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