mp_machdep.c revision 215159 
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 215159 2010-11-12 04:18:19Z 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
101void
102cpu_mp_setmaxid(void)
103{
104	struct cpuref cpuref;
105	int error;
106
107	mp_ncpus = 0;
108	error = platform_smp_first_cpu(&cpuref);
109	while (!error) {
110		mp_ncpus++;
111		error = platform_smp_next_cpu(&cpuref);
112	}
113	/* Sanity. */
114	if (mp_ncpus == 0)
115		mp_ncpus = 1;
116
117	/*
118	 * Set the largest cpuid we're going to use. This is necessary
119	 * for VM initialization.
120	 */
121	mp_maxid = min(mp_ncpus, MAXCPU) - 1;
122}
123
124int
125cpu_mp_probe(void)
126{
127
128	/*
129	 * We're not going to enable SMP if there's only 1 processor.
130	 */
131	return (mp_ncpus > 1);
132}
133
134void
135cpu_mp_start(void)
136{
137	struct cpuref bsp, cpu;
138	struct pcpu *pc;
139	int error;
140
141	error = platform_smp_get_bsp(&bsp);
142	KASSERT(error == 0, ("Don't know BSP"));
143	KASSERT(bsp.cr_cpuid == 0, ("%s: cpuid != 0", __func__));
144
145	error = platform_smp_first_cpu(&cpu);
146	while (!error) {
147		if (cpu.cr_cpuid >= MAXCPU) {
148			printf("SMP: cpu%d: skipped -- ID out of range\n",
149			    cpu.cr_cpuid);
150			goto next;
151		}
152		if (all_cpus & (1 << cpu.cr_cpuid)) {
153			printf("SMP: cpu%d: skipped - duplicate ID\n",
154			    cpu.cr_cpuid);
155			goto next;
156		}
157		if (cpu.cr_cpuid != bsp.cr_cpuid) {
158			void *dpcpu;
159
160			pc = &__pcpu[cpu.cr_cpuid];
161			dpcpu = (void *)kmem_alloc(kernel_map, DPCPU_SIZE);
162			pcpu_init(pc, cpu.cr_cpuid, sizeof(*pc));
163			dpcpu_init(dpcpu, cpu.cr_cpuid);
164		} else {
165			pc = pcpup;
166			pc->pc_cpuid = bsp.cr_cpuid;
167			pc->pc_bsp = 1;
168		}
169		pc->pc_cpumask = 1 << pc->pc_cpuid;
170		pc->pc_hwref = cpu.cr_hwref;
171		all_cpus |= pc->pc_cpumask;
172next:
173		error = platform_smp_next_cpu(&cpu);
174	}
175}
176
177void
178cpu_mp_announce(void)
179{
180	struct pcpu *pc;
181	int i;
182
183	for (i = 0; i <= mp_maxid; i++) {
184		pc = pcpu_find(i);
185		if (pc == NULL)
186			continue;
187		printf("cpu%d: dev=%x", i, (int)pc->pc_hwref);
188		if (pc->pc_bsp)
189			printf(" (BSP)");
190		printf("\n");
191	}
192}
193
194static void
195cpu_mp_unleash(void *dummy)
196{
197	struct pcpu *pc;
198	int cpus, timeout;
199
200	if (mp_ncpus <= 1)
201		return;
202
203	mtx_init(&ap_boot_mtx, "ap boot", NULL, MTX_SPIN);
204
205	cpus = 0;
206	smp_cpus = 0;
207	SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
208		cpus++;
209		pc->pc_other_cpus = all_cpus & ~pc->pc_cpumask;
210		if (!pc->pc_bsp) {
211			if (bootverbose)
212				printf("Waking up CPU %d (dev=%x)\n",
213				    pc->pc_cpuid, (int)pc->pc_hwref);
214
215			platform_smp_start_cpu(pc);
216
217			timeout = 2000;	/* wait 2sec for the AP */
218			while (!pc->pc_awake && --timeout > 0)
219				DELAY(1000);
220
221		} else {
222			PCPU_SET(pir, mfspr(SPR_PIR));
223			pc->pc_awake = 1;
224		}
225		if (pc->pc_awake) {
226			if (bootverbose)
227				printf("Adding CPU %d, pir=%x, awake=%x\n",
228				    pc->pc_cpuid, pc->pc_pir, pc->pc_awake);
229			smp_cpus++;
230		} else
231			stopped_cpus |= (1 << pc->pc_cpuid);
232	}
233
234	ap_awake = 1;
235
236	/* Provide our current DEC and TB values for APs */
237	ap_timebase = mftb() + 10;
238	__asm __volatile("msync; isync");
239
240	/* Let APs continue */
241	atomic_store_rel_int(&ap_letgo, 1);
242
243	mttb(ap_timebase);
244
245	while (ap_awake < smp_cpus)
246		;
247
248	if (smp_cpus != cpus || cpus != mp_ncpus) {
249		printf("SMP: %d CPUs found; %d CPUs usable; %d CPUs woken\n",
250		    mp_ncpus, cpus, smp_cpus);
251	}
252
253	/* Let the APs get into the scheduler */
254	DELAY(10000);
255
256	smp_active = 1;
257	smp_started = 1;
258}
259
260SYSINIT(start_aps, SI_SUB_SMP, SI_ORDER_FIRST, cpu_mp_unleash, NULL);
261
262int
263powerpc_ipi_handler(void *arg)
264{
265	cpumask_t self;
266	uint32_t ipimask;
267	int msg;
268
269	CTR2(KTR_SMP, "%s: MSR 0x%08x", __func__, mfmsr());
270
271	ipimask = atomic_readandclear_32(&(pcpup->pc_ipimask));
272	if (ipimask == 0)
273		return (FILTER_STRAY);
274	while ((msg = ffs(ipimask) - 1) != -1) {
275		ipimask &= ~(1u << msg);
276		ipi_msg_cnt[msg]++;
277		switch (msg) {
278		case IPI_AST:
279			CTR1(KTR_SMP, "%s: IPI_AST", __func__);
280			break;
281		case IPI_PREEMPT:
282			CTR1(KTR_SMP, "%s: IPI_PREEMPT", __func__);
283			sched_preempt(curthread);
284			break;
285		case IPI_RENDEZVOUS:
286			CTR1(KTR_SMP, "%s: IPI_RENDEZVOUS", __func__);
287			smp_rendezvous_action();
288			break;
289		case IPI_STOP:
290
291			/*
292			 * IPI_STOP_HARD is mapped to IPI_STOP so it is not
293			 * necessary to add such case in the switch.
294			 */
295			CTR1(KTR_SMP, "%s: IPI_STOP or IPI_STOP_HARD (stop)",
296			    __func__);
297			self = PCPU_GET(cpumask);
298			savectx(PCPU_GET(curpcb));
299			atomic_set_int(&stopped_cpus, self);
300			while ((started_cpus & self) == 0)
301				cpu_spinwait();
302			atomic_clear_int(&started_cpus, self);
303			atomic_clear_int(&stopped_cpus, self);
304			CTR1(KTR_SMP, "%s: IPI_STOP (restart)", __func__);
305			break;
306		case IPI_HARDCLOCK:
307			CTR1(KTR_SMP, "%s: IPI_HARDCLOCK", __func__);
308			hardclockintr();
309			break;
310		}
311	}
312
313	return (FILTER_HANDLED);
314}
315
316static void
317ipi_send(struct pcpu *pc, int ipi)
318{
319
320	CTR4(KTR_SMP, "%s: pc=%p, targetcpu=%d, IPI=%d", __func__,
321	    pc, pc->pc_cpuid, ipi);
322
323	atomic_set_32(&pc->pc_ipimask, (1 << ipi));
324	PIC_IPI(root_pic, pc->pc_cpuid);
325
326	CTR1(KTR_SMP, "%s: sent", __func__);
327}
328
329/* Send an IPI to a set of cpus. */
330void
331ipi_selected(cpumask_t cpus, int ipi)
332{
333	struct pcpu *pc;
334
335	SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
336		if (cpus & pc->pc_cpumask)
337			ipi_send(pc, ipi);
338	}
339}
340
341/* Send an IPI to a specific CPU. */
342void
343ipi_cpu(int cpu, u_int ipi)
344{
345
346	ipi_send(cpuid_to_pcpu[cpu], ipi);
347}
348
349/* Send an IPI to all CPUs EXCEPT myself. */
350void
351ipi_all_but_self(int ipi)
352{
353	struct pcpu *pc;
354
355	SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
356		if (pc != pcpup)
357			ipi_send(pc, ipi);
358	}
359}
360