xref: /freebsd/sys/powerpc/powerpc/mp_machdep.c (revision 60eddb209b5ad13a549ca74a41b7cb38a31da5ef)
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 	/* Initialize DEC and TB, sync with the BSP values */
85 	platform_smp_timebase_sync(ap_timebase, 1);
86 	decr_ap_init();
87 
88 	/* Give platform code a chance to do anything necessary */
89 	platform_smp_ap_init();
90 
91 	/* Serialize console output and AP count increment */
92 	mtx_lock_spin(&ap_boot_mtx);
93 	ap_awake++;
94 	printf("SMP: AP CPU #%d launched\n", PCPU_GET(cpuid));
95 	mtx_unlock_spin(&ap_boot_mtx);
96 
97 	/* Start per-CPU event timers. */
98 	cpu_initclocks_ap();
99 
100 	/* Announce ourselves awake, and enter the scheduler */
101 	sched_throw(NULL);
102 }
103 
104 void
105 cpu_mp_setmaxid(void)
106 {
107 	struct cpuref cpuref;
108 	int error;
109 
110 	mp_ncpus = 0;
111 	mp_maxid = 0;
112 	error = platform_smp_first_cpu(&cpuref);
113 	while (!error) {
114 		mp_ncpus++;
115 		mp_maxid = max(cpuref.cr_cpuid, mp_maxid);
116 		error = platform_smp_next_cpu(&cpuref);
117 	}
118 	/* Sanity. */
119 	if (mp_ncpus == 0)
120 		mp_ncpus = 1;
121 }
122 
123 int
124 cpu_mp_probe(void)
125 {
126 
127 	/*
128 	 * We're not going to enable SMP if there's only 1 processor.
129 	 */
130 	return (mp_ncpus > 1);
131 }
132 
133 void
134 cpu_mp_start(void)
135 {
136 	struct cpuref bsp, cpu;
137 	struct pcpu *pc;
138 	int error;
139 
140 	error = platform_smp_get_bsp(&bsp);
141 	KASSERT(error == 0, ("Don't know BSP"));
142 
143 	error = platform_smp_first_cpu(&cpu);
144 	while (!error) {
145 		if (cpu.cr_cpuid >= MAXCPU) {
146 			printf("SMP: cpu%d: skipped -- ID out of range\n",
147 			    cpu.cr_cpuid);
148 			goto next;
149 		}
150 		if (CPU_ISSET(cpu.cr_cpuid, &all_cpus)) {
151 			printf("SMP: cpu%d: skipped - duplicate ID\n",
152 			    cpu.cr_cpuid);
153 			goto next;
154 		}
155 		if (cpu.cr_cpuid != bsp.cr_cpuid) {
156 			void *dpcpu;
157 
158 			pc = &__pcpu[cpu.cr_cpuid];
159 			dpcpu = (void *)kmem_malloc(kernel_arena, DPCPU_SIZE,
160 			    M_WAITOK | M_ZERO);
161 			pcpu_init(pc, cpu.cr_cpuid, sizeof(*pc));
162 			dpcpu_init(dpcpu, cpu.cr_cpuid);
163 		} else {
164 			pc = pcpup;
165 			pc->pc_cpuid = bsp.cr_cpuid;
166 			pc->pc_bsp = 1;
167 		}
168 		pc->pc_hwref = cpu.cr_hwref;
169 		CPU_SET(pc->pc_cpuid, &all_cpus);
170 next:
171 		error = platform_smp_next_cpu(&cpu);
172 	}
173 }
174 
175 void
176 cpu_mp_announce(void)
177 {
178 	struct pcpu *pc;
179 	int i;
180 
181 	if (!bootverbose)
182 		return;
183 
184 	CPU_FOREACH(i) {
185 		pc = pcpu_find(i);
186 		if (pc == NULL)
187 			continue;
188 		printf("cpu%d: dev=%x", i, (int)pc->pc_hwref);
189 		if (pc->pc_bsp)
190 			printf(" (BSP)");
191 		printf("\n");
192 	}
193 }
194 
195 static void
196 cpu_mp_unleash(void *dummy)
197 {
198 	struct pcpu *pc;
199 	int cpus, timeout;
200 
201 	if (mp_ncpus <= 1)
202 		return;
203 
204 	mtx_init(&ap_boot_mtx, "ap boot", NULL, MTX_SPIN);
205 
206 	cpus = 0;
207 	smp_cpus = 0;
208 #ifdef BOOKE
209 	tlb1_ap_prep();
210 #endif
211 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
212 		cpus++;
213 		if (!pc->pc_bsp) {
214 			if (bootverbose)
215 				printf("Waking up CPU %d (dev=%x)\n",
216 				    pc->pc_cpuid, (int)pc->pc_hwref);
217 
218 			platform_smp_start_cpu(pc);
219 
220 			timeout = 2000;	/* wait 2sec for the AP */
221 			while (!pc->pc_awake && --timeout > 0)
222 				DELAY(1000);
223 
224 		} else {
225 			pc->pc_awake = 1;
226 		}
227 		if (pc->pc_awake) {
228 			if (bootverbose)
229 				printf("Adding CPU %d, hwref=%jx, awake=%x\n",
230 				    pc->pc_cpuid, (uintmax_t)pc->pc_hwref,
231 				    pc->pc_awake);
232 			smp_cpus++;
233 		} else
234 			CPU_SET(pc->pc_cpuid, &stopped_cpus);
235 	}
236 
237 	ap_awake = 1;
238 
239 	/* Provide our current DEC and TB values for APs */
240 	ap_timebase = mftb() + 10;
241 	__asm __volatile("msync; isync");
242 
243 	/* Let APs continue */
244 	atomic_store_rel_int(&ap_letgo, 1);
245 
246 	platform_smp_timebase_sync(ap_timebase, 0);
247 
248 	while (ap_awake < smp_cpus)
249 		;
250 
251 	if (smp_cpus != cpus || cpus != mp_ncpus) {
252 		printf("SMP: %d CPUs found; %d CPUs usable; %d CPUs woken\n",
253 		    mp_ncpus, cpus, smp_cpus);
254 	}
255 
256 	/* Let the APs get into the scheduler */
257 	DELAY(10000);
258 
259 	/* XXX Atomic set operation? */
260 	smp_started = 1;
261 }
262 
263 SYSINIT(start_aps, SI_SUB_SMP, SI_ORDER_FIRST, cpu_mp_unleash, NULL);
264 
265 int
266 powerpc_ipi_handler(void *arg)
267 {
268 	u_int cpuid;
269 	uint32_t ipimask;
270 	int msg;
271 
272 	CTR2(KTR_SMP, "%s: MSR 0x%08x", __func__, mfmsr());
273 
274 	ipimask = atomic_readandclear_32(&(pcpup->pc_ipimask));
275 	if (ipimask == 0)
276 		return (FILTER_STRAY);
277 	while ((msg = ffs(ipimask) - 1) != -1) {
278 		ipimask &= ~(1u << msg);
279 		ipi_msg_cnt[msg]++;
280 		switch (msg) {
281 		case IPI_AST:
282 			CTR1(KTR_SMP, "%s: IPI_AST", __func__);
283 			break;
284 		case IPI_PREEMPT:
285 			CTR1(KTR_SMP, "%s: IPI_PREEMPT", __func__);
286 			sched_preempt(curthread);
287 			break;
288 		case IPI_RENDEZVOUS:
289 			CTR1(KTR_SMP, "%s: IPI_RENDEZVOUS", __func__);
290 			smp_rendezvous_action();
291 			break;
292 		case IPI_STOP:
293 
294 			/*
295 			 * IPI_STOP_HARD is mapped to IPI_STOP so it is not
296 			 * necessary to add such case in the switch.
297 			 */
298 			CTR1(KTR_SMP, "%s: IPI_STOP or IPI_STOP_HARD (stop)",
299 			    __func__);
300 			cpuid = PCPU_GET(cpuid);
301 			savectx(&stoppcbs[cpuid]);
302 			savectx(PCPU_GET(curpcb));
303 			CPU_SET_ATOMIC(cpuid, &stopped_cpus);
304 			while (!CPU_ISSET(cpuid, &started_cpus))
305 				cpu_spinwait();
306 			CPU_CLR_ATOMIC(cpuid, &stopped_cpus);
307 			CPU_CLR_ATOMIC(cpuid, &started_cpus);
308 			CTR1(KTR_SMP, "%s: IPI_STOP (restart)", __func__);
309 			break;
310 		case IPI_HARDCLOCK:
311 			CTR1(KTR_SMP, "%s: IPI_HARDCLOCK", __func__);
312 			hardclockintr();
313 			break;
314 		}
315 	}
316 
317 	return (FILTER_HANDLED);
318 }
319 
320 static void
321 ipi_send(struct pcpu *pc, int ipi)
322 {
323 
324 	CTR4(KTR_SMP, "%s: pc=%p, targetcpu=%d, IPI=%d", __func__,
325 	    pc, pc->pc_cpuid, ipi);
326 
327 	atomic_set_32(&pc->pc_ipimask, (1 << ipi));
328 	powerpc_sync();
329 	PIC_IPI(root_pic, pc->pc_cpuid);
330 
331 	CTR1(KTR_SMP, "%s: sent", __func__);
332 }
333 
334 /* Send an IPI to a set of cpus. */
335 void
336 ipi_selected(cpuset_t cpus, int ipi)
337 {
338 	struct pcpu *pc;
339 
340 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
341 		if (CPU_ISSET(pc->pc_cpuid, &cpus))
342 			ipi_send(pc, ipi);
343 	}
344 }
345 
346 /* Send an IPI to a specific CPU. */
347 void
348 ipi_cpu(int cpu, u_int ipi)
349 {
350 
351 	ipi_send(cpuid_to_pcpu[cpu], ipi);
352 }
353 
354 /* Send an IPI to all CPUs EXCEPT myself. */
355 void
356 ipi_all_but_self(int ipi)
357 {
358 	struct pcpu *pc;
359 
360 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
361 		if (pc != pcpup)
362 			ipi_send(pc, ipi);
363 	}
364 }
365