xref: /freebsd/sys/powerpc/powerpc/mp_machdep.c (revision 57718be8fa0bd5edc11ab9a72e68cc71982939a6)
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 int longfault(faultbuf, int);
71 
72 void
73 machdep_ap_bootstrap(void)
74 {
75 
76 	/* Set PIR */
77 	PCPU_SET(pir, mfspr(SPR_PIR));
78 	PCPU_SET(awake, 1);
79 	__asm __volatile("msync; isync");
80 
81 	while (ap_letgo == 0)
82 		;
83 
84 	/* Initialize DEC and TB, sync with the BSP values */
85 #ifdef __powerpc64__
86 	/* Writing to the time base register is hypervisor-privileged */
87 	if (mfmsr() & PSL_HV)
88 		mttb(ap_timebase);
89 #else
90 	mttb(ap_timebase);
91 #endif
92 	decr_ap_init();
93 
94 	/* Give platform code a chance to do anything necessary */
95 	platform_smp_ap_init();
96 
97 	/* Serialize console output and AP count increment */
98 	mtx_lock_spin(&ap_boot_mtx);
99 	ap_awake++;
100 	printf("SMP: AP CPU #%d launched\n", PCPU_GET(cpuid));
101 	mtx_unlock_spin(&ap_boot_mtx);
102 
103 	/* Start per-CPU event timers. */
104 	cpu_initclocks_ap();
105 
106 	/* Announce ourselves awake, and enter the scheduler */
107 	sched_throw(NULL);
108 }
109 
110 void
111 cpu_mp_setmaxid(void)
112 {
113 	struct cpuref cpuref;
114 	int error;
115 
116 	mp_ncpus = 0;
117 	error = platform_smp_first_cpu(&cpuref);
118 	while (!error) {
119 		mp_ncpus++;
120 		error = platform_smp_next_cpu(&cpuref);
121 	}
122 	/* Sanity. */
123 	if (mp_ncpus == 0)
124 		mp_ncpus = 1;
125 
126 	/*
127 	 * Set the largest cpuid we're going to use. This is necessary
128 	 * for VM initialization.
129 	 */
130 	mp_maxid = min(mp_ncpus, MAXCPU) - 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 error;
149 
150 	error = platform_smp_get_bsp(&bsp);
151 	KASSERT(error == 0, ("Don't know BSP"));
152 	KASSERT(bsp.cr_cpuid == 0, ("%s: cpuid != 0", __func__));
153 
154 	error = platform_smp_first_cpu(&cpu);
155 	while (!error) {
156 		if (cpu.cr_cpuid >= MAXCPU) {
157 			printf("SMP: cpu%d: skipped -- ID out of range\n",
158 			    cpu.cr_cpuid);
159 			goto next;
160 		}
161 		if (CPU_ISSET(cpu.cr_cpuid, &all_cpus)) {
162 			printf("SMP: cpu%d: skipped - duplicate ID\n",
163 			    cpu.cr_cpuid);
164 			goto next;
165 		}
166 		if (cpu.cr_cpuid != bsp.cr_cpuid) {
167 			void *dpcpu;
168 
169 			pc = &__pcpu[cpu.cr_cpuid];
170 			dpcpu = (void *)kmem_malloc(kernel_arena, DPCPU_SIZE,
171 			    M_WAITOK | M_ZERO);
172 			pcpu_init(pc, cpu.cr_cpuid, sizeof(*pc));
173 			dpcpu_init(dpcpu, cpu.cr_cpuid);
174 		} else {
175 			pc = pcpup;
176 			pc->pc_cpuid = bsp.cr_cpuid;
177 			pc->pc_bsp = 1;
178 		}
179 		pc->pc_hwref = cpu.cr_hwref;
180 		CPU_SET(pc->pc_cpuid, &all_cpus);
181 next:
182 		error = platform_smp_next_cpu(&cpu);
183 	}
184 }
185 
186 void
187 cpu_mp_announce(void)
188 {
189 	struct pcpu *pc;
190 	int i;
191 
192 	for (i = 0; i <= mp_maxid; i++) {
193 		pc = pcpu_find(i);
194 		if (pc == NULL)
195 			continue;
196 		printf("cpu%d: dev=%x", i, (int)pc->pc_hwref);
197 		if (pc->pc_bsp)
198 			printf(" (BSP)");
199 		printf("\n");
200 	}
201 }
202 
203 static void
204 cpu_mp_unleash(void *dummy)
205 {
206 	struct pcpu *pc;
207 	int cpus, timeout;
208 
209 	if (mp_ncpus <= 1)
210 		return;
211 
212 	mtx_init(&ap_boot_mtx, "ap boot", NULL, MTX_SPIN);
213 
214 	cpus = 0;
215 	smp_cpus = 0;
216 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
217 		cpus++;
218 		if (!pc->pc_bsp) {
219 			if (bootverbose)
220 				printf("Waking up CPU %d (dev=%x)\n",
221 				    pc->pc_cpuid, (int)pc->pc_hwref);
222 
223 			platform_smp_start_cpu(pc);
224 
225 			timeout = 2000;	/* wait 2sec for the AP */
226 			while (!pc->pc_awake && --timeout > 0)
227 				DELAY(1000);
228 
229 		} else {
230 			PCPU_SET(pir, mfspr(SPR_PIR));
231 			pc->pc_awake = 1;
232 		}
233 		if (pc->pc_awake) {
234 			if (bootverbose)
235 				printf("Adding CPU %d, pir=%x, awake=%x\n",
236 				    pc->pc_cpuid, pc->pc_pir, pc->pc_awake);
237 			smp_cpus++;
238 		} else
239 			CPU_SET(pc->pc_cpuid, &stopped_cpus);
240 	}
241 
242 	ap_awake = 1;
243 
244 	/* Provide our current DEC and TB values for APs */
245 	ap_timebase = mftb() + 10;
246 	__asm __volatile("msync; isync");
247 
248 	/* Let APs continue */
249 	atomic_store_rel_int(&ap_letgo, 1);
250 
251 #ifdef __powerpc64__
252 	/* Writing to the time base register is hypervisor-privileged */
253 	if (mfmsr() & PSL_HV)
254 		mttb(ap_timebase);
255 #else
256 	mttb(ap_timebase);
257 #endif
258 
259 	while (ap_awake < smp_cpus)
260 		;
261 
262 	if (smp_cpus != cpus || cpus != mp_ncpus) {
263 		printf("SMP: %d CPUs found; %d CPUs usable; %d CPUs woken\n",
264 		    mp_ncpus, cpus, smp_cpus);
265 	}
266 
267 	/* Let the APs get into the scheduler */
268 	DELAY(10000);
269 
270 	/* XXX Atomic set operation? */
271 	smp_started = 1;
272 }
273 
274 SYSINIT(start_aps, SI_SUB_SMP, SI_ORDER_FIRST, cpu_mp_unleash, NULL);
275 
276 int
277 powerpc_ipi_handler(void *arg)
278 {
279 	u_int cpuid;
280 	uint32_t ipimask;
281 	int msg;
282 
283 	CTR2(KTR_SMP, "%s: MSR 0x%08x", __func__, mfmsr());
284 
285 	ipimask = atomic_readandclear_32(&(pcpup->pc_ipimask));
286 	if (ipimask == 0)
287 		return (FILTER_STRAY);
288 	while ((msg = ffs(ipimask) - 1) != -1) {
289 		ipimask &= ~(1u << msg);
290 		ipi_msg_cnt[msg]++;
291 		switch (msg) {
292 		case IPI_AST:
293 			CTR1(KTR_SMP, "%s: IPI_AST", __func__);
294 			break;
295 		case IPI_PREEMPT:
296 			CTR1(KTR_SMP, "%s: IPI_PREEMPT", __func__);
297 			sched_preempt(curthread);
298 			break;
299 		case IPI_RENDEZVOUS:
300 			CTR1(KTR_SMP, "%s: IPI_RENDEZVOUS", __func__);
301 			smp_rendezvous_action();
302 			break;
303 		case IPI_STOP:
304 
305 			/*
306 			 * IPI_STOP_HARD is mapped to IPI_STOP so it is not
307 			 * necessary to add such case in the switch.
308 			 */
309 			CTR1(KTR_SMP, "%s: IPI_STOP or IPI_STOP_HARD (stop)",
310 			    __func__);
311 			cpuid = PCPU_GET(cpuid);
312 			savectx(&stoppcbs[cpuid]);
313 			savectx(PCPU_GET(curpcb));
314 			CPU_SET_ATOMIC(cpuid, &stopped_cpus);
315 			while (!CPU_ISSET(cpuid, &started_cpus))
316 				cpu_spinwait();
317 			CPU_CLR_ATOMIC(cpuid, &stopped_cpus);
318 			CPU_CLR_ATOMIC(cpuid, &started_cpus);
319 			CTR1(KTR_SMP, "%s: IPI_STOP (restart)", __func__);
320 			break;
321 		case IPI_HARDCLOCK:
322 			CTR1(KTR_SMP, "%s: IPI_HARDCLOCK", __func__);
323 			hardclockintr();
324 			break;
325 		}
326 	}
327 
328 	return (FILTER_HANDLED);
329 }
330 
331 static void
332 ipi_send(struct pcpu *pc, int ipi)
333 {
334 
335 	CTR4(KTR_SMP, "%s: pc=%p, targetcpu=%d, IPI=%d", __func__,
336 	    pc, pc->pc_cpuid, ipi);
337 
338 	atomic_set_32(&pc->pc_ipimask, (1 << ipi));
339 	powerpc_sync();
340 	PIC_IPI(root_pic, pc->pc_cpuid);
341 
342 	CTR1(KTR_SMP, "%s: sent", __func__);
343 }
344 
345 /* Send an IPI to a set of cpus. */
346 void
347 ipi_selected(cpuset_t cpus, int ipi)
348 {
349 	struct pcpu *pc;
350 
351 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
352 		if (CPU_ISSET(pc->pc_cpuid, &cpus))
353 			ipi_send(pc, ipi);
354 	}
355 }
356 
357 /* Send an IPI to a specific CPU. */
358 void
359 ipi_cpu(int cpu, u_int ipi)
360 {
361 
362 	ipi_send(cpuid_to_pcpu[cpu], ipi);
363 }
364 
365 /* Send an IPI to all CPUs EXCEPT myself. */
366 void
367 ipi_all_but_self(int ipi)
368 {
369 	struct pcpu *pc;
370 
371 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
372 		if (pc != pcpup)
373 			ipi_send(pc, ipi);
374 	}
375 }
376