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/hpet.h>
19 #include <asm/hw_irq.h>
20 #include <asm/apic.h>
21 #include <asm/irq_remapping.h>
22 #include <asm/xen/hypervisor.h>
23
24 struct irq_domain *x86_pci_msi_default_domain __ro_after_init;
25
26 static void irq_msi_update_msg(struct irq_data *irqd, struct irq_cfg *cfg)
27 {
28 struct msi_msg msg[2] = { [1] = { }, };
29
30 __irq_msi_compose_msg(cfg, msg, false);
31 irq_data_get_irq_chip(irqd)->irq_write_msi_msg(irqd, msg);
32 }
33
34 static int
35 msi_set_affinity(struct irq_data *irqd, const struct cpumask *mask, bool force)
36 {
37 struct irq_cfg old_cfg, *cfg = irqd_cfg(irqd);
38 struct irq_data *parent = irqd->parent_data;
39 unsigned int cpu;
40 int ret;
41
42 /* Save the current configuration */
43 cpu = cpumask_first(irq_data_get_effective_affinity_mask(irqd));
44 old_cfg = *cfg;
45
46 /* Allocate a new target vector */
47 ret = parent->chip->irq_set_affinity(parent, mask, force);
48 if (ret < 0 || ret == IRQ_SET_MASK_OK_DONE)
49 return ret;
50
51 /*
52 * For non-maskable and non-remapped MSI interrupts the migration
53 * to a different destination CPU and a different vector has to be
54 * done careful to handle the possible stray interrupt which can be
55 * caused by the non-atomic update of the address/data pair.
56 *
57 * Direct update is possible when:
58 * - The MSI is maskable (remapped MSI does not use this code path).
59 * The reservation mode bit is set in this case.
60 * - The new vector is the same as the old vector
61 * - The old vector is MANAGED_IRQ_SHUTDOWN_VECTOR (interrupt starts up)
62 * - The interrupt is not yet started up
63 * - The new destination CPU is the same as the old destination CPU
64 */
65 if (!irqd_can_reserve(irqd) ||
66 cfg->vector == old_cfg.vector ||
67 old_cfg.vector == MANAGED_IRQ_SHUTDOWN_VECTOR ||
68 !irqd_is_started(irqd) ||
69 cfg->dest_apicid == old_cfg.dest_apicid) {
70 irq_msi_update_msg(irqd, cfg);
71 return ret;
72 }
73
74 /*
75 * Paranoia: Validate that the interrupt target is the local
76 * CPU.
77 */
78 if (WARN_ON_ONCE(cpu != smp_processor_id())) {
79 irq_msi_update_msg(irqd, cfg);
80 return ret;
81 }
82
83 /*
84 * Redirect the interrupt to the new vector on the current CPU
85 * first. This might cause a spurious interrupt on this vector if
86 * the device raises an interrupt right between this update and the
87 * update to the final destination CPU.
88 *
89 * If the vector is in use then the installed device handler will
90 * denote it as spurious which is no harm as this is a rare event
91 * and interrupt handlers have to cope with spurious interrupts
92 * anyway. If the vector is unused, then it is marked so it won't
93 * trigger the 'No irq handler for vector' warning in
94 * common_interrupt().
95 *
96 * This requires to hold vector lock to prevent concurrent updates to
97 * the affected vector.
98 */
99 lock_vector_lock();
100
101 /*
102 * Mark the new target vector on the local CPU if it is currently
103 * unused. Reuse the VECTOR_RETRIGGERED state which is also used in
104 * the CPU hotplug path for a similar purpose. This cannot be
105 * undone here as the current CPU has interrupts disabled and
106 * cannot handle the interrupt before the whole set_affinity()
107 * section is done. In the CPU unplug case, the current CPU is
108 * about to vanish and will not handle any interrupts anymore. The
109 * vector is cleaned up when the CPU comes online again.
110 */
111 if (IS_ERR_OR_NULL(this_cpu_read(vector_irq[cfg->vector])))
112 this_cpu_write(vector_irq[cfg->vector], VECTOR_RETRIGGERED);
113
114 /* Redirect it to the new vector on the local CPU temporarily */
115 old_cfg.vector = cfg->vector;
116 irq_msi_update_msg(irqd, &old_cfg);
117
118 /* Now transition it to the target CPU */
119 irq_msi_update_msg(irqd, cfg);
120
121 /*
122 * All interrupts after this point are now targeted at the new
123 * vector/CPU.
124 *
125 * Drop vector lock before testing whether the temporary assignment
126 * to the local CPU was hit by an interrupt raised in the device,
127 * because the retrigger function acquires vector lock again.
128 */
129 unlock_vector_lock();
130
131 /*
132 * Check whether the transition raced with a device interrupt and
133 * is pending in the local APICs IRR. It is safe to do this outside
134 * of vector lock as the irq_desc::lock of this interrupt is still
135 * held and interrupts are disabled: The check is not accessing the
136 * underlying vector store. It's just checking the local APIC's
137 * IRR.
138 */
139 if (lapic_vector_set_in_irr(cfg->vector))
140 irq_data_get_irq_chip(irqd)->irq_retrigger(irqd);
141
142 return ret;
143 }
144
145 /**
146 * pci_dev_has_default_msi_parent_domain - Check whether the device has the default
147 * MSI parent domain associated
148 * @dev: Pointer to the PCI device
149 */
150 bool pci_dev_has_default_msi_parent_domain(struct pci_dev *dev)
151 {
152 struct irq_domain *domain = dev_get_msi_domain(&dev->dev);
153
154 if (!domain)
155 domain = dev_get_msi_domain(&dev->bus->dev);
156 if (!domain)
157 return false;
158
159 return domain == x86_vector_domain;
160 }
161
162 /**
163 * x86_msi_prepare - Setup of msi_alloc_info_t for allocations
164 * @domain: The domain for which this setup happens
165 * @dev: The device for which interrupts are allocated
166 * @nvec: The number of vectors to allocate
167 * @alloc: The allocation info structure to initialize
168 *
169 * This function is to be used for all types of MSI domains above the x86
170 * vector domain and any intermediates. It is always invoked from the
171 * top level interrupt domain. The domain specific allocation
172 * functionality is determined via the @domain's bus token which allows to
173 * map the X86 specific allocation type.
174 */
175 static int x86_msi_prepare(struct irq_domain *domain, struct device *dev,
176 int nvec, msi_alloc_info_t *alloc)
177 {
178 struct msi_domain_info *info = domain->host_data;
179
180 init_irq_alloc_info(alloc, NULL);
181
182 switch (info->bus_token) {
183 case DOMAIN_BUS_PCI_DEVICE_MSI:
184 alloc->type = X86_IRQ_ALLOC_TYPE_PCI_MSI;
185 return 0;
186 case DOMAIN_BUS_PCI_DEVICE_MSIX:
187 alloc->type = X86_IRQ_ALLOC_TYPE_PCI_MSIX;
188 return 0;
189 default:
190 return -EINVAL;
191 }
192 }
193
194 /**
195 * x86_init_dev_msi_info - Domain info setup for MSI domains
196 * @dev: The device for which the domain should be created
197 * @domain: The (root) domain providing this callback
198 * @real_parent: The real parent domain of the to initialize domain
199 * @info: The domain info for the to initialize domain
200 *
201 * This function is to be used for all types of MSI domains above the x86
202 * vector domain and any intermediates. The domain specific functionality
203 * is determined via the @real_parent.
204 */
205 static bool x86_init_dev_msi_info(struct device *dev, struct irq_domain *domain,
206 struct irq_domain *real_parent, struct msi_domain_info *info)
207 {
208 const struct msi_parent_ops *pops = real_parent->msi_parent_ops;
209
210 /* MSI parent domain specific settings */
211 switch (real_parent->bus_token) {
212 case DOMAIN_BUS_ANY:
213 /* Only the vector domain can have the ANY token */
214 if (WARN_ON_ONCE(domain != real_parent))
215 return false;
216 info->chip->irq_set_affinity = msi_set_affinity;
217 break;
218 case DOMAIN_BUS_DMAR:
219 case DOMAIN_BUS_AMDVI:
220 break;
221 default:
222 WARN_ON_ONCE(1);
223 return false;
224 }
225
226 /* Is the target supported? */
227 switch(info->bus_token) {
228 case DOMAIN_BUS_PCI_DEVICE_MSI:
229 case DOMAIN_BUS_PCI_DEVICE_MSIX:
230 break;
231 default:
232 WARN_ON_ONCE(1);
233 return false;
234 }
235
236 /*
237 * Mask out the domain specific MSI feature flags which are not
238 * supported by the real parent.
239 */
240 info->flags &= pops->supported_flags;
241 /* Enforce the required flags */
242 info->flags |= X86_VECTOR_MSI_FLAGS_REQUIRED;
243
244 /* This is always invoked from the top level MSI domain! */
245 info->ops->msi_prepare = x86_msi_prepare;
246
247 info->chip->irq_ack = irq_chip_ack_parent;
248 info->chip->irq_retrigger = irq_chip_retrigger_hierarchy;
249 info->chip->flags |= IRQCHIP_SKIP_SET_WAKE |
250 IRQCHIP_AFFINITY_PRE_STARTUP;
251
252 info->handler = handle_edge_irq;
253 info->handler_name = "edge";
254
255 return true;
256 }
257
258 static const struct msi_parent_ops x86_vector_msi_parent_ops = {
259 .supported_flags = X86_VECTOR_MSI_FLAGS_SUPPORTED,
260 .init_dev_msi_info = x86_init_dev_msi_info,
261 };
262
263 struct irq_domain * __init native_create_pci_msi_domain(void)
264 {
265 if (apic_is_disabled)
266 return NULL;
267
268 x86_vector_domain->flags |= IRQ_DOMAIN_FLAG_MSI_PARENT;
269 x86_vector_domain->msi_parent_ops = &x86_vector_msi_parent_ops;
270 return x86_vector_domain;
271 }
272
273 void __init x86_create_pci_msi_domain(void)
274 {
275 x86_pci_msi_default_domain = x86_init.irqs.create_pci_msi_domain();
276 }
277
278 /* Keep around for hyperV */
279 int pci_msi_prepare(struct irq_domain *domain, struct device *dev, int nvec,
280 msi_alloc_info_t *arg)
281 {
282 init_irq_alloc_info(arg, NULL);
283
284 if (to_pci_dev(dev)->msix_enabled)
285 arg->type = X86_IRQ_ALLOC_TYPE_PCI_MSIX;
286 else
287 arg->type = X86_IRQ_ALLOC_TYPE_PCI_MSI;
288 return 0;
289 }
290 EXPORT_SYMBOL_GPL(pci_msi_prepare);
291
292 #ifdef CONFIG_DMAR_TABLE
293 /*
294 * The Intel IOMMU (ab)uses the high bits of the MSI address to contain the
295 * high bits of the destination APIC ID. This can't be done in the general
296 * case for MSIs as it would be targeting real memory above 4GiB not the
297 * APIC.
298 */
299 static void dmar_msi_compose_msg(struct irq_data *data, struct msi_msg *msg)
300 {
301 __irq_msi_compose_msg(irqd_cfg(data), msg, true);
302 }
303
304 static void dmar_msi_write_msg(struct irq_data *data, struct msi_msg *msg)
305 {
306 dmar_msi_write(data->irq, msg);
307 }
308
309 static struct irq_chip dmar_msi_controller = {
310 .name = "DMAR-MSI",
311 .irq_unmask = dmar_msi_unmask,
312 .irq_mask = dmar_msi_mask,
313 .irq_ack = irq_chip_ack_parent,
314 .irq_set_affinity = msi_domain_set_affinity,
315 .irq_retrigger = irq_chip_retrigger_hierarchy,
316 .irq_compose_msi_msg = dmar_msi_compose_msg,
317 .irq_write_msi_msg = dmar_msi_write_msg,
318 .flags = IRQCHIP_SKIP_SET_WAKE |
319 IRQCHIP_AFFINITY_PRE_STARTUP,
320 };
321
322 static int dmar_msi_init(struct irq_domain *domain,
323 struct msi_domain_info *info, unsigned int virq,
324 irq_hw_number_t hwirq, msi_alloc_info_t *arg)
325 {
326 irq_domain_set_info(domain, virq, arg->devid, info->chip, NULL,
327 handle_edge_irq, arg->data, "edge");
328
329 return 0;
330 }
331
332 static struct msi_domain_ops dmar_msi_domain_ops = {
333 .msi_init = dmar_msi_init,
334 };
335
336 static struct msi_domain_info dmar_msi_domain_info = {
337 .ops = &dmar_msi_domain_ops,
338 .chip = &dmar_msi_controller,
339 .flags = MSI_FLAG_USE_DEF_DOM_OPS,
340 };
341
342 static struct irq_domain *dmar_get_irq_domain(void)
343 {
344 static struct irq_domain *dmar_domain;
345 static DEFINE_MUTEX(dmar_lock);
346 struct fwnode_handle *fn;
347
348 mutex_lock(&dmar_lock);
349 if (dmar_domain)
350 goto out;
351
352 fn = irq_domain_alloc_named_fwnode("DMAR-MSI");
353 if (fn) {
354 dmar_domain = msi_create_irq_domain(fn, &dmar_msi_domain_info,
355 x86_vector_domain);
356 if (!dmar_domain)
357 irq_domain_free_fwnode(fn);
358 }
359 out:
360 mutex_unlock(&dmar_lock);
361 return dmar_domain;
362 }
363
364 int dmar_alloc_hwirq(int id, int node, void *arg)
365 {
366 struct irq_domain *domain = dmar_get_irq_domain();
367 struct irq_alloc_info info;
368
369 if (!domain)
370 return -1;
371
372 init_irq_alloc_info(&info, NULL);
373 info.type = X86_IRQ_ALLOC_TYPE_DMAR;
374 info.devid = id;
375 info.hwirq = id;
376 info.data = arg;
377
378 return irq_domain_alloc_irqs(domain, 1, node, &info);
379 }
380
381 void dmar_free_hwirq(int irq)
382 {
383 irq_domain_free_irqs(irq, 1);
384 }
385 #endif
386
387 bool arch_restore_msi_irqs(struct pci_dev *dev)
388 {
389 return xen_initdom_restore_msi(dev);
390 }
391
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