mp_machdep.c revision 198378 
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 198378 2009-10-23 03:17:02Z 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/pcpu.h>
36#include <sys/proc.h>
37#include <sys/sched.h>
38#include <sys/smp.h>
39
40#include <vm/vm.h>
41#include <vm/vm_param.h>
42#include <vm/pmap.h>
43#include <vm/vm_map.h>
44#include <vm/vm_extern.h>
45#include <vm/vm_kern.h>
46
47#include <machine/bus.h>
48#include <machine/cpu.h>
49#include <machine/intr_machdep.h>
50#include <machine/platform.h>
51#include <machine/md_var.h>
52#include <machine/smp.h>
53
54#include "pic_if.h"
55
56extern struct pcpu __pcpu[MAXCPU];
57
58volatile static int ap_awake;
59volatile static u_int ap_letgo;
60volatile static uint32_t ap_decr;
61volatile static u_quad_t ap_timebase;
62static u_int ipi_msg_cnt[32];
63
64void
65machdep_ap_bootstrap(void)
66{
67	/* Set up important bits on the CPU (HID registers, etc.) */
68	cpudep_ap_setup();
69
70	/* Set PIR */
71	PCPU_SET(pir, mfspr(SPR_PIR));
72	PCPU_SET(awake, 1);
73	__asm __volatile("msync; isync");
74
75	while (ap_letgo == 0)
76		;
77
78	/* Initialize DEC and TB, sync with the BSP values */
79	decr_ap_init();
80	mttb(ap_timebase);
81	__asm __volatile("mtdec %0" :: "r"(ap_decr));
82
83	atomic_add_int(&ap_awake, 1);
84	printf("SMP: AP CPU #%d launched\n", PCPU_GET(cpuid));
85
86	/* Initialize curthread */
87	PCPU_SET(curthread, PCPU_GET(idlethread));
88	PCPU_SET(curpcb, curthread->td_pcb);
89
90	/* Let the DEC and external interrupts go */
91	mtmsr(mfmsr() | PSL_EE);
92
93	/* Announce ourselves awake, and enter the scheduler */
94	sched_throw(NULL);
95}
96
97struct cpu_group *
98cpu_topo(void)
99{
100
101	return (smp_topo_none());
102}
103
104void
105cpu_mp_setmaxid(void)
106{
107	struct cpuref cpuref;
108	int error;
109
110	mp_ncpus = 0;
111	error = platform_smp_first_cpu(&cpuref);
112	while (!error) {
113		mp_ncpus++;
114		error = platform_smp_next_cpu(&cpuref);
115	}
116	/* Sanity. */
117	if (mp_ncpus == 0)
118		mp_ncpus = 1;
119
120	/*
121	 * Set the largest cpuid we're going to use. This is necessary
122	 * for VM initialization.
123	 */
124	mp_maxid = min(mp_ncpus, MAXCPU) - 1;
125}
126
127int
128cpu_mp_probe(void)
129{
130
131	/*
132	 * We're not going to enable SMP if there's only 1 processor.
133	 */
134	return (mp_ncpus > 1);
135}
136
137void
138cpu_mp_start(void)
139{
140	struct cpuref bsp, cpu;
141	struct pcpu *pc;
142	int error;
143
144	error = platform_smp_get_bsp(&bsp);
145	KASSERT(error == 0, ("Don't know BSP"));
146	KASSERT(bsp.cr_cpuid == 0, ("%s: cpuid != 0", __func__));
147
148	error = platform_smp_first_cpu(&cpu);
149	while (!error) {
150		if (cpu.cr_cpuid >= MAXCPU) {
151			printf("SMP: cpu%d: skipped -- ID out of range\n",
152			    cpu.cr_cpuid);
153			goto next;
154		}
155		if (all_cpus & (1 << cpu.cr_cpuid)) {
156			printf("SMP: cpu%d: skipped - duplicate ID\n",
157			    cpu.cr_cpuid);
158			goto next;
159		}
160		if (cpu.cr_cpuid != bsp.cr_cpuid) {
161			void *dpcpu;
162
163			pc = &__pcpu[cpu.cr_cpuid];
164			dpcpu = (void *)kmem_alloc(kernel_map, DPCPU_SIZE);
165			pcpu_init(pc, cpu.cr_cpuid, sizeof(*pc));
166			dpcpu_init(dpcpu, cpu.cr_cpuid);
167		} else {
168			pc = pcpup;
169			pc->pc_cpuid = bsp.cr_cpuid;
170			pc->pc_bsp = 1;
171		}
172		pc->pc_cpumask = 1 << pc->pc_cpuid;
173		pc->pc_hwref = cpu.cr_hwref;
174		all_cpus |= pc->pc_cpumask;
175next:
176		error = platform_smp_next_cpu(&cpu);
177	}
178}
179
180void
181cpu_mp_announce(void)
182{
183	struct pcpu *pc;
184	int i;
185
186	for (i = 0; i <= mp_maxid; i++) {
187		pc = pcpu_find(i);
188		if (pc == NULL)
189			continue;
190		printf("cpu%d: dev=%x", i, pc->pc_hwref);
191		if (pc->pc_bsp)
192			printf(" (BSP)");
193		printf("\n");
194	}
195}
196
197static void
198cpu_mp_unleash(void *dummy)
199{
200	struct pcpu *pc;
201	int cpus, timeout;
202
203	if (mp_ncpus <= 1)
204		return;
205
206	cpus = 0;
207	smp_cpus = 0;
208	SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
209		cpus++;
210		pc->pc_other_cpus = all_cpus & ~pc->pc_cpumask;
211		if (!pc->pc_bsp) {
212			if (bootverbose)
213				printf("Waking up CPU %d (dev=%x)\n",
214				    pc->pc_cpuid, pc->pc_hwref);
215
216			platform_smp_start_cpu(pc);
217
218			timeout = 2000;	/* wait 2sec for the AP */
219			while (!pc->pc_awake && --timeout > 0)
220				DELAY(1000);
221
222		} else {
223			PCPU_SET(pir, mfspr(SPR_PIR));
224			pc->pc_awake = 1;
225		}
226		if (pc->pc_awake) {
227			if (bootverbose)
228				printf("Adding CPU %d, pir=%x, awake=%x\n",
229				    pc->pc_cpuid, pc->pc_pir, pc->pc_awake);
230			smp_cpus++;
231		} else
232			stopped_cpus |= (1 << pc->pc_cpuid);
233	}
234
235	ap_awake = 1;
236
237	/* Provide our current DEC and TB values for APs */
238	__asm __volatile("mfdec %0" : "=r"(ap_decr));
239	ap_timebase = mftb() + 10;
240	__asm __volatile("msync; isync");
241
242	/* Let APs continue */
243	atomic_store_rel_int(&ap_letgo, 1);
244
245	mttb(ap_timebase);
246
247	while (ap_awake < smp_cpus)
248		;
249
250	if (smp_cpus != cpus || cpus != mp_ncpus) {
251		printf("SMP: %d CPUs found; %d CPUs usable; %d CPUs woken\n",
252		    mp_ncpus, cpus, smp_cpus);
253	}
254
255	/* Let the APs get into the scheduler */
256	DELAY(10000);
257
258	smp_active = 1;
259	smp_started = 1;
260}
261
262SYSINIT(start_aps, SI_SUB_SMP, SI_ORDER_FIRST, cpu_mp_unleash, NULL);
263
264int
265powerpc_ipi_handler(void *arg)
266{
267	cpumask_t self;
268	uint32_t ipimask;
269	int msg;
270
271	CTR2(KTR_SMP, "%s: MSR 0x%08x", __func__, mfmsr());
272
273	ipimask = atomic_readandclear_32(&(pcpup->pc_ipimask));
274	if (ipimask == 0)
275		return (FILTER_STRAY);
276	while ((msg = ffs(ipimask) - 1) != -1) {
277		ipimask &= ~(1u << msg);
278		ipi_msg_cnt[msg]++;
279		switch (msg) {
280		case IPI_AST:
281			CTR1(KTR_SMP, "%s: IPI_AST", __func__);
282			break;
283		case IPI_PREEMPT:
284			CTR1(KTR_SMP, "%s: IPI_PREEMPT", __func__);
285			sched_preempt(curthread);
286			break;
287		case IPI_RENDEZVOUS:
288			CTR1(KTR_SMP, "%s: IPI_RENDEZVOUS", __func__);
289			smp_rendezvous_action();
290			break;
291		case IPI_STOP:
292
293			/*
294			 * IPI_STOP_HARD is mapped to IPI_STOP so it is not
295			 * necessary to add such case in the switch.
296			 */
297			CTR1(KTR_SMP, "%s: IPI_STOP or IPI_STOP_HARD (stop)",
298			    __func__);
299			self = PCPU_GET(cpumask);
300			savectx(PCPU_GET(curpcb));
301			atomic_set_int(&stopped_cpus, self);
302			while ((started_cpus & self) == 0)
303				cpu_spinwait();
304			atomic_clear_int(&started_cpus, self);
305			atomic_clear_int(&stopped_cpus, self);
306			CTR1(KTR_SMP, "%s: IPI_STOP (restart)", __func__);
307			break;
308		}
309	}
310
311	return (FILTER_HANDLED);
312}
313
314static void
315ipi_send(struct pcpu *pc, int ipi)
316{
317
318	CTR4(KTR_SMP, "%s: pc=%p, targetcpu=%d, IPI=%d", __func__,
319	    pc, pc->pc_cpuid, ipi);
320
321	atomic_set_32(&pc->pc_ipimask, (1 << ipi));
322	PIC_IPI(pic, pc->pc_cpuid);
323
324	CTR1(KTR_SMP, "%s: sent", __func__);
325}
326
327/* Send an IPI to a set of cpus. */
328void
329ipi_selected(cpumask_t cpus, int ipi)
330{
331	struct pcpu *pc;
332
333	SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
334		if (cpus & pc->pc_cpumask)
335			ipi_send(pc, ipi);
336	}
337}
338
339/* Send an IPI to all CPUs EXCEPT myself. */
340void
341ipi_all_but_self(int ipi)
342{
343	struct pcpu *pc;
344
345	SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
346		if (pc != pcpup)
347			ipi_send(pc, ipi);
348	}
349}
350