xref: /freebsd/sys/powerpc/powerpc/mp_machdep.c (revision eb69d1f144a6fcc765d1b9d44a5ae8082353e70b)
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 	printf("SMP: AP CPU #%d launched\n", PCPU_GET(cpuid));
104 	mtx_unlock_spin(&ap_boot_mtx);
105 
106 	while(smp_started == 0)
107 		;
108 
109 	/* Start per-CPU event timers. */
110 	cpu_initclocks_ap();
111 
112 	/* Announce ourselves awake, and enter the scheduler */
113 	sched_throw(NULL);
114 }
115 
116 void
117 cpu_mp_setmaxid(void)
118 {
119 	struct cpuref cpuref;
120 	int error;
121 
122 	mp_ncpus = 0;
123 	mp_maxid = 0;
124 	error = platform_smp_first_cpu(&cpuref);
125 	while (!error) {
126 		mp_ncpus++;
127 		mp_maxid = max(cpuref.cr_cpuid, mp_maxid);
128 		error = platform_smp_next_cpu(&cpuref);
129 	}
130 	/* Sanity. */
131 	if (mp_ncpus == 0)
132 		mp_ncpus = 1;
133 }
134 
135 int
136 cpu_mp_probe(void)
137 {
138 
139 	/*
140 	 * We're not going to enable SMP if there's only 1 processor.
141 	 */
142 	return (mp_ncpus > 1);
143 }
144 
145 void
146 cpu_mp_start(void)
147 {
148 	struct cpuref bsp, cpu;
149 	struct pcpu *pc;
150 	int error;
151 
152 	error = platform_smp_get_bsp(&bsp);
153 	KASSERT(error == 0, ("Don't know BSP"));
154 
155 	error = platform_smp_first_cpu(&cpu);
156 	while (!error) {
157 		if (cpu.cr_cpuid >= MAXCPU) {
158 			printf("SMP: cpu%d: skipped -- ID out of range\n",
159 			    cpu.cr_cpuid);
160 			goto next;
161 		}
162 		if (CPU_ISSET(cpu.cr_cpuid, &all_cpus)) {
163 			printf("SMP: cpu%d: skipped - duplicate ID\n",
164 			    cpu.cr_cpuid);
165 			goto next;
166 		}
167 		if (cpu.cr_cpuid != bsp.cr_cpuid) {
168 			void *dpcpu;
169 
170 			pc = &__pcpu[cpu.cr_cpuid];
171 			dpcpu = (void *)kmem_malloc(kernel_arena, DPCPU_SIZE,
172 			    M_WAITOK | M_ZERO);
173 			pcpu_init(pc, cpu.cr_cpuid, sizeof(*pc));
174 			dpcpu_init(dpcpu, cpu.cr_cpuid);
175 		} else {
176 			pc = pcpup;
177 			pc->pc_cpuid = bsp.cr_cpuid;
178 			pc->pc_bsp = 1;
179 		}
180 		pc->pc_hwref = cpu.cr_hwref;
181 		CPU_SET(pc->pc_cpuid, &all_cpus);
182 next:
183 		error = platform_smp_next_cpu(&cpu);
184 	}
185 }
186 
187 void
188 cpu_mp_announce(void)
189 {
190 	struct pcpu *pc;
191 	int i;
192 
193 	if (!bootverbose)
194 		return;
195 
196 	CPU_FOREACH(i) {
197 		pc = pcpu_find(i);
198 		if (pc == NULL)
199 			continue;
200 		printf("cpu%d: dev=%x", i, (int)pc->pc_hwref);
201 		if (pc->pc_bsp)
202 			printf(" (BSP)");
203 		printf("\n");
204 	}
205 }
206 
207 static void
208 cpu_mp_unleash(void *dummy)
209 {
210 	struct pcpu *pc;
211 	int cpus, timeout;
212 	int ret;
213 
214 	if (mp_ncpus <= 1)
215 		return;
216 
217 	mtx_init(&ap_boot_mtx, "ap boot", NULL, MTX_SPIN);
218 
219 	cpus = 0;
220 	smp_cpus = 0;
221 #ifdef BOOKE
222 	tlb1_ap_prep();
223 #endif
224 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
225 		cpus++;
226 		if (!pc->pc_bsp) {
227 			if (bootverbose)
228 				printf("Waking up CPU %d (dev=%x)\n",
229 				    pc->pc_cpuid, (int)pc->pc_hwref);
230 
231 			ret = platform_smp_start_cpu(pc);
232 			if (ret == 0) {
233 				timeout = 2000;	/* wait 2sec for the AP */
234 				while (!pc->pc_awake && --timeout > 0)
235 					DELAY(1000);
236 			}
237 		} else {
238 			pc->pc_awake = 1;
239 		}
240 		if (pc->pc_awake) {
241 			if (bootverbose)
242 				printf("Adding CPU %d, hwref=%jx, awake=%x\n",
243 				    pc->pc_cpuid, (uintmax_t)pc->pc_hwref,
244 				    pc->pc_awake);
245 			smp_cpus++;
246 		} else
247 			CPU_SET(pc->pc_cpuid, &stopped_cpus);
248 	}
249 
250 	ap_awake = 1;
251 
252 	/* Provide our current DEC and TB values for APs */
253 	ap_timebase = mftb() + 10;
254 	__asm __volatile("msync; isync");
255 
256 	/* Let APs continue */
257 	atomic_store_rel_int(&ap_letgo, 1);
258 
259 	platform_smp_timebase_sync(ap_timebase, 0);
260 
261 	while (ap_awake < smp_cpus)
262 		;
263 
264 	if (smp_cpus != cpus || cpus != mp_ncpus) {
265 		printf("SMP: %d CPUs found; %d CPUs usable; %d CPUs woken\n",
266 		    mp_ncpus, cpus, smp_cpus);
267 	}
268 
269 	if (smp_cpus > 1)
270 		atomic_store_rel_int(&smp_started, 1);
271 
272 	/* Let the APs get into the scheduler */
273 	DELAY(10000);
274 
275 }
276 
277 SYSINIT(start_aps, SI_SUB_SMP, SI_ORDER_FIRST, cpu_mp_unleash, NULL);
278 
279 int
280 powerpc_ipi_handler(void *arg)
281 {
282 	u_int cpuid;
283 	uint32_t ipimask;
284 	int msg;
285 
286 	CTR2(KTR_SMP, "%s: MSR 0x%08x", __func__, mfmsr());
287 
288 	ipimask = atomic_readandclear_32(&(pcpup->pc_ipimask));
289 	if (ipimask == 0)
290 		return (FILTER_STRAY);
291 	while ((msg = ffs(ipimask) - 1) != -1) {
292 		ipimask &= ~(1u << msg);
293 		ipi_msg_cnt[msg]++;
294 		switch (msg) {
295 		case IPI_AST:
296 			CTR1(KTR_SMP, "%s: IPI_AST", __func__);
297 			break;
298 		case IPI_PREEMPT:
299 			CTR1(KTR_SMP, "%s: IPI_PREEMPT", __func__);
300 			sched_preempt(curthread);
301 			break;
302 		case IPI_RENDEZVOUS:
303 			CTR1(KTR_SMP, "%s: IPI_RENDEZVOUS", __func__);
304 			smp_rendezvous_action();
305 			break;
306 		case IPI_STOP:
307 
308 			/*
309 			 * IPI_STOP_HARD is mapped to IPI_STOP so it is not
310 			 * necessary to add such case in the switch.
311 			 */
312 			CTR1(KTR_SMP, "%s: IPI_STOP or IPI_STOP_HARD (stop)",
313 			    __func__);
314 			cpuid = PCPU_GET(cpuid);
315 			savectx(&stoppcbs[cpuid]);
316 			savectx(PCPU_GET(curpcb));
317 			CPU_SET_ATOMIC(cpuid, &stopped_cpus);
318 			while (!CPU_ISSET(cpuid, &started_cpus))
319 				cpu_spinwait();
320 			CPU_CLR_ATOMIC(cpuid, &stopped_cpus);
321 			CPU_CLR_ATOMIC(cpuid, &started_cpus);
322 			CTR1(KTR_SMP, "%s: IPI_STOP (restart)", __func__);
323 			break;
324 		case IPI_HARDCLOCK:
325 			CTR1(KTR_SMP, "%s: IPI_HARDCLOCK", __func__);
326 			hardclockintr();
327 			break;
328 		}
329 	}
330 
331 	return (FILTER_HANDLED);
332 }
333 
334 static void
335 ipi_send(struct pcpu *pc, int ipi)
336 {
337 
338 	CTR4(KTR_SMP, "%s: pc=%p, targetcpu=%d, IPI=%d", __func__,
339 	    pc, pc->pc_cpuid, ipi);
340 
341 	atomic_set_32(&pc->pc_ipimask, (1 << ipi));
342 	powerpc_sync();
343 	PIC_IPI(root_pic, pc->pc_cpuid);
344 
345 	CTR1(KTR_SMP, "%s: sent", __func__);
346 }
347 
348 /* Send an IPI to a set of cpus. */
349 void
350 ipi_selected(cpuset_t cpus, int ipi)
351 {
352 	struct pcpu *pc;
353 
354 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
355 		if (CPU_ISSET(pc->pc_cpuid, &cpus))
356 			ipi_send(pc, ipi);
357 	}
358 }
359 
360 /* Send an IPI to a specific CPU. */
361 void
362 ipi_cpu(int cpu, u_int ipi)
363 {
364 
365 	ipi_send(cpuid_to_pcpu[cpu], ipi);
366 }
367 
368 /* Send an IPI to all CPUs EXCEPT myself. */
369 void
370 ipi_all_but_self(int ipi)
371 {
372 	struct pcpu *pc;
373 
374 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
375 		if (pc != pcpup)
376 			ipi_send(pc, ipi);
377 	}
378 }
379