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/export.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#include <asm/xen/cpuid.h>
27#include <asm/apic.h>
28#include <asm/i8259.h>
29
30static int xen_pcifront_enable_irq(struct pci_dev *dev)
31{
32 int rc;
33 int share = 1;
34 int pirq;
35 u8 gsi;
36
37 rc = pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &gsi);
38 if (rc < 0) {
39 dev_warn(&dev->dev, "Xen PCI: failed to read interrupt line: %d\n",
40 rc);
41 return rc;
42 }
43 /* In PV DomU the Xen PCI backend puts the PIRQ in the interrupt line.*/
44 pirq = gsi;
45
46 if (gsi < nr_legacy_irqs())
47 share = 0;
48
49 rc = xen_bind_pirq_gsi_to_irq(gsi, pirq, share, "pcifront");
50 if (rc < 0) {
51 dev_warn(&dev->dev, "Xen PCI: failed to bind GSI%d (PIRQ%d) to IRQ: %d\n",
52 gsi, pirq, rc);
53 return rc;
54 }
55
56 dev->irq = rc;
57 dev_info(&dev->dev, "Xen PCI mapped GSI%d to IRQ%d\n", gsi, dev->irq);
58 return 0;
59}
60
61#ifdef CONFIG_ACPI
62static int xen_register_pirq(u32 gsi, int gsi_override, int triggering,
63 bool set_pirq)
64{
65 int rc, pirq = -1, irq = -1;
66 struct physdev_map_pirq map_irq;
67 int shareable = 0;
68 char *name;
69
70 irq = xen_irq_from_gsi(gsi);
71 if (irq > 0)
72 return irq;
73
74 if (set_pirq)
75 pirq = gsi;
76
77 map_irq.domid = DOMID_SELF;
78 map_irq.type = MAP_PIRQ_TYPE_GSI;
79 map_irq.index = gsi;
80 map_irq.pirq = pirq;
81
82 rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
83 if (rc) {
84 printk(KERN_WARNING "xen map irq failed %d\n", rc);
85 return -1;
86 }
87
88 if (triggering == ACPI_EDGE_SENSITIVE) {
89 shareable = 0;
90 name = "ioapic-edge";
91 } else {
92 shareable = 1;
93 name = "ioapic-level";
94 }
95
96 if (gsi_override >= 0)
97 gsi = gsi_override;
98
99 irq = xen_bind_pirq_gsi_to_irq(gsi, map_irq.pirq, shareable, name);
100 if (irq < 0)
101 goto out;
102
103 printk(KERN_DEBUG "xen: --> pirq=%d -> irq=%d (gsi=%d)\n", map_irq.pirq, irq, gsi);
104out:
105 return irq;
106}
107
108static int acpi_register_gsi_xen_hvm(struct device *dev, u32 gsi,
109 int trigger, int polarity)
110{
111 if (!xen_hvm_domain())
112 return -1;
113
114 return xen_register_pirq(gsi, -1 /* no GSI override */, trigger,
115 false /* no mapping of GSI to PIRQ */);
116}
117
118#ifdef CONFIG_XEN_DOM0
119static int xen_register_gsi(u32 gsi, int gsi_override, int triggering, int polarity)
120{
121 int rc, irq;
122 struct physdev_setup_gsi setup_gsi;
123
124 if (!xen_pv_domain())
125 return -1;
126
127 printk(KERN_DEBUG "xen: registering gsi %u triggering %d polarity %d\n",
128 gsi, triggering, polarity);
129
130 irq = xen_register_pirq(gsi, gsi_override, triggering, true);
131
132 setup_gsi.gsi = gsi;
133 setup_gsi.triggering = (triggering == ACPI_EDGE_SENSITIVE ? 0 : 1);
134 setup_gsi.polarity = (polarity == ACPI_ACTIVE_HIGH ? 0 : 1);
135
136 rc = HYPERVISOR_physdev_op(PHYSDEVOP_setup_gsi, &setup_gsi);
137 if (rc == -EEXIST)
138 printk(KERN_INFO "Already setup the GSI :%d\n", gsi);
139 else if (rc) {
140 printk(KERN_ERR "Failed to setup GSI :%d, err_code:%d\n",
141 gsi, rc);
142 }
143
144 return irq;
145}
146
147static int acpi_register_gsi_xen(struct device *dev, u32 gsi,
148 int trigger, int polarity)
149{
150 return xen_register_gsi(gsi, -1 /* no GSI override */, trigger, polarity);
151}
152#endif
153#endif
154
155#if defined(CONFIG_PCI_MSI)
156#include <linux/msi.h>
157#include <asm/msidef.h>
158
159struct xen_pci_frontend_ops *xen_pci_frontend;
160EXPORT_SYMBOL_GPL(xen_pci_frontend);
161
162static int xen_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
163{
164 int irq, ret, i;
165 struct msi_desc *msidesc;
166 int *v;
167
168 if (type == PCI_CAP_ID_MSI && nvec > 1)
169 return 1;
170
171 v = kcalloc(max(1, nvec), sizeof(int), GFP_KERNEL);
172 if (!v)
173 return -ENOMEM;
174
175 if (type == PCI_CAP_ID_MSIX)
176 ret = xen_pci_frontend_enable_msix(dev, v, nvec);
177 else
178 ret = xen_pci_frontend_enable_msi(dev, v);
179 if (ret)
180 goto error;
181 i = 0;
182 for_each_pci_msi_entry(msidesc, dev) {
183 irq = xen_bind_pirq_msi_to_irq(dev, msidesc, v[i],
184 (type == PCI_CAP_ID_MSI) ? nvec : 1,
185 (type == PCI_CAP_ID_MSIX) ?
186 "pcifront-msi-x" :
187 "pcifront-msi",
188 DOMID_SELF);
189 if (irq < 0) {
190 ret = irq;
191 goto free;
192 }
193 i++;
194 }
195 kfree(v);
196 return 0;
197
198error:
199 if (ret == -ENOSYS)
200 dev_err(&dev->dev, "Xen PCI frontend has not registered MSI/MSI-X support!\n");
201 else if (ret)
202 dev_err(&dev->dev, "Xen PCI frontend error: %d!\n", ret);
203free:
204 kfree(v);
205 return ret;
206}
207
208#define XEN_PIRQ_MSI_DATA (MSI_DATA_TRIGGER_EDGE | \
209 MSI_DATA_LEVEL_ASSERT | (3 << 8) | MSI_DATA_VECTOR(0))
210
211static void xen_msi_compose_msg(struct pci_dev *pdev, unsigned int pirq,
212 struct msi_msg *msg)
213{
214 /* We set vector == 0 to tell the hypervisor we don't care about it,
215 * but we want a pirq setup instead.
216 * We use the dest_id field to pass the pirq that we want. */
217 msg->address_hi = MSI_ADDR_BASE_HI | MSI_ADDR_EXT_DEST_ID(pirq);
218 msg->address_lo =
219 MSI_ADDR_BASE_LO |
220 MSI_ADDR_DEST_MODE_PHYSICAL |
221 MSI_ADDR_REDIRECTION_CPU |
222 MSI_ADDR_DEST_ID(pirq);
223
224 msg->data = XEN_PIRQ_MSI_DATA;
225}
226
227static int xen_hvm_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
228{
229 int irq, pirq;
230 struct msi_desc *msidesc;
231 struct msi_msg msg;
232
233 if (type == PCI_CAP_ID_MSI && nvec > 1)
234 return 1;
235
236 for_each_pci_msi_entry(msidesc, dev) {
237 pirq = xen_allocate_pirq_msi(dev, msidesc);
238 if (pirq < 0) {
239 irq = -ENODEV;
240 goto error;
241 }
242 xen_msi_compose_msg(dev, pirq, &msg);
243 __pci_write_msi_msg(msidesc, &msg);
244 dev_dbg(&dev->dev, "xen: msi bound to pirq=%d\n", pirq);
245 irq = xen_bind_pirq_msi_to_irq(dev, msidesc, pirq,
246 (type == PCI_CAP_ID_MSI) ? nvec : 1,
247 (type == PCI_CAP_ID_MSIX) ?
248 "msi-x" : "msi",
249 DOMID_SELF);
250 if (irq < 0)
251 goto error;
252 dev_dbg(&dev->dev,
253 "xen: msi --> pirq=%d --> irq=%d\n", pirq, irq);
254 }
255 return 0;
256
257error:
258 dev_err(&dev->dev, "Failed to create MSI%s! ret=%d!\n",
259 type == PCI_CAP_ID_MSI ? "" : "-X", irq);
260 return irq;
261}
262
263#ifdef CONFIG_XEN_DOM0
264static bool __read_mostly pci_seg_supported = true;
265
266static int xen_initdom_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
267{
268 int ret = 0;
269 struct msi_desc *msidesc;
270
271 for_each_pci_msi_entry(msidesc, dev) {
272 struct physdev_map_pirq map_irq;
273 domid_t domid;
274
275 domid = ret = xen_find_device_domain_owner(dev);
276 /* N.B. Casting int's -ENODEV to uint16_t results in 0xFFED,
277 * hence check ret value for < 0. */
278 if (ret < 0)
279 domid = DOMID_SELF;
280
281 memset(&map_irq, 0, sizeof(map_irq));
282 map_irq.domid = domid;
283 map_irq.type = MAP_PIRQ_TYPE_MSI_SEG;
284 map_irq.index = -1;
285 map_irq.pirq = -1;
286 map_irq.bus = dev->bus->number |
287 (pci_domain_nr(dev->bus) << 16);
288 map_irq.devfn = dev->devfn;
289
290 if (type == PCI_CAP_ID_MSI && nvec > 1) {
291 map_irq.type = MAP_PIRQ_TYPE_MULTI_MSI;
292 map_irq.entry_nr = nvec;
293 } else if (type == PCI_CAP_ID_MSIX) {
294 int pos;
295 unsigned long flags;
296 u32 table_offset, bir;
297
298 pos = dev->msix_cap;
299 pci_read_config_dword(dev, pos + PCI_MSIX_TABLE,
300 &table_offset);
301 bir = (u8)(table_offset & PCI_MSIX_TABLE_BIR);
302 flags = pci_resource_flags(dev, bir);
303 if (!flags || (flags & IORESOURCE_UNSET))
304 return -EINVAL;
305
306 map_irq.table_base = pci_resource_start(dev, bir);
307 map_irq.entry_nr = msidesc->msi_attrib.entry_nr;
308 }
309
310 ret = -EINVAL;
311 if (pci_seg_supported)
312 ret = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq,
313 &map_irq);
314 if (type == PCI_CAP_ID_MSI && nvec > 1 && ret) {
315 /*
316 * If MAP_PIRQ_TYPE_MULTI_MSI is not available
317 * there's nothing else we can do in this case.
318 * Just set ret > 0 so driver can retry with
319 * single MSI.
320 */
321 ret = 1;
322 goto out;
323 }
324 if (ret == -EINVAL && !pci_domain_nr(dev->bus)) {
325 map_irq.type = MAP_PIRQ_TYPE_MSI;
326 map_irq.index = -1;
327 map_irq.pirq = -1;
328 map_irq.bus = dev->bus->number;
329 ret = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq,
330 &map_irq);
331 if (ret != -EINVAL)
332 pci_seg_supported = false;
333 }
334 if (ret) {
335 dev_warn(&dev->dev, "xen map irq failed %d for %d domain\n",
336 ret, domid);
337 goto out;
338 }
339
340 ret = xen_bind_pirq_msi_to_irq(dev, msidesc, map_irq.pirq,
341 (type == PCI_CAP_ID_MSI) ? nvec : 1,
342 (type == PCI_CAP_ID_MSIX) ? "msi-x" : "msi",
343 domid);
344 if (ret < 0)
345 goto out;
346 }
347 ret = 0;
348out:
349 return ret;
350}
351
352static void xen_initdom_restore_msi_irqs(struct pci_dev *dev)
353{
354 int ret = 0;
355
356 if (pci_seg_supported) {
357 struct physdev_pci_device restore_ext;
358
359 restore_ext.seg = pci_domain_nr(dev->bus);
360 restore_ext.bus = dev->bus->number;
361 restore_ext.devfn = dev->devfn;
362 ret = HYPERVISOR_physdev_op(PHYSDEVOP_restore_msi_ext,
363 &restore_ext);
364 if (ret == -ENOSYS)
365 pci_seg_supported = false;
366 WARN(ret && ret != -ENOSYS, "restore_msi_ext -> %d\n", ret);
367 }
368 if (!pci_seg_supported) {
369 struct physdev_restore_msi restore;
370
371 restore.bus = dev->bus->number;
372 restore.devfn = dev->devfn;
373 ret = HYPERVISOR_physdev_op(PHYSDEVOP_restore_msi, &restore);
374 WARN(ret && ret != -ENOSYS, "restore_msi -> %d\n", ret);
375 }
376}
377#endif
378
379static void xen_teardown_msi_irqs(struct pci_dev *dev)
380{
381 struct msi_desc *msidesc;
382
383 msidesc = first_pci_msi_entry(dev);
384 if (msidesc->msi_attrib.is_msix)
385 xen_pci_frontend_disable_msix(dev);
386 else
387 xen_pci_frontend_disable_msi(dev);
388
389 /* Free the IRQ's and the msidesc using the generic code. */
390 default_teardown_msi_irqs(dev);
391}
392
393static void xen_teardown_msi_irq(unsigned int irq)
394{
395 xen_destroy_irq(irq);
396}
397
398#endif
399
400int __init pci_xen_init(void)
401{
402 if (!xen_pv_domain() || xen_initial_domain())
403 return -ENODEV;
404
405 printk(KERN_INFO "PCI: setting up Xen PCI frontend stub\n");
406
407 pcibios_set_cache_line_size();
408
409 pcibios_enable_irq = xen_pcifront_enable_irq;
410 pcibios_disable_irq = NULL;
411
412 /* Keep ACPI out of the picture */
413 acpi_noirq_set();
414
415#ifdef CONFIG_PCI_MSI
416 x86_msi.setup_msi_irqs = xen_setup_msi_irqs;
417 x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
418 x86_msi.teardown_msi_irqs = xen_teardown_msi_irqs;
419 pci_msi_ignore_mask = 1;
420#endif
421 return 0;
422}
423
424#ifdef CONFIG_PCI_MSI
425void __init xen_msi_init(void)
426{
427 if (!disable_apic) {
428 /*
429 * If hardware supports (x2)APIC virtualization (as indicated
430 * by hypervisor's leaf 4) then we don't need to use pirqs/
431 * event channels for MSI handling and instead use regular
432 * APIC processing
433 */
434 uint32_t eax = cpuid_eax(xen_cpuid_base() + 4);
435
436 if (((eax & XEN_HVM_CPUID_X2APIC_VIRT) && x2apic_mode) ||
437 ((eax & XEN_HVM_CPUID_APIC_ACCESS_VIRT) && boot_cpu_has(X86_FEATURE_APIC)))
438 return;
439 }
440
441 x86_msi.setup_msi_irqs = xen_hvm_setup_msi_irqs;
442 x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
443}
444#endif
445
446int __init pci_xen_hvm_init(void)
447{
448 if (!xen_have_vector_callback || !xen_feature(XENFEAT_hvm_pirqs))
449 return 0;
450
451#ifdef CONFIG_ACPI
452 /*
453 * We don't want to change the actual ACPI delivery model,
454 * just how GSIs get registered.
455 */
456 __acpi_register_gsi = acpi_register_gsi_xen_hvm;
457 __acpi_unregister_gsi = NULL;
458#endif
459
460#ifdef CONFIG_PCI_MSI
461 /*
462 * We need to wait until after x2apic is initialized
463 * before we can set MSI IRQ ops.
464 */
465 x86_platform.apic_post_init = xen_msi_init;
466#endif
467 return 0;
468}
469
470#ifdef CONFIG_XEN_DOM0
471int __init pci_xen_initial_domain(void)
472{
473 int irq;
474
475#ifdef CONFIG_PCI_MSI
476 x86_msi.setup_msi_irqs = xen_initdom_setup_msi_irqs;
477 x86_msi.teardown_msi_irq = xen_teardown_msi_irq;
478 x86_msi.restore_msi_irqs = xen_initdom_restore_msi_irqs;
479 pci_msi_ignore_mask = 1;
480#endif
481 __acpi_register_gsi = acpi_register_gsi_xen;
482 __acpi_unregister_gsi = NULL;
483 /*
484 * Pre-allocate the legacy IRQs. Use NR_LEGACY_IRQS here
485 * because we don't have a PIC and thus nr_legacy_irqs() is zero.
486 */
487 for (irq = 0; irq < NR_IRQS_LEGACY; irq++) {
488 int trigger, polarity;
489
490 if (acpi_get_override_irq(irq, &trigger, &polarity) == -1)
491 continue;
492
493 xen_register_pirq(irq, -1 /* no GSI override */,
494 trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE,
495 true /* Map GSI to PIRQ */);
496 }
497 if (0 == nr_ioapics) {
498 for (irq = 0; irq < nr_legacy_irqs(); irq++)
499 xen_bind_pirq_gsi_to_irq(irq, irq, 0, "xt-pic");
500 }
501 return 0;
502}
503
504struct xen_device_domain_owner {
505 domid_t domain;
506 struct pci_dev *dev;
507 struct list_head list;
508};
509
510static DEFINE_SPINLOCK(dev_domain_list_spinlock);
511static struct list_head dev_domain_list = LIST_HEAD_INIT(dev_domain_list);
512
513static struct xen_device_domain_owner *find_device(struct pci_dev *dev)
514{
515 struct xen_device_domain_owner *owner;
516
517 list_for_each_entry(owner, &dev_domain_list, list) {
518 if (owner->dev == dev)
519 return owner;
520 }
521 return NULL;
522}
523
524int xen_find_device_domain_owner(struct pci_dev *dev)
525{
526 struct xen_device_domain_owner *owner;
527 int domain = -ENODEV;
528
529 spin_lock(&dev_domain_list_spinlock);
530 owner = find_device(dev);
531 if (owner)
532 domain = owner->domain;
533 spin_unlock(&dev_domain_list_spinlock);
534 return domain;
535}
536EXPORT_SYMBOL_GPL(xen_find_device_domain_owner);
537
538int xen_register_device_domain_owner(struct pci_dev *dev, uint16_t domain)
539{
540 struct xen_device_domain_owner *owner;
541
542 owner = kzalloc(sizeof(struct xen_device_domain_owner), GFP_KERNEL);
543 if (!owner)
544 return -ENODEV;
545
546 spin_lock(&dev_domain_list_spinlock);
547 if (find_device(dev)) {
548 spin_unlock(&dev_domain_list_spinlock);
549 kfree(owner);
550 return -EEXIST;
551 }
552 owner->domain = domain;
553 owner->dev = dev;
554 list_add_tail(&owner->list, &dev_domain_list);
555 spin_unlock(&dev_domain_list_spinlock);
556 return 0;
557}
558EXPORT_SYMBOL_GPL(xen_register_device_domain_owner);
559
560int xen_unregister_device_domain_owner(struct pci_dev *dev)
561{
562 struct xen_device_domain_owner *owner;
563
564 spin_lock(&dev_domain_list_spinlock);
565 owner = find_device(dev);
566 if (!owner) {
567 spin_unlock(&dev_domain_list_spinlock);
568 return -ENODEV;
569 }
570 list_del(&owner->list);
571 spin_unlock(&dev_domain_list_spinlock);
572 kfree(owner);
573 return 0;
574}
575EXPORT_SYMBOL_GPL(xen_unregister_device_domain_owner);
576#endif
577