xref: /freebsd/sys/powerpc/powerpc/mp_machdep.c (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2008 Marcel Moolenaar
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  *
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #include <sys/param.h>
30 #include <sys/systm.h>
31 #include <sys/kernel.h>
32 #include <sys/ktr.h>
33 #include <sys/bus.h>
34 #include <sys/cpuset.h>
35 #include <sys/domainset.h>
36 #include <sys/lock.h>
37 #include <sys/malloc.h>
38 #include <sys/mutex.h>
39 #include <sys/pcpu.h>
40 #include <sys/proc.h>
41 #include <sys/sched.h>
42 #include <sys/smp.h>
43 
44 #include <vm/vm.h>
45 #include <vm/vm_param.h>
46 #include <vm/pmap.h>
47 #include <vm/vm_map.h>
48 #include <vm/vm_extern.h>
49 #include <vm/vm_kern.h>
50 
51 #include <machine/bus.h>
52 #include <machine/cpu.h>
53 #include <machine/intr_machdep.h>
54 #include <machine/pcb.h>
55 #include <machine/platform.h>
56 #include <machine/md_var.h>
57 #include <machine/setjmp.h>
58 #include <machine/smp.h>
59 
60 #include "pic_if.h"
61 
62 volatile static int ap_awake;
63 volatile static u_int ap_letgo;
64 volatile static u_quad_t ap_timebase;
65 static struct mtx ap_boot_mtx;
66 
67 void
68 machdep_ap_bootstrap(void)
69 {
70 
71 	PCPU_SET(awake, 1);
72 	__asm __volatile("msync; isync");
73 
74 	while (ap_letgo == 0)
75 		nop_prio_vlow();
76 	nop_prio_medium();
77 
78 	/*
79 	 * Set timebase as soon as possible to meet an implicit rendezvous
80 	 * from cpu_mp_unleash(), which sets ap_letgo and then immediately
81 	 * sets timebase.
82 	 *
83 	 * Note that this is instrinsically racy and is only relevant on
84 	 * platforms that do not support better mechanisms.
85 	 */
86 	platform_smp_timebase_sync(ap_timebase, 1);
87 
88 	/* Give platform code a chance to do anything else necessary */
89 	platform_smp_ap_init();
90 
91 	/* Initialize decrementer */
92 	decr_ap_init();
93 
94 	/* Serialize console output and AP count increment */
95 	mtx_lock_spin(&ap_boot_mtx);
96 	ap_awake++;
97 	if (bootverbose)
98 		printf("SMP: AP CPU #%d launched\n", PCPU_GET(cpuid));
99 	else
100 		printf("%s%d%s", ap_awake == 2 ? "Launching APs: " : "",
101 		    PCPU_GET(cpuid), ap_awake == mp_ncpus ? "\n" : " ");
102 	mtx_unlock_spin(&ap_boot_mtx);
103 
104 	while(smp_started == 0)
105 		;
106 
107 	/* Start per-CPU event timers. */
108 	cpu_initclocks_ap();
109 
110 	/* Announce ourselves awake, and enter the scheduler */
111 	sched_ap_entry();
112 }
113 
114 void
115 cpu_mp_setmaxid(void)
116 {
117 	struct cpuref cpuref;
118 	int error;
119 
120 	mp_ncpus = 0;
121 	mp_maxid = 0;
122 	error = platform_smp_first_cpu(&cpuref);
123 	while (!error) {
124 		mp_ncpus++;
125 		mp_maxid = max(cpuref.cr_cpuid, mp_maxid);
126 		error = platform_smp_next_cpu(&cpuref);
127 	}
128 	/* Sanity. */
129 	if (mp_ncpus == 0)
130 		mp_ncpus = 1;
131 }
132 
133 int
134 cpu_mp_probe(void)
135 {
136 
137 	/*
138 	 * We're not going to enable SMP if there's only 1 processor.
139 	 */
140 	return (mp_ncpus > 1);
141 }
142 
143 void
144 cpu_mp_start(void)
145 {
146 	struct cpuref bsp, cpu;
147 	struct pcpu *pc;
148 	int domain, error;
149 
150 	error = platform_smp_get_bsp(&bsp);
151 	KASSERT(error == 0, ("Don't know BSP"));
152 
153 	error = platform_smp_first_cpu(&cpu);
154 	while (!error) {
155 		if (cpu.cr_cpuid >= MAXCPU) {
156 			printf("SMP: cpu%d: skipped -- ID out of range\n",
157 			    cpu.cr_cpuid);
158 			goto next;
159 		}
160 		if (CPU_ISSET(cpu.cr_cpuid, &all_cpus)) {
161 			printf("SMP: cpu%d: skipped - duplicate ID\n",
162 			    cpu.cr_cpuid);
163 			goto next;
164 		}
165 
166 		if (vm_ndomains > 1)
167 			domain = cpu.cr_domain;
168 		else
169 			domain = 0;
170 
171 		if (cpu.cr_cpuid != bsp.cr_cpuid) {
172 			void *dpcpu;
173 
174 			pc = &__pcpu[cpu.cr_cpuid];
175 			dpcpu = kmem_malloc_domainset(DOMAINSET_PREF(domain),
176 			    DPCPU_SIZE, M_WAITOK | M_ZERO);
177 			pcpu_init(pc, cpu.cr_cpuid, sizeof(*pc));
178 			dpcpu_init(dpcpu, cpu.cr_cpuid);
179 		} else {
180 			pc = pcpup;
181 			pc->pc_cpuid = bsp.cr_cpuid;
182 			pc->pc_bsp = 1;
183 		}
184 		pc->pc_domain = domain;
185 		pc->pc_hwref = cpu.cr_hwref;
186 
187 		CPU_SET(pc->pc_cpuid, &cpuset_domain[pc->pc_domain]);
188 		KASSERT(pc->pc_domain < MAXMEMDOM, ("bad domain value %d\n",
189 		    pc->pc_domain));
190 		CPU_SET(pc->pc_cpuid, &all_cpus);
191 next:
192 		error = platform_smp_next_cpu(&cpu);
193 	}
194 
195 #ifdef SMP
196 	platform_smp_probe_threads();
197 #endif
198 }
199 
200 void
201 cpu_mp_announce(void)
202 {
203 	struct pcpu *pc;
204 	int i;
205 
206 	if (!bootverbose)
207 		return;
208 
209 	CPU_FOREACH(i) {
210 		pc = pcpu_find(i);
211 		if (pc == NULL)
212 			continue;
213 		printf("cpu%d: dev=%x domain=%d ", i, (int)pc->pc_hwref, pc->pc_domain);
214 		if (pc->pc_bsp)
215 			printf(" (BSP)");
216 		printf("\n");
217 	}
218 }
219 
220 static void
221 cpu_mp_unleash(void *dummy)
222 {
223 	struct pcpu *pc;
224 	int cpus, timeout;
225 	int ret;
226 
227 	if (mp_ncpus <= 1)
228 		return;
229 
230 	mtx_init(&ap_boot_mtx, "ap boot", NULL, MTX_SPIN);
231 
232 	cpus = 0;
233 	smp_cpus = 0;
234 #ifdef BOOKE
235 	tlb1_ap_prep();
236 #endif
237 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
238 		cpus++;
239 		if (!pc->pc_bsp) {
240 			if (bootverbose)
241 				printf("Waking up CPU %d (dev=%x)\n",
242 				    pc->pc_cpuid, (int)pc->pc_hwref);
243 
244 			pc->pc_flags = PCPU_GET(flags); /* Copy cached CPU flags */
245 			ret = platform_smp_start_cpu(pc);
246 			if (ret == 0) {
247 				timeout = 2000;	/* wait 2sec for the AP */
248 				while (!pc->pc_awake && --timeout > 0)
249 					DELAY(1000);
250 			}
251 		} else {
252 			pc->pc_awake = 1;
253 		}
254 		if (pc->pc_awake) {
255 			if (bootverbose)
256 				printf("Adding CPU %d, hwref=%jx, awake=%x\n",
257 				    pc->pc_cpuid, (uintmax_t)pc->pc_hwref,
258 				    pc->pc_awake);
259 			smp_cpus++;
260 		} else
261 			CPU_SET(pc->pc_cpuid, &stopped_cpus);
262 	}
263 
264 	ap_awake = 1;
265 
266 	/* Provide our current DEC and TB values for APs */
267 	ap_timebase = mftb() + 10;
268 	__asm __volatile("msync; isync");
269 
270 	/* Let APs continue */
271 	atomic_store_rel_int(&ap_letgo, 1);
272 
273 	platform_smp_timebase_sync(ap_timebase, 0);
274 
275 	while (ap_awake < smp_cpus)
276 		;
277 
278 	if (smp_cpus != cpus || cpus != mp_ncpus) {
279 		printf("SMP: %d CPUs found; %d CPUs usable; %d CPUs woken\n",
280 		    mp_ncpus, cpus, smp_cpus);
281 	}
282 
283 	if (smp_cpus > 1)
284 		atomic_store_rel_int(&smp_started, 1);
285 
286 	/* Let the APs get into the scheduler */
287 	DELAY(10000);
288 
289 }
290 
291 SYSINIT(start_aps, SI_SUB_SMP, SI_ORDER_FIRST, cpu_mp_unleash, NULL);
292 
293 int
294 powerpc_ipi_handler(void *arg)
295 {
296 	u_int cpuid;
297 	uint32_t ipimask;
298 
299 	CTR2(KTR_SMP, "%s: MSR 0x%08x", __func__, mfmsr());
300 
301 	ipimask = atomic_readandclear_32(&(pcpup->pc_ipimask));
302 	if (ipimask == 0)
303 		return (FILTER_STRAY);
304 	if (ipimask & (1 << IPI_AST)) {
305 		CTR1(KTR_SMP, "%s: IPI_AST", __func__);
306 	}
307 	if (ipimask & (1 << IPI_PREEMPT)) {
308 		CTR1(KTR_SMP, "%s: IPI_PREEMPT", __func__);
309 		sched_preempt(curthread);
310 	}
311 	if (ipimask & (1 << IPI_RENDEZVOUS)) {
312 		CTR1(KTR_SMP, "%s: IPI_RENDEZVOUS", __func__);
313 		smp_rendezvous_action();
314 	}
315 	if (ipimask & (1 << IPI_STOP)) {
316 
317 		/*
318 		 * IPI_STOP_HARD is mapped to IPI_STOP so it is not
319 		 * necessary to add such case.
320 		 */
321 		CTR1(KTR_SMP, "%s: IPI_STOP or IPI_STOP_HARD (stop)",
322 				__func__);
323 		cpuid = PCPU_GET(cpuid);
324 		savectx(&stoppcbs[cpuid]);
325 		CPU_SET_ATOMIC(cpuid, &stopped_cpus);
326 		while (!CPU_ISSET(cpuid, &started_cpus))
327 			cpu_spinwait();
328 		CPU_CLR_ATOMIC(cpuid, &stopped_cpus);
329 		CPU_CLR_ATOMIC(cpuid, &started_cpus);
330 		CTR1(KTR_SMP, "%s: IPI_STOP (restart)", __func__);
331 	}
332 	if (ipimask & (1 << IPI_HARDCLOCK)) {
333 		CTR1(KTR_SMP, "%s: IPI_HARDCLOCK", __func__);
334 		hardclockintr();
335 	}
336 
337 	return (FILTER_HANDLED);
338 }
339 
340 static void
341 ipi_send(struct pcpu *pc, int ipi)
342 {
343 
344 	CTR4(KTR_SMP, "%s: pc=%p, targetcpu=%d, IPI=%d", __func__,
345 	    pc, pc->pc_cpuid, ipi);
346 
347 	atomic_set_32(&pc->pc_ipimask, (1 << ipi));
348 	powerpc_sync();
349 	PIC_IPI(root_pic, pc->pc_cpuid);
350 
351 	CTR1(KTR_SMP, "%s: sent", __func__);
352 }
353 
354 /* Send an IPI to a set of cpus. */
355 void
356 ipi_selected(cpuset_t cpus, int ipi)
357 {
358 	struct pcpu *pc;
359 
360 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
361 		if (CPU_ISSET(pc->pc_cpuid, &cpus))
362 			ipi_send(pc, ipi);
363 	}
364 }
365 
366 /* Send an IPI to a specific CPU. */
367 void
368 ipi_cpu(int cpu, u_int ipi)
369 {
370 
371 	ipi_send(cpuid_to_pcpu[cpu], ipi);
372 }
373 
374 /* Send an IPI to all CPUs EXCEPT myself. */
375 void
376 ipi_all_but_self(int ipi)
377 {
378 	struct pcpu *pc;
379 
380 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
381 		if (pc != pcpup)
382 			ipi_send(pc, ipi);
383 	}
384 }
385