mp_machdep.c revision 212559 
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: head/sys/powerpc/powerpc/mp_machdep.c 212559 2010-09-13 15:36:42Z nwhitehorn $");
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/lock.h>
36#include <sys/mutex.h>
37#include <sys/pcpu.h>
38#include <sys/proc.h>
39#include <sys/sched.h>
40#include <sys/smp.h>
41
42#include <vm/vm.h>
43#include <vm/vm_param.h>
44#include <vm/pmap.h>
45#include <vm/vm_map.h>
46#include <vm/vm_extern.h>
47#include <vm/vm_kern.h>
48
49#include <machine/bus.h>
50#include <machine/cpu.h>
51#include <machine/intr_machdep.h>
52#include <machine/platform.h>
53#include <machine/md_var.h>
54#include <machine/smp.h>
55
56#include "pic_if.h"
57
58extern struct pcpu __pcpu[MAXCPU];
59
60volatile static int ap_awake;
61volatile static u_int ap_letgo;
62volatile static u_quad_t ap_timebase;
63static u_int ipi_msg_cnt[32];
64static struct mtx ap_boot_mtx;
65
66void
67machdep_ap_bootstrap(void)
68{
69	/* Set up important bits on the CPU (HID registers, etc.) */
70	cpudep_ap_setup();
71
72	/* Set PIR */
73	PCPU_SET(pir, mfspr(SPR_PIR));
74	PCPU_SET(awake, 1);
75	__asm __volatile("msync; isync");
76
77	while (ap_letgo == 0)
78		;
79
80	/* Initialize DEC and TB, sync with the BSP values */
81	mttb(ap_timebase);
82	decr_ap_init();
83
84	/* Serialize console output and AP count increment */
85	mtx_lock_spin(&ap_boot_mtx);
86	ap_awake++;
87	printf("SMP: AP CPU #%d launched\n", PCPU_GET(cpuid));
88	mtx_unlock_spin(&ap_boot_mtx);
89
90	/* Initialize curthread */
91	PCPU_SET(curthread, PCPU_GET(idlethread));
92	PCPU_SET(curpcb, curthread->td_pcb);
93
94	/* Start per-CPU event timers. */
95	cpu_initclocks_ap();
96
97	/* Announce ourselves awake, and enter the scheduler */
98	sched_throw(NULL);
99}
100
101struct cpu_group *
102cpu_topo(void)
103{
104
105	return (smp_topo_none());
106}
107
108void
109cpu_mp_setmaxid(void)
110{
111	struct cpuref cpuref;
112	int error;
113
114	mp_ncpus = 0;
115	error = platform_smp_first_cpu(&cpuref);
116	while (!error) {
117		mp_ncpus++;
118		error = platform_smp_next_cpu(&cpuref);
119	}
120	/* Sanity. */
121	if (mp_ncpus == 0)
122		mp_ncpus = 1;
123
124	/*
125	 * Set the largest cpuid we're going to use. This is necessary
126	 * for VM initialization.
127	 */
128	mp_maxid = min(mp_ncpus, MAXCPU) - 1;
129}
130
131int
132cpu_mp_probe(void)
133{
134
135	/*
136	 * We're not going to enable SMP if there's only 1 processor.
137	 */
138	return (mp_ncpus > 1);
139}
140
141void
142cpu_mp_start(void)
143{
144	struct cpuref bsp, cpu;
145	struct pcpu *pc;
146	int error;
147
148	error = platform_smp_get_bsp(&bsp);
149	KASSERT(error == 0, ("Don't know BSP"));
150	KASSERT(bsp.cr_cpuid == 0, ("%s: cpuid != 0", __func__));
151
152	error = platform_smp_first_cpu(&cpu);
153	while (!error) {
154		if (cpu.cr_cpuid >= MAXCPU) {
155			printf("SMP: cpu%d: skipped -- ID out of range\n",
156			    cpu.cr_cpuid);
157			goto next;
158		}
159		if (all_cpus & (1 << cpu.cr_cpuid)) {
160			printf("SMP: cpu%d: skipped - duplicate ID\n",
161			    cpu.cr_cpuid);
162			goto next;
163		}
164		if (cpu.cr_cpuid != bsp.cr_cpuid) {
165			void *dpcpu;
166
167			pc = &__pcpu[cpu.cr_cpuid];
168			dpcpu = (void *)kmem_alloc(kernel_map, DPCPU_SIZE);
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_cpumask = 1 << pc->pc_cpuid;
177		pc->pc_hwref = cpu.cr_hwref;
178		all_cpus |= pc->pc_cpumask;
179next:
180		error = platform_smp_next_cpu(&cpu);
181	}
182}
183
184void
185cpu_mp_announce(void)
186{
187	struct pcpu *pc;
188	int i;
189
190	for (i = 0; i <= mp_maxid; i++) {
191		pc = pcpu_find(i);
192		if (pc == NULL)
193			continue;
194		printf("cpu%d: dev=%x", i, (int)pc->pc_hwref);
195		if (pc->pc_bsp)
196			printf(" (BSP)");
197		printf("\n");
198	}
199}
200
201static void
202cpu_mp_unleash(void *dummy)
203{
204	struct pcpu *pc;
205	int cpus, timeout;
206
207	if (mp_ncpus <= 1)
208		return;
209
210	mtx_init(&ap_boot_mtx, "ap boot", NULL, MTX_SPIN);
211
212	cpus = 0;
213	smp_cpus = 0;
214	SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
215		cpus++;
216		pc->pc_other_cpus = all_cpus & ~pc->pc_cpumask;
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			stopped_cpus |= (1 << pc->pc_cpuid);
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	mttb(ap_timebase);
251
252	while (ap_awake < smp_cpus)
253		;
254
255	if (smp_cpus != cpus || cpus != mp_ncpus) {
256		printf("SMP: %d CPUs found; %d CPUs usable; %d CPUs woken\n",
257		    mp_ncpus, cpus, smp_cpus);
258	}
259
260	/* Let the APs get into the scheduler */
261	DELAY(10000);
262
263	smp_active = 1;
264	smp_started = 1;
265}
266
267SYSINIT(start_aps, SI_SUB_SMP, SI_ORDER_FIRST, cpu_mp_unleash, NULL);
268
269int
270powerpc_ipi_handler(void *arg)
271{
272	cpumask_t self;
273	uint32_t ipimask;
274	int msg;
275
276	CTR2(KTR_SMP, "%s: MSR 0x%08x", __func__, mfmsr());
277
278	ipimask = atomic_readandclear_32(&(pcpup->pc_ipimask));
279	if (ipimask == 0)
280		return (FILTER_STRAY);
281	while ((msg = ffs(ipimask) - 1) != -1) {
282		ipimask &= ~(1u << msg);
283		ipi_msg_cnt[msg]++;
284		switch (msg) {
285		case IPI_AST:
286			CTR1(KTR_SMP, "%s: IPI_AST", __func__);
287			break;
288		case IPI_PREEMPT:
289			CTR1(KTR_SMP, "%s: IPI_PREEMPT", __func__);
290			sched_preempt(curthread);
291			break;
292		case IPI_RENDEZVOUS:
293			CTR1(KTR_SMP, "%s: IPI_RENDEZVOUS", __func__);
294			smp_rendezvous_action();
295			break;
296		case IPI_STOP:
297
298			/*
299			 * IPI_STOP_HARD is mapped to IPI_STOP so it is not
300			 * necessary to add such case in the switch.
301			 */
302			CTR1(KTR_SMP, "%s: IPI_STOP or IPI_STOP_HARD (stop)",
303			    __func__);
304			self = PCPU_GET(cpumask);
305			savectx(PCPU_GET(curpcb));
306			atomic_set_int(&stopped_cpus, self);
307			while ((started_cpus & self) == 0)
308				cpu_spinwait();
309			atomic_clear_int(&started_cpus, self);
310			atomic_clear_int(&stopped_cpus, self);
311			CTR1(KTR_SMP, "%s: IPI_STOP (restart)", __func__);
312			break;
313		case IPI_HARDCLOCK:
314			CTR1(KTR_SMP, "%s: IPI_HARDCLOCK", __func__);
315			hardclockintr();
316			break;
317		}
318	}
319
320	return (FILTER_HANDLED);
321}
322
323static void
324ipi_send(struct pcpu *pc, int ipi)
325{
326
327	CTR4(KTR_SMP, "%s: pc=%p, targetcpu=%d, IPI=%d", __func__,
328	    pc, pc->pc_cpuid, ipi);
329
330	atomic_set_32(&pc->pc_ipimask, (1 << ipi));
331	PIC_IPI(root_pic, pc->pc_cpuid);
332
333	CTR1(KTR_SMP, "%s: sent", __func__);
334}
335
336/* Send an IPI to a set of cpus. */
337void
338ipi_selected(cpumask_t cpus, int ipi)
339{
340	struct pcpu *pc;
341
342	SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
343		if (cpus & pc->pc_cpumask)
344			ipi_send(pc, ipi);
345	}
346}
347
348/* Send an IPI to a specific CPU. */
349void
350ipi_cpu(int cpu, u_int ipi)
351{
352
353	ipi_send(cpuid_to_pcpu[cpu], ipi);
354}
355
356/* Send an IPI to all CPUs EXCEPT myself. */
357void
358ipi_all_but_self(int ipi)
359{
360	struct pcpu *pc;
361
362	SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
363		if (pc != pcpup)
364			ipi_send(pc, ipi);
365	}
366}
367