2 * SPDX-License-Identifier: BSD-4-Clause
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
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.
13 * Redistribution and use in source and binary :forms, with or without
14 * modification, are permitted provided that the following conditions
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.
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
41 * from: @(#)vm_machdep.c 7.3 (Berkeley) 5/13/91
42 * Utah $Hdr: vm_machdep.c 1.16.1.1 89/06/23$
45 #include <sys/cdefs.h>
46 __FBSDID("$FreeBSD$");
48 #include <sys/param.h>
49 #include <sys/systm.h>
50 #include <sys/kernel.h>
51 #include <sys/malloc.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>
60 #include <machine/cpu.h>
61 #include <machine/frame.h>
62 #include <machine/pcb.h>
63 #include <machine/sysarch.h>
65 #include <sys/mutex.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>
76 #include <vm/uma_int.h>
78 #include <machine/md_var.h>
79 #include <machine/vfp.h>
82 * struct switchframe and trapframe must both be a multiple of 8
83 * for correct stack alignment.
85 _Static_assert((sizeof(struct switchframe) % 8) == 0, "Bad alignment");
86 _Static_assert((sizeof(struct trapframe) % 8) == 0, "Bad alignment");
88 uint32_t initial_fpscr = VFPSCR_DN | VFPSCR_FZ;
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.
96 cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags)
102 if ((flags & RFPROC) == 0)
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;
109 /* Store actual state of VFP */
110 if (curthread == td1) {
111 if ((td1->td_pcb->pcb_fpflags & PCB_FP_STARTED) != 0)
112 vfp_save_state(td1, td1->td_pcb);
117 /* Clone td1's pcb */
118 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2));
120 /* Point to mdproc and then copy over td1's contents */
122 bcopy(&td1->td_proc->p_md, mdp2, sizeof(*mdp2));
124 /* Point the frame to the stack in front of pcb and copy td1's frame */
125 td2->td_frame = (struct trapframe *)pcb2 - 1;
126 *td2->td_frame = *td1->td_frame;
129 * Create a new fresh stack for the new process.
130 * Copy the trap frame for the return to user mode as if from a
131 * syscall. This copies most of the user mode register values.
133 pmap_set_pcb_pagedir(vmspace_pmap(p2->p_vmspace), pcb2);
134 pcb2->pcb_regs.sf_r4 = (register_t)fork_return;
135 pcb2->pcb_regs.sf_r5 = (register_t)td2;
136 pcb2->pcb_regs.sf_lr = (register_t)fork_trampoline;
137 pcb2->pcb_regs.sf_sp = STACKALIGN(td2->td_frame);
138 pcb2->pcb_regs.sf_tpidrurw = (register_t)get_tls();
141 vfp_new_thread(td2, td1, true);
145 tf->tf_spsr &= ~PSR_C;
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;
155 cpu_thread_swapin(struct thread *td)
160 cpu_thread_swapout(struct thread *td)
165 cpu_set_syscall_retval(struct thread *td, int error)
167 struct trapframe *frame;
169 frame = td->td_frame;
172 frame->tf_r0 = td->td_retval[0];
173 frame->tf_r1 = td->td_retval[1];
174 frame->tf_spsr &= ~PSR_C; /* carry bit */
178 * Reconstruct the pc to point at the swi.
181 if ((frame->tf_spsr & PSR_T) != 0)
182 frame->tf_pc -= THUMB_INSN_SIZE;
185 frame->tf_pc -= INSN_SIZE;
191 frame->tf_r0 = error;
192 frame->tf_spsr |= PSR_C; /* carry bit */
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.
205 cpu_copy_thread(struct thread *td, struct thread *td0)
208 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe));
209 bcopy(td0->td_pcb, td->td_pcb, sizeof(struct pcb));
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);
216 td->td_frame->tf_spsr &= ~PSR_C;
217 td->td_frame->tf_r0 = 0;
220 vfp_new_thread(td, td0, false);
223 /* Setup to release spin count in fork_exit(). */
224 td->td_md.md_spinlock_count = 1;
225 td->td_md.md_saved_cspr = PSR_SVC32_MODE;
229 * Set that machine state for performing an upcall that starts
230 * the entry function with the given argument.
233 cpu_set_upcall(struct thread *td, void (*entry)(void *), void *arg,
236 struct trapframe *tf = td->td_frame;
238 tf->tf_usr_sp = STACKALIGN((int)stack->ss_sp + stack->ss_size);
239 tf->tf_pc = (int)entry;
240 tf->tf_r0 = (int)arg;
241 tf->tf_spsr = PSR_USR32_MODE;
242 if ((register_t)entry & 1)
243 tf->tf_spsr |= PSR_T;
247 cpu_set_user_tls(struct thread *td, void *tls_base)
250 td->td_pcb->pcb_regs.sf_tpidrurw = (register_t)tls_base;
257 cpu_thread_exit(struct thread *td)
262 cpu_thread_alloc(struct thread *td)
264 td->td_pcb = (struct pcb *)(td->td_kstack + td->td_kstack_pages *
267 * Ensure td_frame is aligned to an 8 byte boundary as it will be
268 * placed into the stack pointer which must be 8 byte aligned in
271 td->td_frame = (struct trapframe *)((caddr_t)td->td_pcb) - 1;
275 cpu_thread_free(struct thread *td)
280 cpu_thread_clean(struct thread *td)
285 * Intercept the return address from a freshly forked process that has NOT
286 * been scheduled yet.
288 * This is needed to make kernel threads stay in kernel mode.
291 cpu_fork_kthread_handler(struct thread *td, void (*func)(void *), void *arg)
293 td->td_pcb->pcb_regs.sf_r4 = (register_t)func; /* function */
294 td->td_pcb->pcb_regs.sf_r5 = (register_t)arg; /* first arg */
298 cpu_exit(struct thread *td)
303 cpu_exec_vmspace_reuse(struct proc *p __unused, vm_map_t map __unused)
310 cpu_procctl(struct thread *td __unused, int idtype __unused, id_t id __unused,
311 int com __unused, void *data __unused)