpu_thread_swapout(struct thread *td) 161 { 162 } 163 164 void 165 cpu_set_syscall_retval(struct thread *td, int error) 166 { 167 struct trapframe *frame; 168 169 frame = td->td_frame; 170 switch (error) { 171 case 0: 172 frame->tf_r0 = td->td_retval[0]; 173 frame->tf_r1 = td->td_retval[1]; 174 frame->tf_spsr &= ~PSR_C; /* carry bit */ 175 break; 176 case ERESTART: 177 /* 178 * Reconstruct the pc to point at the swi. 179 */ 180 #if __ARM_ARCH >= 7 181 if ((frame->tf_spsr & PSR_T) != 0) 182 frame->tf_pc -= THUMB_INSN_SIZE; 183 else 184 #endif 185 frame->tf_pc -= INSN_SIZE; 186 break; 187 case EJUSTRETURN: 188 /* nothing to do */ 189 break; 190 default: 191 frame->tf_r0 = error; 192 frame->tf_spsr |= PSR_C; /* carry bit */ 193 break; 194 } 195 } 196 197 /* 198 * Initialize machine state, mostly pcb and trap frame for a new 199 * thread, about to return to userspace. Put enough state in the new 200 * thread's PCB to get it to go back to the fork_return(), which 201 * finalizes the thread state and handles peculiarities of the first 202 * return to userspace for the new thread. 203 */ 204 void 205 cpu_copy_thread(struct thread *td, struct thread *td0) 206 { 207 208 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe)); 209 bcopy(td0->td_pcb, td->td_pcb, sizeof(struct pcb)); 210 211 td->td_pcb->pcb_regs.sf_r4 = (register_t)fork_return; 212 td->td_pcb->pcb_regs.sf_r5 = (register_t)td; 213 td->td_pcb->pcb_regs.sf_lr = (register_t)fork_trampoline; 214 td->td_pcb->pcb_regs.sf_sp = STACKALIGN(td->td_frame); 215 216 td->td_frame->tf_spsr &= ~PSR_C; 217 td->td_frame->tf_r0 = 0; 218 219 /* Setup to release spin count in fork_exit(). */ 220 td->td_md.md_spinlock_count = 1; 221 td->td_md.md_saved_cspr = PSR_SVC32_MODE; 222 } 223 224 /* 225 * Set that machine state for performing an upcall that starts 226 * the entry function with the given argument. 227 */ 228 void 229 cpu_set_upcall(struct thread *td, void (*entry)(void *), void *arg, 230 stack_t *stack) 231 { 232 struct trapframe *tf = td->td_frame; 233 234 tf->tf_usr_sp = STACKALIGN((int)stack->ss_sp + stack->ss_size); 235 tf->tf_pc = (int)entry; 236 tf->tf_r0 = (int)arg; 237 tf->tf_spsr = PSR_USR32_MODE; 238 } 239 240 int 241 cpu_set_user_tls(struct thread *td, void *tls_base) 242 { 243 244 td->td_pcb->pcb_regs.sf_tpidrurw = (register_t)tls_base; 245 if (td == curthread) 246 set_tls(tls_base); 247 return (0); 248 } 249 250 void 251 cpu_thread_exit(struct thread *td) 252 { 253 } 254 255 void 256 cpu_thread_alloc(struct thread *td) 257 { 258 td->td_pcb = (struct pcb *)(td->td_kstack + td->td_kstack_pages * 259 PAGE_SIZE) - 1; 260 /* 261 * Ensure td_frame is aligned to an 8 byte boundary as it will be 262 * placed into the stack pointer which must be 8 byte aligned in 263 * the ARM EABI. 264 */ 265 td->td_frame = (struct trapframe *)((caddr_t)td->td_pcb) - 1; 266 } 267 268 void 269 cpu_thread_free(struct thread *td) 270 { 271 } 272 273 void 274 cpu_thread_clean(struct thread *td) 275 { 276 } 277 278 /* 279 * Intercept the return address from a freshly forked process that has NOT 280 * been scheduled yet. 281 * 282 * This is needed to make kernel threads stay in kernel mode. 283 */ 284 void 285 cpu_fork_kthread_handler(struct thread *td, void (*func)(void *), void *arg) 286 { 287 td->td_pcb->pcb_regs.sf_r4 = (register_t)func; /* function */ 288 td->td_pcb->pcb_regs.sf_r5 = (register_t)arg; /* first arg */ 289 } 290 291 /* 292 * Software interrupt handler for queued VM system processing. 293 */ 294 void 295 swi_vm(void *dummy) 296 { 297 298 if (busdma_swi_pending) 299 busdma_swi(); 300 } 301 302 void 303 cpu_exit(struct thread *td) 304 { 305 } 306 307 bool 308 cpu_exec_vmspace_reuse(struct proc *p __unused, vm_map_t map __unused) 309 { 310 311 return (true); 312 } 313 314 int 315 cpu_procctl(struct thread *td __unused, int idtype __unused, id_t id __unused, 316 int com __unused, void *data __unused) 317 { 318 319 return (EINVAL); 320 } 321