summaryrefslogtreecommitdiff
path: root/arch/x86/pci/xen.c
blob: ff0068b8ce5e230fc291bac3fc4a74b12e73cab5 (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
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
/*
 * Xen PCI - handle PCI (INTx) and MSI infrastructure calls for PV, HVM and
 * initial domain support. We also handle the DSDT _PRT callbacks for GSI's
 * used in HVM and initial domain mode (PV does not parse ACPI, so it has no
 * concept of GSIs). Under PV we hook under the pnbbios API for IRQs and
 * 0xcf8 PCI configuration read/write.
 *
 *   Author: Ryan Wilson <hap9@epoch.ncsc.mil>
 *           Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
 *           Stefano Stabellini <stefano.stabellini@eu.citrix.com>
 */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/pci.h>
#include <linux/acpi.h>

#include <linux/io.h>
#include <asm/io_apic.h>
#include <asm/pci_x86.h>

#include <asm/xen/hypervisor.h>

#include <xen/features.h>
#include <xen/events.h>
#include <asm/xen/pci.h>
#include <asm/i8259.h>

static int xen_pcifront_enable_irq(struct pci_dev *dev)
{
	int rc;
	int share = 1;
	int pirq;
	u8 gsi;

	rc = pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &gsi);
	if (rc < 0) {
		dev_warn(&dev->dev, "Xen PCI: failed to read interrupt line: %d\n",
			 rc);
		return rc;
	}
	/* In PV DomU the Xen PCI backend puts the PIRQ in the interrupt line.*/
	pirq = gsi;

	if (gsi < nr_legacy_irqs())
		share = 0;

	rc = xen_bind_pirq_gsi_to_irq(gsi, pirq, share, "pcifront");
	if (rc < 0) {
		dev_warn(&dev->dev, "Xen PCI: failed to bind GSI%d (PIRQ%d) to IRQ: %d\n",
			 gsi, pirq, rc);
		return rc;
	}

	dev->irq = rc;
	dev_info(&dev->dev, "Xen PCI mapped GSI%d to IRQ%d\n", gsi, dev->irq);
	return 0;
}

#ifdef CONFIG_ACPI
static int xen_register_pirq(u32 gsi, int gsi_override, int triggering,
			     bool set_pirq)
{
	int rc, pirq = -1, irq = -1;
	struct physdev_map_pirq map_irq;
	int shareable = 0;
	char *name;

	irq = xen_irq_from_gsi(gsi);
	if (irq > 0)
		return irq;

	if (set_pirq)
		pirq = gsi;

	map_irq.domid = DOMID_SELF;
	map_irq.type = MAP_PIRQ_TYPE_GSI;
	map_irq.index = gsi;
	map_irq.pirq = pirq;

	rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
	if (rc) {
		printk(KERN_WARNING "xen map irq failed %d\n", rc);
		return -1;
	}

	if (triggering == ACPI_EDGE_SENSITIVE) {
		shareable = 0;
		name = "ioapic-edge";
	} else {
		shareable = 1;
		name = "ioapic-level";
	}

	if (gsi_override >= 0)
		gsi = gsi_override;

	irq = xen_bind_pirq_gsi_to_irq(gsi, map_irq.pirq, shareable, name);
	if (irq < 0)
		goto out;

	printk(KERN_DEBUG "xen: --> pirq=%d -> irq=%d (gsi=%d)\n", map_irq.pirq, irq, gsi);
out:
	return irq;
}

static int acpi_register_gsi_xen_hvm(struct device *dev, u32 gsi,
				     int trigger, int polarity)
{
	if (!xen_hvm_domain())
		return -1;

	return xen_register_pirq(gsi, -1 /* no GSI override */, trigger,
				 false /* no mapping of GSI to PIRQ */);
}

#ifdef CONFIG_XEN_DOM0
static int xen_register_gsi(u32 gsi, int gsi_override, int triggering, int polarity)
{
	int rc, irq;
	struct physdev_setup_gsi setup_gsi;

	if (!xen_pv_domain())
		return -1;

	printk(KERN_DEBUG "xen: registering gsi %u triggering %d polarity %d\n",
			gsi, triggering, polarity);

	irq = xen_register_pirq(gsi, gsi_override, triggering, true);

	setup_gsi.gsi = gsi;
	setup_gsi.triggering = (triggering == ACPI_EDGE_SENSITIVE ? 0 : 1);
	setup_gsi.polarity = (polarity == ACPI_ACTIVE_HIGH ? 0 : 1);

	rc = HYPERVISOR_physdev_op(PHYSDEVOP_setup_gsi, &setup_gsi);
	if (rc == -EEXIST)
		printk(KERN_INFO "Already setup the GSI :%d\n", gsi);
	else if (rc) {
		printk(KERN_ERR "Failed to setup GSI :%d, err_code:%d\n",
				gsi, rc);
	}

	return irq;
}

static int acpi_register_gsi_xen(struct device *dev, u32 gsi,
				 int trigger, int polarity)
{
	return xen_register_gsi(gsi, -1 /* no GSI override */, trigger, polarity);
}
#endif
#endif

#if defined(CONFIG_PCI_MSI)
#include <linux/msi.h>
#include <asm/msidef.h>

struct xen_pci_frontend_ops *xen_pci_frontend;
EXPORT_SYMBOL_GPL(xen_pci_frontend);

static int xen_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
{
	int irq, ret, i;
	struct msi_desc *msidesc;
	int *v;

	if (type == PCI_CAP_ID_MSI && nvec > 1)
		return 1;

	v = kzalloc(sizeof(int) * max(1, nvec), GFP_KERNEL);
	if (!v)
		return -ENOMEM;

	if (type == PCI_CAP_ID_MSIX)
		ret = xen_pci_frontend_enable_msix(dev, v, nvec);
	else
		ret = xen_pci_frontend_enable_msi(dev, v);
	if (ret)
		goto error;
	i = 0;
	list_for_each_entry(msidesc, &dev->msi_list, list) {
		irq = xen_bind_pirq_msi_to_irq(dev, msidesc, v[i],
					       (type == PCI_CAP_ID_MSI) ? nvec : 1,
					       (type == PCI_CAP_ID_MSIX) ?
					       "pcifront-msi-x" :
					       "pcifront-msi",
						DOMID_SELF);
		if (irq < 0) {
			ret = irq;
			goto free;
		}
		i++;
	}
	kfree(v);
	return 0;

error:
	dev_err(&dev->dev, "Xen PCI frontend has not registered MSI/MSI-X support!\n");
free:
	kfree(v);
	return ret;
}

#define XEN_PIRQ_MSI_DATA  (MSI_DATA_TRIGGER_EDGE | \
		MSI_DATA_LEVEL_ASSERT | (3 << 8) | MSI_DATA_VECTOR(0))

static void xen_msi_compose_msg(struct pci_dev *pdev, unsigned int pirq,
		struct msi_msg *msg)
{
	/* We set vector == 0 to tell the hypervisor we don't care about it,
	 * but we want a pirq setup instead.
	 * We use the dest_id field to pass the pirq that we want. */
	msg->address_hi = MSI_ADDR_BASE_HI | MSI_ADDR_EXT_DEST_ID(pirq);
	msg->address_lo =
		MSI_ADDR_BASE_LO |
		MSI_ADDR_DEST_MODE_PHYSICAL |
		MSI_ADDR_REDIRECTION_CPU |
		MSI_ADDR_DEST_ID(pirq);

	msg->data = XEN_PIRQ_MSI_DATA;
}

static int xen_hvm_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
{
	int irq, pirq;
	struct msi_desc *msidesc;
	struct msi_msg msg;

	if (type == PCI_CAP_ID_MSI && nvec > 1)
		return 1;

	list_for_each_entry(msidesc, &dev->msi_list, list) {
		__pci_read_msi_msg(msidesc, &msg);
		pirq = MSI_ADDR_EXT_DEST_ID(msg.address_hi) |
			((msg.address_lo >> MSI_ADDR_DEST_ID_SHIFT) & 0xff);
		if (msg.data != XEN_PIRQ_MSI_DATA ||
		    xen_irq_from_pirq(pirq) < 0) {
			pirq = xen_allocate_pirq_msi(dev, msidesc);
			if (pirq < 0) {
				irq = -ENODEV;
				goto error;
			}
			xen_msi_compose_msg(dev, pirq, &msg);
			__write_msi_msg(msidesc, &msg);
			dev_dbg(&dev->dev, "xen: msi bound to pirq=%d\n", pirq);
		} else {
			dev_dbg(&dev->dev,
				"xen: msi already bound to pirq=%d\n", pirq);
		}
		irq = xen_bind_pirq_msi_to_irq(dev, msidesc, pirq,
					       (type == PCI_CAP_ID_MSI) ? nvec : 1,
					       (type == PCI_CAP_ID_MSIX) ?
					       "msi-x" : "msi",
					       DOMID_SELF);
		if (irq < 0)
			goto error;
		dev_dbg(&dev->dev,
			"xen: msi --> pirq=%d --> irq=%d\n", pirq, irq);
	}
	return 0;

error:
	dev_err(&dev->dev,
		"Xen PCI frontend has not registered MSI/MSI-X support!\n");
	return irq;
}

#ifdef CONFIG_XEN_DOM0
static bool __read_mostly pci_seg_supported = true;

static int xen_initdom_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
{
	int ret = 0;
	struct msi_desc *msidesc;

	list_for_each_entry(msidesc, &dev->msi_list, list) {
		struct physdev_map_pirq map_irq;
		domid_t domid;

		domid = ret = xen_find_device_domain_owner(dev);
		/* N.B. Casting int's -ENODEV to uint16_t results in 0xFFED,
		 * hence check ret value for < 0. */
		if (ret < 0)
			domid = DOMID_SELF;

		memset(&map_irq, 0, sizeof(map_irq));
		map_irq.domid = domid;
		map_irq.type = MAP_PIRQ_TYPE_MSI_SEG;
		map_irq.index = -1;
		map_irq.pirq = -1;
		map_irq.bus = dev->bus->number |
			      (pci_domain_nr(dev->bus) << 16);
		map_irq.devfn = dev->devfn;

		if (type == PCI_CAP_ID_MSI && nvec > 1) {
			map_irq.type = MAP_PIRQ_TYPE_MULTI_MSI;
			map_irq.entry_nr = nvec;
		} else if (type == PCI_CAP_ID_MSIX) {
			int pos;
			u32 table_offset, bir;

			pos = dev->msix_cap;
			pci_read_config_dword(dev, pos + PCI_MSIX_TABLE,
					      &table_offset);
			bir = (u8)(table_offset & PCI_MSIX_TABLE_BIR);

			map_irq.table_base = pci_resource_start(dev, bir);
			map_irq.entry_nr = msidesc->msi_attrib.entry_nr;
		}

		ret = -EINVAL;
		if (pci_seg_supported)
			ret = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq,
						    &map_irq);
		if (type == PCI_CAP_ID_MSI && nvec > 1 && ret) {
			/*
			 * If MAP_PIRQ_TYPE_MULTI_MSI is not available
			 * there's nothing else we can do in this case.
			 * Just set ret > 0 so driver can retry with
			 * single MSI.
			 */
			ret = 1;
			goto out;
		}
		if (ret == -EINVAL && !pci_domain_nr(dev->bus)) {
			map_irq.type = MAP_PIRQ_TYPE_MSI;
			map_irq.index = -1;
			map_irq.pirq = -1;
			map_irq.bus = dev->bus->number;
			ret = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq,
						    &map_irq);
			if (ret != -EINVAL)
				pci_seg_supported = false;
		}
		if (ret) {
			dev_warn(&dev->dev, "xen map irq failed %d for %d domain\n",
				 ret, domid);
			goto out;
		}

		ret = xen_bind_pirq_msi_to_irq(dev, msidesc, map_irq.pirq,
		                               (type == PCI_CAP_ID_MSI) ? nvec : 1,
		                               (type == PCI_CAP_ID_MSIX) ? "msi-x" : "msi",
		                               domid);
		if (ret < 0)
			goto out;
	}
	ret = 0;
out:
	return ret;
}

static void xen_initdom_restore_msi_irqs(struct pci_dev *dev)
{
	int ret = 0;

	if (pci_seg_supported) {
		struct physdev_pci_device restore_ext;

		restore_ext.seg = pci_domain_nr(dev->bus);
		restore_ext.bus = dev->bus->number;
		restore_ext.devfn = dev->devfn;
		ret = HYPERVISOR_physdev_op(PHYSDEVOP_restore_msi_ext,
					&restore_ext);
		if (ret == -ENOSYS)
			pci_seg_supported = false;
		WARN(ret && ret != -ENOSYS, "restore_msi_ext -> %d\n", ret);
	}
	if (!pci_seg_supported) {
		struct physdev_restore_msi restore;

		restore.bus = dev->bus->number;
		restore.devfn = dev->devfn;
		ret = HYPERVISOR_physdev_op(PHYSDEVOP_restore_msi, &restore);
		WARN(ret && ret != -ENOSYS, "restore_msi -> %d\n", ret);
	}
}
#endif

static void xen_teardown_msi_irqs(struct pci_dev *dev)
{
	struct msi_desc *msidesc;

	msidesc = list_entry(dev->msi_list.next, struct msi_desc, list);
	if (msidesc->msi_attrib.is_msix)
		xen_pci_frontend_disable_msix(dev);
	else
		xen_pci_frontend_disable_msi(dev);

	/* Free the IRQ's and the msidesc using the generic code. */
	default_teardown_msi_irqs(dev);
}

static void xen_teardown_msi_irq(unsigned int irq)
{
	xen_destroy_irq(irq);
}

#endif

int __init pci_xen_init(void)
{
	if (!xen_pv_domain() || xen_initial_domain())
		return -ENODEV;

	printk(KERN_INFO "PCI: setting up Xen PCI frontend stub\n");

	pcibios_set_cache_line_size();

	pcibios_enable_irq = xen_pcifront_enable_irq;
	pcibios_disable_irq = NULL;

#ifdef CONFIG_ACPI
	/* Keep ACPI out of the picture */
	acpi_noirq = 1;
#endif

#ifdef CONFIG_PCI_MSI
	x86_msi.setup_msi_irqs = xen_setup_msi_irqs;
	x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
	x86_msi.teardown_msi_irqs = xen_teardown_msi_irqs;
	pci_msi_ignore_mask = 1;
#endif
	return 0;
}

int __init pci_xen_hvm_init(void)
{
	if (!xen_have_vector_callback || !xen_feature(XENFEAT_hvm_pirqs))
		return 0;

#ifdef CONFIG_ACPI
	/*
	 * We don't want to change the actual ACPI delivery model,
	 * just how GSIs get registered.
	 */
	__acpi_register_gsi = acpi_register_gsi_xen_hvm;
#endif

#ifdef CONFIG_PCI_MSI
	x86_msi.setup_msi_irqs = xen_hvm_setup_msi_irqs;
	x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
#endif
	return 0;
}

#ifdef CONFIG_XEN_DOM0
static __init void xen_setup_acpi_sci(void)
{
	int rc;
	int trigger, polarity;
	int gsi = acpi_sci_override_gsi;
	int irq = -1;
	int gsi_override = -1;

	if (!gsi)
		return;

	rc = acpi_get_override_irq(gsi, &trigger, &polarity);
	if (rc) {
		printk(KERN_WARNING "xen: acpi_get_override_irq failed for acpi"
				" sci, rc=%d\n", rc);
		return;
	}
	trigger = trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
	polarity = polarity ? ACPI_ACTIVE_LOW : ACPI_ACTIVE_HIGH;

	printk(KERN_INFO "xen: sci override: global_irq=%d trigger=%d "
			"polarity=%d\n", gsi, trigger, polarity);

	/* Before we bind the GSI to a Linux IRQ, check whether
	 * we need to override it with bus_irq (IRQ) value. Usually for
	 * IRQs below IRQ_LEGACY_IRQ this holds IRQ == GSI, as so:
	 *  ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 low level)
	 * but there are oddballs where the IRQ != GSI:
	 *  ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 20 low level)
	 * which ends up being: gsi_to_irq[9] == 20
	 * (which is what acpi_gsi_to_irq ends up calling when starting the
	 * the ACPI interpreter and keels over since IRQ 9 has not been
	 * setup as we had setup IRQ 20 for it).
	 */
	if (acpi_gsi_to_irq(gsi, &irq) == 0) {
		/* Use the provided value if it's valid. */
		if (irq >= 0)
			gsi_override = irq;
	}

	gsi = xen_register_gsi(gsi, gsi_override, trigger, polarity);
	printk(KERN_INFO "xen: acpi sci %d\n", gsi);

	return;
}

int __init pci_xen_initial_domain(void)
{
	int irq;

#ifdef CONFIG_PCI_MSI
	x86_msi.setup_msi_irqs = xen_initdom_setup_msi_irqs;
	x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
	x86_msi.restore_msi_irqs = xen_initdom_restore_msi_irqs;
	pci_msi_ignore_mask = 1;
#endif
	xen_setup_acpi_sci();
	__acpi_register_gsi = acpi_register_gsi_xen;
	/* Pre-allocate legacy irqs */
	for (irq = 0; irq < nr_legacy_irqs(); irq++) {
		int trigger, polarity;

		if (acpi_get_override_irq(irq, &trigger, &polarity) == -1)
			continue;

		xen_register_pirq(irq, -1 /* no GSI override */,
			trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE,
			true /* Map GSI to PIRQ */);
	}
	if (0 == nr_ioapics) {
		for (irq = 0; irq < nr_legacy_irqs(); irq++)
			xen_bind_pirq_gsi_to_irq(irq, irq, 0, "xt-pic");
	}
	return 0;
}

struct xen_device_domain_owner {
	domid_t domain;
	struct pci_dev *dev;
	struct list_head list;
};

static DEFINE_SPINLOCK(dev_domain_list_spinlock);
static struct list_head dev_domain_list = LIST_HEAD_INIT(dev_domain_list);

static struct xen_device_domain_owner *find_device(struct pci_dev *dev)
{
	struct xen_device_domain_owner *owner;

	list_for_each_entry(owner, &dev_domain_list, list) {
		if (owner->dev == dev)
			return owner;
	}
	return NULL;
}

int xen_find_device_domain_owner(struct pci_dev *dev)
{
	struct xen_device_domain_owner *owner;
	int domain = -ENODEV;

	spin_lock(&dev_domain_list_spinlock);
	owner = find_device(dev);
	if (owner)
		domain = owner->domain;
	spin_unlock(&dev_domain_list_spinlock);
	return domain;
}
EXPORT_SYMBOL_GPL(xen_find_device_domain_owner);

int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t domain)
{
	struct xen_device_domain_owner *owner;

	owner = kzalloc(sizeof(struct xen_device_domain_owner), GFP_KERNEL);
	if (!owner)
		return -ENODEV;

	spin_lock(&dev_domain_list_spinlock);
	if (find_device(dev)) {
		spin_unlock(&dev_domain_list_spinlock);
		kfree(owner);
		return -EEXIST;
	}
	owner->domain = domain;
	owner->dev = dev;
	list_add_tail(&owner->list, &dev_domain_list);
	spin_unlock(&dev_domain_list_spinlock);
	return 0;
}
EXPORT_SYMBOL_GPL(xen_register_device_domain_owner);

int xen_unregister_device_domain_owner(struct pci_dev *dev)
{
	struct xen_device_domain_owner *owner;

	spin_lock(&dev_domain_list_spinlock);
	owner = find_device(dev);
	if (!owner) {
		spin_unlock(&dev_domain_list_spinlock);
		return -ENODEV;
	}
	list_del(&owner->list);
	spin_unlock(&dev_domain_list_spinlock);
	kfree(owner);
	return 0;
}
EXPORT_SYMBOL_GPL(xen_unregister_device_domain_owner);
#endif