• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
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 struct irq_domain *x86_pci_msi_default_domain __ro_after_init;
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 
x86_vector_msi_compose_msg(struct irq_data * data,struct msi_msg * msg)48 void x86_vector_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
121 	 * common_interrupt().
122 	 *
123 	 * This requires to hold vector lock to prevent concurrent updates to
124 	 * the affected vector.
125 	 */
126 	lock_vector_lock();
127 
128 	/*
129 	 * Mark the new target vector on the local CPU if it is currently
130 	 * unused. Reuse the VECTOR_RETRIGGERED state which is also used in
131 	 * the CPU hotplug path for a similar purpose. This cannot be
132 	 * undone here as the current CPU has interrupts disabled and
133 	 * cannot handle the interrupt before the whole set_affinity()
134 	 * section is done. In the CPU unplug case, the current CPU is
135 	 * about to vanish and will not handle any interrupts anymore. The
136 	 * vector is cleaned up when the CPU comes online again.
137 	 */
138 	if (IS_ERR_OR_NULL(this_cpu_read(vector_irq[cfg->vector])))
139 		this_cpu_write(vector_irq[cfg->vector], VECTOR_RETRIGGERED);
140 
141 	/* Redirect it to the new vector on the local CPU temporarily */
142 	old_cfg.vector = cfg->vector;
143 	irq_msi_update_msg(irqd, &old_cfg);
144 
145 	/* Now transition it to the target CPU */
146 	irq_msi_update_msg(irqd, cfg);
147 
148 	/*
149 	 * All interrupts after this point are now targeted at the new
150 	 * vector/CPU.
151 	 *
152 	 * Drop vector lock before testing whether the temporary assignment
153 	 * to the local CPU was hit by an interrupt raised in the device,
154 	 * because the retrigger function acquires vector lock again.
155 	 */
156 	unlock_vector_lock();
157 
158 	/*
159 	 * Check whether the transition raced with a device interrupt and
160 	 * is pending in the local APICs IRR. It is safe to do this outside
161 	 * of vector lock as the irq_desc::lock of this interrupt is still
162 	 * held and interrupts are disabled: The check is not accessing the
163 	 * underlying vector store. It's just checking the local APIC's
164 	 * IRR.
165 	 */
166 	if (lapic_vector_set_in_irr(cfg->vector))
167 		irq_data_get_irq_chip(irqd)->irq_retrigger(irqd);
168 
169 	return ret;
170 }
171 
172 /*
173  * IRQ Chip for MSI PCI/PCI-X/PCI-Express Devices,
174  * which implement the MSI or MSI-X Capability Structure.
175  */
176 static struct irq_chip pci_msi_controller = {
177 	.name			= "PCI-MSI",
178 	.irq_unmask		= pci_msi_unmask_irq,
179 	.irq_mask		= pci_msi_mask_irq,
180 	.irq_ack		= irq_chip_ack_parent,
181 	.irq_retrigger		= irq_chip_retrigger_hierarchy,
182 	.irq_set_affinity	= msi_set_affinity,
183 	.flags			= IRQCHIP_SKIP_SET_WAKE |
184 				  IRQCHIP_AFFINITY_PRE_STARTUP,
185 };
186 
pci_msi_prepare(struct irq_domain * domain,struct device * dev,int nvec,msi_alloc_info_t * arg)187 int pci_msi_prepare(struct irq_domain *domain, struct device *dev, int nvec,
188 		    msi_alloc_info_t *arg)
189 {
190 	struct pci_dev *pdev = to_pci_dev(dev);
191 	struct msi_desc *desc = first_pci_msi_entry(pdev);
192 
193 	init_irq_alloc_info(arg, NULL);
194 	if (desc->msi_attrib.is_msix) {
195 		arg->type = X86_IRQ_ALLOC_TYPE_PCI_MSIX;
196 	} else {
197 		arg->type = X86_IRQ_ALLOC_TYPE_PCI_MSI;
198 		arg->flags |= X86_IRQ_ALLOC_CONTIGUOUS_VECTORS;
199 	}
200 
201 	return 0;
202 }
203 EXPORT_SYMBOL_GPL(pci_msi_prepare);
204 
205 static struct msi_domain_ops pci_msi_domain_ops = {
206 	.msi_prepare	= pci_msi_prepare,
207 };
208 
209 static struct msi_domain_info pci_msi_domain_info = {
210 	.flags		= MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
211 			  MSI_FLAG_PCI_MSIX,
212 	.ops		= &pci_msi_domain_ops,
213 	.chip		= &pci_msi_controller,
214 	.handler	= handle_edge_irq,
215 	.handler_name	= "edge",
216 };
217 
native_create_pci_msi_domain(void)218 struct irq_domain * __init native_create_pci_msi_domain(void)
219 {
220 	struct fwnode_handle *fn;
221 	struct irq_domain *d;
222 
223 	if (disable_apic)
224 		return NULL;
225 
226 	fn = irq_domain_alloc_named_fwnode("PCI-MSI");
227 	if (!fn)
228 		return NULL;
229 
230 	d = pci_msi_create_irq_domain(fn, &pci_msi_domain_info,
231 				      x86_vector_domain);
232 	if (!d) {
233 		irq_domain_free_fwnode(fn);
234 		pr_warn("Failed to initialize PCI-MSI irqdomain.\n");
235 	} else {
236 		d->flags |= IRQ_DOMAIN_MSI_NOMASK_QUIRK;
237 	}
238 	return d;
239 }
240 
x86_create_pci_msi_domain(void)241 void __init x86_create_pci_msi_domain(void)
242 {
243 	x86_pci_msi_default_domain = x86_init.irqs.create_pci_msi_domain();
244 }
245 
246 #ifdef CONFIG_IRQ_REMAP
247 static struct irq_chip pci_msi_ir_controller = {
248 	.name			= "IR-PCI-MSI",
249 	.irq_unmask		= pci_msi_unmask_irq,
250 	.irq_mask		= pci_msi_mask_irq,
251 	.irq_ack		= irq_chip_ack_parent,
252 	.irq_retrigger		= irq_chip_retrigger_hierarchy,
253 	.flags			= IRQCHIP_SKIP_SET_WAKE |
254 				  IRQCHIP_AFFINITY_PRE_STARTUP,
255 };
256 
257 static struct msi_domain_info pci_msi_ir_domain_info = {
258 	.flags		= MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
259 			  MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX,
260 	.ops		= &pci_msi_domain_ops,
261 	.chip		= &pci_msi_ir_controller,
262 	.handler	= handle_edge_irq,
263 	.handler_name	= "edge",
264 };
265 
arch_create_remap_msi_irq_domain(struct irq_domain * parent,const char * name,int id)266 struct irq_domain *arch_create_remap_msi_irq_domain(struct irq_domain *parent,
267 						    const char *name, int id)
268 {
269 	struct fwnode_handle *fn;
270 	struct irq_domain *d;
271 
272 	fn = irq_domain_alloc_named_id_fwnode(name, id);
273 	if (!fn)
274 		return NULL;
275 	d = pci_msi_create_irq_domain(fn, &pci_msi_ir_domain_info, parent);
276 	if (!d)
277 		irq_domain_free_fwnode(fn);
278 	return d;
279 }
280 #endif
281 
282 #ifdef CONFIG_DMAR_TABLE
dmar_msi_write_msg(struct irq_data * data,struct msi_msg * msg)283 static void dmar_msi_write_msg(struct irq_data *data, struct msi_msg *msg)
284 {
285 	dmar_msi_write(data->irq, msg);
286 }
287 
288 static struct irq_chip dmar_msi_controller = {
289 	.name			= "DMAR-MSI",
290 	.irq_unmask		= dmar_msi_unmask,
291 	.irq_mask		= dmar_msi_mask,
292 	.irq_ack		= irq_chip_ack_parent,
293 	.irq_set_affinity	= msi_domain_set_affinity,
294 	.irq_retrigger		= irq_chip_retrigger_hierarchy,
295 	.irq_write_msi_msg	= dmar_msi_write_msg,
296 	.flags			= IRQCHIP_SKIP_SET_WAKE |
297 				  IRQCHIP_AFFINITY_PRE_STARTUP,
298 };
299 
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)300 static int dmar_msi_init(struct irq_domain *domain,
301 			 struct msi_domain_info *info, unsigned int virq,
302 			 irq_hw_number_t hwirq, msi_alloc_info_t *arg)
303 {
304 	irq_domain_set_info(domain, virq, arg->devid, info->chip, NULL,
305 			    handle_edge_irq, arg->data, "edge");
306 
307 	return 0;
308 }
309 
310 static struct msi_domain_ops dmar_msi_domain_ops = {
311 	.msi_init	= dmar_msi_init,
312 };
313 
314 static struct msi_domain_info dmar_msi_domain_info = {
315 	.ops		= &dmar_msi_domain_ops,
316 	.chip		= &dmar_msi_controller,
317 	.flags		= MSI_FLAG_USE_DEF_DOM_OPS,
318 };
319 
dmar_get_irq_domain(void)320 static struct irq_domain *dmar_get_irq_domain(void)
321 {
322 	static struct irq_domain *dmar_domain;
323 	static DEFINE_MUTEX(dmar_lock);
324 	struct fwnode_handle *fn;
325 
326 	mutex_lock(&dmar_lock);
327 	if (dmar_domain)
328 		goto out;
329 
330 	fn = irq_domain_alloc_named_fwnode("DMAR-MSI");
331 	if (fn) {
332 		dmar_domain = msi_create_irq_domain(fn, &dmar_msi_domain_info,
333 						    x86_vector_domain);
334 		if (!dmar_domain)
335 			irq_domain_free_fwnode(fn);
336 	}
337 out:
338 	mutex_unlock(&dmar_lock);
339 	return dmar_domain;
340 }
341 
dmar_alloc_hwirq(int id,int node,void * arg)342 int dmar_alloc_hwirq(int id, int node, void *arg)
343 {
344 	struct irq_domain *domain = dmar_get_irq_domain();
345 	struct irq_alloc_info info;
346 
347 	if (!domain)
348 		return -1;
349 
350 	init_irq_alloc_info(&info, NULL);
351 	info.type = X86_IRQ_ALLOC_TYPE_DMAR;
352 	info.devid = id;
353 	info.hwirq = id;
354 	info.data = arg;
355 
356 	return irq_domain_alloc_irqs(domain, 1, node, &info);
357 }
358 
dmar_free_hwirq(int irq)359 void dmar_free_hwirq(int irq)
360 {
361 	irq_domain_free_irqs(irq, 1);
362 }
363 #endif
364 
365 /*
366  * MSI message composition
367  */
368 #ifdef CONFIG_HPET_TIMER
hpet_dev_id(struct irq_domain * domain)369 static inline int hpet_dev_id(struct irq_domain *domain)
370 {
371 	struct msi_domain_info *info = msi_get_domain_info(domain);
372 
373 	return (int)(long)info->data;
374 }
375 
hpet_msi_write_msg(struct irq_data * data,struct msi_msg * msg)376 static void hpet_msi_write_msg(struct irq_data *data, struct msi_msg *msg)
377 {
378 	hpet_msi_write(irq_data_get_irq_handler_data(data), msg);
379 }
380 
381 static struct irq_chip hpet_msi_controller __ro_after_init = {
382 	.name = "HPET-MSI",
383 	.irq_unmask = hpet_msi_unmask,
384 	.irq_mask = hpet_msi_mask,
385 	.irq_ack = irq_chip_ack_parent,
386 	.irq_set_affinity = msi_domain_set_affinity,
387 	.irq_retrigger = irq_chip_retrigger_hierarchy,
388 	.irq_write_msi_msg = hpet_msi_write_msg,
389 	.flags = IRQCHIP_SKIP_SET_WAKE | IRQCHIP_AFFINITY_PRE_STARTUP,
390 };
391 
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)392 static int hpet_msi_init(struct irq_domain *domain,
393 			 struct msi_domain_info *info, unsigned int virq,
394 			 irq_hw_number_t hwirq, msi_alloc_info_t *arg)
395 {
396 	irq_set_status_flags(virq, IRQ_MOVE_PCNTXT);
397 	irq_domain_set_info(domain, virq, arg->hwirq, info->chip, NULL,
398 			    handle_edge_irq, arg->data, "edge");
399 
400 	return 0;
401 }
402 
hpet_msi_free(struct irq_domain * domain,struct msi_domain_info * info,unsigned int virq)403 static void hpet_msi_free(struct irq_domain *domain,
404 			  struct msi_domain_info *info, unsigned int virq)
405 {
406 	irq_clear_status_flags(virq, IRQ_MOVE_PCNTXT);
407 }
408 
409 static struct msi_domain_ops hpet_msi_domain_ops = {
410 	.msi_init	= hpet_msi_init,
411 	.msi_free	= hpet_msi_free,
412 };
413 
414 static struct msi_domain_info hpet_msi_domain_info = {
415 	.ops		= &hpet_msi_domain_ops,
416 	.chip		= &hpet_msi_controller,
417 	.flags		= MSI_FLAG_USE_DEF_DOM_OPS,
418 };
419 
hpet_create_irq_domain(int hpet_id)420 struct irq_domain *hpet_create_irq_domain(int hpet_id)
421 {
422 	struct msi_domain_info *domain_info;
423 	struct irq_domain *parent, *d;
424 	struct irq_alloc_info info;
425 	struct fwnode_handle *fn;
426 
427 	if (x86_vector_domain == NULL)
428 		return NULL;
429 
430 	domain_info = kzalloc(sizeof(*domain_info), GFP_KERNEL);
431 	if (!domain_info)
432 		return NULL;
433 
434 	*domain_info = hpet_msi_domain_info;
435 	domain_info->data = (void *)(long)hpet_id;
436 
437 	init_irq_alloc_info(&info, NULL);
438 	info.type = X86_IRQ_ALLOC_TYPE_HPET_GET_PARENT;
439 	info.devid = hpet_id;
440 	parent = irq_remapping_get_irq_domain(&info);
441 	if (parent == NULL)
442 		parent = x86_vector_domain;
443 	else
444 		hpet_msi_controller.name = "IR-HPET-MSI";
445 
446 	fn = irq_domain_alloc_named_id_fwnode(hpet_msi_controller.name,
447 					      hpet_id);
448 	if (!fn) {
449 		kfree(domain_info);
450 		return NULL;
451 	}
452 
453 	d = msi_create_irq_domain(fn, domain_info, parent);
454 	if (!d) {
455 		irq_domain_free_fwnode(fn);
456 		kfree(domain_info);
457 	}
458 	return d;
459 }
460 
hpet_assign_irq(struct irq_domain * domain,struct hpet_channel * hc,int dev_num)461 int hpet_assign_irq(struct irq_domain *domain, struct hpet_channel *hc,
462 		    int dev_num)
463 {
464 	struct irq_alloc_info info;
465 
466 	init_irq_alloc_info(&info, NULL);
467 	info.type = X86_IRQ_ALLOC_TYPE_HPET;
468 	info.data = hc;
469 	info.devid = hpet_dev_id(domain);
470 	info.hwirq = dev_num;
471 
472 	return irq_domain_alloc_irqs(domain, 1, NUMA_NO_NODE, &info);
473 }
474 #endif
475