1 /*
2 * Xen PCI - handle PCI (INTx) and MSI infrastructure calls for PV, HVM and
3 * initial domain support. We also handle the DSDT _PRT callbacks for GSI's
4 * used in HVM and initial domain mode (PV does not parse ACPI, so it has no
5 * concept of GSIs). Under PV we hook under the pnbbios API for IRQs and
6 * 0xcf8 PCI configuration read/write.
7 *
8 * Author: Ryan Wilson <hap9@epoch.ncsc.mil>
9 * Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
10 * Stefano Stabellini <stefano.stabellini@eu.citrix.com>
11 */
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/pci.h>
15 #include <linux/acpi.h>
16
17 #include <linux/io.h>
18 #include <asm/io_apic.h>
19 #include <asm/pci_x86.h>
20
21 #include <asm/xen/hypervisor.h>
22
23 #include <xen/features.h>
24 #include <xen/events.h>
25 #include <asm/xen/pci.h>
26
xen_pcifront_enable_irq(struct pci_dev * dev)27 static int xen_pcifront_enable_irq(struct pci_dev *dev)
28 {
29 int rc;
30 int share = 1;
31 int pirq;
32 u8 gsi;
33
34 rc = pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &gsi);
35 if (rc < 0) {
36 dev_warn(&dev->dev, "Xen PCI: failed to read interrupt line: %d\n",
37 rc);
38 return rc;
39 }
40 /* In PV DomU the Xen PCI backend puts the PIRQ in the interrupt line.*/
41 pirq = gsi;
42
43 if (gsi < NR_IRQS_LEGACY)
44 share = 0;
45
46 rc = xen_bind_pirq_gsi_to_irq(gsi, pirq, share, "pcifront");
47 if (rc < 0) {
48 dev_warn(&dev->dev, "Xen PCI: failed to bind GSI%d (PIRQ%d) to IRQ: %d\n",
49 gsi, pirq, rc);
50 return rc;
51 }
52
53 dev->irq = rc;
54 dev_info(&dev->dev, "Xen PCI mapped GSI%d to IRQ%d\n", gsi, dev->irq);
55 return 0;
56 }
57
58 #ifdef CONFIG_ACPI
xen_register_pirq(u32 gsi,int gsi_override,int triggering,bool set_pirq)59 static int xen_register_pirq(u32 gsi, int gsi_override, int triggering,
60 bool set_pirq)
61 {
62 int rc, pirq = -1, irq = -1;
63 struct physdev_map_pirq map_irq;
64 int shareable = 0;
65 char *name;
66
67 irq = xen_irq_from_gsi(gsi);
68 if (irq > 0)
69 return irq;
70
71 if (set_pirq)
72 pirq = gsi;
73
74 map_irq.domid = DOMID_SELF;
75 map_irq.type = MAP_PIRQ_TYPE_GSI;
76 map_irq.index = gsi;
77 map_irq.pirq = pirq;
78
79 rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
80 if (rc) {
81 printk(KERN_WARNING "xen map irq failed %d\n", rc);
82 return -1;
83 }
84
85 if (triggering == ACPI_EDGE_SENSITIVE) {
86 shareable = 0;
87 name = "ioapic-edge";
88 } else {
89 shareable = 1;
90 name = "ioapic-level";
91 }
92
93 if (gsi_override >= 0)
94 gsi = gsi_override;
95
96 irq = xen_bind_pirq_gsi_to_irq(gsi, map_irq.pirq, shareable, name);
97 if (irq < 0)
98 goto out;
99
100 printk(KERN_DEBUG "xen: --> pirq=%d -> irq=%d (gsi=%d)\n", map_irq.pirq, irq, gsi);
101 out:
102 return irq;
103 }
104
acpi_register_gsi_xen_hvm(struct device * dev,u32 gsi,int trigger,int polarity)105 static int acpi_register_gsi_xen_hvm(struct device *dev, u32 gsi,
106 int trigger, int polarity)
107 {
108 if (!xen_hvm_domain())
109 return -1;
110
111 return xen_register_pirq(gsi, -1 /* no GSI override */, trigger,
112 false /* no mapping of GSI to PIRQ */);
113 }
114
115 #ifdef CONFIG_XEN_DOM0
xen_register_gsi(u32 gsi,int gsi_override,int triggering,int polarity)116 static int xen_register_gsi(u32 gsi, int gsi_override, int triggering, int polarity)
117 {
118 int rc, irq;
119 struct physdev_setup_gsi setup_gsi;
120
121 if (!xen_pv_domain())
122 return -1;
123
124 printk(KERN_DEBUG "xen: registering gsi %u triggering %d polarity %d\n",
125 gsi, triggering, polarity);
126
127 irq = xen_register_pirq(gsi, gsi_override, triggering, true);
128
129 setup_gsi.gsi = gsi;
130 setup_gsi.triggering = (triggering == ACPI_EDGE_SENSITIVE ? 0 : 1);
131 setup_gsi.polarity = (polarity == ACPI_ACTIVE_HIGH ? 0 : 1);
132
133 rc = HYPERVISOR_physdev_op(PHYSDEVOP_setup_gsi, &setup_gsi);
134 if (rc == -EEXIST)
135 printk(KERN_INFO "Already setup the GSI :%d\n", gsi);
136 else if (rc) {
137 printk(KERN_ERR "Failed to setup GSI :%d, err_code:%d\n",
138 gsi, rc);
139 }
140
141 return irq;
142 }
143
acpi_register_gsi_xen(struct device * dev,u32 gsi,int trigger,int polarity)144 static int acpi_register_gsi_xen(struct device *dev, u32 gsi,
145 int trigger, int polarity)
146 {
147 return xen_register_gsi(gsi, -1 /* no GSI override */, trigger, polarity);
148 }
149 #endif
150 #endif
151
152 #if defined(CONFIG_PCI_MSI)
153 #include <linux/msi.h>
154 #include <asm/msidef.h>
155
156 struct xen_pci_frontend_ops *xen_pci_frontend;
157 EXPORT_SYMBOL_GPL(xen_pci_frontend);
158
xen_setup_msi_irqs(struct pci_dev * dev,int nvec,int type)159 static int xen_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
160 {
161 int irq, ret, i;
162 struct msi_desc *msidesc;
163 int *v;
164
165 if (type == PCI_CAP_ID_MSI && nvec > 1)
166 return 1;
167
168 v = kzalloc(sizeof(int) * max(1, nvec), GFP_KERNEL);
169 if (!v)
170 return -ENOMEM;
171
172 if (type == PCI_CAP_ID_MSIX)
173 ret = xen_pci_frontend_enable_msix(dev, v, nvec);
174 else
175 ret = xen_pci_frontend_enable_msi(dev, v);
176 if (ret)
177 goto error;
178 i = 0;
179 list_for_each_entry(msidesc, &dev->msi_list, list) {
180 irq = xen_bind_pirq_msi_to_irq(dev, msidesc, v[i], 0,
181 (type == PCI_CAP_ID_MSIX) ?
182 "pcifront-msi-x" :
183 "pcifront-msi",
184 DOMID_SELF);
185 if (irq < 0) {
186 ret = irq;
187 goto free;
188 }
189 i++;
190 }
191 kfree(v);
192 return 0;
193
194 error:
195 dev_err(&dev->dev, "Xen PCI frontend has not registered MSI/MSI-X support!\n");
196 free:
197 kfree(v);
198 return ret;
199 }
200
201 #define XEN_PIRQ_MSI_DATA (MSI_DATA_TRIGGER_EDGE | \
202 MSI_DATA_LEVEL_ASSERT | (3 << 8) | MSI_DATA_VECTOR(0))
203
xen_msi_compose_msg(struct pci_dev * pdev,unsigned int pirq,struct msi_msg * msg)204 static void xen_msi_compose_msg(struct pci_dev *pdev, unsigned int pirq,
205 struct msi_msg *msg)
206 {
207 /* We set vector == 0 to tell the hypervisor we don't care about it,
208 * but we want a pirq setup instead.
209 * We use the dest_id field to pass the pirq that we want. */
210 msg->address_hi = MSI_ADDR_BASE_HI | MSI_ADDR_EXT_DEST_ID(pirq);
211 msg->address_lo =
212 MSI_ADDR_BASE_LO |
213 MSI_ADDR_DEST_MODE_PHYSICAL |
214 MSI_ADDR_REDIRECTION_CPU |
215 MSI_ADDR_DEST_ID(pirq);
216
217 msg->data = XEN_PIRQ_MSI_DATA;
218 }
219
xen_hvm_setup_msi_irqs(struct pci_dev * dev,int nvec,int type)220 static int xen_hvm_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
221 {
222 int irq, pirq;
223 struct msi_desc *msidesc;
224 struct msi_msg msg;
225
226 if (type == PCI_CAP_ID_MSI && nvec > 1)
227 return 1;
228
229 list_for_each_entry(msidesc, &dev->msi_list, list) {
230 __read_msi_msg(msidesc, &msg);
231 pirq = MSI_ADDR_EXT_DEST_ID(msg.address_hi) |
232 ((msg.address_lo >> MSI_ADDR_DEST_ID_SHIFT) & 0xff);
233 if (msg.data != XEN_PIRQ_MSI_DATA ||
234 xen_irq_from_pirq(pirq) < 0) {
235 pirq = xen_allocate_pirq_msi(dev, msidesc);
236 if (pirq < 0) {
237 irq = -ENODEV;
238 goto error;
239 }
240 xen_msi_compose_msg(dev, pirq, &msg);
241 __write_msi_msg(msidesc, &msg);
242 dev_dbg(&dev->dev, "xen: msi bound to pirq=%d\n", pirq);
243 } else {
244 dev_dbg(&dev->dev,
245 "xen: msi already bound to pirq=%d\n", pirq);
246 }
247 irq = xen_bind_pirq_msi_to_irq(dev, msidesc, pirq, 0,
248 (type == PCI_CAP_ID_MSIX) ?
249 "msi-x" : "msi",
250 DOMID_SELF);
251 if (irq < 0)
252 goto error;
253 dev_dbg(&dev->dev,
254 "xen: msi --> pirq=%d --> irq=%d\n", pirq, irq);
255 }
256 return 0;
257
258 error:
259 dev_err(&dev->dev,
260 "Xen PCI frontend has not registered MSI/MSI-X support!\n");
261 return irq;
262 }
263
264 #ifdef CONFIG_XEN_DOM0
265 static bool __read_mostly pci_seg_supported = true;
266
xen_initdom_setup_msi_irqs(struct pci_dev * dev,int nvec,int type)267 static int xen_initdom_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
268 {
269 int ret = 0;
270 struct msi_desc *msidesc;
271
272 if (type == PCI_CAP_ID_MSI && nvec > 1)
273 return 1;
274
275 list_for_each_entry(msidesc, &dev->msi_list, list) {
276 struct physdev_map_pirq map_irq;
277 domid_t domid;
278
279 domid = ret = xen_find_device_domain_owner(dev);
280 /* N.B. Casting int's -ENODEV to uint16_t results in 0xFFED,
281 * hence check ret value for < 0. */
282 if (ret < 0)
283 domid = DOMID_SELF;
284
285 memset(&map_irq, 0, sizeof(map_irq));
286 map_irq.domid = domid;
287 map_irq.type = MAP_PIRQ_TYPE_MSI_SEG;
288 map_irq.index = -1;
289 map_irq.pirq = -1;
290 map_irq.bus = dev->bus->number |
291 (pci_domain_nr(dev->bus) << 16);
292 map_irq.devfn = dev->devfn;
293
294 if (type == PCI_CAP_ID_MSIX) {
295 int pos;
296 u32 table_offset, bir;
297
298 pos = pci_find_capability(dev, PCI_CAP_ID_MSIX);
299
300 pci_read_config_dword(dev, pos + PCI_MSIX_TABLE,
301 &table_offset);
302 bir = (u8)(table_offset & PCI_MSIX_FLAGS_BIRMASK);
303
304 map_irq.table_base = pci_resource_start(dev, bir);
305 map_irq.entry_nr = msidesc->msi_attrib.entry_nr;
306 }
307
308 ret = -EINVAL;
309 if (pci_seg_supported)
310 ret = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq,
311 &map_irq);
312 if (ret == -EINVAL && !pci_domain_nr(dev->bus)) {
313 map_irq.type = MAP_PIRQ_TYPE_MSI;
314 map_irq.index = -1;
315 map_irq.pirq = -1;
316 map_irq.bus = dev->bus->number;
317 ret = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq,
318 &map_irq);
319 if (ret != -EINVAL)
320 pci_seg_supported = false;
321 }
322 if (ret) {
323 dev_warn(&dev->dev, "xen map irq failed %d for %d domain\n",
324 ret, domid);
325 goto out;
326 }
327
328 ret = xen_bind_pirq_msi_to_irq(dev, msidesc,
329 map_irq.pirq, map_irq.index,
330 (type == PCI_CAP_ID_MSIX) ?
331 "msi-x" : "msi",
332 domid);
333 if (ret < 0)
334 goto out;
335 }
336 ret = 0;
337 out:
338 return ret;
339 }
340
xen_initdom_restore_msi_irqs(struct pci_dev * dev,int irq)341 static void xen_initdom_restore_msi_irqs(struct pci_dev *dev, int irq)
342 {
343 int ret = 0;
344
345 if (pci_seg_supported) {
346 struct physdev_pci_device restore_ext;
347
348 restore_ext.seg = pci_domain_nr(dev->bus);
349 restore_ext.bus = dev->bus->number;
350 restore_ext.devfn = dev->devfn;
351 ret = HYPERVISOR_physdev_op(PHYSDEVOP_restore_msi_ext,
352 &restore_ext);
353 if (ret == -ENOSYS)
354 pci_seg_supported = false;
355 WARN(ret && ret != -ENOSYS, "restore_msi_ext -> %d\n", ret);
356 }
357 if (!pci_seg_supported) {
358 struct physdev_restore_msi restore;
359
360 restore.bus = dev->bus->number;
361 restore.devfn = dev->devfn;
362 ret = HYPERVISOR_physdev_op(PHYSDEVOP_restore_msi, &restore);
363 WARN(ret && ret != -ENOSYS, "restore_msi -> %d\n", ret);
364 }
365 }
366 #endif
367
xen_teardown_msi_irqs(struct pci_dev * dev)368 static void xen_teardown_msi_irqs(struct pci_dev *dev)
369 {
370 struct msi_desc *msidesc;
371
372 msidesc = list_entry(dev->msi_list.next, struct msi_desc, list);
373 if (msidesc->msi_attrib.is_msix)
374 xen_pci_frontend_disable_msix(dev);
375 else
376 xen_pci_frontend_disable_msi(dev);
377
378 /* Free the IRQ's and the msidesc using the generic code. */
379 default_teardown_msi_irqs(dev);
380 }
381
xen_teardown_msi_irq(unsigned int irq)382 static void xen_teardown_msi_irq(unsigned int irq)
383 {
384 xen_destroy_irq(irq);
385 }
386
387 #endif
388
pci_xen_init(void)389 int __init pci_xen_init(void)
390 {
391 if (!xen_pv_domain() || xen_initial_domain())
392 return -ENODEV;
393
394 printk(KERN_INFO "PCI: setting up Xen PCI frontend stub\n");
395
396 pcibios_set_cache_line_size();
397
398 pcibios_enable_irq = xen_pcifront_enable_irq;
399 pcibios_disable_irq = NULL;
400
401 #ifdef CONFIG_ACPI
402 /* Keep ACPI out of the picture */
403 acpi_noirq = 1;
404 #endif
405
406 #ifdef CONFIG_PCI_MSI
407 x86_msi.setup_msi_irqs = xen_setup_msi_irqs;
408 x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
409 x86_msi.teardown_msi_irqs = xen_teardown_msi_irqs;
410 #endif
411 return 0;
412 }
413
pci_xen_hvm_init(void)414 int __init pci_xen_hvm_init(void)
415 {
416 if (!xen_have_vector_callback || !xen_feature(XENFEAT_hvm_pirqs))
417 return 0;
418
419 #ifdef CONFIG_ACPI
420 /*
421 * We don't want to change the actual ACPI delivery model,
422 * just how GSIs get registered.
423 */
424 __acpi_register_gsi = acpi_register_gsi_xen_hvm;
425 #endif
426
427 #ifdef CONFIG_PCI_MSI
428 x86_msi.setup_msi_irqs = xen_hvm_setup_msi_irqs;
429 x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
430 #endif
431 return 0;
432 }
433
434 #ifdef CONFIG_XEN_DOM0
xen_setup_acpi_sci(void)435 static __init void xen_setup_acpi_sci(void)
436 {
437 int rc;
438 int trigger, polarity;
439 int gsi = acpi_sci_override_gsi;
440 int irq = -1;
441 int gsi_override = -1;
442
443 if (!gsi)
444 return;
445
446 rc = acpi_get_override_irq(gsi, &trigger, &polarity);
447 if (rc) {
448 printk(KERN_WARNING "xen: acpi_get_override_irq failed for acpi"
449 " sci, rc=%d\n", rc);
450 return;
451 }
452 trigger = trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
453 polarity = polarity ? ACPI_ACTIVE_LOW : ACPI_ACTIVE_HIGH;
454
455 printk(KERN_INFO "xen: sci override: global_irq=%d trigger=%d "
456 "polarity=%d\n", gsi, trigger, polarity);
457
458 /* Before we bind the GSI to a Linux IRQ, check whether
459 * we need to override it with bus_irq (IRQ) value. Usually for
460 * IRQs below IRQ_LEGACY_IRQ this holds IRQ == GSI, as so:
461 * ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 9 low level)
462 * but there are oddballs where the IRQ != GSI:
463 * ACPI: INT_SRC_OVR (bus 0 bus_irq 9 global_irq 20 low level)
464 * which ends up being: gsi_to_irq[9] == 20
465 * (which is what acpi_gsi_to_irq ends up calling when starting the
466 * the ACPI interpreter and keels over since IRQ 9 has not been
467 * setup as we had setup IRQ 20 for it).
468 */
469 if (acpi_gsi_to_irq(gsi, &irq) == 0) {
470 /* Use the provided value if it's valid. */
471 if (irq >= 0)
472 gsi_override = irq;
473 }
474
475 gsi = xen_register_gsi(gsi, gsi_override, trigger, polarity);
476 printk(KERN_INFO "xen: acpi sci %d\n", gsi);
477
478 return;
479 }
480
pci_xen_initial_domain(void)481 int __init pci_xen_initial_domain(void)
482 {
483 int irq;
484
485 #ifdef CONFIG_PCI_MSI
486 x86_msi.setup_msi_irqs = xen_initdom_setup_msi_irqs;
487 x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
488 x86_msi.restore_msi_irqs = xen_initdom_restore_msi_irqs;
489 #endif
490 xen_setup_acpi_sci();
491 __acpi_register_gsi = acpi_register_gsi_xen;
492 /* Pre-allocate legacy irqs */
493 for (irq = 0; irq < NR_IRQS_LEGACY; irq++) {
494 int trigger, polarity;
495
496 if (acpi_get_override_irq(irq, &trigger, &polarity) == -1)
497 continue;
498
499 xen_register_pirq(irq, -1 /* no GSI override */,
500 trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE,
501 true /* Map GSI to PIRQ */);
502 }
503 if (0 == nr_ioapics) {
504 for (irq = 0; irq < NR_IRQS_LEGACY; irq++)
505 xen_bind_pirq_gsi_to_irq(irq, irq, 0, "xt-pic");
506 }
507 return 0;
508 }
509
510 struct xen_device_domain_owner {
511 domid_t domain;
512 struct pci_dev *dev;
513 struct list_head list;
514 };
515
516 static DEFINE_SPINLOCK(dev_domain_list_spinlock);
517 static struct list_head dev_domain_list = LIST_HEAD_INIT(dev_domain_list);
518
find_device(struct pci_dev * dev)519 static struct xen_device_domain_owner *find_device(struct pci_dev *dev)
520 {
521 struct xen_device_domain_owner *owner;
522
523 list_for_each_entry(owner, &dev_domain_list, list) {
524 if (owner->dev == dev)
525 return owner;
526 }
527 return NULL;
528 }
529
xen_find_device_domain_owner(struct pci_dev * dev)530 int xen_find_device_domain_owner(struct pci_dev *dev)
531 {
532 struct xen_device_domain_owner *owner;
533 int domain = -ENODEV;
534
535 spin_lock(&dev_domain_list_spinlock);
536 owner = find_device(dev);
537 if (owner)
538 domain = owner->domain;
539 spin_unlock(&dev_domain_list_spinlock);
540 return domain;
541 }
542 EXPORT_SYMBOL_GPL(xen_find_device_domain_owner);
543
xen_register_device_domain_owner(struct pci_dev * dev,uint16_t domain)544 int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t domain)
545 {
546 struct xen_device_domain_owner *owner;
547
548 owner = kzalloc(sizeof(struct xen_device_domain_owner), GFP_KERNEL);
549 if (!owner)
550 return -ENODEV;
551
552 spin_lock(&dev_domain_list_spinlock);
553 if (find_device(dev)) {
554 spin_unlock(&dev_domain_list_spinlock);
555 kfree(owner);
556 return -EEXIST;
557 }
558 owner->domain = domain;
559 owner->dev = dev;
560 list_add_tail(&owner->list, &dev_domain_list);
561 spin_unlock(&dev_domain_list_spinlock);
562 return 0;
563 }
564 EXPORT_SYMBOL_GPL(xen_register_device_domain_owner);
565
xen_unregister_device_domain_owner(struct pci_dev * dev)566 int xen_unregister_device_domain_owner(struct pci_dev *dev)
567 {
568 struct xen_device_domain_owner *owner;
569
570 spin_lock(&dev_domain_list_spinlock);
571 owner = find_device(dev);
572 if (!owner) {
573 spin_unlock(&dev_domain_list_spinlock);
574 return -ENODEV;
575 }
576 list_del(&owner->list);
577 spin_unlock(&dev_domain_list_spinlock);
578 kfree(owner);
579 return 0;
580 }
581 EXPORT_SYMBOL_GPL(xen_unregister_device_domain_owner);
582 #endif
583