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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Support of MSI, HPET and DMAR interrupts.
4  *
5  * Copyright (C) 1997, 1998, 1999, 2000, 2009 Ingo Molnar, Hajnalka Szabo
6  *	Moved from arch/x86/kernel/apic/io_apic.c.
7  * Jiang Liu <jiang.liu@linux.intel.com>
8  *	Convert to hierarchical irqdomain
9  */
10 #include <linux/mm.h>
11 #include <linux/interrupt.h>
12 #include <linux/irq.h>
13 #include <linux/pci.h>
14 #include <linux/dmar.h>
15 #include <linux/hpet.h>
16 #include <linux/msi.h>
17 #include <asm/irqdomain.h>
18 #include <asm/msidef.h>
19 #include <asm/hpet.h>
20 #include <asm/hw_irq.h>
21 #include <asm/apic.h>
22 #include <asm/irq_remapping.h>
23 
24 static struct irq_domain *msi_default_domain;
25 
__irq_msi_compose_msg(struct irq_cfg * cfg,struct msi_msg * msg)26 static void __irq_msi_compose_msg(struct irq_cfg *cfg, struct msi_msg *msg)
27 {
28 	msg->address_hi = MSI_ADDR_BASE_HI;
29 
30 	if (x2apic_enabled())
31 		msg->address_hi |= MSI_ADDR_EXT_DEST_ID(cfg->dest_apicid);
32 
33 	msg->address_lo =
34 		MSI_ADDR_BASE_LO |
35 		((apic->irq_dest_mode == 0) ?
36 			MSI_ADDR_DEST_MODE_PHYSICAL :
37 			MSI_ADDR_DEST_MODE_LOGICAL) |
38 		MSI_ADDR_REDIRECTION_CPU |
39 		MSI_ADDR_DEST_ID(cfg->dest_apicid);
40 
41 	msg->data =
42 		MSI_DATA_TRIGGER_EDGE |
43 		MSI_DATA_LEVEL_ASSERT |
44 		MSI_DATA_DELIVERY_FIXED |
45 		MSI_DATA_VECTOR(cfg->vector);
46 }
47 
irq_msi_compose_msg(struct irq_data * data,struct msi_msg * msg)48 static void irq_msi_compose_msg(struct irq_data *data, struct msi_msg *msg)
49 {
50 	__irq_msi_compose_msg(irqd_cfg(data), msg);
51 }
52 
irq_msi_update_msg(struct irq_data * irqd,struct irq_cfg * cfg)53 static void irq_msi_update_msg(struct irq_data *irqd, struct irq_cfg *cfg)
54 {
55 	struct msi_msg msg[2] = { [1] = { }, };
56 
57 	__irq_msi_compose_msg(cfg, msg);
58 	irq_data_get_irq_chip(irqd)->irq_write_msi_msg(irqd, msg);
59 }
60 
61 static int
msi_set_affinity(struct irq_data * irqd,const struct cpumask * mask,bool force)62 msi_set_affinity(struct irq_data *irqd, const struct cpumask *mask, bool force)
63 {
64 	struct irq_cfg old_cfg, *cfg = irqd_cfg(irqd);
65 	struct irq_data *parent = irqd->parent_data;
66 	unsigned int cpu;
67 	int ret;
68 
69 	/* Save the current configuration */
70 	cpu = cpumask_first(irq_data_get_effective_affinity_mask(irqd));
71 	old_cfg = *cfg;
72 
73 	/* Allocate a new target vector */
74 	ret = parent->chip->irq_set_affinity(parent, mask, force);
75 	if (ret < 0 || ret == IRQ_SET_MASK_OK_DONE)
76 		return ret;
77 
78 	/*
79 	 * For non-maskable and non-remapped MSI interrupts the migration
80 	 * to a different destination CPU and a different vector has to be
81 	 * done careful to handle the possible stray interrupt which can be
82 	 * caused by the non-atomic update of the address/data pair.
83 	 *
84 	 * Direct update is possible when:
85 	 * - The MSI is maskable (remapped MSI does not use this code path)).
86 	 *   The quirk bit is not set in this case.
87 	 * - The new vector is the same as the old vector
88 	 * - The old vector is MANAGED_IRQ_SHUTDOWN_VECTOR (interrupt starts up)
89 	 * - The interrupt is not yet started up
90 	 * - The new destination CPU is the same as the old destination CPU
91 	 */
92 	if (!irqd_msi_nomask_quirk(irqd) ||
93 	    cfg->vector == old_cfg.vector ||
94 	    old_cfg.vector == MANAGED_IRQ_SHUTDOWN_VECTOR ||
95 	    !irqd_is_started(irqd) ||
96 	    cfg->dest_apicid == old_cfg.dest_apicid) {
97 		irq_msi_update_msg(irqd, cfg);
98 		return ret;
99 	}
100 
101 	/*
102 	 * Paranoia: Validate that the interrupt target is the local
103 	 * CPU.
104 	 */
105 	if (WARN_ON_ONCE(cpu != smp_processor_id())) {
106 		irq_msi_update_msg(irqd, cfg);
107 		return ret;
108 	}
109 
110 	/*
111 	 * Redirect the interrupt to the new vector on the current CPU
112 	 * first. This might cause a spurious interrupt on this vector if
113 	 * the device raises an interrupt right between this update and the
114 	 * update to the final destination CPU.
115 	 *
116 	 * If the vector is in use then the installed device handler will
117 	 * denote it as spurious which is no harm as this is a rare event
118 	 * and interrupt handlers have to cope with spurious interrupts
119 	 * anyway. If the vector is unused, then it is marked so it won't
120 	 * trigger the 'No irq handler for vector' warning in do_IRQ().
121 	 *
122 	 * This requires to hold vector lock to prevent concurrent updates to
123 	 * the affected vector.
124 	 */
125 	lock_vector_lock();
126 
127 	/*
128 	 * Mark the new target vector on the local CPU if it is currently
129 	 * unused. Reuse the VECTOR_RETRIGGERED state which is also used in
130 	 * the CPU hotplug path for a similar purpose. This cannot be
131 	 * undone here as the current CPU has interrupts disabled and
132 	 * cannot handle the interrupt before the whole set_affinity()
133 	 * section is done. In the CPU unplug case, the current CPU is
134 	 * about to vanish and will not handle any interrupts anymore. The
135 	 * vector is cleaned up when the CPU comes online again.
136 	 */
137 	if (IS_ERR_OR_NULL(this_cpu_read(vector_irq[cfg->vector])))
138 		this_cpu_write(vector_irq[cfg->vector], VECTOR_RETRIGGERED);
139 
140 	/* Redirect it to the new vector on the local CPU temporarily */
141 	old_cfg.vector = cfg->vector;
142 	irq_msi_update_msg(irqd, &old_cfg);
143 
144 	/* Now transition it to the target CPU */
145 	irq_msi_update_msg(irqd, cfg);
146 
147 	/*
148 	 * All interrupts after this point are now targeted at the new
149 	 * vector/CPU.
150 	 *
151 	 * Drop vector lock before testing whether the temporary assignment
152 	 * to the local CPU was hit by an interrupt raised in the device,
153 	 * because the retrigger function acquires vector lock again.
154 	 */
155 	unlock_vector_lock();
156 
157 	/*
158 	 * Check whether the transition raced with a device interrupt and
159 	 * is pending in the local APICs IRR. It is safe to do this outside
160 	 * of vector lock as the irq_desc::lock of this interrupt is still
161 	 * held and interrupts are disabled: The check is not accessing the
162 	 * underlying vector store. It's just checking the local APIC's
163 	 * IRR.
164 	 */
165 	if (lapic_vector_set_in_irr(cfg->vector))
166 		irq_data_get_irq_chip(irqd)->irq_retrigger(irqd);
167 
168 	return ret;
169 }
170 
171 /*
172  * IRQ Chip for MSI PCI/PCI-X/PCI-Express Devices,
173  * which implement the MSI or MSI-X Capability Structure.
174  */
175 static struct irq_chip pci_msi_controller = {
176 	.name			= "PCI-MSI",
177 	.irq_unmask		= pci_msi_unmask_irq,
178 	.irq_mask		= pci_msi_mask_irq,
179 	.irq_ack		= irq_chip_ack_parent,
180 	.irq_retrigger		= irq_chip_retrigger_hierarchy,
181 	.irq_compose_msi_msg	= irq_msi_compose_msg,
182 	.irq_set_affinity	= msi_set_affinity,
183 	.flags			= IRQCHIP_SKIP_SET_WAKE |
184 				  IRQCHIP_AFFINITY_PRE_STARTUP,
185 };
186 
native_setup_msi_irqs(struct pci_dev * dev,int nvec,int type)187 int native_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
188 {
189 	struct irq_domain *domain;
190 	struct irq_alloc_info info;
191 
192 	init_irq_alloc_info(&info, NULL);
193 	info.type = X86_IRQ_ALLOC_TYPE_MSI;
194 	info.msi_dev = dev;
195 
196 	domain = irq_remapping_get_irq_domain(&info);
197 	if (domain == NULL)
198 		domain = msi_default_domain;
199 	if (domain == NULL)
200 		return -ENOSYS;
201 
202 	return msi_domain_alloc_irqs(domain, &dev->dev, nvec);
203 }
204 
native_teardown_msi_irq(unsigned int irq)205 void native_teardown_msi_irq(unsigned int irq)
206 {
207 	irq_domain_free_irqs(irq, 1);
208 }
209 
pci_msi_get_hwirq(struct msi_domain_info * info,msi_alloc_info_t * arg)210 static irq_hw_number_t pci_msi_get_hwirq(struct msi_domain_info *info,
211 					 msi_alloc_info_t *arg)
212 {
213 	return arg->msi_hwirq;
214 }
215 
pci_msi_prepare(struct irq_domain * domain,struct device * dev,int nvec,msi_alloc_info_t * arg)216 int pci_msi_prepare(struct irq_domain *domain, struct device *dev, int nvec,
217 		    msi_alloc_info_t *arg)
218 {
219 	struct pci_dev *pdev = to_pci_dev(dev);
220 	struct msi_desc *desc = first_pci_msi_entry(pdev);
221 
222 	init_irq_alloc_info(arg, NULL);
223 	arg->msi_dev = pdev;
224 	if (desc->msi_attrib.is_msix) {
225 		arg->type = X86_IRQ_ALLOC_TYPE_MSIX;
226 	} else {
227 		arg->type = X86_IRQ_ALLOC_TYPE_MSI;
228 		arg->flags |= X86_IRQ_ALLOC_CONTIGUOUS_VECTORS;
229 	}
230 
231 	return 0;
232 }
233 EXPORT_SYMBOL_GPL(pci_msi_prepare);
234 
pci_msi_set_desc(msi_alloc_info_t * arg,struct msi_desc * desc)235 void pci_msi_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc)
236 {
237 	arg->msi_hwirq = pci_msi_domain_calc_hwirq(arg->msi_dev, desc);
238 }
239 EXPORT_SYMBOL_GPL(pci_msi_set_desc);
240 
241 static struct msi_domain_ops pci_msi_domain_ops = {
242 	.get_hwirq	= pci_msi_get_hwirq,
243 	.msi_prepare	= pci_msi_prepare,
244 	.set_desc	= pci_msi_set_desc,
245 };
246 
247 static struct msi_domain_info pci_msi_domain_info = {
248 	.flags		= MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
249 			  MSI_FLAG_PCI_MSIX,
250 	.ops		= &pci_msi_domain_ops,
251 	.chip		= &pci_msi_controller,
252 	.handler	= handle_edge_irq,
253 	.handler_name	= "edge",
254 };
255 
arch_init_msi_domain(struct irq_domain * parent)256 void __init arch_init_msi_domain(struct irq_domain *parent)
257 {
258 	struct fwnode_handle *fn;
259 
260 	if (disable_apic)
261 		return;
262 
263 	fn = irq_domain_alloc_named_fwnode("PCI-MSI");
264 	if (fn) {
265 		msi_default_domain =
266 			pci_msi_create_irq_domain(fn, &pci_msi_domain_info,
267 						  parent);
268 	}
269 	if (!msi_default_domain) {
270 		irq_domain_free_fwnode(fn);
271 		pr_warn("failed to initialize irqdomain for MSI/MSI-x.\n");
272 	} else {
273 		msi_default_domain->flags |= IRQ_DOMAIN_MSI_NOMASK_QUIRK;
274 	}
275 }
276 
277 #ifdef CONFIG_IRQ_REMAP
278 static struct irq_chip pci_msi_ir_controller = {
279 	.name			= "IR-PCI-MSI",
280 	.irq_unmask		= pci_msi_unmask_irq,
281 	.irq_mask		= pci_msi_mask_irq,
282 	.irq_ack		= irq_chip_ack_parent,
283 	.irq_retrigger		= irq_chip_retrigger_hierarchy,
284 	.irq_set_vcpu_affinity	= irq_chip_set_vcpu_affinity_parent,
285 	.flags			= IRQCHIP_SKIP_SET_WAKE |
286 				  IRQCHIP_AFFINITY_PRE_STARTUP,
287 };
288 
289 static struct msi_domain_info pci_msi_ir_domain_info = {
290 	.flags		= MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
291 			  MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX,
292 	.ops		= &pci_msi_domain_ops,
293 	.chip		= &pci_msi_ir_controller,
294 	.handler	= handle_edge_irq,
295 	.handler_name	= "edge",
296 };
297 
arch_create_remap_msi_irq_domain(struct irq_domain * parent,const char * name,int id)298 struct irq_domain *arch_create_remap_msi_irq_domain(struct irq_domain *parent,
299 						    const char *name, int id)
300 {
301 	struct fwnode_handle *fn;
302 	struct irq_domain *d;
303 
304 	fn = irq_domain_alloc_named_id_fwnode(name, id);
305 	if (!fn)
306 		return NULL;
307 	d = pci_msi_create_irq_domain(fn, &pci_msi_ir_domain_info, parent);
308 	if (!d)
309 		irq_domain_free_fwnode(fn);
310 	return d;
311 }
312 #endif
313 
314 #ifdef CONFIG_DMAR_TABLE
dmar_msi_write_msg(struct irq_data * data,struct msi_msg * msg)315 static void dmar_msi_write_msg(struct irq_data *data, struct msi_msg *msg)
316 {
317 	dmar_msi_write(data->irq, msg);
318 }
319 
320 static struct irq_chip dmar_msi_controller = {
321 	.name			= "DMAR-MSI",
322 	.irq_unmask		= dmar_msi_unmask,
323 	.irq_mask		= dmar_msi_mask,
324 	.irq_ack		= irq_chip_ack_parent,
325 	.irq_set_affinity	= msi_domain_set_affinity,
326 	.irq_retrigger		= irq_chip_retrigger_hierarchy,
327 	.irq_compose_msi_msg	= irq_msi_compose_msg,
328 	.irq_write_msi_msg	= dmar_msi_write_msg,
329 	.flags			= IRQCHIP_SKIP_SET_WAKE |
330 				  IRQCHIP_AFFINITY_PRE_STARTUP,
331 };
332 
dmar_msi_get_hwirq(struct msi_domain_info * info,msi_alloc_info_t * arg)333 static irq_hw_number_t dmar_msi_get_hwirq(struct msi_domain_info *info,
334 					  msi_alloc_info_t *arg)
335 {
336 	return arg->dmar_id;
337 }
338 
dmar_msi_init(struct irq_domain * domain,struct msi_domain_info * info,unsigned int virq,irq_hw_number_t hwirq,msi_alloc_info_t * arg)339 static int dmar_msi_init(struct irq_domain *domain,
340 			 struct msi_domain_info *info, unsigned int virq,
341 			 irq_hw_number_t hwirq, msi_alloc_info_t *arg)
342 {
343 	irq_domain_set_info(domain, virq, arg->dmar_id, info->chip, NULL,
344 			    handle_edge_irq, arg->dmar_data, "edge");
345 
346 	return 0;
347 }
348 
349 static struct msi_domain_ops dmar_msi_domain_ops = {
350 	.get_hwirq	= dmar_msi_get_hwirq,
351 	.msi_init	= dmar_msi_init,
352 };
353 
354 static struct msi_domain_info dmar_msi_domain_info = {
355 	.ops		= &dmar_msi_domain_ops,
356 	.chip		= &dmar_msi_controller,
357 };
358 
dmar_get_irq_domain(void)359 static struct irq_domain *dmar_get_irq_domain(void)
360 {
361 	static struct irq_domain *dmar_domain;
362 	static DEFINE_MUTEX(dmar_lock);
363 	struct fwnode_handle *fn;
364 
365 	mutex_lock(&dmar_lock);
366 	if (dmar_domain)
367 		goto out;
368 
369 	fn = irq_domain_alloc_named_fwnode("DMAR-MSI");
370 	if (fn) {
371 		dmar_domain = msi_create_irq_domain(fn, &dmar_msi_domain_info,
372 						    x86_vector_domain);
373 		if (!dmar_domain)
374 			irq_domain_free_fwnode(fn);
375 	}
376 out:
377 	mutex_unlock(&dmar_lock);
378 	return dmar_domain;
379 }
380 
dmar_alloc_hwirq(int id,int node,void * arg)381 int dmar_alloc_hwirq(int id, int node, void *arg)
382 {
383 	struct irq_domain *domain = dmar_get_irq_domain();
384 	struct irq_alloc_info info;
385 
386 	if (!domain)
387 		return -1;
388 
389 	init_irq_alloc_info(&info, NULL);
390 	info.type = X86_IRQ_ALLOC_TYPE_DMAR;
391 	info.dmar_id = id;
392 	info.dmar_data = arg;
393 
394 	return irq_domain_alloc_irqs(domain, 1, node, &info);
395 }
396 
dmar_free_hwirq(int irq)397 void dmar_free_hwirq(int irq)
398 {
399 	irq_domain_free_irqs(irq, 1);
400 }
401 #endif
402 
403 /*
404  * MSI message composition
405  */
406 #ifdef CONFIG_HPET_TIMER
hpet_dev_id(struct irq_domain * domain)407 static inline int hpet_dev_id(struct irq_domain *domain)
408 {
409 	struct msi_domain_info *info = msi_get_domain_info(domain);
410 
411 	return (int)(long)info->data;
412 }
413 
hpet_msi_write_msg(struct irq_data * data,struct msi_msg * msg)414 static void hpet_msi_write_msg(struct irq_data *data, struct msi_msg *msg)
415 {
416 	hpet_msi_write(irq_data_get_irq_handler_data(data), msg);
417 }
418 
419 static struct irq_chip hpet_msi_controller __ro_after_init = {
420 	.name = "HPET-MSI",
421 	.irq_unmask = hpet_msi_unmask,
422 	.irq_mask = hpet_msi_mask,
423 	.irq_ack = irq_chip_ack_parent,
424 	.irq_set_affinity = msi_domain_set_affinity,
425 	.irq_retrigger = irq_chip_retrigger_hierarchy,
426 	.irq_compose_msi_msg = irq_msi_compose_msg,
427 	.irq_write_msi_msg = hpet_msi_write_msg,
428 	.flags = IRQCHIP_SKIP_SET_WAKE | IRQCHIP_AFFINITY_PRE_STARTUP,
429 };
430 
hpet_msi_get_hwirq(struct msi_domain_info * info,msi_alloc_info_t * arg)431 static irq_hw_number_t hpet_msi_get_hwirq(struct msi_domain_info *info,
432 					  msi_alloc_info_t *arg)
433 {
434 	return arg->hpet_index;
435 }
436 
hpet_msi_init(struct irq_domain * domain,struct msi_domain_info * info,unsigned int virq,irq_hw_number_t hwirq,msi_alloc_info_t * arg)437 static int hpet_msi_init(struct irq_domain *domain,
438 			 struct msi_domain_info *info, unsigned int virq,
439 			 irq_hw_number_t hwirq, msi_alloc_info_t *arg)
440 {
441 	irq_set_status_flags(virq, IRQ_MOVE_PCNTXT);
442 	irq_domain_set_info(domain, virq, arg->hpet_index, info->chip, NULL,
443 			    handle_edge_irq, arg->hpet_data, "edge");
444 
445 	return 0;
446 }
447 
hpet_msi_free(struct irq_domain * domain,struct msi_domain_info * info,unsigned int virq)448 static void hpet_msi_free(struct irq_domain *domain,
449 			  struct msi_domain_info *info, unsigned int virq)
450 {
451 	irq_clear_status_flags(virq, IRQ_MOVE_PCNTXT);
452 }
453 
454 static struct msi_domain_ops hpet_msi_domain_ops = {
455 	.get_hwirq	= hpet_msi_get_hwirq,
456 	.msi_init	= hpet_msi_init,
457 	.msi_free	= hpet_msi_free,
458 };
459 
460 static struct msi_domain_info hpet_msi_domain_info = {
461 	.ops		= &hpet_msi_domain_ops,
462 	.chip		= &hpet_msi_controller,
463 };
464 
hpet_create_irq_domain(int hpet_id)465 struct irq_domain *hpet_create_irq_domain(int hpet_id)
466 {
467 	struct msi_domain_info *domain_info;
468 	struct irq_domain *parent, *d;
469 	struct irq_alloc_info info;
470 	struct fwnode_handle *fn;
471 
472 	if (x86_vector_domain == NULL)
473 		return NULL;
474 
475 	domain_info = kzalloc(sizeof(*domain_info), GFP_KERNEL);
476 	if (!domain_info)
477 		return NULL;
478 
479 	*domain_info = hpet_msi_domain_info;
480 	domain_info->data = (void *)(long)hpet_id;
481 
482 	init_irq_alloc_info(&info, NULL);
483 	info.type = X86_IRQ_ALLOC_TYPE_HPET;
484 	info.hpet_id = hpet_id;
485 	parent = irq_remapping_get_ir_irq_domain(&info);
486 	if (parent == NULL)
487 		parent = x86_vector_domain;
488 	else
489 		hpet_msi_controller.name = "IR-HPET-MSI";
490 
491 	fn = irq_domain_alloc_named_id_fwnode(hpet_msi_controller.name,
492 					      hpet_id);
493 	if (!fn) {
494 		kfree(domain_info);
495 		return NULL;
496 	}
497 
498 	d = msi_create_irq_domain(fn, domain_info, parent);
499 	if (!d) {
500 		irq_domain_free_fwnode(fn);
501 		kfree(domain_info);
502 	}
503 	return d;
504 }
505 
hpet_assign_irq(struct irq_domain * domain,struct hpet_channel * hc,int dev_num)506 int hpet_assign_irq(struct irq_domain *domain, struct hpet_channel *hc,
507 		    int dev_num)
508 {
509 	struct irq_alloc_info info;
510 
511 	init_irq_alloc_info(&info, NULL);
512 	info.type = X86_IRQ_ALLOC_TYPE_HPET;
513 	info.hpet_data = hc;
514 	info.hpet_id = hpet_dev_id(domain);
515 	info.hpet_index = dev_num;
516 
517 	return irq_domain_alloc_irqs(domain, 1, NUMA_NO_NODE, &info);
518 }
519 #endif
520