xref: /freebsd/sys/powerpc/powerpc/mp_machdep.c (revision 63cbe8d1d95f97e93929ec66f1138693d08dd9f6)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/param.h>
33 #include <sys/systm.h>
34 #include <sys/kernel.h>
35 #include <sys/ktr.h>
36 #include <sys/bus.h>
37 #include <sys/cpuset.h>
38 #include <sys/lock.h>
39 #include <sys/malloc.h>
40 #include <sys/mutex.h>
41 #include <sys/pcpu.h>
42 #include <sys/proc.h>
43 #include <sys/sched.h>
44 #include <sys/smp.h>
45 
46 #include <vm/vm.h>
47 #include <vm/vm_param.h>
48 #include <vm/pmap.h>
49 #include <vm/vm_map.h>
50 #include <vm/vm_extern.h>
51 #include <vm/vm_kern.h>
52 
53 #include <machine/bus.h>
54 #include <machine/cpu.h>
55 #include <machine/intr_machdep.h>
56 #include <machine/pcb.h>
57 #include <machine/platform.h>
58 #include <machine/md_var.h>
59 #include <machine/setjmp.h>
60 #include <machine/smp.h>
61 
62 #include "pic_if.h"
63 
64 extern struct pcpu __pcpu[MAXCPU];
65 
66 volatile static int ap_awake;
67 volatile static u_int ap_letgo;
68 volatile static u_quad_t ap_timebase;
69 static u_int ipi_msg_cnt[32];
70 static struct mtx ap_boot_mtx;
71 struct pcb stoppcbs[MAXCPU];
72 
73 void
74 machdep_ap_bootstrap(void)
75 {
76 
77 	PCPU_SET(awake, 1);
78 	__asm __volatile("msync; isync");
79 
80 	while (ap_letgo == 0)
81 		__asm __volatile("or 27,27,27");
82 	__asm __volatile("or 6,6,6");
83 
84 	/*
85 	 * Set timebase as soon as possible to meet an implicit rendezvous
86 	 * from cpu_mp_unleash(), which sets ap_letgo and then immediately
87 	 * sets timebase.
88 	 *
89 	 * Note that this is instrinsically racy and is only relevant on
90 	 * platforms that do not support better mechanisms.
91 	 */
92 	platform_smp_timebase_sync(ap_timebase, 1);
93 
94 	/* Give platform code a chance to do anything else necessary */
95 	platform_smp_ap_init();
96 
97 	/* Initialize decrementer */
98 	decr_ap_init();
99 
100 	/* Serialize console output and AP count increment */
101 	mtx_lock_spin(&ap_boot_mtx);
102 	ap_awake++;
103 	if (bootverbose)
104 		printf("SMP: AP CPU #%d launched\n", PCPU_GET(cpuid));
105 	else
106 		printf("%s%d%s", ap_awake == 2 ? "Launching APs: " : "",
107 		    PCPU_GET(cpuid), ap_awake == mp_ncpus ? "\n" : " ");
108 	mtx_unlock_spin(&ap_boot_mtx);
109 
110 	while(smp_started == 0)
111 		;
112 
113 	/* Start per-CPU event timers. */
114 	cpu_initclocks_ap();
115 
116 	/* Announce ourselves awake, and enter the scheduler */
117 	sched_throw(NULL);
118 }
119 
120 void
121 cpu_mp_setmaxid(void)
122 {
123 	struct cpuref cpuref;
124 	int error;
125 
126 	mp_ncpus = 0;
127 	mp_maxid = 0;
128 	error = platform_smp_first_cpu(&cpuref);
129 	while (!error) {
130 		mp_ncpus++;
131 		mp_maxid = max(cpuref.cr_cpuid, mp_maxid);
132 		error = platform_smp_next_cpu(&cpuref);
133 	}
134 	/* Sanity. */
135 	if (mp_ncpus == 0)
136 		mp_ncpus = 1;
137 }
138 
139 int
140 cpu_mp_probe(void)
141 {
142 
143 	/*
144 	 * We're not going to enable SMP if there's only 1 processor.
145 	 */
146 	return (mp_ncpus > 1);
147 }
148 
149 void
150 cpu_mp_start(void)
151 {
152 	struct cpuref bsp, cpu;
153 	struct pcpu *pc;
154 	int error;
155 
156 	error = platform_smp_get_bsp(&bsp);
157 	KASSERT(error == 0, ("Don't know BSP"));
158 
159 	error = platform_smp_first_cpu(&cpu);
160 	while (!error) {
161 		if (cpu.cr_cpuid >= MAXCPU) {
162 			printf("SMP: cpu%d: skipped -- ID out of range\n",
163 			    cpu.cr_cpuid);
164 			goto next;
165 		}
166 		if (CPU_ISSET(cpu.cr_cpuid, &all_cpus)) {
167 			printf("SMP: cpu%d: skipped - duplicate ID\n",
168 			    cpu.cr_cpuid);
169 			goto next;
170 		}
171 		if (cpu.cr_cpuid != bsp.cr_cpuid) {
172 			void *dpcpu;
173 
174 			pc = &__pcpu[cpu.cr_cpuid];
175 			dpcpu = (void *)kmem_malloc(DPCPU_SIZE, M_WAITOK |
176 			    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_hwref = cpu.cr_hwref;
185 		CPU_SET(pc->pc_cpuid, &all_cpus);
186 next:
187 		error = platform_smp_next_cpu(&cpu);
188 	}
189 }
190 
191 void
192 cpu_mp_announce(void)
193 {
194 	struct pcpu *pc;
195 	int i;
196 
197 	if (!bootverbose)
198 		return;
199 
200 	CPU_FOREACH(i) {
201 		pc = pcpu_find(i);
202 		if (pc == NULL)
203 			continue;
204 		printf("cpu%d: dev=%x", i, (int)pc->pc_hwref);
205 		if (pc->pc_bsp)
206 			printf(" (BSP)");
207 		printf("\n");
208 	}
209 }
210 
211 static void
212 cpu_mp_unleash(void *dummy)
213 {
214 	struct pcpu *pc;
215 	int cpus, timeout;
216 	int ret;
217 
218 	if (mp_ncpus <= 1)
219 		return;
220 
221 	mtx_init(&ap_boot_mtx, "ap boot", NULL, MTX_SPIN);
222 
223 	cpus = 0;
224 	smp_cpus = 0;
225 #ifdef BOOKE
226 	tlb1_ap_prep();
227 #endif
228 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
229 		cpus++;
230 		if (!pc->pc_bsp) {
231 			if (bootverbose)
232 				printf("Waking up CPU %d (dev=%x)\n",
233 				    pc->pc_cpuid, (int)pc->pc_hwref);
234 
235 			ret = platform_smp_start_cpu(pc);
236 			if (ret == 0) {
237 				timeout = 2000;	/* wait 2sec for the AP */
238 				while (!pc->pc_awake && --timeout > 0)
239 					DELAY(1000);
240 			}
241 		} else {
242 			pc->pc_awake = 1;
243 		}
244 		if (pc->pc_awake) {
245 			if (bootverbose)
246 				printf("Adding CPU %d, hwref=%jx, awake=%x\n",
247 				    pc->pc_cpuid, (uintmax_t)pc->pc_hwref,
248 				    pc->pc_awake);
249 			smp_cpus++;
250 		} else
251 			CPU_SET(pc->pc_cpuid, &stopped_cpus);
252 	}
253 
254 	ap_awake = 1;
255 
256 	/* Provide our current DEC and TB values for APs */
257 	ap_timebase = mftb() + 10;
258 	__asm __volatile("msync; isync");
259 
260 	/* Let APs continue */
261 	atomic_store_rel_int(&ap_letgo, 1);
262 
263 	platform_smp_timebase_sync(ap_timebase, 0);
264 
265 	while (ap_awake < smp_cpus)
266 		;
267 
268 	if (smp_cpus != cpus || cpus != mp_ncpus) {
269 		printf("SMP: %d CPUs found; %d CPUs usable; %d CPUs woken\n",
270 		    mp_ncpus, cpus, smp_cpus);
271 	}
272 
273 	if (smp_cpus > 1)
274 		atomic_store_rel_int(&smp_started, 1);
275 
276 	/* Let the APs get into the scheduler */
277 	DELAY(10000);
278 
279 }
280 
281 SYSINIT(start_aps, SI_SUB_SMP, SI_ORDER_FIRST, cpu_mp_unleash, NULL);
282 
283 int
284 powerpc_ipi_handler(void *arg)
285 {
286 	u_int cpuid;
287 	uint32_t ipimask;
288 	int msg;
289 
290 	CTR2(KTR_SMP, "%s: MSR 0x%08x", __func__, mfmsr());
291 
292 	ipimask = atomic_readandclear_32(&(pcpup->pc_ipimask));
293 	if (ipimask == 0)
294 		return (FILTER_STRAY);
295 	while ((msg = ffs(ipimask) - 1) != -1) {
296 		ipimask &= ~(1u << msg);
297 		ipi_msg_cnt[msg]++;
298 		switch (msg) {
299 		case IPI_AST:
300 			CTR1(KTR_SMP, "%s: IPI_AST", __func__);
301 			break;
302 		case IPI_PREEMPT:
303 			CTR1(KTR_SMP, "%s: IPI_PREEMPT", __func__);
304 			sched_preempt(curthread);
305 			break;
306 		case IPI_RENDEZVOUS:
307 			CTR1(KTR_SMP, "%s: IPI_RENDEZVOUS", __func__);
308 			smp_rendezvous_action();
309 			break;
310 		case IPI_STOP:
311 
312 			/*
313 			 * IPI_STOP_HARD is mapped to IPI_STOP so it is not
314 			 * necessary to add such case in the switch.
315 			 */
316 			CTR1(KTR_SMP, "%s: IPI_STOP or IPI_STOP_HARD (stop)",
317 			    __func__);
318 			cpuid = PCPU_GET(cpuid);
319 			savectx(&stoppcbs[cpuid]);
320 			savectx(PCPU_GET(curpcb));
321 			CPU_SET_ATOMIC(cpuid, &stopped_cpus);
322 			while (!CPU_ISSET(cpuid, &started_cpus))
323 				cpu_spinwait();
324 			CPU_CLR_ATOMIC(cpuid, &stopped_cpus);
325 			CPU_CLR_ATOMIC(cpuid, &started_cpus);
326 			CTR1(KTR_SMP, "%s: IPI_STOP (restart)", __func__);
327 			break;
328 		case IPI_HARDCLOCK:
329 			CTR1(KTR_SMP, "%s: IPI_HARDCLOCK", __func__);
330 			hardclockintr();
331 			break;
332 		}
333 	}
334 
335 	return (FILTER_HANDLED);
336 }
337 
338 static void
339 ipi_send(struct pcpu *pc, int ipi)
340 {
341 
342 	CTR4(KTR_SMP, "%s: pc=%p, targetcpu=%d, IPI=%d", __func__,
343 	    pc, pc->pc_cpuid, ipi);
344 
345 	atomic_set_32(&pc->pc_ipimask, (1 << ipi));
346 	powerpc_sync();
347 	PIC_IPI(root_pic, pc->pc_cpuid);
348 
349 	CTR1(KTR_SMP, "%s: sent", __func__);
350 }
351 
352 /* Send an IPI to a set of cpus. */
353 void
354 ipi_selected(cpuset_t cpus, int ipi)
355 {
356 	struct pcpu *pc;
357 
358 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
359 		if (CPU_ISSET(pc->pc_cpuid, &cpus))
360 			ipi_send(pc, ipi);
361 	}
362 }
363 
364 /* Send an IPI to a specific CPU. */
365 void
366 ipi_cpu(int cpu, u_int ipi)
367 {
368 
369 	ipi_send(cpuid_to_pcpu[cpu], ipi);
370 }
371 
372 /* Send an IPI to all CPUs EXCEPT myself. */
373 void
374 ipi_all_but_self(int ipi)
375 {
376 	struct pcpu *pc;
377 
378 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
379 		if (pc != pcpup)
380 			ipi_send(pc, ipi);
381 	}
382 }
383