xref: /freebsd/sys/powerpc/powerpc/mp_machdep.c (revision 1c05a6ea6b849ff95e539c31adea887c644a6a01)
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 	mp_maxid = 0;
117 	error = platform_smp_first_cpu(&cpuref);
118 	while (!error) {
119 		mp_ncpus++;
120 		mp_maxid = max(cpuref.cr_cpuid, mp_maxid);
121 		error = platform_smp_next_cpu(&cpuref);
122 	}
123 	/* Sanity. */
124 	if (mp_ncpus == 0)
125 		mp_ncpus = 1;
126 }
127 
128 int
129 cpu_mp_probe(void)
130 {
131 
132 	/*
133 	 * We're not going to enable SMP if there's only 1 processor.
134 	 */
135 	return (mp_ncpus > 1);
136 }
137 
138 void
139 cpu_mp_start(void)
140 {
141 	struct cpuref bsp, cpu;
142 	struct pcpu *pc;
143 	int error;
144 
145 	error = platform_smp_get_bsp(&bsp);
146 	KASSERT(error == 0, ("Don't know BSP"));
147 	KASSERT(bsp.cr_cpuid == 0, ("%s: cpuid != 0", __func__));
148 
149 	error = platform_smp_first_cpu(&cpu);
150 	while (!error) {
151 		if (cpu.cr_cpuid >= MAXCPU) {
152 			printf("SMP: cpu%d: skipped -- ID out of range\n",
153 			    cpu.cr_cpuid);
154 			goto next;
155 		}
156 		if (CPU_ISSET(cpu.cr_cpuid, &all_cpus)) {
157 			printf("SMP: cpu%d: skipped - duplicate ID\n",
158 			    cpu.cr_cpuid);
159 			goto next;
160 		}
161 		if (cpu.cr_cpuid != bsp.cr_cpuid) {
162 			void *dpcpu;
163 
164 			pc = &__pcpu[cpu.cr_cpuid];
165 			dpcpu = (void *)kmem_malloc(kernel_arena, DPCPU_SIZE,
166 			    M_WAITOK | M_ZERO);
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 #ifdef BOOKE
212 	tlb1_ap_prep();
213 #endif
214 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
215 		cpus++;
216 		if (!pc->pc_bsp) {
217 			if (bootverbose)
218 				printf("Waking up CPU %d (dev=%x)\n",
219 				    pc->pc_cpuid, (int)pc->pc_hwref);
220 
221 			platform_smp_start_cpu(pc);
222 
223 			timeout = 2000;	/* wait 2sec for the AP */
224 			while (!pc->pc_awake && --timeout > 0)
225 				DELAY(1000);
226 
227 		} else {
228 			PCPU_SET(pir, mfspr(SPR_PIR));
229 			pc->pc_awake = 1;
230 		}
231 		if (pc->pc_awake) {
232 			if (bootverbose)
233 				printf("Adding CPU %d, pir=%x, awake=%x\n",
234 				    pc->pc_cpuid, pc->pc_pir, pc->pc_awake);
235 			smp_cpus++;
236 		} else
237 			CPU_SET(pc->pc_cpuid, &stopped_cpus);
238 	}
239 
240 	ap_awake = 1;
241 
242 	/* Provide our current DEC and TB values for APs */
243 	ap_timebase = mftb() + 10;
244 	__asm __volatile("msync; isync");
245 
246 	/* Let APs continue */
247 	atomic_store_rel_int(&ap_letgo, 1);
248 
249 #ifdef __powerpc64__
250 	/* Writing to the time base register is hypervisor-privileged */
251 	if (mfmsr() & PSL_HV)
252 		mttb(ap_timebase);
253 #else
254 	mttb(ap_timebase);
255 #endif
256 
257 	while (ap_awake < smp_cpus)
258 		;
259 
260 	if (smp_cpus != cpus || cpus != mp_ncpus) {
261 		printf("SMP: %d CPUs found; %d CPUs usable; %d CPUs woken\n",
262 		    mp_ncpus, cpus, smp_cpus);
263 	}
264 
265 	/* Let the APs get into the scheduler */
266 	DELAY(10000);
267 
268 	/* XXX Atomic set operation? */
269 	smp_started = 1;
270 }
271 
272 SYSINIT(start_aps, SI_SUB_SMP, SI_ORDER_FIRST, cpu_mp_unleash, NULL);
273 
274 int
275 powerpc_ipi_handler(void *arg)
276 {
277 	u_int cpuid;
278 	uint32_t ipimask;
279 	int msg;
280 
281 	CTR2(KTR_SMP, "%s: MSR 0x%08x", __func__, mfmsr());
282 
283 	ipimask = atomic_readandclear_32(&(pcpup->pc_ipimask));
284 	if (ipimask == 0)
285 		return (FILTER_STRAY);
286 	while ((msg = ffs(ipimask) - 1) != -1) {
287 		ipimask &= ~(1u << msg);
288 		ipi_msg_cnt[msg]++;
289 		switch (msg) {
290 		case IPI_AST:
291 			CTR1(KTR_SMP, "%s: IPI_AST", __func__);
292 			break;
293 		case IPI_PREEMPT:
294 			CTR1(KTR_SMP, "%s: IPI_PREEMPT", __func__);
295 			sched_preempt(curthread);
296 			break;
297 		case IPI_RENDEZVOUS:
298 			CTR1(KTR_SMP, "%s: IPI_RENDEZVOUS", __func__);
299 			smp_rendezvous_action();
300 			break;
301 		case IPI_STOP:
302 
303 			/*
304 			 * IPI_STOP_HARD is mapped to IPI_STOP so it is not
305 			 * necessary to add such case in the switch.
306 			 */
307 			CTR1(KTR_SMP, "%s: IPI_STOP or IPI_STOP_HARD (stop)",
308 			    __func__);
309 			cpuid = PCPU_GET(cpuid);
310 			savectx(&stoppcbs[cpuid]);
311 			savectx(PCPU_GET(curpcb));
312 			CPU_SET_ATOMIC(cpuid, &stopped_cpus);
313 			while (!CPU_ISSET(cpuid, &started_cpus))
314 				cpu_spinwait();
315 			CPU_CLR_ATOMIC(cpuid, &stopped_cpus);
316 			CPU_CLR_ATOMIC(cpuid, &started_cpus);
317 			CTR1(KTR_SMP, "%s: IPI_STOP (restart)", __func__);
318 			break;
319 		case IPI_HARDCLOCK:
320 			CTR1(KTR_SMP, "%s: IPI_HARDCLOCK", __func__);
321 			hardclockintr();
322 			break;
323 		}
324 	}
325 
326 	return (FILTER_HANDLED);
327 }
328 
329 static void
330 ipi_send(struct pcpu *pc, int ipi)
331 {
332 
333 	CTR4(KTR_SMP, "%s: pc=%p, targetcpu=%d, IPI=%d", __func__,
334 	    pc, pc->pc_cpuid, ipi);
335 
336 	atomic_set_32(&pc->pc_ipimask, (1 << ipi));
337 	powerpc_sync();
338 	PIC_IPI(root_pic, pc->pc_cpuid);
339 
340 	CTR1(KTR_SMP, "%s: sent", __func__);
341 }
342 
343 /* Send an IPI to a set of cpus. */
344 void
345 ipi_selected(cpuset_t cpus, int ipi)
346 {
347 	struct pcpu *pc;
348 
349 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
350 		if (CPU_ISSET(pc->pc_cpuid, &cpus))
351 			ipi_send(pc, ipi);
352 	}
353 }
354 
355 /* Send an IPI to a specific CPU. */
356 void
357 ipi_cpu(int cpu, u_int ipi)
358 {
359 
360 	ipi_send(cpuid_to_pcpu[cpu], ipi);
361 }
362 
363 /* Send an IPI to all CPUs EXCEPT myself. */
364 void
365 ipi_all_but_self(int ipi)
366 {
367 	struct pcpu *pc;
368 
369 	STAILQ_FOREACH(pc, &cpuhead, pc_allcpu) {
370 		if (pc != pcpup)
371 			ipi_send(pc, ipi);
372 	}
373 }
374