summaryrefslogtreecommitdiffstats
path: root/arch/ia64/xen/irq_xen.c
blob: 3bb12230721fed28140164dfcb707fb679ae6fdb (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
/******************************************************************************
 * arch/ia64/xen/irq_xen.c
 *
 * Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp>
 *                    VA Linux Systems Japan K.K.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

#include <linux/cpu.h>

#include <xen/interface/xen.h>
#include <xen/interface/callback.h>
#include <xen/events.h>

#include <asm/xen/privop.h>

#include "irq_xen.h"

/***************************************************************************
 * pv_irq_ops
 * irq operations
 */

static int
xen_assign_irq_vector(int irq)
{
	struct physdev_irq irq_op;

	irq_op.irq = irq;
	if (HYPERVISOR_physdev_op(PHYSDEVOP_alloc_irq_vector, &irq_op))
		return -ENOSPC;

	return irq_op.vector;
}

static void
xen_free_irq_vector(int vector)
{
	struct physdev_irq irq_op;

	if (vector < IA64_FIRST_DEVICE_VECTOR ||
	    vector > IA64_LAST_DEVICE_VECTOR)
		return;

	irq_op.vector = vector;
	if (HYPERVISOR_physdev_op(PHYSDEVOP_free_irq_vector, &irq_op))
		printk(KERN_WARNING "%s: xen_free_irq_vector fail vector=%d\n",
		       __func__, vector);
}


static DEFINE_PER_CPU(int, xen_timer_irq) = -1;
static DEFINE_PER_CPU(int, xen_ipi_irq) = -1;
static DEFINE_PER_CPU(int, xen_resched_irq) = -1;
static DEFINE_PER_CPU(int, xen_cmc_irq) = -1;
static DEFINE_PER_CPU(int, xen_cmcp_irq) = -1;
static DEFINE_PER_CPU(int, xen_cpep_irq) = -1;
#define NAME_SIZE	15
static DEFINE_PER_CPU(char[NAME_SIZE], xen_timer_name);
static DEFINE_PER_CPU(char[NAME_SIZE], xen_ipi_name);
static DEFINE_PER_CPU(char[NAME_SIZE], xen_resched_name);
static DEFINE_PER_CPU(char[NAME_SIZE], xen_cmc_name);
static DEFINE_PER_CPU(char[NAME_SIZE], xen_cmcp_name);
static DEFINE_PER_CPU(char[NAME_SIZE], xen_cpep_name);
#undef NAME_SIZE

struct saved_irq {
	unsigned int irq;
	struct irqaction *action;
};
/* 16 should be far optimistic value, since only several percpu irqs
 * are registered early.
 */
#define MAX_LATE_IRQ	16
static struct saved_irq saved_percpu_irqs[MAX_LATE_IRQ];
static unsigned short late_irq_cnt;
static unsigned short saved_irq_cnt;
static int xen_slab_ready;

#ifdef CONFIG_SMP
#include <linux/sched.h>

/* Dummy stub. Though we may check XEN_RESCHEDULE_VECTOR before __do_IRQ,
 * it ends up to issue several memory accesses upon percpu data and
 * thus adds unnecessary traffic to other paths.
 */
static irqreturn_t
xen_dummy_handler(int irq, void *dev_id)
{
	return IRQ_HANDLED;
}

static irqreturn_t
xen_resched_handler(int irq, void *dev_id)
{
	scheduler_ipi();
	return IRQ_HANDLED;
}

static struct irqaction xen_ipi_irqaction = {
	.handler =	handle_IPI,
	.flags =	IRQF_DISABLED,
	.name =		"IPI"
};

static struct irqaction xen_resched_irqaction = {
	.handler =	xen_resched_handler,
	.flags =	IRQF_DISABLED,
	.name =		"resched"
};

static struct irqaction xen_tlb_irqaction = {
	.handler =	xen_dummy_handler,
	.flags =	IRQF_DISABLED,
	.name =		"tlb_flush"
};
#endif

/*
 * This is xen version percpu irq registration, which needs bind
 * to xen specific evtchn sub-system. One trick here is that xen
 * evtchn binding interface depends on kmalloc because related
 * port needs to be freed at device/cpu down. So we cache the
 * registration on BSP before slab is ready and then deal them
 * at later point. For rest instances happening after slab ready,
 * we hook them to xen evtchn immediately.
 *
 * FIXME: MCA is not supported by far, and thus "nomca" boot param is
 * required.
 */
static void
__xen_register_percpu_irq(unsigned int cpu, unsigned int vec,
			struct irqaction *action, int save)
{
	int irq = 0;

	if (xen_slab_ready) {
		switch (vec) {
		case IA64_TIMER_VECTOR:
			snprintf(per_cpu(xen_timer_name, cpu),
				 sizeof(per_cpu(xen_timer_name, cpu)),
				 "%s%d", action->name, cpu);
			irq = bind_virq_to_irqhandler(VIRQ_ITC, cpu,
				action->handler, action->flags,
				per_cpu(xen_timer_name, cpu), action->dev_id);
			per_cpu(xen_timer_irq, cpu) = irq;
			break;
		case IA64_IPI_RESCHEDULE:
			snprintf(per_cpu(xen_resched_name, cpu),
				 sizeof(per_cpu(xen_resched_name, cpu)),
				 "%s%d", action->name, cpu);
			irq = bind_ipi_to_irqhandler(XEN_RESCHEDULE_VECTOR, cpu,
				action->handler, action->flags,
				per_cpu(xen_resched_name, cpu), action->dev_id);
			per_cpu(xen_resched_irq, cpu) = irq;
			break;
		case IA64_IPI_VECTOR:
			snprintf(per_cpu(xen_ipi_name, cpu),
				 sizeof(per_cpu(xen_ipi_name, cpu)),
				 "%s%d", action->name, cpu);
			irq = bind_ipi_to_irqhandler(XEN_IPI_VECTOR, cpu,
				action->handler, action->flags,
				per_cpu(xen_ipi_name, cpu), action->dev_id);
			per_cpu(xen_ipi_irq, cpu) = irq;
			break;
		case IA64_CMC_VECTOR:
			snprintf(per_cpu(xen_cmc_name, cpu),
				 sizeof(per_cpu(xen_cmc_name, cpu)),
				 "%s%d", action->name, cpu);
			irq = bind_virq_to_irqhandler(VIRQ_MCA_CMC, cpu,
						action->handler,
						action->flags,
						per_cpu(xen_cmc_name, cpu),
						action->dev_id);
			per_cpu(xen_cmc_irq, cpu) = irq;
			break;
		case IA64_CMCP_VECTOR:
			snprintf(per_cpu(xen_cmcp_name, cpu),
				 sizeof(per_cpu(xen_cmcp_name, cpu)),
				 "%s%d", action->name, cpu);
			irq = bind_ipi_to_irqhandler(XEN_CMCP_VECTOR, cpu,
						action->handler,
						action->flags,
						per_cpu(xen_cmcp_name, cpu),
						action->dev_id);
			per_cpu(xen_cmcp_irq, cpu) = irq;
			break;
		case IA64_CPEP_VECTOR:
			snprintf(per_cpu(xen_cpep_name, cpu),
				 sizeof(per_cpu(xen_cpep_name, cpu)),
				 "%s%d", action->name, cpu);
			irq = bind_ipi_to_irqhandler(XEN_CPEP_VECTOR, cpu,
						action->handler,
						action->flags,
						per_cpu(xen_cpep_name, cpu),
						action->dev_id);
			per_cpu(xen_cpep_irq, cpu) = irq;
			break;
		case IA64_CPE_VECTOR:
		case IA64_MCA_RENDEZ_VECTOR:
		case IA64_PERFMON_VECTOR:
		case IA64_MCA_WAKEUP_VECTOR:
		case IA64_SPURIOUS_INT_VECTOR:
			/* No need to complain, these aren't supported. */
			break;
		default:
			printk(KERN_WARNING "Percpu irq %d is unsupported "
			       "by xen!\n", vec);
			break;
		}
		BUG_ON(irq < 0);

		if (irq > 0) {
			/*
			 * Mark percpu.  Without this, migrate_irqs() will
			 * mark the interrupt for migrations and trigger it
			 * on cpu hotplug.
			 */
			irq_set_status_flags(irq, IRQ_PER_CPU);
		}
	}

	/* For BSP, we cache registered percpu irqs, and then re-walk
	 * them when initializing APs
	 */
	if (!cpu && save) {
		BUG_ON(saved_irq_cnt == MAX_LATE_IRQ);
		saved_percpu_irqs[saved_irq_cnt].irq = vec;
		saved_percpu_irqs[saved_irq_cnt].action = action;
		saved_irq_cnt++;
		if (!xen_slab_ready)
			late_irq_cnt++;
	}
}

static void
xen_register_percpu_irq(ia64_vector vec, struct irqaction *action)
{
	__xen_register_percpu_irq(smp_processor_id(), vec, action, 1);
}

static void
xen_bind_early_percpu_irq(void)
{
	int i;

	xen_slab_ready = 1;
	/* There's no race when accessing this cached array, since only
	 * BSP will face with such step shortly
	 */
	for (i = 0; i < late_irq_cnt; i++)
		__xen_register_percpu_irq(smp_processor_id(),
					  saved_percpu_irqs[i].irq,
					  saved_percpu_irqs[i].action, 0);
}

/* FIXME: There's no obvious point to check whether slab is ready. So
 * a hack is used here by utilizing a late time hook.
 */

#ifdef CONFIG_HOTPLUG_CPU
static int __devinit
unbind_evtchn_callback(struct notifier_block *nfb,
		       unsigned long action, void *hcpu)
{
	unsigned int cpu = (unsigned long)hcpu;

	if (action == CPU_DEAD) {
		/* Unregister evtchn.  */
		if (per_cpu(xen_cpep_irq, cpu) >= 0) {
			unbind_from_irqhandler(per_cpu(xen_cpep_irq, cpu),
					       NULL);
			per_cpu(xen_cpep_irq, cpu) = -1;
		}
		if (per_cpu(xen_cmcp_irq, cpu) >= 0) {
			unbind_from_irqhandler(per_cpu(xen_cmcp_irq, cpu),
					       NULL);
			per_cpu(xen_cmcp_irq, cpu) = -1;
		}
		if (per_cpu(xen_cmc_irq, cpu) >= 0) {
			unbind_from_irqhandler(per_cpu(xen_cmc_irq, cpu), NULL);
			per_cpu(xen_cmc_irq, cpu) = -1;
		}
		if (per_cpu(xen_ipi_irq, cpu) >= 0) {
			unbind_from_irqhandler(per_cpu(xen_ipi_irq, cpu), NULL);
			per_cpu(xen_ipi_irq, cpu) = -1;
		}
		if (per_cpu(xen_resched_irq, cpu) >= 0) {
			unbind_from_irqhandler(per_cpu(xen_resched_irq, cpu),
					       NULL);
			per_cpu(xen_resched_irq, cpu) = -1;
		}
		if (per_cpu(xen_timer_irq, cpu) >= 0) {
			unbind_from_irqhandler(per_cpu(xen_timer_irq, cpu),
					       NULL);
			per_cpu(xen_timer_irq, cpu) = -1;
		}
	}
	return NOTIFY_OK;
}

static struct notifier_block unbind_evtchn_notifier = {
	.notifier_call = unbind_evtchn_callback,
	.priority = 0
};
#endif

void xen_smp_intr_init_early(unsigned int cpu)
{
#ifdef CONFIG_SMP
	unsigned int i;

	for (i = 0; i < saved_irq_cnt; i++)
		__xen_register_percpu_irq(cpu, saved_percpu_irqs[i].irq,
					  saved_percpu_irqs[i].action, 0);
#endif
}

void xen_smp_intr_init(void)
{
#ifdef CONFIG_SMP
	unsigned int cpu = smp_processor_id();
	struct callback_register event = {
		.type = CALLBACKTYPE_event,
		.address = { .ip = (unsigned long)&xen_event_callback },
	};

	if (cpu == 0) {
		/* Initialization was already done for boot cpu.  */
#ifdef CONFIG_HOTPLUG_CPU
		/* Register the notifier only once.  */
		register_cpu_notifier(&unbind_evtchn_notifier);
#endif
		return;
	}

	/* This should be piggyback when setup vcpu guest context */
	BUG_ON(HYPERVISOR_callback_op(CALLBACKOP_register, &event));
#endif /* CONFIG_SMP */
}

void __init
xen_irq_init(void)
{
	struct callback_register event = {
		.type = CALLBACKTYPE_event,
		.address = { .ip = (unsigned long)&xen_event_callback },
	};

	xen_init_IRQ();
	BUG_ON(HYPERVISOR_callback_op(CALLBACKOP_register, &event));
	late_time_init = xen_bind_early_percpu_irq;
}

void
xen_platform_send_ipi(int cpu, int vector, int delivery_mode, int redirect)
{
#ifdef CONFIG_SMP
	/* TODO: we need to call vcpu_up here */
	if (unlikely(vector == ap_wakeup_vector)) {
		/* XXX
		 * This should be in __cpu_up(cpu) in ia64 smpboot.c
		 * like x86. But don't want to modify it,
		 * keep it untouched.
		 */
		xen_smp_intr_init_early(cpu);

		xen_send_ipi(cpu, vector);
		/* vcpu_prepare_and_up(cpu); */
		return;
	}
#endif

	switch (vector) {
	case IA64_IPI_VECTOR:
		xen_send_IPI_one(cpu, XEN_IPI_VECTOR);
		break;
	case IA64_IPI_RESCHEDULE:
		xen_send_IPI_one(cpu, XEN_RESCHEDULE_VECTOR);
		break;
	case IA64_CMCP_VECTOR:
		xen_send_IPI_one(cpu, XEN_CMCP_VECTOR);
		break;
	case IA64_CPEP_VECTOR:
		xen_send_IPI_one(cpu, XEN_CPEP_VECTOR);
		break;
	case IA64_TIMER_VECTOR: {
		/* this is used only once by check_sal_cache_flush()
		   at boot time */
		static int used = 0;
		if (!used) {
			xen_send_ipi(cpu, IA64_TIMER_VECTOR);
			used = 1;
			break;
		}
		/* fallthrough */
	}
	default:
		printk(KERN_WARNING "Unsupported IPI type 0x%x\n",
		       vector);
		notify_remote_via_irq(0); /* defaults to 0 irq */
		break;
	}
}

static void __init
xen_register_ipi(void)
{
#ifdef CONFIG_SMP
	register_percpu_irq(IA64_IPI_VECTOR, &xen_ipi_irqaction);
	register_percpu_irq(IA64_IPI_RESCHEDULE, &xen_resched_irqaction);
	register_percpu_irq(IA64_IPI_LOCAL_TLB_FLUSH, &xen_tlb_irqaction);
#endif
}

static void
xen_resend_irq(unsigned int vector)
{
	(void)resend_irq_on_evtchn(vector);
}

const struct pv_irq_ops xen_irq_ops __initdata = {
	.register_ipi = xen_register_ipi,

	.assign_irq_vector = xen_assign_irq_vector,
	.free_irq_vector = xen_free_irq_vector,
	.register_percpu_irq = xen_register_percpu_irq,

	.resend_irq = xen_resend_irq,
};