xref: /freebsd/sys/powerpc/powerpc/mp_machdep.c (revision 7e9ed7352231d59b01f8270d35c2b201d3c1c052)
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/smp.h>
58 
59 #include "pic_if.h"
60 
61 extern struct pcpu __pcpu[MAXCPU];
62 
63 volatile static int ap_awake;
64 volatile static u_int ap_letgo;
65 volatile static u_quad_t ap_timebase;
66 static u_int ipi_msg_cnt[32];
67 static struct mtx ap_boot_mtx;
68 struct pcb stoppcbs[MAXCPU];
69 
70 void
71 machdep_ap_bootstrap(void)
72 {
73 	/* Set up important bits on the CPU (HID registers, etc.) */
74 	cpudep_ap_setup();
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 	/* Serialize console output and AP count increment */
95 	mtx_lock_spin(&ap_boot_mtx);
96 	ap_awake++;
97 	printf("SMP: AP CPU #%d launched\n", PCPU_GET(cpuid));
98 	mtx_unlock_spin(&ap_boot_mtx);
99 
100 	/* Start per-CPU event timers. */
101 	cpu_initclocks_ap();
102 
103 	/* Announce ourselves awake, and enter the scheduler */
104 	sched_throw(NULL);
105 }
106 
107 void
108 cpu_mp_setmaxid(void)
109 {
110 	struct cpuref cpuref;
111 	int error;
112 
113 	mp_ncpus = 0;
114 	error = platform_smp_first_cpu(&cpuref);
115 	while (!error) {
116 		mp_ncpus++;
117 		error = platform_smp_next_cpu(&cpuref);
118 	}
119 	/* Sanity. */
120 	if (mp_ncpus == 0)
121 		mp_ncpus = 1;
122 
123 	/*
124 	 * Set the largest cpuid we're going to use. This is necessary
125 	 * for VM initialization.
126 	 */
127 	mp_maxid = min(mp_ncpus, MAXCPU) - 1;
128 }
129 
130 int
131 cpu_mp_probe(void)
132 {
133 
134 	/*
135 	 * We're not going to enable SMP if there's only 1 processor.
136 	 */
137 	return (mp_ncpus > 1);
138 }
139 
140 void
141 cpu_mp_start(void)
142 {
143 	struct cpuref bsp, cpu;
144 	struct pcpu *pc;
145 	int error;
146 
147 	error = platform_smp_get_bsp(&bsp);
148 	KASSERT(error == 0, ("Don't know BSP"));
149 	KASSERT(bsp.cr_cpuid == 0, ("%s: cpuid != 0", __func__));
150 
151 	error = platform_smp_first_cpu(&cpu);
152 	while (!error) {
153 		if (cpu.cr_cpuid >= MAXCPU) {
154 			printf("SMP: cpu%d: skipped -- ID out of range\n",
155 			    cpu.cr_cpuid);
156 			goto next;
157 		}
158 		if (CPU_ISSET(cpu.cr_cpuid, &all_cpus)) {
159 			printf("SMP: cpu%d: skipped - duplicate ID\n",
160 			    cpu.cr_cpuid);
161 			goto next;
162 		}
163 		if (cpu.cr_cpuid != bsp.cr_cpuid) {
164 			void *dpcpu;
165 
166 			pc = &__pcpu[cpu.cr_cpuid];
167 			dpcpu = (void *)kmem_malloc(kernel_arena, DPCPU_SIZE,
168 			    M_WAITOK | M_ZERO);
169 			pcpu_init(pc, cpu.cr_cpuid, sizeof(*pc));
170 			dpcpu_init(dpcpu, cpu.cr_cpuid);
171 		} else {
172 			pc = pcpup;
173 			pc->pc_cpuid = bsp.cr_cpuid;
174 			pc->pc_bsp = 1;
175 		}
176 		pc->pc_hwref = cpu.cr_hwref;
177 		CPU_SET(pc->pc_cpuid, &all_cpus);
178 next:
179 		error = platform_smp_next_cpu(&cpu);
180 	}
181 }
182 
183 void
184 cpu_mp_announce(void)
185 {
186 	struct pcpu *pc;
187 	int i;
188 
189 	for (i = 0; i <= mp_maxid; i++) {
190 		pc = pcpu_find(i);
191 		if (pc == NULL)
192 			continue;
193 		printf("cpu%d: dev=%x", i, (int)pc->pc_hwref);
194 		if (pc->pc_bsp)
195 			printf(" (BSP)");
196 		printf("\n");
197 	}
198 }
199 
200 static void
201 cpu_mp_unleash(void *dummy)
202 {
203 	struct pcpu *pc;
204 	int cpus, timeout;
205 
206 	if (mp_ncpus <= 1)
207 		return;
208 
209 	mtx_init(&ap_boot_mtx, "ap boot", NULL, MTX_SPIN);
210 
211 	cpus = 0;
212 	smp_cpus = 0;
213 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
214 		cpus++;
215 		if (!pc->pc_bsp) {
216 			if (bootverbose)
217 				printf("Waking up CPU %d (dev=%x)\n",
218 				    pc->pc_cpuid, (int)pc->pc_hwref);
219 
220 			platform_smp_start_cpu(pc);
221 
222 			timeout = 2000;	/* wait 2sec for the AP */
223 			while (!pc->pc_awake && --timeout > 0)
224 				DELAY(1000);
225 
226 		} else {
227 			PCPU_SET(pir, mfspr(SPR_PIR));
228 			pc->pc_awake = 1;
229 		}
230 		if (pc->pc_awake) {
231 			if (bootverbose)
232 				printf("Adding CPU %d, pir=%x, awake=%x\n",
233 				    pc->pc_cpuid, pc->pc_pir, pc->pc_awake);
234 			smp_cpus++;
235 		} else
236 			CPU_SET(pc->pc_cpuid, &stopped_cpus);
237 	}
238 
239 	ap_awake = 1;
240 
241 	/* Provide our current DEC and TB values for APs */
242 	ap_timebase = mftb() + 10;
243 	__asm __volatile("msync; isync");
244 
245 	/* Let APs continue */
246 	atomic_store_rel_int(&ap_letgo, 1);
247 
248 #ifdef __powerpc64__
249 	/* Writing to the time base register is hypervisor-privileged */
250 	if (mfmsr() & PSL_HV)
251 		mttb(ap_timebase);
252 #else
253 	mttb(ap_timebase);
254 #endif
255 
256 	while (ap_awake < smp_cpus)
257 		;
258 
259 	if (smp_cpus != cpus || cpus != mp_ncpus) {
260 		printf("SMP: %d CPUs found; %d CPUs usable; %d CPUs woken\n",
261 		    mp_ncpus, cpus, smp_cpus);
262 	}
263 
264 	/* Let the APs get into the scheduler */
265 	DELAY(10000);
266 
267 	smp_active = 1;
268 	smp_started = 1;
269 }
270 
271 SYSINIT(start_aps, SI_SUB_SMP, SI_ORDER_FIRST, cpu_mp_unleash, NULL);
272 
273 int
274 powerpc_ipi_handler(void *arg)
275 {
276 	u_int cpuid;
277 	uint32_t ipimask;
278 	int msg;
279 
280 	CTR2(KTR_SMP, "%s: MSR 0x%08x", __func__, mfmsr());
281 
282 	ipimask = atomic_readandclear_32(&(pcpup->pc_ipimask));
283 	if (ipimask == 0)
284 		return (FILTER_STRAY);
285 	while ((msg = ffs(ipimask) - 1) != -1) {
286 		ipimask &= ~(1u << msg);
287 		ipi_msg_cnt[msg]++;
288 		switch (msg) {
289 		case IPI_AST:
290 			CTR1(KTR_SMP, "%s: IPI_AST", __func__);
291 			break;
292 		case IPI_PREEMPT:
293 			CTR1(KTR_SMP, "%s: IPI_PREEMPT", __func__);
294 			sched_preempt(curthread);
295 			break;
296 		case IPI_RENDEZVOUS:
297 			CTR1(KTR_SMP, "%s: IPI_RENDEZVOUS", __func__);
298 			smp_rendezvous_action();
299 			break;
300 		case IPI_STOP:
301 
302 			/*
303 			 * IPI_STOP_HARD is mapped to IPI_STOP so it is not
304 			 * necessary to add such case in the switch.
305 			 */
306 			CTR1(KTR_SMP, "%s: IPI_STOP or IPI_STOP_HARD (stop)",
307 			    __func__);
308 			cpuid = PCPU_GET(cpuid);
309 			savectx(&stoppcbs[cpuid]);
310 			savectx(PCPU_GET(curpcb));
311 			CPU_SET_ATOMIC(cpuid, &stopped_cpus);
312 			while (!CPU_ISSET(cpuid, &started_cpus))
313 				cpu_spinwait();
314 			CPU_CLR_ATOMIC(cpuid, &stopped_cpus);
315 			CPU_CLR_ATOMIC(cpuid, &started_cpus);
316 			CTR1(KTR_SMP, "%s: IPI_STOP (restart)", __func__);
317 			break;
318 		case IPI_HARDCLOCK:
319 			CTR1(KTR_SMP, "%s: IPI_HARDCLOCK", __func__);
320 			hardclockintr();
321 			break;
322 		}
323 	}
324 
325 	return (FILTER_HANDLED);
326 }
327 
328 static void
329 ipi_send(struct pcpu *pc, int ipi)
330 {
331 
332 	CTR4(KTR_SMP, "%s: pc=%p, targetcpu=%d, IPI=%d", __func__,
333 	    pc, pc->pc_cpuid, ipi);
334 
335 	atomic_set_32(&pc->pc_ipimask, (1 << ipi));
336 	PIC_IPI(root_pic, pc->pc_cpuid);
337 
338 	CTR1(KTR_SMP, "%s: sent", __func__);
339 }
340 
341 /* Send an IPI to a set of cpus. */
342 void
343 ipi_selected(cpuset_t cpus, int ipi)
344 {
345 	struct pcpu *pc;
346 
347 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
348 		if (CPU_ISSET(pc->pc_cpuid, &cpus))
349 			ipi_send(pc, ipi);
350 	}
351 }
352 
353 /* Send an IPI to a specific CPU. */
354 void
355 ipi_cpu(int cpu, u_int ipi)
356 {
357 
358 	ipi_send(cpuid_to_pcpu[cpu], ipi);
359 }
360 
361 /* Send an IPI to all CPUs EXCEPT myself. */
362 void
363 ipi_all_but_self(int ipi)
364 {
365 	struct pcpu *pc;
366 
367 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
368 		if (pc != pcpup)
369 			ipi_send(pc, ipi);
370 	}
371 }
372