xref: /freebsd-src/sys/arm/arm/mp_machdep.c (revision 4f12b529f40422589404fc939ed4a92710412a61)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2011 Semihalf.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 #include "opt_ddb.h"
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/bus.h>
33 #include <sys/intr.h>
34 #include <sys/kernel.h>
35 #include <sys/lock.h>
36 #include <sys/mutex.h>
37 #include <sys/proc.h>
38 #include <sys/pcpu.h>
39 #include <sys/sched.h>
40 #include <sys/smp.h>
41 #include <sys/ktr.h>
42 #include <sys/malloc.h>
43 
44 #include <vm/vm.h>
45 #include <vm/vm_extern.h>
46 #include <vm/vm_kern.h>
47 #include <vm/pmap.h>
48 
49 #include <machine/armreg.h>
50 #include <machine/cpu.h>
51 #include <machine/cpufunc.h>
52 #include <machine/debug_monitor.h>
53 #include <machine/smp.h>
54 #include <machine/pcb.h>
55 #include <machine/vmparam.h>
56 #ifdef VFP
57 #include <machine/vfp.h>
58 #endif
59 #ifdef CPU_MV_PJ4B
60 #include <arm/mv/mvwin.h>
61 #endif
62 
63 /* used to hold the AP's until we are ready to release them */
64 struct mtx ap_boot_mtx;
65 
66 /* # of Applications processors */
67 volatile int mp_naps;
68 
69 /* Set to 1 once we're ready to let the APs out of the pen. */
70 volatile int aps_ready = 0;
71 
72 void set_stackptrs(int cpu);
73 
74 /* Temporary variables for init_secondary()  */
75 void *dpcpu[MAXCPU - 1];
76 
77 /* Determine if we running MP machine */
78 int
79 cpu_mp_probe(void)
80 {
81 
82 	KASSERT(mp_ncpus != 0, ("cpu_mp_probe: mp_ncpus is unset"));
83 
84 	CPU_SETOF(0, &all_cpus);
85 
86 	return (mp_ncpus > 1);
87 }
88 
89 /* Start Application Processor via platform specific function */
90 static int
91 check_ap(void)
92 {
93 	uint32_t ms;
94 
95 	for (ms = 0; ms < 2000; ++ms) {
96 		if ((mp_naps + 1) == mp_ncpus)
97 			return (0);		/* success */
98 		else
99 			DELAY(1000);
100 	}
101 
102 	return (-2);
103 }
104 
105 /* Initialize and fire up non-boot processors */
106 void
107 cpu_mp_start(void)
108 {
109 	int error, i;
110 
111 	mtx_init(&ap_boot_mtx, "ap boot", NULL, MTX_SPIN);
112 
113 	/* Reserve memory for application processors */
114 	for(i = 0; i < (mp_ncpus - 1); i++)
115 		dpcpu[i] = kmem_malloc(DPCPU_SIZE, M_WAITOK | M_ZERO);
116 
117 	dcache_wbinv_poc_all();
118 
119 	/* Initialize boot code and start up processors */
120 	platform_mp_start_ap();
121 
122 	/*  Check if ap's started properly */
123 	error = check_ap();
124 	if (error)
125 		printf("WARNING: Some AP's failed to start\n");
126 	else
127 		for (i = 1; i < mp_ncpus; i++)
128 			CPU_SET(i, &all_cpus);
129 }
130 
131 /* Introduce rest of cores to the world */
132 void
133 cpu_mp_announce(void)
134 {
135 
136 }
137 
138 void
139 init_secondary(int cpu)
140 {
141 	struct pcpu *pc;
142 	uint32_t loop_counter;
143 
144 	pmap_set_tex();
145 	cpuinfo_reinit_mmu(pmap_kern_ttb);
146 	cpu_setup();
147 
148 	/* Provide stack pointers for other processor modes. */
149 	set_stackptrs(cpu);
150 
151 	enable_interrupts(PSR_A);
152 	pc = &__pcpu[cpu];
153 
154 	/*
155 	 * pcpu_init() updates queue, so it should not be executed in parallel
156 	 * on several cores
157 	 */
158 	while(mp_naps < (cpu - 1))
159 		;
160 
161 	pcpu_init(pc, cpu, sizeof(struct pcpu));
162 	pc->pc_mpidr = cp15_mpidr_get() & 0xFFFFFF;
163 	dpcpu_init(dpcpu[cpu - 1], cpu);
164 #if defined(DDB)
165 	dbg_monitor_init_secondary();
166 #endif
167 	/* Signal our startup to BSP */
168 	atomic_add_rel_32(&mp_naps, 1);
169 
170 	/* Spin until the BSP releases the APs */
171 	while (!atomic_load_acq_int(&aps_ready)) {
172 		__asm __volatile("wfe");
173 	}
174 
175 	/* Initialize curthread */
176 	KASSERT(PCPU_GET(idlethread) != NULL, ("no idle thread"));
177 	pc->pc_curthread = pc->pc_idlethread;
178 	pc->pc_curpcb = pc->pc_idlethread->td_pcb;
179 	set_curthread(pc->pc_idlethread);
180 	schedinit_ap();
181 #ifdef VFP
182 	vfp_init();
183 #endif
184 
185 	/* Configure the interrupt controller */
186 	intr_pic_init_secondary();
187 
188 	/* Apply possible BP hardening */
189 	cpuinfo_init_bp_hardening();
190 
191 	mtx_lock_spin(&ap_boot_mtx);
192 
193 	atomic_add_rel_32(&smp_cpus, 1);
194 
195 	if (smp_cpus == mp_ncpus) {
196 		/* enable IPI's, tlb shootdown, freezes etc */
197 		atomic_store_rel_int(&smp_started, 1);
198 	}
199 
200 	mtx_unlock_spin(&ap_boot_mtx);
201 
202 	loop_counter = 0;
203 	while (smp_started == 0) {
204 		DELAY(100);
205 		loop_counter++;
206 		if (loop_counter == 1000)
207 			CTR0(KTR_SMP, "AP still wait for smp_started");
208 	}
209 	/* Start per-CPU event timers. */
210 	cpu_initclocks_ap();
211 
212 	CTR0(KTR_SMP, "go into scheduler");
213 
214 	/* Enter the scheduler */
215 	sched_ap_entry();
216 
217 	panic("scheduler returned us to %s", __func__);
218 	/* NOTREACHED */
219 }
220 
221 static void
222 ipi_rendezvous(void *dummy __unused)
223 {
224 
225 	CTR0(KTR_SMP, "IPI_RENDEZVOUS");
226 	smp_rendezvous_action();
227 }
228 
229 static void
230 ipi_ast(void *dummy __unused)
231 {
232 
233 	CTR0(KTR_SMP, "IPI_AST");
234 }
235 
236 static void
237 ipi_stop(void *dummy __unused)
238 {
239 	u_int cpu;
240 
241 	/*
242 	 * IPI_STOP_HARD is mapped to IPI_STOP.
243 	 */
244 	CTR0(KTR_SMP, "IPI_STOP or IPI_STOP_HARD");
245 
246 	cpu = PCPU_GET(cpuid);
247 	savectx(&stoppcbs[cpu]);
248 
249 	/*
250 	 * CPUs are stopped when entering the debugger and at
251 	 * system shutdown, both events which can precede a
252 	 * panic dump.  For the dump to be correct, all caches
253 	 * must be flushed and invalidated, but on ARM there's
254 	 * no way to broadcast a wbinv_all to other cores.
255 	 * Instead, we have each core do the local wbinv_all as
256 	 * part of stopping the core.  The core requesting the
257 	 * stop will do the l2 cache flush after all other cores
258 	 * have done their l1 flushes and stopped.
259 	 */
260 	dcache_wbinv_poc_all();
261 
262 	/* Indicate we are stopped */
263 	CPU_SET_ATOMIC(cpu, &stopped_cpus);
264 
265 	/* Wait for restart */
266 	while (!CPU_ISSET(cpu, &started_cpus))
267 		cpu_spinwait();
268 
269 	CPU_CLR_ATOMIC(cpu, &started_cpus);
270 	CPU_CLR_ATOMIC(cpu, &stopped_cpus);
271 #ifdef DDB
272 	dbg_resume_dbreg();
273 #endif
274 	CTR0(KTR_SMP, "IPI_STOP (restart)");
275 }
276 
277 static void
278 ipi_preempt(void *arg)
279 {
280 
281 	CTR1(KTR_SMP, "%s: IPI_PREEMPT", __func__);
282 	sched_preempt(curthread);
283 }
284 
285 static void
286 ipi_hardclock(void *arg)
287 {
288 
289 	CTR1(KTR_SMP, "%s: IPI_HARDCLOCK", __func__);
290 	hardclockintr();
291 }
292 
293 static void
294 release_aps(void *dummy __unused)
295 {
296 	uint32_t loop_counter;
297 
298 	if (mp_ncpus == 1)
299 		return;
300 
301 	intr_ipi_setup(IPI_RENDEZVOUS, "rendezvous", ipi_rendezvous, NULL);
302 	intr_ipi_setup(IPI_AST, "ast", ipi_ast, NULL);
303 	intr_ipi_setup(IPI_STOP, "stop", ipi_stop, NULL);
304 	intr_ipi_setup(IPI_PREEMPT, "preempt", ipi_preempt, NULL);
305 	intr_ipi_setup(IPI_HARDCLOCK, "hardclock", ipi_hardclock, NULL);
306 
307 	atomic_store_rel_int(&aps_ready, 1);
308 	/* Wake the other threads up */
309 	dsb();
310 	sev();
311 
312 	printf("Release APs\n");
313 
314 	for (loop_counter = 0; loop_counter < 2000; loop_counter++) {
315 		if (smp_started)
316 			return;
317 		DELAY(1000);
318 	}
319 	printf("AP's not started\n");
320 }
321 
322 SYSINIT(start_aps, SI_SUB_SMP, SI_ORDER_FIRST, release_aps, NULL);
323 
324 struct cpu_group *
325 cpu_topo(void)
326 {
327 
328 	return (smp_topo_1level(CG_SHARE_L2, mp_ncpus, 0));
329 }
330 
331 void
332 cpu_mp_setmaxid(void)
333 {
334 
335 	platform_mp_setmaxid();
336 }
337 
338 /* Sending IPI */
339 void
340 ipi_all_but_self(u_int ipi)
341 {
342 	cpuset_t other_cpus;
343 
344 	other_cpus = all_cpus;
345 	CPU_CLR(PCPU_GET(cpuid), &other_cpus);
346 	CTR2(KTR_SMP, "%s: ipi: %x", __func__, ipi);
347 	intr_ipi_send(other_cpus, ipi);
348 }
349 
350 void
351 ipi_cpu(int cpu, u_int ipi)
352 {
353 	cpuset_t cpus;
354 
355 	CPU_ZERO(&cpus);
356 	CPU_SET(cpu, &cpus);
357 
358 	CTR3(KTR_SMP, "%s: cpu: %d, ipi: %x", __func__, cpu, ipi);
359 	intr_ipi_send(cpus, ipi);
360 }
361 
362 void
363 ipi_selected(cpuset_t cpus, u_int ipi)
364 {
365 
366 	CTR2(KTR_SMP, "%s: ipi: %x", __func__, ipi);
367 	intr_ipi_send(cpus, ipi);
368 }
369