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) {
112 vfp_store(&td1->td_pcb->pcb_vfpstate, false);
118 /* Clone td1's pcb */
119 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2));
121 /* Point to mdproc and then copy over td1's contents */
123 bcopy(&td1->td_proc->p_md, mdp2, sizeof(*mdp2));
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;
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.
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);
140 pcb2->pcb_regs.sf_tpidrurw = (register_t)get_tls();
143 pcb2->pcb_vfpcpu = -1;
144 pcb2->pcb_vfpstate.fpscr = initial_fpscr;
147 tf->tf_spsr &= ~PSR_C;
152 /* Setup to release spin count in fork_exit(). */
153 td2->td_md.md_spinlock_count = 1;
154 td2->td_md.md_saved_cspr = PSR_SVC32_MODE;
156 td2->td_md.md_tp = *(register_t *)ARM_TP_ADDRESS;
161 cpu_thread_swapin(struct thread *td)
166 cpu_thread_swapout(struct thread *td)
171 cpu_set_syscall_retval(struct thread *td, int error)
173 struct trapframe *frame;
179 frame = td->td_frame;
184 * __syscall returns an off_t while most other syscalls return an
185 * int. As an off_t is 64-bits and an int is 32-bits we need to
186 * place the returned data into r1. As the lseek and freebsd6_lseek
187 * syscalls also return an off_t they do not need this fixup.
190 if (call == SYS___syscall) {
191 register_t *ap = &frame->tf_r0;
192 register_t code = ap[_QUAD_LOWWORD];
193 fixup = (code != SYS_lseek);
201 frame->tf_r1 = td->td_retval[0];
203 frame->tf_r0 = td->td_retval[0];
204 frame->tf_r1 = td->td_retval[1];
206 frame->tf_spsr &= ~PSR_C; /* carry bit */
210 * Reconstruct the pc to point at the swi.
213 if ((frame->tf_spsr & PSR_T) != 0)
214 frame->tf_pc -= THUMB_INSN_SIZE;
217 frame->tf_pc -= INSN_SIZE;
223 frame->tf_r0 = SV_ABI_ERRNO(td->td_proc, error);
224 frame->tf_spsr |= PSR_C; /* carry bit */
230 * Initialize machine state, mostly pcb and trap frame for a new
231 * thread, about to return to userspace. Put enough state in the new
232 * thread's PCB to get it to go back to the fork_return(), which
233 * finalizes the thread state and handles peculiarities of the first
234 * return to userspace for the new thread.
237 cpu_copy_thread(struct thread *td, struct thread *td0)
240 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe));
241 bcopy(td0->td_pcb, td->td_pcb, sizeof(struct pcb));
243 td->td_pcb->pcb_regs.sf_r4 = (register_t)fork_return;
244 td->td_pcb->pcb_regs.sf_r5 = (register_t)td;
245 td->td_pcb->pcb_regs.sf_lr = (register_t)fork_trampoline;
246 td->td_pcb->pcb_regs.sf_sp = STACKALIGN(td->td_frame);
248 td->td_frame->tf_spsr &= ~PSR_C;
249 td->td_frame->tf_r0 = 0;
251 /* Setup to release spin count in fork_exit(). */
252 td->td_md.md_spinlock_count = 1;
253 td->td_md.md_saved_cspr = PSR_SVC32_MODE;
257 * Set that machine state for performing an upcall that starts
258 * the entry function with the given argument.
261 cpu_set_upcall(struct thread *td, void (*entry)(void *), void *arg,
264 struct trapframe *tf = td->td_frame;
266 tf->tf_usr_sp = STACKALIGN((int)stack->ss_sp + stack->ss_size);
267 tf->tf_pc = (int)entry;
268 tf->tf_r0 = (int)arg;
269 tf->tf_spsr = PSR_USR32_MODE;
273 cpu_set_user_tls(struct thread *td, void *tls_base)
277 td->td_pcb->pcb_regs.sf_tpidrurw = (register_t)tls_base;
281 td->td_md.md_tp = (register_t)tls_base;
282 if (td == curthread) {
284 *(register_t *)ARM_TP_ADDRESS = (register_t)tls_base;
292 cpu_thread_exit(struct thread *td)
297 cpu_thread_alloc(struct thread *td)
299 td->td_pcb = (struct pcb *)(td->td_kstack + td->td_kstack_pages *
302 * Ensure td_frame is aligned to an 8 byte boundary as it will be
303 * placed into the stack pointer which must be 8 byte aligned in
306 td->td_frame = (struct trapframe *)((caddr_t)td->td_pcb) - 1;
310 cpu_thread_free(struct thread *td)
315 cpu_thread_clean(struct thread *td)
320 * Intercept the return address from a freshly forked process that has NOT
321 * been scheduled yet.
323 * This is needed to make kernel threads stay in kernel mode.
326 cpu_fork_kthread_handler(struct thread *td, void (*func)(void *), void *arg)
328 td->td_pcb->pcb_regs.sf_r4 = (register_t)func; /* function */
329 td->td_pcb->pcb_regs.sf_r5 = (register_t)arg; /* first arg */
333 * Software interrupt handler for queued VM system processing.
339 if (busdma_swi_pending)
344 cpu_exit(struct thread *td)
349 cpu_exec_vmspace_reuse(struct proc *p __unused, vm_map_t map __unused)