mp_machdep.c revision 196196 
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 196196 2009-08-13 17:09:45Z attilio $");
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
68	PCPU_SET(pir, mfspr(SPR_PIR));
69	PCPU_SET(awake, 1);
70	__asm __volatile("msync; isync");
71
72	while (ap_letgo == 0)
73		;
74
75	/* Initialize DEC and TB, sync with the BSP values */
76	decr_ap_init();
77	mttb(ap_timebase);
78	__asm __volatile("mtdec %0" :: "r"(ap_decr));
79
80	atomic_add_int(&ap_awake, 1);
81	CTR1(KTR_SMP, "SMP: AP CPU%d launched", PCPU_GET(cpuid));
82
83	/* Initialize curthread */
84	PCPU_SET(curthread, PCPU_GET(idlethread));
85	PCPU_SET(curpcb, curthread->td_pcb);
86
87	/* Let the DEC and external interrupts go */
88	mtmsr(mfmsr() | PSL_EE);
89	sched_throw(NULL);
90}
91
92struct cpu_group *
93cpu_topo(void)
94{
95
96	return (smp_topo_none());
97}
98
99void
100cpu_mp_setmaxid(void)
101{
102	struct cpuref cpuref;
103	int error;
104
105	mp_ncpus = 0;
106	error = platform_smp_first_cpu(&cpuref);
107	while (!error) {
108		mp_ncpus++;
109		error = platform_smp_next_cpu(&cpuref);
110	}
111	/* Sanity. */
112	if (mp_ncpus == 0)
113		mp_ncpus = 1;
114
115	/*
116	 * Set the largest cpuid we're going to use. This is necessary
117	 * for VM initialization.
118	 */
119	mp_maxid = min(mp_ncpus, MAXCPU) - 1;
120}
121
122int
123cpu_mp_probe(void)
124{
125
126	/*
127	 * We're not going to enable SMP if there's only 1 processor.
128	 */
129	return (mp_ncpus > 1);
130}
131
132void
133cpu_mp_start(void)
134{
135	struct cpuref bsp, cpu;
136	struct pcpu *pc;
137	int error;
138
139	error = platform_smp_get_bsp(&bsp);
140	KASSERT(error == 0, ("Don't know BSP"));
141	KASSERT(bsp.cr_cpuid == 0, ("%s: cpuid != 0", __func__));
142
143	error = platform_smp_first_cpu(&cpu);
144	while (!error) {
145		if (cpu.cr_cpuid >= MAXCPU) {
146			printf("SMP: cpu%d: skipped -- ID out of range\n",
147			    cpu.cr_cpuid);
148			goto next;
149		}
150		if (all_cpus & (1 << cpu.cr_cpuid)) {
151			printf("SMP: cpu%d: skipped - duplicate ID\n",
152			    cpu.cr_cpuid);
153			goto next;
154		}
155		if (cpu.cr_cpuid != bsp.cr_cpuid) {
156			void *dpcpu;
157
158			pc = &__pcpu[cpu.cr_cpuid];
159			dpcpu = (void *)kmem_alloc(kernel_map, DPCPU_SIZE);
160			pcpu_init(pc, cpu.cr_cpuid, sizeof(*pc));
161			dpcpu_init(dpcpu, cpu.cr_cpuid);
162		} else {
163			pc = pcpup;
164			pc->pc_cpuid = bsp.cr_cpuid;
165			pc->pc_bsp = 1;
166		}
167		pc->pc_cpumask = 1 << pc->pc_cpuid;
168		pc->pc_hwref = cpu.cr_hwref;
169		all_cpus |= pc->pc_cpumask;
170next:
171		error = platform_smp_next_cpu(&cpu);
172	}
173}
174
175void
176cpu_mp_announce(void)
177{
178	struct pcpu *pc;
179	int i;
180
181	for (i = 0; i <= mp_maxid; i++) {
182		pc = pcpu_find(i);
183		if (pc == NULL)
184			continue;
185		printf("cpu%d: dev=%x", i, pc->pc_hwref);
186		if (pc->pc_bsp)
187			printf(" (BSP)");
188		printf("\n");
189	}
190}
191
192static void
193cpu_mp_unleash(void *dummy)
194{
195	struct pcpu *pc;
196	int cpus, timeout;
197
198	if (mp_ncpus <= 1)
199		return;
200
201	cpus = 0;
202	smp_cpus = 0;
203	SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
204		cpus++;
205		pc->pc_other_cpus = all_cpus & ~pc->pc_cpumask;
206		if (!pc->pc_bsp) {
207			if (bootverbose)
208				printf("Waking up CPU %d (dev=%x)\n",
209				    pc->pc_cpuid, pc->pc_hwref);
210
211			platform_smp_start_cpu(pc);
212
213			timeout = 2000;	/* wait 2sec for the AP */
214			while (!pc->pc_awake && --timeout > 0)
215				DELAY(1000);
216
217		} else {
218			PCPU_SET(pir, mfspr(SPR_PIR));
219			pc->pc_awake = 1;
220		}
221		if (pc->pc_awake) {
222			if (bootverbose)
223				printf("Adding CPU %d, pir=%x, awake=%x\n",
224				    pc->pc_cpuid, pc->pc_pir, pc->pc_awake);
225			smp_cpus++;
226		} else
227			stopped_cpus |= (1 << pc->pc_cpuid);
228	}
229
230	ap_awake = 1;
231
232	/* Provide our current DEC and TB values for APs */
233	__asm __volatile("mfdec %0" : "=r"(ap_decr));
234	ap_timebase = mftb() + 10;
235	__asm __volatile("msync; isync");
236
237	/* Let APs continue */
238	atomic_store_rel_int(&ap_letgo, 1);
239
240	mttb(ap_timebase);
241
242	while (ap_awake < smp_cpus)
243		;
244
245	if (smp_cpus != cpus || cpus != mp_ncpus) {
246		printf("SMP: %d CPUs found; %d CPUs usable; %d CPUs woken\n",
247		    mp_ncpus, cpus, smp_cpus);
248	}
249
250	smp_active = 1;
251	smp_started = 1;
252}
253
254SYSINIT(start_aps, SI_SUB_SMP, SI_ORDER_FIRST, cpu_mp_unleash, NULL);
255
256int
257powerpc_ipi_handler(void *arg)
258{
259	cpumask_t self;
260	uint32_t ipimask;
261	int msg;
262
263	CTR2(KTR_SMP, "%s: MSR 0x%08x", __func__, mfmsr());
264
265	ipimask = atomic_readandclear_32(&(pcpup->pc_ipimask));
266	if (ipimask == 0)
267		return (FILTER_STRAY);
268	while ((msg = ffs(ipimask) - 1) != -1) {
269		ipimask &= ~(1u << msg);
270		ipi_msg_cnt[msg]++;
271		switch (msg) {
272		case IPI_AST:
273			CTR1(KTR_SMP, "%s: IPI_AST", __func__);
274			break;
275		case IPI_PREEMPT:
276			CTR1(KTR_SMP, "%s: IPI_PREEMPT", __func__);
277			sched_preempt(curthread);
278			break;
279		case IPI_RENDEZVOUS:
280			CTR1(KTR_SMP, "%s: IPI_RENDEZVOUS", __func__);
281			smp_rendezvous_action();
282			break;
283		case IPI_STOP:
284
285			/*
286			 * IPI_STOP_HARD is mapped to IPI_STOP so it is not
287			 * necessary to add such case in the switch.
288			 */
289			CTR1(KTR_SMP, "%s: IPI_STOP or IPI_STOP_HARD (stop)",
290			    __func__);
291			self = PCPU_GET(cpumask);
292			savectx(PCPU_GET(curpcb));
293			atomic_set_int(&stopped_cpus, self);
294			while ((started_cpus & self) == 0)
295				cpu_spinwait();
296			atomic_clear_int(&started_cpus, self);
297			atomic_clear_int(&stopped_cpus, self);
298			CTR1(KTR_SMP, "%s: IPI_STOP (restart)", __func__);
299			break;
300		}
301	}
302
303	return (FILTER_HANDLED);
304}
305
306static void
307ipi_send(struct pcpu *pc, int ipi)
308{
309
310	CTR4(KTR_SMP, "%s: pc=%p, targetcpu=%d, IPI=%d", __func__,
311	    pc, pc->pc_cpuid, ipi);
312
313	atomic_set_32(&pc->pc_ipimask, (1 << ipi));
314	PIC_IPI(pic, pc->pc_cpuid);
315
316	CTR1(KTR_SMP, "%s: sent", __func__);
317}
318
319/* Send an IPI to a set of cpus. */
320void
321ipi_selected(cpumask_t cpus, int ipi)
322{
323	struct pcpu *pc;
324
325	SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
326		if (cpus & pc->pc_cpumask)
327			ipi_send(pc, ipi);
328	}
329}
330
331/* Send an IPI to all CPUs EXCEPT myself. */
332void
333ipi_all_but_self(int ipi)
334{
335	struct pcpu *pc;
336
337	SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
338		if (pc != pcpup)
339			ipi_send(pc, ipi);
340	}
341}
342