mp_machdep.c revision 183439 
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 183439 2008-09-28 18:34:14Z marius $");
29
30#include <sys/param.h>
31#include <sys/systm.h>
32#include <sys/kernel.h>
33#include <sys/bus.h>
34#include <sys/pcpu.h>
35#include <sys/proc.h>
36#include <sys/sched.h>
37#include <sys/smp.h>
38
39#include <machine/bus.h>
40#include <machine/cpu.h>
41#include <machine/intr_machdep.h>
42#include <machine/smp.h>
43
44#include "pic_if.h"
45
46extern struct pcpu __pcpu[MAXCPU];
47
48volatile static int ap_awake;
49volatile static u_int ap_state;
50volatile static uint32_t ap_decr;
51volatile static uint32_t ap_tbl;
52
53void
54machdep_ap_bootstrap(void)
55{
56
57	pcpup->pc_awake = 1;
58
59	while (ap_state == 0)
60		;
61
62	mtspr(SPR_TBL, 0);
63	mtspr(SPR_TBU, 0);
64	mtspr(SPR_TBL, ap_tbl);
65	__asm __volatile("mtdec %0" :: "r"(ap_decr));
66
67	ap_awake++;
68
69	/* Initialize curthread. */
70	PCPU_SET(curthread, PCPU_GET(idlethread));
71	PCPU_SET(curpcb, curthread->td_pcb);
72
73	mtmsr(mfmsr() | PSL_EE);
74	sched_throw(NULL);
75}
76
77struct cpu_group *
78cpu_topo(void)
79{
80
81	return (smp_topo_none());
82}
83
84void
85cpu_mp_setmaxid(void)
86{
87	struct cpuref cpuref;
88	int error;
89
90	mp_ncpus = 0;
91	error = powerpc_smp_first_cpu(&cpuref);
92	while (!error) {
93		mp_ncpus++;
94		error = powerpc_smp_next_cpu(&cpuref);
95	}
96	/* Sanity. */
97	if (mp_ncpus == 0)
98		mp_ncpus = 1;
99
100	/*
101	 * Set the largest cpuid we're going to use. This is necessary
102	 * for VM initialization.
103	 */
104	mp_maxid = min(mp_ncpus, MAXCPU) - 1;
105}
106
107int
108cpu_mp_probe(void)
109{
110
111	/*
112	 * We're not going to enable SMP if there's only 1 processor.
113	 */
114	return (mp_ncpus > 1);
115}
116
117void
118cpu_mp_start(void)
119{
120	struct cpuref bsp, cpu;
121	struct pcpu *pc;
122	int error;
123
124	error = powerpc_smp_get_bsp(&bsp);
125	KASSERT(error == 0, ("Don't know BSP"));
126	KASSERT(bsp.cr_cpuid == 0, ("%s: cpuid != 0", __func__));
127
128	error = powerpc_smp_first_cpu(&cpu);
129	while (!error) {
130		if (cpu.cr_cpuid >= MAXCPU) {
131			printf("SMP: cpu%d: skipped -- ID out of range\n",
132			    cpu.cr_cpuid);
133			goto next;
134		}
135		if (all_cpus & (1 << cpu.cr_cpuid)) {
136			printf("SMP: cpu%d: skipped - duplicate ID\n",
137			    cpu.cr_cpuid);
138			goto next;
139		}
140		if (cpu.cr_cpuid != bsp.cr_cpuid) {
141			pc = &__pcpu[cpu.cr_cpuid];
142			pcpu_init(pc, cpu.cr_cpuid, sizeof(*pc));
143		} else {
144			pc = pcpup;
145			pc->pc_cpuid = bsp.cr_cpuid;
146			pc->pc_bsp = 1;
147		}
148		pc->pc_cpumask = 1 << pc->pc_cpuid;
149		pc->pc_hwref = cpu.cr_hwref;
150		all_cpus |= pc->pc_cpumask;
151
152 next:
153		error = powerpc_smp_next_cpu(&cpu);
154	}
155}
156
157void
158cpu_mp_announce(void)
159{
160	struct pcpu *pc;
161	int i;
162
163	for (i = 0; i <= mp_maxid; i++) {
164		pc = pcpu_find(i);
165		if (pc == NULL)
166			continue;
167		printf("cpu%d: dev=%x", i, pc->pc_hwref);
168		if (pc->pc_bsp)
169			printf(" (BSP)");
170		printf("\n");
171	}
172}
173
174static void
175cpu_mp_unleash(void *dummy)
176{
177	struct pcpu *pc;
178	int cpus;
179
180	if (mp_ncpus <= 1)
181		return;
182
183	cpus = 0;
184	smp_cpus = 0;
185	SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
186		cpus++;
187		pc->pc_other_cpus = all_cpus & ~pc->pc_cpumask;
188		if (!pc->pc_bsp) {
189			printf("Waking up CPU %d (dev=%x)\n", pc->pc_cpuid,
190			    pc->pc_hwref);
191			powerpc_smp_start_cpu(pc);
192		} else {
193			__asm __volatile("mfspr %0,1023" : "=r"(pc->pc_pir));
194			pc->pc_awake = 1;
195		}
196		if (pc->pc_awake)
197			smp_cpus++;
198	}
199
200	ap_awake = 1;
201
202	__asm __volatile("mftb %0" : "=r"(ap_tbl));
203	ap_tbl += 10;
204	__asm __volatile("mfdec %0" : "=r"(ap_decr));
205	ap_state++;
206	powerpc_sync();
207
208	mtspr(SPR_TBL, 0);
209	mtspr(SPR_TBU, 0);
210	mtspr(SPR_TBL, ap_tbl);
211
212	while (ap_awake < smp_cpus)
213		;
214
215	if (smp_cpus != cpus || cpus != mp_ncpus) {
216		printf("SMP: %d CPUs found; %d CPUs usable; %d CPUs woken\n",
217			mp_ncpus, cpus, smp_cpus);
218	}
219
220	smp_active = 1;
221	smp_started = 1;
222}
223
224SYSINIT(start_aps, SI_SUB_SMP, SI_ORDER_FIRST, cpu_mp_unleash, NULL);
225
226static u_int ipi_msg_cnt[32];
227
228int
229powerpc_ipi_handler(void *arg)
230{
231	cpumask_t self;
232	uint32_t ipimask;
233	int msg;
234
235	ipimask = atomic_readandclear_32(&(pcpup->pc_ipimask));
236	if (ipimask == 0)
237		return (FILTER_STRAY);
238	while ((msg = ffs(ipimask) - 1) != -1) {
239		ipimask &= ~(1u << msg);
240		ipi_msg_cnt[msg]++;
241		switch (msg) {
242		case IPI_AST:
243			break;
244		case IPI_PREEMPT:
245			sched_preempt(curthread);
246			break;
247		case IPI_RENDEZVOUS:
248			smp_rendezvous_action();
249			break;
250		case IPI_STOP:
251			self = PCPU_GET(cpumask);
252			savectx(PCPU_GET(curpcb));
253			atomic_set_int(&stopped_cpus, self);
254			while ((started_cpus & self) == 0)
255				cpu_spinwait();
256			atomic_clear_int(&started_cpus, self);
257			atomic_clear_int(&stopped_cpus, self);
258			break;
259		}
260	}
261
262	return (FILTER_HANDLED);
263}
264
265static void
266ipi_send(struct pcpu *pc, int ipi)
267{
268
269	atomic_set_32(&pc->pc_ipimask, (1 << ipi));
270	PIC_IPI(pic, pc->pc_cpuid);
271}
272
273/* Send an IPI to a set of cpus. */
274void
275ipi_selected(cpumask_t cpus, int ipi)
276{
277	struct pcpu *pc;
278
279	SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
280		if (cpus & pc->pc_cpumask)
281			ipi_send(pc, ipi);
282	}
283}
284
285/* Send an IPI to all CPUs EXCEPT myself. */
286void
287ipi_all_but_self(int ipi)
288{
289	struct pcpu *pc;
290
291	SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
292		if (pc != pcpup)
293			ipi_send(pc, ipi);
294	}
295}
296