mp_machdep.c revision 192067 
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 192067 2009-05-14 00:34:26Z nwhitehorn $");
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/platform.h>
43#include <machine/smp.h>
44
45#include "pic_if.h"
46
47extern struct pcpu __pcpu[MAXCPU];
48
49volatile static int ap_awake;
50volatile static u_int ap_state;
51volatile static uint32_t ap_decr;
52volatile static uint32_t ap_tbl;
53
54void
55machdep_ap_bootstrap(void)
56{
57
58	pcpup->pc_awake = 1;
59
60	while (ap_state == 0)
61		;
62
63	mtspr(SPR_TBL, 0);
64	mtspr(SPR_TBU, 0);
65	mtspr(SPR_TBL, ap_tbl);
66	__asm __volatile("mtdec %0" :: "r"(ap_decr));
67
68	ap_awake++;
69
70	/* Initialize curthread. */
71	PCPU_SET(curthread, PCPU_GET(idlethread));
72	PCPU_SET(curpcb, curthread->td_pcb);
73
74	mtmsr(mfmsr() | PSL_EE);
75	sched_throw(NULL);
76}
77
78struct cpu_group *
79cpu_topo(void)
80{
81
82	return (smp_topo_none());
83}
84
85void
86cpu_mp_setmaxid(void)
87{
88	struct cpuref cpuref;
89	int error;
90
91	mp_ncpus = 0;
92	error = platform_smp_first_cpu(&cpuref);
93	while (!error) {
94		mp_ncpus++;
95		error = platform_smp_next_cpu(&cpuref);
96	}
97	/* Sanity. */
98	if (mp_ncpus == 0)
99		mp_ncpus = 1;
100
101	/*
102	 * Set the largest cpuid we're going to use. This is necessary
103	 * for VM initialization.
104	 */
105	mp_maxid = min(mp_ncpus, MAXCPU) - 1;
106}
107
108int
109cpu_mp_probe(void)
110{
111
112	/*
113	 * We're not going to enable SMP if there's only 1 processor.
114	 */
115	return (mp_ncpus > 1);
116}
117
118void
119cpu_mp_start(void)
120{
121	struct cpuref bsp, cpu;
122	struct pcpu *pc;
123	int error;
124
125	error = platform_smp_get_bsp(&bsp);
126	KASSERT(error == 0, ("Don't know BSP"));
127	KASSERT(bsp.cr_cpuid == 0, ("%s: cpuid != 0", __func__));
128
129	error = platform_smp_first_cpu(&cpu);
130	while (!error) {
131		if (cpu.cr_cpuid >= MAXCPU) {
132			printf("SMP: cpu%d: skipped -- ID out of range\n",
133			    cpu.cr_cpuid);
134			goto next;
135		}
136		if (all_cpus & (1 << cpu.cr_cpuid)) {
137			printf("SMP: cpu%d: skipped - duplicate ID\n",
138			    cpu.cr_cpuid);
139			goto next;
140		}
141		if (cpu.cr_cpuid != bsp.cr_cpuid) {
142			pc = &__pcpu[cpu.cr_cpuid];
143			pcpu_init(pc, cpu.cr_cpuid, sizeof(*pc));
144		} else {
145			pc = pcpup;
146			pc->pc_cpuid = bsp.cr_cpuid;
147			pc->pc_bsp = 1;
148		}
149		pc->pc_cpumask = 1 << pc->pc_cpuid;
150		pc->pc_hwref = cpu.cr_hwref;
151		all_cpus |= pc->pc_cpumask;
152
153 next:
154		error = platform_smp_next_cpu(&cpu);
155	}
156}
157
158void
159cpu_mp_announce(void)
160{
161	struct pcpu *pc;
162	int i;
163
164	for (i = 0; i <= mp_maxid; i++) {
165		pc = pcpu_find(i);
166		if (pc == NULL)
167			continue;
168		printf("cpu%d: dev=%x", i, pc->pc_hwref);
169		if (pc->pc_bsp)
170			printf(" (BSP)");
171		printf("\n");
172	}
173}
174
175static void
176cpu_mp_unleash(void *dummy)
177{
178	struct pcpu *pc;
179	int cpus;
180
181	if (mp_ncpus <= 1)
182		return;
183
184	cpus = 0;
185	smp_cpus = 0;
186	SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
187		cpus++;
188		pc->pc_other_cpus = all_cpus & ~pc->pc_cpumask;
189		if (!pc->pc_bsp) {
190			printf("Waking up CPU %d (dev=%x)\n", pc->pc_cpuid,
191			    pc->pc_hwref);
192			platform_smp_start_cpu(pc);
193		} else {
194			__asm __volatile("mfspr %0,1023" : "=r"(pc->pc_pir));
195			pc->pc_awake = 1;
196		}
197		if (pc->pc_awake)
198			smp_cpus++;
199	}
200
201	ap_awake = 1;
202
203	__asm __volatile("mftb %0" : "=r"(ap_tbl));
204	ap_tbl += 10;
205	__asm __volatile("mfdec %0" : "=r"(ap_decr));
206	ap_state++;
207	powerpc_sync();
208
209	mtspr(SPR_TBL, 0);
210	mtspr(SPR_TBU, 0);
211	mtspr(SPR_TBL, ap_tbl);
212
213	while (ap_awake < smp_cpus)
214		;
215
216	if (smp_cpus != cpus || cpus != mp_ncpus) {
217		printf("SMP: %d CPUs found; %d CPUs usable; %d CPUs woken\n",
218			mp_ncpus, cpus, smp_cpus);
219	}
220
221	smp_active = 1;
222	smp_started = 1;
223}
224
225SYSINIT(start_aps, SI_SUB_SMP, SI_ORDER_FIRST, cpu_mp_unleash, NULL);
226
227static u_int ipi_msg_cnt[32];
228
229int
230powerpc_ipi_handler(void *arg)
231{
232	cpumask_t self;
233	uint32_t ipimask;
234	int msg;
235
236	ipimask = atomic_readandclear_32(&(pcpup->pc_ipimask));
237	if (ipimask == 0)
238		return (FILTER_STRAY);
239	while ((msg = ffs(ipimask) - 1) != -1) {
240		ipimask &= ~(1u << msg);
241		ipi_msg_cnt[msg]++;
242		switch (msg) {
243		case IPI_AST:
244			break;
245		case IPI_PREEMPT:
246			sched_preempt(curthread);
247			break;
248		case IPI_RENDEZVOUS:
249			smp_rendezvous_action();
250			break;
251		case IPI_STOP:
252			self = PCPU_GET(cpumask);
253			savectx(PCPU_GET(curpcb));
254			atomic_set_int(&stopped_cpus, self);
255			while ((started_cpus & self) == 0)
256				cpu_spinwait();
257			atomic_clear_int(&started_cpus, self);
258			atomic_clear_int(&stopped_cpus, self);
259			break;
260		}
261	}
262
263	return (FILTER_HANDLED);
264}
265
266static void
267ipi_send(struct pcpu *pc, int ipi)
268{
269
270	atomic_set_32(&pc->pc_ipimask, (1 << ipi));
271	PIC_IPI(pic, pc->pc_cpuid);
272}
273
274/* Send an IPI to a set of cpus. */
275void
276ipi_selected(cpumask_t cpus, int ipi)
277{
278	struct pcpu *pc;
279
280	SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
281		if (cpus & pc->pc_cpumask)
282			ipi_send(pc, ipi);
283	}
284}
285
286/* Send an IPI to all CPUs EXCEPT myself. */
287void
288ipi_all_but_self(int ipi)
289{
290	struct pcpu *pc;
291
292	SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
293		if (pc != pcpup)
294			ipi_send(pc, ipi);
295	}
296}
297