xref: /freebsd/sys/powerpc/powerpc/mp_machdep.c (revision 10b59a9b4add0320d52c15ce057dd697261e7dfc)
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/mutex.h>
38 #include <sys/pcpu.h>
39 #include <sys/proc.h>
40 #include <sys/sched.h>
41 #include <sys/smp.h>
42 
43 #include <vm/vm.h>
44 #include <vm/vm_param.h>
45 #include <vm/pmap.h>
46 #include <vm/vm_map.h>
47 #include <vm/vm_extern.h>
48 #include <vm/vm_kern.h>
49 
50 #include <machine/bus.h>
51 #include <machine/cpu.h>
52 #include <machine/intr_machdep.h>
53 #include <machine/pcb.h>
54 #include <machine/platform.h>
55 #include <machine/md_var.h>
56 #include <machine/smp.h>
57 
58 #include "pic_if.h"
59 
60 extern struct pcpu __pcpu[MAXCPU];
61 
62 volatile static int ap_awake;
63 volatile static u_int ap_letgo;
64 volatile static u_quad_t ap_timebase;
65 static u_int ipi_msg_cnt[32];
66 static struct mtx ap_boot_mtx;
67 struct pcb stoppcbs[MAXCPU];
68 
69 void
70 machdep_ap_bootstrap(void)
71 {
72 	/* Set up important bits on the CPU (HID registers, etc.) */
73 	cpudep_ap_setup();
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 	/* Serialize console output and AP count increment */
94 	mtx_lock_spin(&ap_boot_mtx);
95 	ap_awake++;
96 	printf("SMP: AP CPU #%d launched\n", PCPU_GET(cpuid));
97 	mtx_unlock_spin(&ap_boot_mtx);
98 
99 	/* Start per-CPU event timers. */
100 	cpu_initclocks_ap();
101 
102 	/* Announce ourselves awake, and enter the scheduler */
103 	sched_throw(NULL);
104 }
105 
106 void
107 cpu_mp_setmaxid(void)
108 {
109 	struct cpuref cpuref;
110 	int error;
111 
112 	mp_ncpus = 0;
113 	error = platform_smp_first_cpu(&cpuref);
114 	while (!error) {
115 		mp_ncpus++;
116 		error = platform_smp_next_cpu(&cpuref);
117 	}
118 	/* Sanity. */
119 	if (mp_ncpus == 0)
120 		mp_ncpus = 1;
121 
122 	/*
123 	 * Set the largest cpuid we're going to use. This is necessary
124 	 * for VM initialization.
125 	 */
126 	mp_maxid = min(mp_ncpus, MAXCPU) - 1;
127 }
128 
129 int
130 cpu_mp_probe(void)
131 {
132 
133 	/*
134 	 * We're not going to enable SMP if there's only 1 processor.
135 	 */
136 	return (mp_ncpus > 1);
137 }
138 
139 void
140 cpu_mp_start(void)
141 {
142 	struct cpuref bsp, cpu;
143 	struct pcpu *pc;
144 	int error;
145 
146 	error = platform_smp_get_bsp(&bsp);
147 	KASSERT(error == 0, ("Don't know BSP"));
148 	KASSERT(bsp.cr_cpuid == 0, ("%s: cpuid != 0", __func__));
149 
150 	error = platform_smp_first_cpu(&cpu);
151 	while (!error) {
152 		if (cpu.cr_cpuid >= MAXCPU) {
153 			printf("SMP: cpu%d: skipped -- ID out of range\n",
154 			    cpu.cr_cpuid);
155 			goto next;
156 		}
157 		if (CPU_ISSET(cpu.cr_cpuid, &all_cpus)) {
158 			printf("SMP: cpu%d: skipped - duplicate ID\n",
159 			    cpu.cr_cpuid);
160 			goto next;
161 		}
162 		if (cpu.cr_cpuid != bsp.cr_cpuid) {
163 			void *dpcpu;
164 
165 			pc = &__pcpu[cpu.cr_cpuid];
166 			dpcpu = (void *)kmem_alloc(kernel_map, DPCPU_SIZE);
167 			pcpu_init(pc, cpu.cr_cpuid, sizeof(*pc));
168 			dpcpu_init(dpcpu, cpu.cr_cpuid);
169 		} else {
170 			pc = pcpup;
171 			pc->pc_cpuid = bsp.cr_cpuid;
172 			pc->pc_bsp = 1;
173 		}
174 		pc->pc_hwref = cpu.cr_hwref;
175 		CPU_SET(pc->pc_cpuid, &all_cpus);
176 next:
177 		error = platform_smp_next_cpu(&cpu);
178 	}
179 }
180 
181 void
182 cpu_mp_announce(void)
183 {
184 	struct pcpu *pc;
185 	int i;
186 
187 	for (i = 0; i <= mp_maxid; i++) {
188 		pc = pcpu_find(i);
189 		if (pc == NULL)
190 			continue;
191 		printf("cpu%d: dev=%x", i, (int)pc->pc_hwref);
192 		if (pc->pc_bsp)
193 			printf(" (BSP)");
194 		printf("\n");
195 	}
196 }
197 
198 static void
199 cpu_mp_unleash(void *dummy)
200 {
201 	struct pcpu *pc;
202 	int cpus, timeout;
203 
204 	if (mp_ncpus <= 1)
205 		return;
206 
207 	mtx_init(&ap_boot_mtx, "ap boot", NULL, MTX_SPIN);
208 
209 	cpus = 0;
210 	smp_cpus = 0;
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 			PCPU_SET(pir, mfspr(SPR_PIR));
226 			pc->pc_awake = 1;
227 		}
228 		if (pc->pc_awake) {
229 			if (bootverbose)
230 				printf("Adding CPU %d, pir=%x, awake=%x\n",
231 				    pc->pc_cpuid, pc->pc_pir, 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 #ifdef __powerpc64__
247 	/* Writing to the time base register is hypervisor-privileged */
248 	if (mfmsr() & PSL_HV)
249 		mttb(ap_timebase);
250 #else
251 	mttb(ap_timebase);
252 #endif
253 
254 	while (ap_awake < smp_cpus)
255 		;
256 
257 	if (smp_cpus != cpus || cpus != mp_ncpus) {
258 		printf("SMP: %d CPUs found; %d CPUs usable; %d CPUs woken\n",
259 		    mp_ncpus, cpus, smp_cpus);
260 	}
261 
262 	/* Let the APs get into the scheduler */
263 	DELAY(10000);
264 
265 	smp_active = 1;
266 	smp_started = 1;
267 }
268 
269 SYSINIT(start_aps, SI_SUB_SMP, SI_ORDER_FIRST, cpu_mp_unleash, NULL);
270 
271 int
272 powerpc_ipi_handler(void *arg)
273 {
274 	u_int cpuid;
275 	uint32_t ipimask;
276 	int msg;
277 
278 	CTR2(KTR_SMP, "%s: MSR 0x%08x", __func__, mfmsr());
279 
280 	ipimask = atomic_readandclear_32(&(pcpup->pc_ipimask));
281 	if (ipimask == 0)
282 		return (FILTER_STRAY);
283 	while ((msg = ffs(ipimask) - 1) != -1) {
284 		ipimask &= ~(1u << msg);
285 		ipi_msg_cnt[msg]++;
286 		switch (msg) {
287 		case IPI_AST:
288 			CTR1(KTR_SMP, "%s: IPI_AST", __func__);
289 			break;
290 		case IPI_PREEMPT:
291 			CTR1(KTR_SMP, "%s: IPI_PREEMPT", __func__);
292 			sched_preempt(curthread);
293 			break;
294 		case IPI_RENDEZVOUS:
295 			CTR1(KTR_SMP, "%s: IPI_RENDEZVOUS", __func__);
296 			smp_rendezvous_action();
297 			break;
298 		case IPI_STOP:
299 
300 			/*
301 			 * IPI_STOP_HARD is mapped to IPI_STOP so it is not
302 			 * necessary to add such case in the switch.
303 			 */
304 			CTR1(KTR_SMP, "%s: IPI_STOP or IPI_STOP_HARD (stop)",
305 			    __func__);
306 			cpuid = PCPU_GET(cpuid);
307 			savectx(&stoppcbs[cpuid]);
308 			savectx(PCPU_GET(curpcb));
309 			CPU_SET_ATOMIC(cpuid, &stopped_cpus);
310 			while (!CPU_ISSET(cpuid, &started_cpus))
311 				cpu_spinwait();
312 			CPU_CLR_ATOMIC(cpuid, &stopped_cpus);
313 			CPU_CLR_ATOMIC(cpuid, &started_cpus);
314 			CTR1(KTR_SMP, "%s: IPI_STOP (restart)", __func__);
315 			break;
316 		case IPI_HARDCLOCK:
317 			CTR1(KTR_SMP, "%s: IPI_HARDCLOCK", __func__);
318 			hardclockintr();
319 			break;
320 		}
321 	}
322 
323 	return (FILTER_HANDLED);
324 }
325 
326 static void
327 ipi_send(struct pcpu *pc, int ipi)
328 {
329 
330 	CTR4(KTR_SMP, "%s: pc=%p, targetcpu=%d, IPI=%d", __func__,
331 	    pc, pc->pc_cpuid, ipi);
332 
333 	atomic_set_32(&pc->pc_ipimask, (1 << ipi));
334 	PIC_IPI(root_pic, pc->pc_cpuid);
335 
336 	CTR1(KTR_SMP, "%s: sent", __func__);
337 }
338 
339 /* Send an IPI to a set of cpus. */
340 void
341 ipi_selected(cpuset_t cpus, int ipi)
342 {
343 	struct pcpu *pc;
344 
345 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
346 		if (CPU_ISSET(pc->pc_cpuid, &cpus))
347 			ipi_send(pc, ipi);
348 	}
349 }
350 
351 /* Send an IPI to a specific CPU. */
352 void
353 ipi_cpu(int cpu, u_int ipi)
354 {
355 
356 	ipi_send(cpuid_to_pcpu[cpu], ipi);
357 }
358 
359 /* Send an IPI to all CPUs EXCEPT myself. */
360 void
361 ipi_all_but_self(int ipi)
362 {
363 	struct pcpu *pc;
364 
365 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
366 		if (pc != pcpup)
367 			ipi_send(pc, ipi);
368 	}
369 }
370