xref: /freebsd/sys/powerpc/powerpc/mp_machdep.c (revision 1f4bcc459a76b7aa664f3fd557684cd0ba6da352)
1 /*-
2  * Copyright (c) 2008 Marcel Moolenaar
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/systm.h>
32 #include <sys/kernel.h>
33 #include <sys/ktr.h>
34 #include <sys/bus.h>
35 #include <sys/cpuset.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 extern struct pcpu __pcpu[MAXCPU];
63 
64 volatile static int ap_awake;
65 volatile static u_int ap_letgo;
66 volatile static u_quad_t ap_timebase;
67 static u_int ipi_msg_cnt[32];
68 static struct mtx ap_boot_mtx;
69 struct pcb stoppcbs[MAXCPU];
70 
71 void
72 machdep_ap_bootstrap(void)
73 {
74 
75 	/* Set PIR */
76 	PCPU_SET(pir, mfspr(SPR_PIR));
77 	PCPU_SET(awake, 1);
78 	__asm __volatile("msync; isync");
79 
80 	while (ap_letgo == 0)
81 		;
82 
83 	/* Initialize DEC and TB, sync with the BSP values */
84 #ifdef __powerpc64__
85 	/* Writing to the time base register is hypervisor-privileged */
86 	if (mfmsr() & PSL_HV)
87 		mttb(ap_timebase);
88 #else
89 	mttb(ap_timebase);
90 #endif
91 	decr_ap_init();
92 
93 	/* Give platform code a chance to do anything necessary */
94 	platform_smp_ap_init();
95 
96 	/* Serialize console output and AP count increment */
97 	mtx_lock_spin(&ap_boot_mtx);
98 	ap_awake++;
99 	printf("SMP: AP CPU #%d launched\n", PCPU_GET(cpuid));
100 	mtx_unlock_spin(&ap_boot_mtx);
101 
102 	/* Start per-CPU event timers. */
103 	cpu_initclocks_ap();
104 
105 	/* Announce ourselves awake, and enter the scheduler */
106 	sched_throw(NULL);
107 }
108 
109 void
110 cpu_mp_setmaxid(void)
111 {
112 	struct cpuref cpuref;
113 	int error;
114 
115 	mp_ncpus = 0;
116 	error = platform_smp_first_cpu(&cpuref);
117 	while (!error) {
118 		mp_ncpus++;
119 		error = platform_smp_next_cpu(&cpuref);
120 	}
121 	/* Sanity. */
122 	if (mp_ncpus == 0)
123 		mp_ncpus = 1;
124 
125 	/*
126 	 * Set the largest cpuid we're going to use. This is necessary
127 	 * for VM initialization.
128 	 */
129 	mp_maxid = min(mp_ncpus, MAXCPU) - 1;
130 }
131 
132 int
133 cpu_mp_probe(void)
134 {
135 
136 	/*
137 	 * We're not going to enable SMP if there's only 1 processor.
138 	 */
139 	return (mp_ncpus > 1);
140 }
141 
142 void
143 cpu_mp_start(void)
144 {
145 	struct cpuref bsp, cpu;
146 	struct pcpu *pc;
147 	int error;
148 
149 	error = platform_smp_get_bsp(&bsp);
150 	KASSERT(error == 0, ("Don't know BSP"));
151 	KASSERT(bsp.cr_cpuid == 0, ("%s: cpuid != 0", __func__));
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 		if (cpu.cr_cpuid != bsp.cr_cpuid) {
166 			void *dpcpu;
167 
168 			pc = &__pcpu[cpu.cr_cpuid];
169 			dpcpu = (void *)kmem_malloc(kernel_arena, DPCPU_SIZE,
170 			    M_WAITOK | M_ZERO);
171 			pcpu_init(pc, cpu.cr_cpuid, sizeof(*pc));
172 			dpcpu_init(dpcpu, cpu.cr_cpuid);
173 		} else {
174 			pc = pcpup;
175 			pc->pc_cpuid = bsp.cr_cpuid;
176 			pc->pc_bsp = 1;
177 		}
178 		pc->pc_hwref = cpu.cr_hwref;
179 		CPU_SET(pc->pc_cpuid, &all_cpus);
180 next:
181 		error = platform_smp_next_cpu(&cpu);
182 	}
183 }
184 
185 void
186 cpu_mp_announce(void)
187 {
188 	struct pcpu *pc;
189 	int i;
190 
191 	for (i = 0; i <= mp_maxid; i++) {
192 		pc = pcpu_find(i);
193 		if (pc == NULL)
194 			continue;
195 		printf("cpu%d: dev=%x", i, (int)pc->pc_hwref);
196 		if (pc->pc_bsp)
197 			printf(" (BSP)");
198 		printf("\n");
199 	}
200 }
201 
202 static void
203 cpu_mp_unleash(void *dummy)
204 {
205 	struct pcpu *pc;
206 	int cpus, timeout;
207 
208 	if (mp_ncpus <= 1)
209 		return;
210 
211 	mtx_init(&ap_boot_mtx, "ap boot", NULL, MTX_SPIN);
212 
213 	cpus = 0;
214 	smp_cpus = 0;
215 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
216 		cpus++;
217 		if (!pc->pc_bsp) {
218 			if (bootverbose)
219 				printf("Waking up CPU %d (dev=%x)\n",
220 				    pc->pc_cpuid, (int)pc->pc_hwref);
221 
222 			platform_smp_start_cpu(pc);
223 
224 			timeout = 2000;	/* wait 2sec for the AP */
225 			while (!pc->pc_awake && --timeout > 0)
226 				DELAY(1000);
227 
228 		} else {
229 			PCPU_SET(pir, mfspr(SPR_PIR));
230 			pc->pc_awake = 1;
231 		}
232 		if (pc->pc_awake) {
233 			if (bootverbose)
234 				printf("Adding CPU %d, pir=%x, awake=%x\n",
235 				    pc->pc_cpuid, pc->pc_pir, pc->pc_awake);
236 			smp_cpus++;
237 		} else
238 			CPU_SET(pc->pc_cpuid, &stopped_cpus);
239 	}
240 
241 	ap_awake = 1;
242 
243 	/* Provide our current DEC and TB values for APs */
244 	ap_timebase = mftb() + 10;
245 	__asm __volatile("msync; isync");
246 
247 	/* Let APs continue */
248 	atomic_store_rel_int(&ap_letgo, 1);
249 
250 #ifdef __powerpc64__
251 	/* Writing to the time base register is hypervisor-privileged */
252 	if (mfmsr() & PSL_HV)
253 		mttb(ap_timebase);
254 #else
255 	mttb(ap_timebase);
256 #endif
257 
258 	while (ap_awake < smp_cpus)
259 		;
260 
261 	if (smp_cpus != cpus || cpus != mp_ncpus) {
262 		printf("SMP: %d CPUs found; %d CPUs usable; %d CPUs woken\n",
263 		    mp_ncpus, cpus, smp_cpus);
264 	}
265 
266 	/* Let the APs get into the scheduler */
267 	DELAY(10000);
268 
269 	/* XXX Atomic set operation? */
270 	smp_started = 1;
271 }
272 
273 SYSINIT(start_aps, SI_SUB_SMP, SI_ORDER_FIRST, cpu_mp_unleash, NULL);
274 
275 int
276 powerpc_ipi_handler(void *arg)
277 {
278 	u_int cpuid;
279 	uint32_t ipimask;
280 	int msg;
281 
282 	CTR2(KTR_SMP, "%s: MSR 0x%08x", __func__, mfmsr());
283 
284 	ipimask = atomic_readandclear_32(&(pcpup->pc_ipimask));
285 	if (ipimask == 0)
286 		return (FILTER_STRAY);
287 	while ((msg = ffs(ipimask) - 1) != -1) {
288 		ipimask &= ~(1u << msg);
289 		ipi_msg_cnt[msg]++;
290 		switch (msg) {
291 		case IPI_AST:
292 			CTR1(KTR_SMP, "%s: IPI_AST", __func__);
293 			break;
294 		case IPI_PREEMPT:
295 			CTR1(KTR_SMP, "%s: IPI_PREEMPT", __func__);
296 			sched_preempt(curthread);
297 			break;
298 		case IPI_RENDEZVOUS:
299 			CTR1(KTR_SMP, "%s: IPI_RENDEZVOUS", __func__);
300 			smp_rendezvous_action();
301 			break;
302 		case IPI_STOP:
303 
304 			/*
305 			 * IPI_STOP_HARD is mapped to IPI_STOP so it is not
306 			 * necessary to add such case in the switch.
307 			 */
308 			CTR1(KTR_SMP, "%s: IPI_STOP or IPI_STOP_HARD (stop)",
309 			    __func__);
310 			cpuid = PCPU_GET(cpuid);
311 			savectx(&stoppcbs[cpuid]);
312 			savectx(PCPU_GET(curpcb));
313 			CPU_SET_ATOMIC(cpuid, &stopped_cpus);
314 			while (!CPU_ISSET(cpuid, &started_cpus))
315 				cpu_spinwait();
316 			CPU_CLR_ATOMIC(cpuid, &stopped_cpus);
317 			CPU_CLR_ATOMIC(cpuid, &started_cpus);
318 			CTR1(KTR_SMP, "%s: IPI_STOP (restart)", __func__);
319 			break;
320 		case IPI_HARDCLOCK:
321 			CTR1(KTR_SMP, "%s: IPI_HARDCLOCK", __func__);
322 			hardclockintr();
323 			break;
324 		}
325 	}
326 
327 	return (FILTER_HANDLED);
328 }
329 
330 static void
331 ipi_send(struct pcpu *pc, int ipi)
332 {
333 
334 	CTR4(KTR_SMP, "%s: pc=%p, targetcpu=%d, IPI=%d", __func__,
335 	    pc, pc->pc_cpuid, ipi);
336 
337 	atomic_set_32(&pc->pc_ipimask, (1 << ipi));
338 	powerpc_sync();
339 	PIC_IPI(root_pic, pc->pc_cpuid);
340 
341 	CTR1(KTR_SMP, "%s: sent", __func__);
342 }
343 
344 /* Send an IPI to a set of cpus. */
345 void
346 ipi_selected(cpuset_t cpus, int ipi)
347 {
348 	struct pcpu *pc;
349 
350 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
351 		if (CPU_ISSET(pc->pc_cpuid, &cpus))
352 			ipi_send(pc, ipi);
353 	}
354 }
355 
356 /* Send an IPI to a specific CPU. */
357 void
358 ipi_cpu(int cpu, u_int ipi)
359 {
360 
361 	ipi_send(cpuid_to_pcpu[cpu], ipi);
362 }
363 
364 /* Send an IPI to all CPUs EXCEPT myself. */
365 void
366 ipi_all_but_self(int ipi)
367 {
368 	struct pcpu *pc;
369 
370 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
371 		if (pc != pcpup)
372 			ipi_send(pc, ipi);
373 	}
374 }
375