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 }
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