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v6.8
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Xen PCI - handle PCI (INTx) and MSI infrastructure calls for PV, HVM and
  4 * initial domain support. We also handle the DSDT _PRT callbacks for GSI's
  5 * used in HVM and initial domain mode (PV does not parse ACPI, so it has no
  6 * concept of GSIs). Under PV we hook under the pnbbios API for IRQs and
  7 * 0xcf8 PCI configuration read/write.
  8 *
  9 *   Author: Ryan Wilson <hap9@epoch.ncsc.mil>
 10 *           Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
 11 *           Stefano Stabellini <stefano.stabellini@eu.citrix.com>
 12 */
 13#include <linux/export.h>
 14#include <linux/init.h>
 15#include <linux/pci.h>
 16#include <linux/acpi.h>
 17
 18#include <linux/io.h>
 19#include <asm/io_apic.h>
 20#include <asm/pci_x86.h>
 21
 22#include <asm/xen/hypervisor.h>
 23
 24#include <xen/features.h>
 25#include <xen/events.h>
 26#include <xen/pci.h>
 27#include <asm/xen/pci.h>
 28#include <asm/xen/cpuid.h>
 29#include <asm/apic.h>
 30#include <asm/acpi.h>
 31#include <asm/i8259.h>
 32
 33static int xen_pcifront_enable_irq(struct pci_dev *dev)
 34{
 35	int rc;
 36	int share = 1;
 37	int pirq;
 38	u8 gsi;
 39
 40	rc = pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &gsi);
 41	if (rc < 0) {
 42		dev_warn(&dev->dev, "Xen PCI: failed to read interrupt line: %d\n",
 43			 rc);
 44		return rc;
 45	}
 46	/* In PV DomU the Xen PCI backend puts the PIRQ in the interrupt line.*/
 47	pirq = gsi;
 48
 49	if (gsi < nr_legacy_irqs())
 50		share = 0;
 51
 52	rc = xen_bind_pirq_gsi_to_irq(gsi, pirq, share, "pcifront");
 53	if (rc < 0) {
 54		dev_warn(&dev->dev, "Xen PCI: failed to bind GSI%d (PIRQ%d) to IRQ: %d\n",
 55			 gsi, pirq, rc);
 56		return rc;
 57	}
 58
 59	dev->irq = rc;
 60	dev_info(&dev->dev, "Xen PCI mapped GSI%d to IRQ%d\n", gsi, dev->irq);
 61	return 0;
 62}
 63
 64#ifdef CONFIG_ACPI
 65static int xen_register_pirq(u32 gsi, int triggering, bool set_pirq)
 66{
 67	int rc, pirq = -1, irq;
 68	struct physdev_map_pirq map_irq;
 69	int shareable = 0;
 70	char *name;
 71
 72	irq = xen_irq_from_gsi(gsi);
 73	if (irq > 0)
 74		return irq;
 75
 76	if (set_pirq)
 77		pirq = gsi;
 78
 79	map_irq.domid = DOMID_SELF;
 80	map_irq.type = MAP_PIRQ_TYPE_GSI;
 81	map_irq.index = gsi;
 82	map_irq.pirq = pirq;
 83
 84	rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
 85	if (rc) {
 86		printk(KERN_WARNING "xen map irq failed %d\n", rc);
 87		return -1;
 88	}
 89
 90	if (triggering == ACPI_EDGE_SENSITIVE) {
 91		shareable = 0;
 92		name = "ioapic-edge";
 93	} else {
 94		shareable = 1;
 95		name = "ioapic-level";
 96	}
 97
 98	irq = xen_bind_pirq_gsi_to_irq(gsi, map_irq.pirq, shareable, name);
 99	if (irq < 0)
100		goto out;
101
102	printk(KERN_DEBUG "xen: --> pirq=%d -> irq=%d (gsi=%d)\n", map_irq.pirq, irq, gsi);
103out:
104	return irq;
105}
106
107static int acpi_register_gsi_xen_hvm(struct device *dev, u32 gsi,
108				     int trigger, int polarity)
109{
110	if (!xen_hvm_domain())
111		return -1;
112
113	return xen_register_pirq(gsi, trigger,
114				 false /* no mapping of GSI to PIRQ */);
115}
116
117#ifdef CONFIG_XEN_PV_DOM0
118static int xen_register_gsi(u32 gsi, int triggering, int polarity)
119{
120	int rc, irq;
121	struct physdev_setup_gsi setup_gsi;
122
123	if (!xen_pv_domain())
124		return -1;
125
126	printk(KERN_DEBUG "xen: registering gsi %u triggering %d polarity %d\n",
127			gsi, triggering, polarity);
128
129	irq = xen_register_pirq(gsi, triggering, true);
130
131	setup_gsi.gsi = gsi;
132	setup_gsi.triggering = (triggering == ACPI_EDGE_SENSITIVE ? 0 : 1);
133	setup_gsi.polarity = (polarity == ACPI_ACTIVE_HIGH ? 0 : 1);
134
135	rc = HYPERVISOR_physdev_op(PHYSDEVOP_setup_gsi, &setup_gsi);
136	if (rc == -EEXIST)
137		printk(KERN_INFO "Already setup the GSI :%d\n", gsi);
138	else if (rc) {
139		printk(KERN_ERR "Failed to setup GSI :%d, err_code:%d\n",
140				gsi, rc);
141	}
142
143	return irq;
144}
145
146static int acpi_register_gsi_xen(struct device *dev, u32 gsi,
147				 int trigger, int polarity)
148{
149	return xen_register_gsi(gsi, trigger, polarity);
150}
151#endif
152#endif
153
154#if defined(CONFIG_PCI_MSI)
155#include <linux/msi.h>
156
157struct xen_pci_frontend_ops *xen_pci_frontend;
158EXPORT_SYMBOL_GPL(xen_pci_frontend);
159
160struct xen_msi_ops {
161	int (*setup_msi_irqs)(struct pci_dev *dev, int nvec, int type);
162	void (*teardown_msi_irqs)(struct pci_dev *dev);
163};
164
165static struct xen_msi_ops xen_msi_ops __ro_after_init;
166
167static int xen_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
168{
169	int irq, ret, i;
170	struct msi_desc *msidesc;
171	int *v;
172
173	if (type == PCI_CAP_ID_MSI && nvec > 1)
174		return 1;
175
176	v = kcalloc(max(1, nvec), sizeof(int), GFP_KERNEL);
177	if (!v)
178		return -ENOMEM;
179
180	if (type == PCI_CAP_ID_MSIX)
181		ret = xen_pci_frontend_enable_msix(dev, v, nvec);
182	else
183		ret = xen_pci_frontend_enable_msi(dev, v);
184	if (ret)
185		goto error;
186	i = 0;
187	msi_for_each_desc(msidesc, &dev->dev, MSI_DESC_NOTASSOCIATED) {
188		irq = xen_bind_pirq_msi_to_irq(dev, msidesc, v[i],
189					       (type == PCI_CAP_ID_MSI) ? nvec : 1,
190					       (type == PCI_CAP_ID_MSIX) ?
191					       "pcifront-msi-x" :
192					       "pcifront-msi",
193						DOMID_SELF);
194		if (irq < 0) {
195			ret = irq;
196			goto free;
197		}
198		i++;
199	}
200	kfree(v);
201	return msi_device_populate_sysfs(&dev->dev);
202
203error:
204	if (ret == -ENOSYS)
205		dev_err(&dev->dev, "Xen PCI frontend has not registered MSI/MSI-X support!\n");
206	else if (ret)
207		dev_err(&dev->dev, "Xen PCI frontend error: %d!\n", ret);
208free:
209	kfree(v);
210	return ret;
211}
212
213static void xen_msi_compose_msg(struct pci_dev *pdev, unsigned int pirq,
214		struct msi_msg *msg)
215{
216	/*
217	 * We set vector == 0 to tell the hypervisor we don't care about
218	 * it, but we want a pirq setup instead.  We use the dest_id fields
219	 * to pass the pirq that we want.
220	 */
221	memset(msg, 0, sizeof(*msg));
222	msg->address_hi = X86_MSI_BASE_ADDRESS_HIGH;
223	msg->arch_addr_hi.destid_8_31 = pirq >> 8;
224	msg->arch_addr_lo.destid_0_7 = pirq & 0xFF;
225	msg->arch_addr_lo.base_address = X86_MSI_BASE_ADDRESS_LOW;
226	msg->arch_data.delivery_mode = APIC_DELIVERY_MODE_EXTINT;
227}
228
229static int xen_hvm_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
230{
231	int irq, pirq;
232	struct msi_desc *msidesc;
233	struct msi_msg msg;
234
235	if (type == PCI_CAP_ID_MSI && nvec > 1)
236		return 1;
237
238	msi_for_each_desc(msidesc, &dev->dev, MSI_DESC_NOTASSOCIATED) {
239		pirq = xen_allocate_pirq_msi(dev, msidesc);
240		if (pirq < 0) {
241			irq = -ENODEV;
242			goto error;
243		}
244		xen_msi_compose_msg(dev, pirq, &msg);
245		__pci_write_msi_msg(msidesc, &msg);
246		dev_dbg(&dev->dev, "xen: msi bound to pirq=%d\n", pirq);
247		irq = xen_bind_pirq_msi_to_irq(dev, msidesc, pirq,
248					       (type == PCI_CAP_ID_MSI) ? nvec : 1,
249					       (type == PCI_CAP_ID_MSIX) ?
250					       "msi-x" : "msi",
251					       DOMID_SELF);
252		if (irq < 0)
253			goto error;
254		dev_dbg(&dev->dev,
255			"xen: msi --> pirq=%d --> irq=%d\n", pirq, irq);
256	}
257	return msi_device_populate_sysfs(&dev->dev);
258
259error:
260	dev_err(&dev->dev, "Failed to create MSI%s! ret=%d!\n",
261		type == PCI_CAP_ID_MSI ? "" : "-X", irq);
262	return irq;
263}
264
265#ifdef CONFIG_XEN_PV_DOM0
266static bool __read_mostly pci_seg_supported = true;
267
268static int xen_initdom_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
269{
270	int ret = 0;
271	struct msi_desc *msidesc;
272
273	msi_for_each_desc(msidesc, &dev->dev, MSI_DESC_NOTASSOCIATED) {
274		struct physdev_map_pirq map_irq;
275		domid_t domid;
276
277		domid = ret = xen_find_device_domain_owner(dev);
278		/* N.B. Casting int's -ENODEV to uint16_t results in 0xFFED,
279		 * hence check ret value for < 0. */
280		if (ret < 0)
281			domid = DOMID_SELF;
282
283		memset(&map_irq, 0, sizeof(map_irq));
284		map_irq.domid = domid;
285		map_irq.type = MAP_PIRQ_TYPE_MSI_SEG;
286		map_irq.index = -1;
287		map_irq.pirq = -1;
288		map_irq.bus = dev->bus->number |
289			      (pci_domain_nr(dev->bus) << 16);
290		map_irq.devfn = dev->devfn;
291
292		if (type == PCI_CAP_ID_MSI && nvec > 1) {
293			map_irq.type = MAP_PIRQ_TYPE_MULTI_MSI;
294			map_irq.entry_nr = nvec;
295		} else if (type == PCI_CAP_ID_MSIX) {
296			int pos;
297			unsigned long flags;
298			u32 table_offset, bir;
299
300			pos = dev->msix_cap;
301			pci_read_config_dword(dev, pos + PCI_MSIX_TABLE,
302					      &table_offset);
303			bir = (u8)(table_offset & PCI_MSIX_TABLE_BIR);
304			flags = pci_resource_flags(dev, bir);
305			if (!flags || (flags & IORESOURCE_UNSET))
306				return -EINVAL;
307
308			map_irq.table_base = pci_resource_start(dev, bir);
309			map_irq.entry_nr = msidesc->msi_index;
310		}
311
312		ret = -EINVAL;
313		if (pci_seg_supported)
314			ret = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq,
315						    &map_irq);
316		if (type == PCI_CAP_ID_MSI && nvec > 1 && ret) {
317			/*
318			 * If MAP_PIRQ_TYPE_MULTI_MSI is not available
319			 * there's nothing else we can do in this case.
320			 * Just set ret > 0 so driver can retry with
321			 * single MSI.
322			 */
323			ret = 1;
324			goto out;
325		}
326		if (ret == -EINVAL && !pci_domain_nr(dev->bus)) {
327			map_irq.type = MAP_PIRQ_TYPE_MSI;
328			map_irq.index = -1;
329			map_irq.pirq = -1;
330			map_irq.bus = dev->bus->number;
331			ret = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq,
332						    &map_irq);
333			if (ret != -EINVAL)
334				pci_seg_supported = false;
335		}
336		if (ret) {
337			dev_warn(&dev->dev, "xen map irq failed %d for %d domain\n",
338				 ret, domid);
339			goto out;
340		}
341
342		ret = xen_bind_pirq_msi_to_irq(dev, msidesc, map_irq.pirq,
343		                               (type == PCI_CAP_ID_MSI) ? nvec : 1,
344		                               (type == PCI_CAP_ID_MSIX) ? "msi-x" : "msi",
345		                               domid);
346		if (ret < 0)
347			goto out;
348	}
349	ret = msi_device_populate_sysfs(&dev->dev);
350out:
351	return ret;
352}
353
354bool xen_initdom_restore_msi(struct pci_dev *dev)
355{
356	int ret = 0;
357
358	if (!xen_initial_domain())
359		return true;
360
361	if (pci_seg_supported) {
362		struct physdev_pci_device restore_ext;
363
364		restore_ext.seg = pci_domain_nr(dev->bus);
365		restore_ext.bus = dev->bus->number;
366		restore_ext.devfn = dev->devfn;
367		ret = HYPERVISOR_physdev_op(PHYSDEVOP_restore_msi_ext,
368					&restore_ext);
369		if (ret == -ENOSYS)
370			pci_seg_supported = false;
371		WARN(ret && ret != -ENOSYS, "restore_msi_ext -> %d\n", ret);
372	}
373	if (!pci_seg_supported) {
374		struct physdev_restore_msi restore;
375
376		restore.bus = dev->bus->number;
377		restore.devfn = dev->devfn;
378		ret = HYPERVISOR_physdev_op(PHYSDEVOP_restore_msi, &restore);
379		WARN(ret && ret != -ENOSYS, "restore_msi -> %d\n", ret);
380	}
381	return false;
382}
383#else /* CONFIG_XEN_PV_DOM0 */
384#define xen_initdom_setup_msi_irqs	NULL
385#endif /* !CONFIG_XEN_PV_DOM0 */
386
387static void xen_teardown_msi_irqs(struct pci_dev *dev)
388{
389	struct msi_desc *msidesc;
390	int i;
391
392	msi_for_each_desc(msidesc, &dev->dev, MSI_DESC_ASSOCIATED) {
393		for (i = 0; i < msidesc->nvec_used; i++)
394			xen_destroy_irq(msidesc->irq + i);
395		msidesc->irq = 0;
396	}
397
398	msi_device_destroy_sysfs(&dev->dev);
399}
400
401static void xen_pv_teardown_msi_irqs(struct pci_dev *dev)
402{
403	if (dev->msix_enabled)
404		xen_pci_frontend_disable_msix(dev);
405	else
406		xen_pci_frontend_disable_msi(dev);
407
408	xen_teardown_msi_irqs(dev);
409}
410
411static int xen_msi_domain_alloc_irqs(struct irq_domain *domain,
412				     struct device *dev,  int nvec)
413{
414	int type;
415
416	if (WARN_ON_ONCE(!dev_is_pci(dev)))
417		return -EINVAL;
418
419	type = to_pci_dev(dev)->msix_enabled ? PCI_CAP_ID_MSIX : PCI_CAP_ID_MSI;
420
421	return xen_msi_ops.setup_msi_irqs(to_pci_dev(dev), nvec, type);
422}
423
424static void xen_msi_domain_free_irqs(struct irq_domain *domain,
425				     struct device *dev)
426{
427	if (WARN_ON_ONCE(!dev_is_pci(dev)))
428		return;
429
430	xen_msi_ops.teardown_msi_irqs(to_pci_dev(dev));
431}
432
433static struct msi_domain_ops xen_pci_msi_domain_ops = {
434	.domain_alloc_irqs	= xen_msi_domain_alloc_irqs,
435	.domain_free_irqs	= xen_msi_domain_free_irqs,
436};
437
438static struct msi_domain_info xen_pci_msi_domain_info = {
439	.flags			= MSI_FLAG_PCI_MSIX | MSI_FLAG_FREE_MSI_DESCS | MSI_FLAG_DEV_SYSFS,
440	.ops			= &xen_pci_msi_domain_ops,
441};
442
443/*
444 * This irq domain is a blatant violation of the irq domain design, but
445 * distangling XEN into real irq domains is not a job for mere mortals with
446 * limited XENology. But it's the least dangerous way for a mere mortal to
447 * get rid of the arch_*_msi_irqs() hackery in order to store the irq
448 * domain pointer in struct device. This irq domain wrappery allows to do
449 * that without breaking XEN terminally.
450 */
451static __init struct irq_domain *xen_create_pci_msi_domain(void)
452{
453	struct irq_domain *d = NULL;
454	struct fwnode_handle *fn;
455
456	fn = irq_domain_alloc_named_fwnode("XEN-MSI");
457	if (fn)
458		d = msi_create_irq_domain(fn, &xen_pci_msi_domain_info, NULL);
459
460	/* FIXME: No idea how to survive if this fails */
461	BUG_ON(!d);
462
463	return d;
464}
465
466static __init void xen_setup_pci_msi(void)
467{
468	if (xen_pv_domain()) {
469		if (xen_initial_domain())
470			xen_msi_ops.setup_msi_irqs = xen_initdom_setup_msi_irqs;
471		else
472			xen_msi_ops.setup_msi_irqs = xen_setup_msi_irqs;
473		xen_msi_ops.teardown_msi_irqs = xen_pv_teardown_msi_irqs;
474	} else if (xen_hvm_domain()) {
475		xen_msi_ops.setup_msi_irqs = xen_hvm_setup_msi_irqs;
476		xen_msi_ops.teardown_msi_irqs = xen_teardown_msi_irqs;
477	} else {
478		WARN_ON_ONCE(1);
479		return;
480	}
481
482	/*
483	 * Override the PCI/MSI irq domain init function. No point
484	 * in allocating the native domain and never use it.
485	 */
486	x86_init.irqs.create_pci_msi_domain = xen_create_pci_msi_domain;
487	/*
488	 * With XEN PIRQ/Eventchannels in use PCI/MSI[-X] masking is solely
489	 * controlled by the hypervisor.
490	 */
491	pci_msi_ignore_mask = 1;
492}
493
494#else /* CONFIG_PCI_MSI */
495static inline void xen_setup_pci_msi(void) { }
496#endif /* CONFIG_PCI_MSI */
497
498int __init pci_xen_init(void)
499{
500	if (!xen_pv_domain() || xen_initial_domain())
501		return -ENODEV;
502
503	printk(KERN_INFO "PCI: setting up Xen PCI frontend stub\n");
504
505	pcibios_set_cache_line_size();
506
507	pcibios_enable_irq = xen_pcifront_enable_irq;
508	pcibios_disable_irq = NULL;
509
510	/* Keep ACPI out of the picture */
511	acpi_noirq_set();
512
513	xen_setup_pci_msi();
514	return 0;
515}
516
517#ifdef CONFIG_PCI_MSI
518static void __init xen_hvm_msi_init(void)
519{
520	if (!apic_is_disabled) {
521		/*
522		 * If hardware supports (x2)APIC virtualization (as indicated
523		 * by hypervisor's leaf 4) then we don't need to use pirqs/
524		 * event channels for MSI handling and instead use regular
525		 * APIC processing
526		 */
527		uint32_t eax = cpuid_eax(xen_cpuid_base() + 4);
528
529		if (((eax & XEN_HVM_CPUID_X2APIC_VIRT) && x2apic_mode) ||
530		    ((eax & XEN_HVM_CPUID_APIC_ACCESS_VIRT) && boot_cpu_has(X86_FEATURE_APIC)))
531			return;
532	}
533	xen_setup_pci_msi();
534}
535#endif
536
537int __init pci_xen_hvm_init(void)
538{
539	if (!xen_have_vector_callback || !xen_feature(XENFEAT_hvm_pirqs))
540		return 0;
541
542#ifdef CONFIG_ACPI
543	/*
544	 * We don't want to change the actual ACPI delivery model,
545	 * just how GSIs get registered.
546	 */
547	__acpi_register_gsi = acpi_register_gsi_xen_hvm;
548	__acpi_unregister_gsi = NULL;
549#endif
550
551#ifdef CONFIG_PCI_MSI
552	/*
553	 * We need to wait until after x2apic is initialized
554	 * before we can set MSI IRQ ops.
555	 */
556	x86_platform.apic_post_init = xen_hvm_msi_init;
557#endif
558	return 0;
559}
560
561#ifdef CONFIG_XEN_PV_DOM0
562int __init pci_xen_initial_domain(void)
563{
564	int irq;
565
566	xen_setup_pci_msi();
567	__acpi_register_gsi = acpi_register_gsi_xen;
568	__acpi_unregister_gsi = NULL;
569	/*
570	 * Pre-allocate the legacy IRQs.  Use NR_LEGACY_IRQS here
571	 * because we don't have a PIC and thus nr_legacy_irqs() is zero.
572	 */
573	for (irq = 0; irq < NR_IRQS_LEGACY; irq++) {
574		int trigger, polarity;
575
576		if (acpi_get_override_irq(irq, &trigger, &polarity) == -1)
577			continue;
578
579		xen_register_pirq(irq,
580			trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE,
581			true /* Map GSI to PIRQ */);
582	}
583	if (0 == nr_ioapics) {
584		for (irq = 0; irq < nr_legacy_irqs(); irq++)
585			xen_bind_pirq_gsi_to_irq(irq, irq, 0, "xt-pic");
586	}
587	return 0;
588}
589#endif
590
v6.2
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Xen PCI - handle PCI (INTx) and MSI infrastructure calls for PV, HVM and
  4 * initial domain support. We also handle the DSDT _PRT callbacks for GSI's
  5 * used in HVM and initial domain mode (PV does not parse ACPI, so it has no
  6 * concept of GSIs). Under PV we hook under the pnbbios API for IRQs and
  7 * 0xcf8 PCI configuration read/write.
  8 *
  9 *   Author: Ryan Wilson <hap9@epoch.ncsc.mil>
 10 *           Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
 11 *           Stefano Stabellini <stefano.stabellini@eu.citrix.com>
 12 */
 13#include <linux/export.h>
 14#include <linux/init.h>
 15#include <linux/pci.h>
 16#include <linux/acpi.h>
 17
 18#include <linux/io.h>
 19#include <asm/io_apic.h>
 20#include <asm/pci_x86.h>
 21
 22#include <asm/xen/hypervisor.h>
 23
 24#include <xen/features.h>
 25#include <xen/events.h>
 26#include <xen/pci.h>
 27#include <asm/xen/pci.h>
 28#include <asm/xen/cpuid.h>
 29#include <asm/apic.h>
 30#include <asm/acpi.h>
 31#include <asm/i8259.h>
 32
 33static int xen_pcifront_enable_irq(struct pci_dev *dev)
 34{
 35	int rc;
 36	int share = 1;
 37	int pirq;
 38	u8 gsi;
 39
 40	rc = pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &gsi);
 41	if (rc < 0) {
 42		dev_warn(&dev->dev, "Xen PCI: failed to read interrupt line: %d\n",
 43			 rc);
 44		return rc;
 45	}
 46	/* In PV DomU the Xen PCI backend puts the PIRQ in the interrupt line.*/
 47	pirq = gsi;
 48
 49	if (gsi < nr_legacy_irqs())
 50		share = 0;
 51
 52	rc = xen_bind_pirq_gsi_to_irq(gsi, pirq, share, "pcifront");
 53	if (rc < 0) {
 54		dev_warn(&dev->dev, "Xen PCI: failed to bind GSI%d (PIRQ%d) to IRQ: %d\n",
 55			 gsi, pirq, rc);
 56		return rc;
 57	}
 58
 59	dev->irq = rc;
 60	dev_info(&dev->dev, "Xen PCI mapped GSI%d to IRQ%d\n", gsi, dev->irq);
 61	return 0;
 62}
 63
 64#ifdef CONFIG_ACPI
 65static int xen_register_pirq(u32 gsi, int triggering, bool set_pirq)
 66{
 67	int rc, pirq = -1, irq;
 68	struct physdev_map_pirq map_irq;
 69	int shareable = 0;
 70	char *name;
 71
 72	irq = xen_irq_from_gsi(gsi);
 73	if (irq > 0)
 74		return irq;
 75
 76	if (set_pirq)
 77		pirq = gsi;
 78
 79	map_irq.domid = DOMID_SELF;
 80	map_irq.type = MAP_PIRQ_TYPE_GSI;
 81	map_irq.index = gsi;
 82	map_irq.pirq = pirq;
 83
 84	rc = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq, &map_irq);
 85	if (rc) {
 86		printk(KERN_WARNING "xen map irq failed %d\n", rc);
 87		return -1;
 88	}
 89
 90	if (triggering == ACPI_EDGE_SENSITIVE) {
 91		shareable = 0;
 92		name = "ioapic-edge";
 93	} else {
 94		shareable = 1;
 95		name = "ioapic-level";
 96	}
 97
 98	irq = xen_bind_pirq_gsi_to_irq(gsi, map_irq.pirq, shareable, name);
 99	if (irq < 0)
100		goto out;
101
102	printk(KERN_DEBUG "xen: --> pirq=%d -> irq=%d (gsi=%d)\n", map_irq.pirq, irq, gsi);
103out:
104	return irq;
105}
106
107static int acpi_register_gsi_xen_hvm(struct device *dev, u32 gsi,
108				     int trigger, int polarity)
109{
110	if (!xen_hvm_domain())
111		return -1;
112
113	return xen_register_pirq(gsi, trigger,
114				 false /* no mapping of GSI to PIRQ */);
115}
116
117#ifdef CONFIG_XEN_PV_DOM0
118static int xen_register_gsi(u32 gsi, int triggering, int polarity)
119{
120	int rc, irq;
121	struct physdev_setup_gsi setup_gsi;
122
123	if (!xen_pv_domain())
124		return -1;
125
126	printk(KERN_DEBUG "xen: registering gsi %u triggering %d polarity %d\n",
127			gsi, triggering, polarity);
128
129	irq = xen_register_pirq(gsi, triggering, true);
130
131	setup_gsi.gsi = gsi;
132	setup_gsi.triggering = (triggering == ACPI_EDGE_SENSITIVE ? 0 : 1);
133	setup_gsi.polarity = (polarity == ACPI_ACTIVE_HIGH ? 0 : 1);
134
135	rc = HYPERVISOR_physdev_op(PHYSDEVOP_setup_gsi, &setup_gsi);
136	if (rc == -EEXIST)
137		printk(KERN_INFO "Already setup the GSI :%d\n", gsi);
138	else if (rc) {
139		printk(KERN_ERR "Failed to setup GSI :%d, err_code:%d\n",
140				gsi, rc);
141	}
142
143	return irq;
144}
145
146static int acpi_register_gsi_xen(struct device *dev, u32 gsi,
147				 int trigger, int polarity)
148{
149	return xen_register_gsi(gsi, trigger, polarity);
150}
151#endif
152#endif
153
154#if defined(CONFIG_PCI_MSI)
155#include <linux/msi.h>
156
157struct xen_pci_frontend_ops *xen_pci_frontend;
158EXPORT_SYMBOL_GPL(xen_pci_frontend);
159
160struct xen_msi_ops {
161	int (*setup_msi_irqs)(struct pci_dev *dev, int nvec, int type);
162	void (*teardown_msi_irqs)(struct pci_dev *dev);
163};
164
165static struct xen_msi_ops xen_msi_ops __ro_after_init;
166
167static int xen_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
168{
169	int irq, ret, i;
170	struct msi_desc *msidesc;
171	int *v;
172
173	if (type == PCI_CAP_ID_MSI && nvec > 1)
174		return 1;
175
176	v = kcalloc(max(1, nvec), sizeof(int), GFP_KERNEL);
177	if (!v)
178		return -ENOMEM;
179
180	if (type == PCI_CAP_ID_MSIX)
181		ret = xen_pci_frontend_enable_msix(dev, v, nvec);
182	else
183		ret = xen_pci_frontend_enable_msi(dev, v);
184	if (ret)
185		goto error;
186	i = 0;
187	msi_for_each_desc(msidesc, &dev->dev, MSI_DESC_NOTASSOCIATED) {
188		irq = xen_bind_pirq_msi_to_irq(dev, msidesc, v[i],
189					       (type == PCI_CAP_ID_MSI) ? nvec : 1,
190					       (type == PCI_CAP_ID_MSIX) ?
191					       "pcifront-msi-x" :
192					       "pcifront-msi",
193						DOMID_SELF);
194		if (irq < 0) {
195			ret = irq;
196			goto free;
197		}
198		i++;
199	}
200	kfree(v);
201	return 0;
202
203error:
204	if (ret == -ENOSYS)
205		dev_err(&dev->dev, "Xen PCI frontend has not registered MSI/MSI-X support!\n");
206	else if (ret)
207		dev_err(&dev->dev, "Xen PCI frontend error: %d!\n", ret);
208free:
209	kfree(v);
210	return ret;
211}
212
213static void xen_msi_compose_msg(struct pci_dev *pdev, unsigned int pirq,
214		struct msi_msg *msg)
215{
216	/*
217	 * We set vector == 0 to tell the hypervisor we don't care about
218	 * it, but we want a pirq setup instead.  We use the dest_id fields
219	 * to pass the pirq that we want.
220	 */
221	memset(msg, 0, sizeof(*msg));
222	msg->address_hi = X86_MSI_BASE_ADDRESS_HIGH;
223	msg->arch_addr_hi.destid_8_31 = pirq >> 8;
224	msg->arch_addr_lo.destid_0_7 = pirq & 0xFF;
225	msg->arch_addr_lo.base_address = X86_MSI_BASE_ADDRESS_LOW;
226	msg->arch_data.delivery_mode = APIC_DELIVERY_MODE_EXTINT;
227}
228
229static int xen_hvm_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
230{
231	int irq, pirq;
232	struct msi_desc *msidesc;
233	struct msi_msg msg;
234
235	if (type == PCI_CAP_ID_MSI && nvec > 1)
236		return 1;
237
238	msi_for_each_desc(msidesc, &dev->dev, MSI_DESC_NOTASSOCIATED) {
239		pirq = xen_allocate_pirq_msi(dev, msidesc);
240		if (pirq < 0) {
241			irq = -ENODEV;
242			goto error;
243		}
244		xen_msi_compose_msg(dev, pirq, &msg);
245		__pci_write_msi_msg(msidesc, &msg);
246		dev_dbg(&dev->dev, "xen: msi bound to pirq=%d\n", pirq);
247		irq = xen_bind_pirq_msi_to_irq(dev, msidesc, pirq,
248					       (type == PCI_CAP_ID_MSI) ? nvec : 1,
249					       (type == PCI_CAP_ID_MSIX) ?
250					       "msi-x" : "msi",
251					       DOMID_SELF);
252		if (irq < 0)
253			goto error;
254		dev_dbg(&dev->dev,
255			"xen: msi --> pirq=%d --> irq=%d\n", pirq, irq);
256	}
257	return 0;
258
259error:
260	dev_err(&dev->dev, "Failed to create MSI%s! ret=%d!\n",
261		type == PCI_CAP_ID_MSI ? "" : "-X", irq);
262	return irq;
263}
264
265#ifdef CONFIG_XEN_PV_DOM0
266static bool __read_mostly pci_seg_supported = true;
267
268static int xen_initdom_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
269{
270	int ret = 0;
271	struct msi_desc *msidesc;
272
273	msi_for_each_desc(msidesc, &dev->dev, MSI_DESC_NOTASSOCIATED) {
274		struct physdev_map_pirq map_irq;
275		domid_t domid;
276
277		domid = ret = xen_find_device_domain_owner(dev);
278		/* N.B. Casting int's -ENODEV to uint16_t results in 0xFFED,
279		 * hence check ret value for < 0. */
280		if (ret < 0)
281			domid = DOMID_SELF;
282
283		memset(&map_irq, 0, sizeof(map_irq));
284		map_irq.domid = domid;
285		map_irq.type = MAP_PIRQ_TYPE_MSI_SEG;
286		map_irq.index = -1;
287		map_irq.pirq = -1;
288		map_irq.bus = dev->bus->number |
289			      (pci_domain_nr(dev->bus) << 16);
290		map_irq.devfn = dev->devfn;
291
292		if (type == PCI_CAP_ID_MSI && nvec > 1) {
293			map_irq.type = MAP_PIRQ_TYPE_MULTI_MSI;
294			map_irq.entry_nr = nvec;
295		} else if (type == PCI_CAP_ID_MSIX) {
296			int pos;
297			unsigned long flags;
298			u32 table_offset, bir;
299
300			pos = dev->msix_cap;
301			pci_read_config_dword(dev, pos + PCI_MSIX_TABLE,
302					      &table_offset);
303			bir = (u8)(table_offset & PCI_MSIX_TABLE_BIR);
304			flags = pci_resource_flags(dev, bir);
305			if (!flags || (flags & IORESOURCE_UNSET))
306				return -EINVAL;
307
308			map_irq.table_base = pci_resource_start(dev, bir);
309			map_irq.entry_nr = msidesc->msi_index;
310		}
311
312		ret = -EINVAL;
313		if (pci_seg_supported)
314			ret = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq,
315						    &map_irq);
316		if (type == PCI_CAP_ID_MSI && nvec > 1 && ret) {
317			/*
318			 * If MAP_PIRQ_TYPE_MULTI_MSI is not available
319			 * there's nothing else we can do in this case.
320			 * Just set ret > 0 so driver can retry with
321			 * single MSI.
322			 */
323			ret = 1;
324			goto out;
325		}
326		if (ret == -EINVAL && !pci_domain_nr(dev->bus)) {
327			map_irq.type = MAP_PIRQ_TYPE_MSI;
328			map_irq.index = -1;
329			map_irq.pirq = -1;
330			map_irq.bus = dev->bus->number;
331			ret = HYPERVISOR_physdev_op(PHYSDEVOP_map_pirq,
332						    &map_irq);
333			if (ret != -EINVAL)
334				pci_seg_supported = false;
335		}
336		if (ret) {
337			dev_warn(&dev->dev, "xen map irq failed %d for %d domain\n",
338				 ret, domid);
339			goto out;
340		}
341
342		ret = xen_bind_pirq_msi_to_irq(dev, msidesc, map_irq.pirq,
343		                               (type == PCI_CAP_ID_MSI) ? nvec : 1,
344		                               (type == PCI_CAP_ID_MSIX) ? "msi-x" : "msi",
345		                               domid);
346		if (ret < 0)
347			goto out;
348	}
349	ret = 0;
350out:
351	return ret;
352}
353
354bool xen_initdom_restore_msi(struct pci_dev *dev)
355{
356	int ret = 0;
357
358	if (!xen_initial_domain())
359		return true;
360
361	if (pci_seg_supported) {
362		struct physdev_pci_device restore_ext;
363
364		restore_ext.seg = pci_domain_nr(dev->bus);
365		restore_ext.bus = dev->bus->number;
366		restore_ext.devfn = dev->devfn;
367		ret = HYPERVISOR_physdev_op(PHYSDEVOP_restore_msi_ext,
368					&restore_ext);
369		if (ret == -ENOSYS)
370			pci_seg_supported = false;
371		WARN(ret && ret != -ENOSYS, "restore_msi_ext -> %d\n", ret);
372	}
373	if (!pci_seg_supported) {
374		struct physdev_restore_msi restore;
375
376		restore.bus = dev->bus->number;
377		restore.devfn = dev->devfn;
378		ret = HYPERVISOR_physdev_op(PHYSDEVOP_restore_msi, &restore);
379		WARN(ret && ret != -ENOSYS, "restore_msi -> %d\n", ret);
380	}
381	return false;
382}
383#else /* CONFIG_XEN_PV_DOM0 */
384#define xen_initdom_setup_msi_irqs	NULL
385#endif /* !CONFIG_XEN_PV_DOM0 */
386
387static void xen_teardown_msi_irqs(struct pci_dev *dev)
388{
389	struct msi_desc *msidesc;
390	int i;
391
392	msi_for_each_desc(msidesc, &dev->dev, MSI_DESC_ASSOCIATED) {
393		for (i = 0; i < msidesc->nvec_used; i++)
394			xen_destroy_irq(msidesc->irq + i);
395		msidesc->irq = 0;
396	}
 
 
397}
398
399static void xen_pv_teardown_msi_irqs(struct pci_dev *dev)
400{
401	if (dev->msix_enabled)
402		xen_pci_frontend_disable_msix(dev);
403	else
404		xen_pci_frontend_disable_msi(dev);
405
406	xen_teardown_msi_irqs(dev);
407}
408
409static int xen_msi_domain_alloc_irqs(struct irq_domain *domain,
410				     struct device *dev,  int nvec)
411{
412	int type;
413
414	if (WARN_ON_ONCE(!dev_is_pci(dev)))
415		return -EINVAL;
416
417	type = to_pci_dev(dev)->msix_enabled ? PCI_CAP_ID_MSIX : PCI_CAP_ID_MSI;
418
419	return xen_msi_ops.setup_msi_irqs(to_pci_dev(dev), nvec, type);
420}
421
422static void xen_msi_domain_free_irqs(struct irq_domain *domain,
423				     struct device *dev)
424{
425	if (WARN_ON_ONCE(!dev_is_pci(dev)))
426		return;
427
428	xen_msi_ops.teardown_msi_irqs(to_pci_dev(dev));
429}
430
431static struct msi_domain_ops xen_pci_msi_domain_ops = {
432	.domain_alloc_irqs	= xen_msi_domain_alloc_irqs,
433	.domain_free_irqs	= xen_msi_domain_free_irqs,
434};
435
436static struct msi_domain_info xen_pci_msi_domain_info = {
437	.flags			= MSI_FLAG_PCI_MSIX | MSI_FLAG_FREE_MSI_DESCS | MSI_FLAG_DEV_SYSFS,
438	.ops			= &xen_pci_msi_domain_ops,
439};
440
441/*
442 * This irq domain is a blatant violation of the irq domain design, but
443 * distangling XEN into real irq domains is not a job for mere mortals with
444 * limited XENology. But it's the least dangerous way for a mere mortal to
445 * get rid of the arch_*_msi_irqs() hackery in order to store the irq
446 * domain pointer in struct device. This irq domain wrappery allows to do
447 * that without breaking XEN terminally.
448 */
449static __init struct irq_domain *xen_create_pci_msi_domain(void)
450{
451	struct irq_domain *d = NULL;
452	struct fwnode_handle *fn;
453
454	fn = irq_domain_alloc_named_fwnode("XEN-MSI");
455	if (fn)
456		d = msi_create_irq_domain(fn, &xen_pci_msi_domain_info, NULL);
457
458	/* FIXME: No idea how to survive if this fails */
459	BUG_ON(!d);
460
461	return d;
462}
463
464static __init void xen_setup_pci_msi(void)
465{
466	if (xen_pv_domain()) {
467		if (xen_initial_domain())
468			xen_msi_ops.setup_msi_irqs = xen_initdom_setup_msi_irqs;
469		else
470			xen_msi_ops.setup_msi_irqs = xen_setup_msi_irqs;
471		xen_msi_ops.teardown_msi_irqs = xen_pv_teardown_msi_irqs;
472	} else if (xen_hvm_domain()) {
473		xen_msi_ops.setup_msi_irqs = xen_hvm_setup_msi_irqs;
474		xen_msi_ops.teardown_msi_irqs = xen_teardown_msi_irqs;
475	} else {
476		WARN_ON_ONCE(1);
477		return;
478	}
479
480	/*
481	 * Override the PCI/MSI irq domain init function. No point
482	 * in allocating the native domain and never use it.
483	 */
484	x86_init.irqs.create_pci_msi_domain = xen_create_pci_msi_domain;
485	/*
486	 * With XEN PIRQ/Eventchannels in use PCI/MSI[-X] masking is solely
487	 * controlled by the hypervisor.
488	 */
489	pci_msi_ignore_mask = 1;
490}
491
492#else /* CONFIG_PCI_MSI */
493static inline void xen_setup_pci_msi(void) { }
494#endif /* CONFIG_PCI_MSI */
495
496int __init pci_xen_init(void)
497{
498	if (!xen_pv_domain() || xen_initial_domain())
499		return -ENODEV;
500
501	printk(KERN_INFO "PCI: setting up Xen PCI frontend stub\n");
502
503	pcibios_set_cache_line_size();
504
505	pcibios_enable_irq = xen_pcifront_enable_irq;
506	pcibios_disable_irq = NULL;
507
508	/* Keep ACPI out of the picture */
509	acpi_noirq_set();
510
511	xen_setup_pci_msi();
512	return 0;
513}
514
515#ifdef CONFIG_PCI_MSI
516static void __init xen_hvm_msi_init(void)
517{
518	if (!disable_apic) {
519		/*
520		 * If hardware supports (x2)APIC virtualization (as indicated
521		 * by hypervisor's leaf 4) then we don't need to use pirqs/
522		 * event channels for MSI handling and instead use regular
523		 * APIC processing
524		 */
525		uint32_t eax = cpuid_eax(xen_cpuid_base() + 4);
526
527		if (((eax & XEN_HVM_CPUID_X2APIC_VIRT) && x2apic_mode) ||
528		    ((eax & XEN_HVM_CPUID_APIC_ACCESS_VIRT) && boot_cpu_has(X86_FEATURE_APIC)))
529			return;
530	}
531	xen_setup_pci_msi();
532}
533#endif
534
535int __init pci_xen_hvm_init(void)
536{
537	if (!xen_have_vector_callback || !xen_feature(XENFEAT_hvm_pirqs))
538		return 0;
539
540#ifdef CONFIG_ACPI
541	/*
542	 * We don't want to change the actual ACPI delivery model,
543	 * just how GSIs get registered.
544	 */
545	__acpi_register_gsi = acpi_register_gsi_xen_hvm;
546	__acpi_unregister_gsi = NULL;
547#endif
548
549#ifdef CONFIG_PCI_MSI
550	/*
551	 * We need to wait until after x2apic is initialized
552	 * before we can set MSI IRQ ops.
553	 */
554	x86_platform.apic_post_init = xen_hvm_msi_init;
555#endif
556	return 0;
557}
558
559#ifdef CONFIG_XEN_PV_DOM0
560int __init pci_xen_initial_domain(void)
561{
562	int irq;
563
564	xen_setup_pci_msi();
565	__acpi_register_gsi = acpi_register_gsi_xen;
566	__acpi_unregister_gsi = NULL;
567	/*
568	 * Pre-allocate the legacy IRQs.  Use NR_LEGACY_IRQS here
569	 * because we don't have a PIC and thus nr_legacy_irqs() is zero.
570	 */
571	for (irq = 0; irq < NR_IRQS_LEGACY; irq++) {
572		int trigger, polarity;
573
574		if (acpi_get_override_irq(irq, &trigger, &polarity) == -1)
575			continue;
576
577		xen_register_pirq(irq,
578			trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE,
579			true /* Map GSI to PIRQ */);
580	}
581	if (0 == nr_ioapics) {
582		for (irq = 0; irq < nr_legacy_irqs(); irq++)
583			xen_bind_pirq_gsi_to_irq(irq, irq, 0, "xt-pic");
584	}
585	return 0;
586}
587#endif
588