mp_machdep.c revision 212453 
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 212453 2010-09-11 04:45:51Z mav $");
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	/* Let the DEC and external interrupts go */
95	mtmsr(mfmsr() | PSL_EE);
96
97	/* Start per-CPU event timers. */
98	cpu_initclocks_ap();
99
100	/* Announce ourselves awake, and enter the scheduler */
101	sched_throw(NULL);
102}
103
104struct cpu_group *
105cpu_topo(void)
106{
107
108	return (smp_topo_none());
109}
110
111void
112cpu_mp_setmaxid(void)
113{
114	struct cpuref cpuref;
115	int error;
116
117	mp_ncpus = 0;
118	error = platform_smp_first_cpu(&cpuref);
119	while (!error) {
120		mp_ncpus++;
121		error = platform_smp_next_cpu(&cpuref);
122	}
123	/* Sanity. */
124	if (mp_ncpus == 0)
125		mp_ncpus = 1;
126
127	/*
128	 * Set the largest cpuid we're going to use. This is necessary
129	 * for VM initialization.
130	 */
131	mp_maxid = min(mp_ncpus, MAXCPU) - 1;
132}
133
134int
135cpu_mp_probe(void)
136{
137
138	/*
139	 * We're not going to enable SMP if there's only 1 processor.
140	 */
141	return (mp_ncpus > 1);
142}
143
144void
145cpu_mp_start(void)
146{
147	struct cpuref bsp, cpu;
148	struct pcpu *pc;
149	int error;
150
151	error = platform_smp_get_bsp(&bsp);
152	KASSERT(error == 0, ("Don't know BSP"));
153	KASSERT(bsp.cr_cpuid == 0, ("%s: cpuid != 0", __func__));
154
155	error = platform_smp_first_cpu(&cpu);
156	while (!error) {
157		if (cpu.cr_cpuid >= MAXCPU) {
158			printf("SMP: cpu%d: skipped -- ID out of range\n",
159			    cpu.cr_cpuid);
160			goto next;
161		}
162		if (all_cpus & (1 << cpu.cr_cpuid)) {
163			printf("SMP: cpu%d: skipped - duplicate ID\n",
164			    cpu.cr_cpuid);
165			goto next;
166		}
167		if (cpu.cr_cpuid != bsp.cr_cpuid) {
168			void *dpcpu;
169
170			pc = &__pcpu[cpu.cr_cpuid];
171			dpcpu = (void *)kmem_alloc(kernel_map, DPCPU_SIZE);
172			pcpu_init(pc, cpu.cr_cpuid, sizeof(*pc));
173			dpcpu_init(dpcpu, cpu.cr_cpuid);
174		} else {
175			pc = pcpup;
176			pc->pc_cpuid = bsp.cr_cpuid;
177			pc->pc_bsp = 1;
178		}
179		pc->pc_cpumask = 1 << pc->pc_cpuid;
180		pc->pc_hwref = cpu.cr_hwref;
181		all_cpus |= pc->pc_cpumask;
182next:
183		error = platform_smp_next_cpu(&cpu);
184	}
185}
186
187void
188cpu_mp_announce(void)
189{
190	struct pcpu *pc;
191	int i;
192
193	for (i = 0; i <= mp_maxid; i++) {
194		pc = pcpu_find(i);
195		if (pc == NULL)
196			continue;
197		printf("cpu%d: dev=%x", i, (int)pc->pc_hwref);
198		if (pc->pc_bsp)
199			printf(" (BSP)");
200		printf("\n");
201	}
202}
203
204static void
205cpu_mp_unleash(void *dummy)
206{
207	struct pcpu *pc;
208	int cpus, timeout;
209
210	if (mp_ncpus <= 1)
211		return;
212
213	mtx_init(&ap_boot_mtx, "ap boot", NULL, MTX_SPIN);
214
215	cpus = 0;
216	smp_cpus = 0;
217	SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
218		cpus++;
219		pc->pc_other_cpus = all_cpus & ~pc->pc_cpumask;
220		if (!pc->pc_bsp) {
221			if (bootverbose)
222				printf("Waking up CPU %d (dev=%x)\n",
223				    pc->pc_cpuid, (int)pc->pc_hwref);
224
225			platform_smp_start_cpu(pc);
226
227			timeout = 2000;	/* wait 2sec for the AP */
228			while (!pc->pc_awake && --timeout > 0)
229				DELAY(1000);
230
231		} else {
232			PCPU_SET(pir, mfspr(SPR_PIR));
233			pc->pc_awake = 1;
234		}
235		if (pc->pc_awake) {
236			if (bootverbose)
237				printf("Adding CPU %d, pir=%x, awake=%x\n",
238				    pc->pc_cpuid, pc->pc_pir, pc->pc_awake);
239			smp_cpus++;
240		} else
241			stopped_cpus |= (1 << pc->pc_cpuid);
242	}
243
244	ap_awake = 1;
245
246	/* Provide our current DEC and TB values for APs */
247	ap_timebase = mftb() + 10;
248	__asm __volatile("msync; isync");
249
250	/* Let APs continue */
251	atomic_store_rel_int(&ap_letgo, 1);
252
253	mttb(ap_timebase);
254
255	while (ap_awake < smp_cpus)
256		;
257
258	if (smp_cpus != cpus || cpus != mp_ncpus) {
259		printf("SMP: %d CPUs found; %d CPUs usable; %d CPUs woken\n",
260		    mp_ncpus, cpus, smp_cpus);
261	}
262
263	/* Let the APs get into the scheduler */
264	DELAY(10000);
265
266	smp_active = 1;
267	smp_started = 1;
268}
269
270SYSINIT(start_aps, SI_SUB_SMP, SI_ORDER_FIRST, cpu_mp_unleash, NULL);
271
272int
273powerpc_ipi_handler(void *arg)
274{
275	cpumask_t self;
276	uint32_t ipimask;
277	int msg;
278
279	CTR2(KTR_SMP, "%s: MSR 0x%08x", __func__, mfmsr());
280
281	ipimask = atomic_readandclear_32(&(pcpup->pc_ipimask));
282	if (ipimask == 0)
283		return (FILTER_STRAY);
284	while ((msg = ffs(ipimask) - 1) != -1) {
285		ipimask &= ~(1u << msg);
286		ipi_msg_cnt[msg]++;
287		switch (msg) {
288		case IPI_AST:
289			CTR1(KTR_SMP, "%s: IPI_AST", __func__);
290			break;
291		case IPI_PREEMPT:
292			CTR1(KTR_SMP, "%s: IPI_PREEMPT", __func__);
293			sched_preempt(curthread);
294			break;
295		case IPI_RENDEZVOUS:
296			CTR1(KTR_SMP, "%s: IPI_RENDEZVOUS", __func__);
297			smp_rendezvous_action();
298			break;
299		case IPI_STOP:
300
301			/*
302			 * IPI_STOP_HARD is mapped to IPI_STOP so it is not
303			 * necessary to add such case in the switch.
304			 */
305			CTR1(KTR_SMP, "%s: IPI_STOP or IPI_STOP_HARD (stop)",
306			    __func__);
307			self = PCPU_GET(cpumask);
308			savectx(PCPU_GET(curpcb));
309			atomic_set_int(&stopped_cpus, self);
310			while ((started_cpus & self) == 0)
311				cpu_spinwait();
312			atomic_clear_int(&started_cpus, self);
313			atomic_clear_int(&stopped_cpus, self);
314			CTR1(KTR_SMP, "%s: IPI_STOP (restart)", __func__);
315			break;
316		case IPI_HARDCLOCK:
317			CTR1(KTR_SMP, "%s: IPI_HARDCLOCK", __func__);
318			hardclockintr(curthread->td_intr_frame);
319			break;
320		}
321	}
322
323	return (FILTER_HANDLED);
324}
325
326static void
327ipi_send(struct pcpu *pc, int ipi)
328{
329
330	CTR4(KTR_SMP, "%s: pc=%p, targetcpu=%d, IPI=%d", __func__,
331	    pc, pc->pc_cpuid, ipi);
332
333	atomic_set_32(&pc->pc_ipimask, (1 << ipi));
334	PIC_IPI(root_pic, pc->pc_cpuid);
335
336	CTR1(KTR_SMP, "%s: sent", __func__);
337}
338
339/* Send an IPI to a set of cpus. */
340void
341ipi_selected(cpumask_t cpus, int ipi)
342{
343	struct pcpu *pc;
344
345	SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
346		if (cpus & pc->pc_cpumask)
347			ipi_send(pc, ipi);
348	}
349}
350
351/* Send an IPI to a specific CPU. */
352void
353ipi_cpu(int cpu, u_int ipi)
354{
355
356	ipi_send(cpuid_to_pcpu[cpu], ipi);
357}
358
359/* Send an IPI to all CPUs EXCEPT myself. */
360void
361ipi_all_but_self(int ipi)
362{
363	struct pcpu *pc;
364
365	SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
366		if (pc != pcpup)
367			ipi_send(pc, ipi);
368	}
369}
370