xref: /linux/drivers/iommu/intel/dmar.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2006, Intel Corporation.
4  *
5  * Copyright (C) 2006-2008 Intel Corporation
6  * Author: Ashok Raj <ashok.raj@intel.com>
7  * Author: Shaohua Li <shaohua.li@intel.com>
8  * Author: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
9  *
10  * This file implements early detection/parsing of Remapping Devices
11  * reported to OS through BIOS via DMA remapping reporting (DMAR) ACPI
12  * tables.
13  *
14  * These routines are used by both DMA-remapping and Interrupt-remapping
15  */
16 
17 #define pr_fmt(fmt)     "DMAR: " fmt
18 
19 #include <linux/pci.h>
20 #include <linux/dmar.h>
21 #include <linux/iova.h>
22 #include <linux/timer.h>
23 #include <linux/irq.h>
24 #include <linux/interrupt.h>
25 #include <linux/tboot.h>
26 #include <linux/dmi.h>
27 #include <linux/slab.h>
28 #include <linux/iommu.h>
29 #include <linux/numa.h>
30 #include <linux/limits.h>
31 #include <asm/irq_remapping.h>
32 
33 #include "iommu.h"
34 #include "../irq_remapping.h"
35 #include "../iommu-pages.h"
36 #include "perf.h"
37 #include "trace.h"
38 #include "perfmon.h"
39 
40 typedef int (*dmar_res_handler_t)(struct acpi_dmar_header *, void *);
41 struct dmar_res_callback {
42 	dmar_res_handler_t	cb[ACPI_DMAR_TYPE_RESERVED];
43 	void			*arg[ACPI_DMAR_TYPE_RESERVED];
44 	bool			ignore_unhandled;
45 	bool			print_entry;
46 };
47 
48 /*
49  * Assumptions:
50  * 1) The hotplug framework guarentees that DMAR unit will be hot-added
51  *    before IO devices managed by that unit.
52  * 2) The hotplug framework guarantees that DMAR unit will be hot-removed
53  *    after IO devices managed by that unit.
54  * 3) Hotplug events are rare.
55  *
56  * Locking rules for DMA and interrupt remapping related global data structures:
57  * 1) Use dmar_global_lock in process context
58  * 2) Use RCU in interrupt context
59  */
60 DECLARE_RWSEM(dmar_global_lock);
61 LIST_HEAD(dmar_drhd_units);
62 
63 struct acpi_table_header * __initdata dmar_tbl;
64 static int dmar_dev_scope_status = 1;
65 static DEFINE_IDA(dmar_seq_ids);
66 
67 static int alloc_iommu(struct dmar_drhd_unit *drhd);
68 static void free_iommu(struct intel_iommu *iommu);
69 
70 static void dmar_register_drhd_unit(struct dmar_drhd_unit *drhd)
71 {
72 	/*
73 	 * add INCLUDE_ALL at the tail, so scan the list will find it at
74 	 * the very end.
75 	 */
76 	if (drhd->include_all)
77 		list_add_tail_rcu(&drhd->list, &dmar_drhd_units);
78 	else
79 		list_add_rcu(&drhd->list, &dmar_drhd_units);
80 }
81 
82 void *dmar_alloc_dev_scope(void *start, void *end, int *cnt)
83 {
84 	struct acpi_dmar_device_scope *scope;
85 
86 	*cnt = 0;
87 	while (start < end) {
88 		scope = start;
89 		if (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_NAMESPACE ||
90 		    scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT ||
91 		    scope->entry_type == ACPI_DMAR_SCOPE_TYPE_BRIDGE)
92 			(*cnt)++;
93 		else if (scope->entry_type != ACPI_DMAR_SCOPE_TYPE_IOAPIC &&
94 			scope->entry_type != ACPI_DMAR_SCOPE_TYPE_HPET) {
95 			pr_warn("Unsupported device scope\n");
96 		}
97 		start += scope->length;
98 	}
99 	if (*cnt == 0)
100 		return NULL;
101 
102 	return kcalloc(*cnt, sizeof(struct dmar_dev_scope), GFP_KERNEL);
103 }
104 
105 void dmar_free_dev_scope(struct dmar_dev_scope **devices, int *cnt)
106 {
107 	int i;
108 	struct device *tmp_dev;
109 
110 	if (*devices && *cnt) {
111 		for_each_active_dev_scope(*devices, *cnt, i, tmp_dev)
112 			put_device(tmp_dev);
113 		kfree(*devices);
114 	}
115 
116 	*devices = NULL;
117 	*cnt = 0;
118 }
119 
120 /* Optimize out kzalloc()/kfree() for normal cases */
121 static char dmar_pci_notify_info_buf[64];
122 
123 static struct dmar_pci_notify_info *
124 dmar_alloc_pci_notify_info(struct pci_dev *dev, unsigned long event)
125 {
126 	int level = 0;
127 	size_t size;
128 	struct pci_dev *tmp;
129 	struct dmar_pci_notify_info *info;
130 
131 	/*
132 	 * Ignore devices that have a domain number higher than what can
133 	 * be looked up in DMAR, e.g. VMD subdevices with domain 0x10000
134 	 */
135 	if (pci_domain_nr(dev->bus) > U16_MAX)
136 		return NULL;
137 
138 	/* Only generate path[] for device addition event */
139 	if (event == BUS_NOTIFY_ADD_DEVICE)
140 		for (tmp = dev; tmp; tmp = tmp->bus->self)
141 			level++;
142 
143 	size = struct_size(info, path, level);
144 	if (size <= sizeof(dmar_pci_notify_info_buf)) {
145 		info = (struct dmar_pci_notify_info *)dmar_pci_notify_info_buf;
146 	} else {
147 		info = kzalloc(size, GFP_KERNEL);
148 		if (!info) {
149 			if (dmar_dev_scope_status == 0)
150 				dmar_dev_scope_status = -ENOMEM;
151 			return NULL;
152 		}
153 	}
154 
155 	info->event = event;
156 	info->dev = dev;
157 	info->seg = pci_domain_nr(dev->bus);
158 	info->level = level;
159 	if (event == BUS_NOTIFY_ADD_DEVICE) {
160 		for (tmp = dev; tmp; tmp = tmp->bus->self) {
161 			level--;
162 			info->path[level].bus = tmp->bus->number;
163 			info->path[level].device = PCI_SLOT(tmp->devfn);
164 			info->path[level].function = PCI_FUNC(tmp->devfn);
165 			if (pci_is_root_bus(tmp->bus))
166 				info->bus = tmp->bus->number;
167 		}
168 	}
169 
170 	return info;
171 }
172 
173 static inline void dmar_free_pci_notify_info(struct dmar_pci_notify_info *info)
174 {
175 	if ((void *)info != dmar_pci_notify_info_buf)
176 		kfree(info);
177 }
178 
179 static bool dmar_match_pci_path(struct dmar_pci_notify_info *info, int bus,
180 				struct acpi_dmar_pci_path *path, int count)
181 {
182 	int i;
183 
184 	if (info->bus != bus)
185 		goto fallback;
186 	if (info->level != count)
187 		goto fallback;
188 
189 	for (i = 0; i < count; i++) {
190 		if (path[i].device != info->path[i].device ||
191 		    path[i].function != info->path[i].function)
192 			goto fallback;
193 	}
194 
195 	return true;
196 
197 fallback:
198 
199 	if (count != 1)
200 		return false;
201 
202 	i = info->level - 1;
203 	if (bus              == info->path[i].bus &&
204 	    path[0].device   == info->path[i].device &&
205 	    path[0].function == info->path[i].function) {
206 		pr_info(FW_BUG "RMRR entry for device %02x:%02x.%x is broken - applying workaround\n",
207 			bus, path[0].device, path[0].function);
208 		return true;
209 	}
210 
211 	return false;
212 }
213 
214 /* Return: > 0 if match found, 0 if no match found, < 0 if error happens */
215 int dmar_insert_dev_scope(struct dmar_pci_notify_info *info,
216 			  void *start, void*end, u16 segment,
217 			  struct dmar_dev_scope *devices,
218 			  int devices_cnt)
219 {
220 	int i, level;
221 	struct device *tmp, *dev = &info->dev->dev;
222 	struct acpi_dmar_device_scope *scope;
223 	struct acpi_dmar_pci_path *path;
224 
225 	if (segment != info->seg)
226 		return 0;
227 
228 	for (; start < end; start += scope->length) {
229 		scope = start;
230 		if (scope->entry_type != ACPI_DMAR_SCOPE_TYPE_ENDPOINT &&
231 		    scope->entry_type != ACPI_DMAR_SCOPE_TYPE_BRIDGE)
232 			continue;
233 
234 		path = (struct acpi_dmar_pci_path *)(scope + 1);
235 		level = (scope->length - sizeof(*scope)) / sizeof(*path);
236 		if (!dmar_match_pci_path(info, scope->bus, path, level))
237 			continue;
238 
239 		/*
240 		 * We expect devices with endpoint scope to have normal PCI
241 		 * headers, and devices with bridge scope to have bridge PCI
242 		 * headers.  However PCI NTB devices may be listed in the
243 		 * DMAR table with bridge scope, even though they have a
244 		 * normal PCI header.  NTB devices are identified by class
245 		 * "BRIDGE_OTHER" (0680h) - we don't declare a socpe mismatch
246 		 * for this special case.
247 		 */
248 		if ((scope->entry_type == ACPI_DMAR_SCOPE_TYPE_ENDPOINT &&
249 		     info->dev->hdr_type != PCI_HEADER_TYPE_NORMAL) ||
250 		    (scope->entry_type == ACPI_DMAR_SCOPE_TYPE_BRIDGE &&
251 		     (info->dev->hdr_type == PCI_HEADER_TYPE_NORMAL &&
252 		      info->dev->class >> 16 != PCI_BASE_CLASS_BRIDGE))) {
253 			pr_warn("Device scope type does not match for %s\n",
254 				pci_name(info->dev));
255 			return -EINVAL;
256 		}
257 
258 		for_each_dev_scope(devices, devices_cnt, i, tmp)
259 			if (tmp == NULL) {
260 				devices[i].bus = info->dev->bus->number;
261 				devices[i].devfn = info->dev->devfn;
262 				rcu_assign_pointer(devices[i].dev,
263 						   get_device(dev));
264 				return 1;
265 			}
266 		if (WARN_ON(i >= devices_cnt))
267 			return -EINVAL;
268 	}
269 
270 	return 0;
271 }
272 
273 int dmar_remove_dev_scope(struct dmar_pci_notify_info *info, u16 segment,
274 			  struct dmar_dev_scope *devices, int count)
275 {
276 	int index;
277 	struct device *tmp;
278 
279 	if (info->seg != segment)
280 		return 0;
281 
282 	for_each_active_dev_scope(devices, count, index, tmp)
283 		if (tmp == &info->dev->dev) {
284 			RCU_INIT_POINTER(devices[index].dev, NULL);
285 			synchronize_rcu();
286 			put_device(tmp);
287 			return 1;
288 		}
289 
290 	return 0;
291 }
292 
293 static int dmar_pci_bus_add_dev(struct dmar_pci_notify_info *info)
294 {
295 	int ret = 0;
296 	struct dmar_drhd_unit *dmaru;
297 	struct acpi_dmar_hardware_unit *drhd;
298 
299 	for_each_drhd_unit(dmaru) {
300 		if (dmaru->include_all)
301 			continue;
302 
303 		drhd = container_of(dmaru->hdr,
304 				    struct acpi_dmar_hardware_unit, header);
305 		ret = dmar_insert_dev_scope(info, (void *)(drhd + 1),
306 				((void *)drhd) + drhd->header.length,
307 				dmaru->segment,
308 				dmaru->devices, dmaru->devices_cnt);
309 		if (ret)
310 			break;
311 	}
312 	if (ret >= 0)
313 		ret = dmar_iommu_notify_scope_dev(info);
314 	if (ret < 0 && dmar_dev_scope_status == 0)
315 		dmar_dev_scope_status = ret;
316 
317 	if (ret >= 0)
318 		intel_irq_remap_add_device(info);
319 
320 	return ret;
321 }
322 
323 static void  dmar_pci_bus_del_dev(struct dmar_pci_notify_info *info)
324 {
325 	struct dmar_drhd_unit *dmaru;
326 
327 	for_each_drhd_unit(dmaru)
328 		if (dmar_remove_dev_scope(info, dmaru->segment,
329 			dmaru->devices, dmaru->devices_cnt))
330 			break;
331 	dmar_iommu_notify_scope_dev(info);
332 }
333 
334 static inline void vf_inherit_msi_domain(struct pci_dev *pdev)
335 {
336 	struct pci_dev *physfn = pci_physfn(pdev);
337 
338 	dev_set_msi_domain(&pdev->dev, dev_get_msi_domain(&physfn->dev));
339 }
340 
341 static int dmar_pci_bus_notifier(struct notifier_block *nb,
342 				 unsigned long action, void *data)
343 {
344 	struct pci_dev *pdev = to_pci_dev(data);
345 	struct dmar_pci_notify_info *info;
346 
347 	/* Only care about add/remove events for physical functions.
348 	 * For VFs we actually do the lookup based on the corresponding
349 	 * PF in device_to_iommu() anyway. */
350 	if (pdev->is_virtfn) {
351 		/*
352 		 * Ensure that the VF device inherits the irq domain of the
353 		 * PF device. Ideally the device would inherit the domain
354 		 * from the bus, but DMAR can have multiple units per bus
355 		 * which makes this impossible. The VF 'bus' could inherit
356 		 * from the PF device, but that's yet another x86'sism to
357 		 * inflict on everybody else.
358 		 */
359 		if (action == BUS_NOTIFY_ADD_DEVICE)
360 			vf_inherit_msi_domain(pdev);
361 		return NOTIFY_DONE;
362 	}
363 
364 	if (action != BUS_NOTIFY_ADD_DEVICE &&
365 	    action != BUS_NOTIFY_REMOVED_DEVICE)
366 		return NOTIFY_DONE;
367 
368 	info = dmar_alloc_pci_notify_info(pdev, action);
369 	if (!info)
370 		return NOTIFY_DONE;
371 
372 	down_write(&dmar_global_lock);
373 	if (action == BUS_NOTIFY_ADD_DEVICE)
374 		dmar_pci_bus_add_dev(info);
375 	else if (action == BUS_NOTIFY_REMOVED_DEVICE)
376 		dmar_pci_bus_del_dev(info);
377 	up_write(&dmar_global_lock);
378 
379 	dmar_free_pci_notify_info(info);
380 
381 	return NOTIFY_OK;
382 }
383 
384 static struct notifier_block dmar_pci_bus_nb = {
385 	.notifier_call = dmar_pci_bus_notifier,
386 	.priority = 1,
387 };
388 
389 static struct dmar_drhd_unit *
390 dmar_find_dmaru(struct acpi_dmar_hardware_unit *drhd)
391 {
392 	struct dmar_drhd_unit *dmaru;
393 
394 	list_for_each_entry_rcu(dmaru, &dmar_drhd_units, list,
395 				dmar_rcu_check())
396 		if (dmaru->segment == drhd->segment &&
397 		    dmaru->reg_base_addr == drhd->address)
398 			return dmaru;
399 
400 	return NULL;
401 }
402 
403 /*
404  * dmar_parse_one_drhd - parses exactly one DMA remapping hardware definition
405  * structure which uniquely represent one DMA remapping hardware unit
406  * present in the platform
407  */
408 static int dmar_parse_one_drhd(struct acpi_dmar_header *header, void *arg)
409 {
410 	struct acpi_dmar_hardware_unit *drhd;
411 	struct dmar_drhd_unit *dmaru;
412 	int ret;
413 
414 	drhd = (struct acpi_dmar_hardware_unit *)header;
415 	dmaru = dmar_find_dmaru(drhd);
416 	if (dmaru)
417 		goto out;
418 
419 	dmaru = kzalloc(sizeof(*dmaru) + header->length, GFP_KERNEL);
420 	if (!dmaru)
421 		return -ENOMEM;
422 
423 	/*
424 	 * If header is allocated from slab by ACPI _DSM method, we need to
425 	 * copy the content because the memory buffer will be freed on return.
426 	 */
427 	dmaru->hdr = (void *)(dmaru + 1);
428 	memcpy(dmaru->hdr, header, header->length);
429 	dmaru->reg_base_addr = drhd->address;
430 	dmaru->segment = drhd->segment;
431 	/* The size of the register set is 2 ^ N 4 KB pages. */
432 	dmaru->reg_size = 1UL << (drhd->size + 12);
433 	dmaru->include_all = drhd->flags & 0x1; /* BIT0: INCLUDE_ALL */
434 	dmaru->devices = dmar_alloc_dev_scope((void *)(drhd + 1),
435 					      ((void *)drhd) + drhd->header.length,
436 					      &dmaru->devices_cnt);
437 	if (dmaru->devices_cnt && dmaru->devices == NULL) {
438 		kfree(dmaru);
439 		return -ENOMEM;
440 	}
441 
442 	ret = alloc_iommu(dmaru);
443 	if (ret) {
444 		dmar_free_dev_scope(&dmaru->devices,
445 				    &dmaru->devices_cnt);
446 		kfree(dmaru);
447 		return ret;
448 	}
449 	dmar_register_drhd_unit(dmaru);
450 
451 out:
452 	if (arg)
453 		(*(int *)arg)++;
454 
455 	return 0;
456 }
457 
458 static void dmar_free_drhd(struct dmar_drhd_unit *dmaru)
459 {
460 	if (dmaru->devices && dmaru->devices_cnt)
461 		dmar_free_dev_scope(&dmaru->devices, &dmaru->devices_cnt);
462 	if (dmaru->iommu)
463 		free_iommu(dmaru->iommu);
464 	kfree(dmaru);
465 }
466 
467 static int __init dmar_parse_one_andd(struct acpi_dmar_header *header,
468 				      void *arg)
469 {
470 	struct acpi_dmar_andd *andd = (void *)header;
471 
472 	/* Check for NUL termination within the designated length */
473 	if (strnlen(andd->device_name, header->length - 8) == header->length - 8) {
474 		pr_warn(FW_BUG
475 			   "Your BIOS is broken; ANDD object name is not NUL-terminated\n"
476 			   "BIOS vendor: %s; Ver: %s; Product Version: %s\n",
477 			   dmi_get_system_info(DMI_BIOS_VENDOR),
478 			   dmi_get_system_info(DMI_BIOS_VERSION),
479 			   dmi_get_system_info(DMI_PRODUCT_VERSION));
480 		add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK);
481 		return -EINVAL;
482 	}
483 	pr_info("ANDD device: %x name: %s\n", andd->device_number,
484 		andd->device_name);
485 
486 	return 0;
487 }
488 
489 #ifdef CONFIG_ACPI_NUMA
490 static int dmar_parse_one_rhsa(struct acpi_dmar_header *header, void *arg)
491 {
492 	struct acpi_dmar_rhsa *rhsa;
493 	struct dmar_drhd_unit *drhd;
494 
495 	rhsa = (struct acpi_dmar_rhsa *)header;
496 	for_each_drhd_unit(drhd) {
497 		if (drhd->reg_base_addr == rhsa->base_address) {
498 			int node = pxm_to_node(rhsa->proximity_domain);
499 
500 			if (node != NUMA_NO_NODE && !node_online(node))
501 				node = NUMA_NO_NODE;
502 			drhd->iommu->node = node;
503 			return 0;
504 		}
505 	}
506 	pr_warn(FW_BUG
507 		"Your BIOS is broken; RHSA refers to non-existent DMAR unit at %llx\n"
508 		"BIOS vendor: %s; Ver: %s; Product Version: %s\n",
509 		rhsa->base_address,
510 		dmi_get_system_info(DMI_BIOS_VENDOR),
511 		dmi_get_system_info(DMI_BIOS_VERSION),
512 		dmi_get_system_info(DMI_PRODUCT_VERSION));
513 	add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK);
514 
515 	return 0;
516 }
517 #else
518 #define	dmar_parse_one_rhsa		dmar_res_noop
519 #endif
520 
521 static void
522 dmar_table_print_dmar_entry(struct acpi_dmar_header *header)
523 {
524 	struct acpi_dmar_hardware_unit *drhd;
525 	struct acpi_dmar_reserved_memory *rmrr;
526 	struct acpi_dmar_atsr *atsr;
527 	struct acpi_dmar_rhsa *rhsa;
528 	struct acpi_dmar_satc *satc;
529 
530 	switch (header->type) {
531 	case ACPI_DMAR_TYPE_HARDWARE_UNIT:
532 		drhd = container_of(header, struct acpi_dmar_hardware_unit,
533 				    header);
534 		pr_info("DRHD base: %#016Lx flags: %#x\n",
535 			(unsigned long long)drhd->address, drhd->flags);
536 		break;
537 	case ACPI_DMAR_TYPE_RESERVED_MEMORY:
538 		rmrr = container_of(header, struct acpi_dmar_reserved_memory,
539 				    header);
540 		pr_info("RMRR base: %#016Lx end: %#016Lx\n",
541 			(unsigned long long)rmrr->base_address,
542 			(unsigned long long)rmrr->end_address);
543 		break;
544 	case ACPI_DMAR_TYPE_ROOT_ATS:
545 		atsr = container_of(header, struct acpi_dmar_atsr, header);
546 		pr_info("ATSR flags: %#x\n", atsr->flags);
547 		break;
548 	case ACPI_DMAR_TYPE_HARDWARE_AFFINITY:
549 		rhsa = container_of(header, struct acpi_dmar_rhsa, header);
550 		pr_info("RHSA base: %#016Lx proximity domain: %#x\n",
551 		       (unsigned long long)rhsa->base_address,
552 		       rhsa->proximity_domain);
553 		break;
554 	case ACPI_DMAR_TYPE_NAMESPACE:
555 		/* We don't print this here because we need to sanity-check
556 		   it first. So print it in dmar_parse_one_andd() instead. */
557 		break;
558 	case ACPI_DMAR_TYPE_SATC:
559 		satc = container_of(header, struct acpi_dmar_satc, header);
560 		pr_info("SATC flags: 0x%x\n", satc->flags);
561 		break;
562 	}
563 }
564 
565 /**
566  * dmar_table_detect - checks to see if the platform supports DMAR devices
567  */
568 static int __init dmar_table_detect(void)
569 {
570 	acpi_status status = AE_OK;
571 
572 	/* if we could find DMAR table, then there are DMAR devices */
573 	status = acpi_get_table(ACPI_SIG_DMAR, 0, &dmar_tbl);
574 
575 	if (ACPI_SUCCESS(status) && !dmar_tbl) {
576 		pr_warn("Unable to map DMAR\n");
577 		status = AE_NOT_FOUND;
578 	}
579 
580 	return ACPI_SUCCESS(status) ? 0 : -ENOENT;
581 }
582 
583 static int dmar_walk_remapping_entries(struct acpi_dmar_header *start,
584 				       size_t len, struct dmar_res_callback *cb)
585 {
586 	struct acpi_dmar_header *iter, *next;
587 	struct acpi_dmar_header *end = ((void *)start) + len;
588 
589 	for (iter = start; iter < end; iter = next) {
590 		next = (void *)iter + iter->length;
591 		if (iter->length == 0) {
592 			/* Avoid looping forever on bad ACPI tables */
593 			pr_debug(FW_BUG "Invalid 0-length structure\n");
594 			break;
595 		} else if (next > end) {
596 			/* Avoid passing table end */
597 			pr_warn(FW_BUG "Record passes table end\n");
598 			return -EINVAL;
599 		}
600 
601 		if (cb->print_entry)
602 			dmar_table_print_dmar_entry(iter);
603 
604 		if (iter->type >= ACPI_DMAR_TYPE_RESERVED) {
605 			/* continue for forward compatibility */
606 			pr_debug("Unknown DMAR structure type %d\n",
607 				 iter->type);
608 		} else if (cb->cb[iter->type]) {
609 			int ret;
610 
611 			ret = cb->cb[iter->type](iter, cb->arg[iter->type]);
612 			if (ret)
613 				return ret;
614 		} else if (!cb->ignore_unhandled) {
615 			pr_warn("No handler for DMAR structure type %d\n",
616 				iter->type);
617 			return -EINVAL;
618 		}
619 	}
620 
621 	return 0;
622 }
623 
624 static inline int dmar_walk_dmar_table(struct acpi_table_dmar *dmar,
625 				       struct dmar_res_callback *cb)
626 {
627 	return dmar_walk_remapping_entries((void *)(dmar + 1),
628 			dmar->header.length - sizeof(*dmar), cb);
629 }
630 
631 /**
632  * parse_dmar_table - parses the DMA reporting table
633  */
634 static int __init
635 parse_dmar_table(void)
636 {
637 	struct acpi_table_dmar *dmar;
638 	int drhd_count = 0;
639 	int ret;
640 	struct dmar_res_callback cb = {
641 		.print_entry = true,
642 		.ignore_unhandled = true,
643 		.arg[ACPI_DMAR_TYPE_HARDWARE_UNIT] = &drhd_count,
644 		.cb[ACPI_DMAR_TYPE_HARDWARE_UNIT] = &dmar_parse_one_drhd,
645 		.cb[ACPI_DMAR_TYPE_RESERVED_MEMORY] = &dmar_parse_one_rmrr,
646 		.cb[ACPI_DMAR_TYPE_ROOT_ATS] = &dmar_parse_one_atsr,
647 		.cb[ACPI_DMAR_TYPE_HARDWARE_AFFINITY] = &dmar_parse_one_rhsa,
648 		.cb[ACPI_DMAR_TYPE_NAMESPACE] = &dmar_parse_one_andd,
649 		.cb[ACPI_DMAR_TYPE_SATC] = &dmar_parse_one_satc,
650 	};
651 
652 	/*
653 	 * Do it again, earlier dmar_tbl mapping could be mapped with
654 	 * fixed map.
655 	 */
656 	dmar_table_detect();
657 
658 	/*
659 	 * ACPI tables may not be DMA protected by tboot, so use DMAR copy
660 	 * SINIT saved in SinitMleData in TXT heap (which is DMA protected)
661 	 */
662 	dmar_tbl = tboot_get_dmar_table(dmar_tbl);
663 
664 	dmar = (struct acpi_table_dmar *)dmar_tbl;
665 	if (!dmar)
666 		return -ENODEV;
667 
668 	if (dmar->width < PAGE_SHIFT - 1) {
669 		pr_warn("Invalid DMAR haw\n");
670 		return -EINVAL;
671 	}
672 
673 	pr_info("Host address width %d\n", dmar->width + 1);
674 	ret = dmar_walk_dmar_table(dmar, &cb);
675 	if (ret == 0 && drhd_count == 0)
676 		pr_warn(FW_BUG "No DRHD structure found in DMAR table\n");
677 
678 	return ret;
679 }
680 
681 static int dmar_pci_device_match(struct dmar_dev_scope devices[],
682 				 int cnt, struct pci_dev *dev)
683 {
684 	int index;
685 	struct device *tmp;
686 
687 	while (dev) {
688 		for_each_active_dev_scope(devices, cnt, index, tmp)
689 			if (dev_is_pci(tmp) && dev == to_pci_dev(tmp))
690 				return 1;
691 
692 		/* Check our parent */
693 		dev = dev->bus->self;
694 	}
695 
696 	return 0;
697 }
698 
699 struct dmar_drhd_unit *
700 dmar_find_matched_drhd_unit(struct pci_dev *dev)
701 {
702 	struct dmar_drhd_unit *dmaru;
703 	struct acpi_dmar_hardware_unit *drhd;
704 
705 	dev = pci_physfn(dev);
706 
707 	rcu_read_lock();
708 	for_each_drhd_unit(dmaru) {
709 		drhd = container_of(dmaru->hdr,
710 				    struct acpi_dmar_hardware_unit,
711 				    header);
712 
713 		if (dmaru->include_all &&
714 		    drhd->segment == pci_domain_nr(dev->bus))
715 			goto out;
716 
717 		if (dmar_pci_device_match(dmaru->devices,
718 					  dmaru->devices_cnt, dev))
719 			goto out;
720 	}
721 	dmaru = NULL;
722 out:
723 	rcu_read_unlock();
724 
725 	return dmaru;
726 }
727 
728 static void __init dmar_acpi_insert_dev_scope(u8 device_number,
729 					      struct acpi_device *adev)
730 {
731 	struct dmar_drhd_unit *dmaru;
732 	struct acpi_dmar_hardware_unit *drhd;
733 	struct acpi_dmar_device_scope *scope;
734 	struct device *tmp;
735 	int i;
736 	struct acpi_dmar_pci_path *path;
737 
738 	for_each_drhd_unit(dmaru) {
739 		drhd = container_of(dmaru->hdr,
740 				    struct acpi_dmar_hardware_unit,
741 				    header);
742 
743 		for (scope = (void *)(drhd + 1);
744 		     (unsigned long)scope < ((unsigned long)drhd) + drhd->header.length;
745 		     scope = ((void *)scope) + scope->length) {
746 			if (scope->entry_type != ACPI_DMAR_SCOPE_TYPE_NAMESPACE)
747 				continue;
748 			if (scope->enumeration_id != device_number)
749 				continue;
750 
751 			path = (void *)(scope + 1);
752 			pr_info("ACPI device \"%s\" under DMAR at %llx as %02x:%02x.%d\n",
753 				dev_name(&adev->dev), dmaru->reg_base_addr,
754 				scope->bus, path->device, path->function);
755 			for_each_dev_scope(dmaru->devices, dmaru->devices_cnt, i, tmp)
756 				if (tmp == NULL) {
757 					dmaru->devices[i].bus = scope->bus;
758 					dmaru->devices[i].devfn = PCI_DEVFN(path->device,
759 									    path->function);
760 					rcu_assign_pointer(dmaru->devices[i].dev,
761 							   get_device(&adev->dev));
762 					return;
763 				}
764 			BUG_ON(i >= dmaru->devices_cnt);
765 		}
766 	}
767 	pr_warn("No IOMMU scope found for ANDD enumeration ID %d (%s)\n",
768 		device_number, dev_name(&adev->dev));
769 }
770 
771 static int __init dmar_acpi_dev_scope_init(void)
772 {
773 	struct acpi_dmar_andd *andd;
774 
775 	if (dmar_tbl == NULL)
776 		return -ENODEV;
777 
778 	for (andd = (void *)dmar_tbl + sizeof(struct acpi_table_dmar);
779 	     ((unsigned long)andd) < ((unsigned long)dmar_tbl) + dmar_tbl->length;
780 	     andd = ((void *)andd) + andd->header.length) {
781 		if (andd->header.type == ACPI_DMAR_TYPE_NAMESPACE) {
782 			acpi_handle h;
783 			struct acpi_device *adev;
784 
785 			if (!ACPI_SUCCESS(acpi_get_handle(ACPI_ROOT_OBJECT,
786 							  andd->device_name,
787 							  &h))) {
788 				pr_err("Failed to find handle for ACPI object %s\n",
789 				       andd->device_name);
790 				continue;
791 			}
792 			adev = acpi_fetch_acpi_dev(h);
793 			if (!adev) {
794 				pr_err("Failed to get device for ACPI object %s\n",
795 				       andd->device_name);
796 				continue;
797 			}
798 			dmar_acpi_insert_dev_scope(andd->device_number, adev);
799 		}
800 	}
801 	return 0;
802 }
803 
804 int __init dmar_dev_scope_init(void)
805 {
806 	struct pci_dev *dev = NULL;
807 	struct dmar_pci_notify_info *info;
808 
809 	if (dmar_dev_scope_status != 1)
810 		return dmar_dev_scope_status;
811 
812 	if (list_empty(&dmar_drhd_units)) {
813 		dmar_dev_scope_status = -ENODEV;
814 	} else {
815 		dmar_dev_scope_status = 0;
816 
817 		dmar_acpi_dev_scope_init();
818 
819 		for_each_pci_dev(dev) {
820 			if (dev->is_virtfn)
821 				continue;
822 
823 			info = dmar_alloc_pci_notify_info(dev,
824 					BUS_NOTIFY_ADD_DEVICE);
825 			if (!info) {
826 				pci_dev_put(dev);
827 				return dmar_dev_scope_status;
828 			} else {
829 				dmar_pci_bus_add_dev(info);
830 				dmar_free_pci_notify_info(info);
831 			}
832 		}
833 	}
834 
835 	return dmar_dev_scope_status;
836 }
837 
838 void __init dmar_register_bus_notifier(void)
839 {
840 	bus_register_notifier(&pci_bus_type, &dmar_pci_bus_nb);
841 }
842 
843 
844 int __init dmar_table_init(void)
845 {
846 	static int dmar_table_initialized;
847 	int ret;
848 
849 	if (dmar_table_initialized == 0) {
850 		ret = parse_dmar_table();
851 		if (ret < 0) {
852 			if (ret != -ENODEV)
853 				pr_info("Parse DMAR table failure.\n");
854 		} else  if (list_empty(&dmar_drhd_units)) {
855 			pr_info("No DMAR devices found\n");
856 			ret = -ENODEV;
857 		}
858 
859 		if (ret < 0)
860 			dmar_table_initialized = ret;
861 		else
862 			dmar_table_initialized = 1;
863 	}
864 
865 	return dmar_table_initialized < 0 ? dmar_table_initialized : 0;
866 }
867 
868 static void warn_invalid_dmar(u64 addr, const char *message)
869 {
870 	pr_warn_once(FW_BUG
871 		"Your BIOS is broken; DMAR reported at address %llx%s!\n"
872 		"BIOS vendor: %s; Ver: %s; Product Version: %s\n",
873 		addr, message,
874 		dmi_get_system_info(DMI_BIOS_VENDOR),
875 		dmi_get_system_info(DMI_BIOS_VERSION),
876 		dmi_get_system_info(DMI_PRODUCT_VERSION));
877 	add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK);
878 }
879 
880 static int __ref
881 dmar_validate_one_drhd(struct acpi_dmar_header *entry, void *arg)
882 {
883 	struct acpi_dmar_hardware_unit *drhd;
884 	void __iomem *addr;
885 	u64 cap, ecap;
886 
887 	drhd = (void *)entry;
888 	if (!drhd->address) {
889 		warn_invalid_dmar(0, "");
890 		return -EINVAL;
891 	}
892 
893 	if (arg)
894 		addr = ioremap(drhd->address, VTD_PAGE_SIZE);
895 	else
896 		addr = early_ioremap(drhd->address, VTD_PAGE_SIZE);
897 	if (!addr) {
898 		pr_warn("Can't validate DRHD address: %llx\n", drhd->address);
899 		return -EINVAL;
900 	}
901 
902 	cap = dmar_readq(addr + DMAR_CAP_REG);
903 	ecap = dmar_readq(addr + DMAR_ECAP_REG);
904 
905 	if (arg)
906 		iounmap(addr);
907 	else
908 		early_iounmap(addr, VTD_PAGE_SIZE);
909 
910 	if (cap == (uint64_t)-1 && ecap == (uint64_t)-1) {
911 		warn_invalid_dmar(drhd->address, " returns all ones");
912 		return -EINVAL;
913 	}
914 
915 	return 0;
916 }
917 
918 void __init detect_intel_iommu(void)
919 {
920 	int ret;
921 	struct dmar_res_callback validate_drhd_cb = {
922 		.cb[ACPI_DMAR_TYPE_HARDWARE_UNIT] = &dmar_validate_one_drhd,
923 		.ignore_unhandled = true,
924 	};
925 
926 	down_write(&dmar_global_lock);
927 	ret = dmar_table_detect();
928 	if (!ret)
929 		ret = dmar_walk_dmar_table((struct acpi_table_dmar *)dmar_tbl,
930 					   &validate_drhd_cb);
931 	if (!ret && !no_iommu && !iommu_detected &&
932 	    (!dmar_disabled || dmar_platform_optin())) {
933 		iommu_detected = 1;
934 		/* Make sure ACS will be enabled */
935 		pci_request_acs();
936 	}
937 
938 #ifdef CONFIG_X86
939 	if (!ret) {
940 		x86_init.iommu.iommu_init = intel_iommu_init;
941 		x86_platform.iommu_shutdown = intel_iommu_shutdown;
942 	}
943 
944 #endif
945 
946 	if (dmar_tbl) {
947 		acpi_put_table(dmar_tbl);
948 		dmar_tbl = NULL;
949 	}
950 	up_write(&dmar_global_lock);
951 }
952 
953 static void unmap_iommu(struct intel_iommu *iommu)
954 {
955 	iounmap(iommu->reg);
956 	release_mem_region(iommu->reg_phys, iommu->reg_size);
957 }
958 
959 /**
960  * map_iommu: map the iommu's registers
961  * @iommu: the iommu to map
962  * @drhd: DMA remapping hardware definition structure
963  *
964  * Memory map the iommu's registers.  Start w/ a single page, and
965  * possibly expand if that turns out to be insufficent.
966  */
967 static int map_iommu(struct intel_iommu *iommu, struct dmar_drhd_unit *drhd)
968 {
969 	u64 phys_addr = drhd->reg_base_addr;
970 	int map_size, err=0;
971 
972 	iommu->reg_phys = phys_addr;
973 	iommu->reg_size = drhd->reg_size;
974 
975 	if (!request_mem_region(iommu->reg_phys, iommu->reg_size, iommu->name)) {
976 		pr_err("Can't reserve memory\n");
977 		err = -EBUSY;
978 		goto out;
979 	}
980 
981 	iommu->reg = ioremap(iommu->reg_phys, iommu->reg_size);
982 	if (!iommu->reg) {
983 		pr_err("Can't map the region\n");
984 		err = -ENOMEM;
985 		goto release;
986 	}
987 
988 	iommu->cap = dmar_readq(iommu->reg + DMAR_CAP_REG);
989 	iommu->ecap = dmar_readq(iommu->reg + DMAR_ECAP_REG);
990 
991 	if (iommu->cap == (uint64_t)-1 && iommu->ecap == (uint64_t)-1) {
992 		err = -EINVAL;
993 		warn_invalid_dmar(phys_addr, " returns all ones");
994 		goto unmap;
995 	}
996 
997 	/* the registers might be more than one page */
998 	map_size = max_t(int, ecap_max_iotlb_offset(iommu->ecap),
999 			 cap_max_fault_reg_offset(iommu->cap));
1000 	map_size = VTD_PAGE_ALIGN(map_size);
1001 	if (map_size > iommu->reg_size) {
1002 		iounmap(iommu->reg);
1003 		release_mem_region(iommu->reg_phys, iommu->reg_size);
1004 		iommu->reg_size = map_size;
1005 		if (!request_mem_region(iommu->reg_phys, iommu->reg_size,
1006 					iommu->name)) {
1007 			pr_err("Can't reserve memory\n");
1008 			err = -EBUSY;
1009 			goto out;
1010 		}
1011 		iommu->reg = ioremap(iommu->reg_phys, iommu->reg_size);
1012 		if (!iommu->reg) {
1013 			pr_err("Can't map the region\n");
1014 			err = -ENOMEM;
1015 			goto release;
1016 		}
1017 	}
1018 
1019 	if (cap_ecmds(iommu->cap)) {
1020 		int i;
1021 
1022 		for (i = 0; i < DMA_MAX_NUM_ECMDCAP; i++) {
1023 			iommu->ecmdcap[i] = dmar_readq(iommu->reg + DMAR_ECCAP_REG +
1024 						       i * DMA_ECMD_REG_STEP);
1025 		}
1026 	}
1027 
1028 	err = 0;
1029 	goto out;
1030 
1031 unmap:
1032 	iounmap(iommu->reg);
1033 release:
1034 	release_mem_region(iommu->reg_phys, iommu->reg_size);
1035 out:
1036 	return err;
1037 }
1038 
1039 static int alloc_iommu(struct dmar_drhd_unit *drhd)
1040 {
1041 	struct intel_iommu *iommu;
1042 	u32 ver, sts;
1043 	int agaw = -1;
1044 	int msagaw = -1;
1045 	int err;
1046 
1047 	if (!drhd->reg_base_addr) {
1048 		warn_invalid_dmar(0, "");
1049 		return -EINVAL;
1050 	}
1051 
1052 	iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
1053 	if (!iommu)
1054 		return -ENOMEM;
1055 
1056 	iommu->seq_id = ida_alloc_range(&dmar_seq_ids, 0,
1057 					DMAR_UNITS_SUPPORTED - 1, GFP_KERNEL);
1058 	if (iommu->seq_id < 0) {
1059 		pr_err("Failed to allocate seq_id\n");
1060 		err = iommu->seq_id;
1061 		goto error;
1062 	}
1063 	snprintf(iommu->name, sizeof(iommu->name), "dmar%d", iommu->seq_id);
1064 
1065 	err = map_iommu(iommu, drhd);
1066 	if (err) {
1067 		pr_err("Failed to map %s\n", iommu->name);
1068 		goto error_free_seq_id;
1069 	}
1070 
1071 	if (!cap_sagaw(iommu->cap) &&
1072 	    (!ecap_smts(iommu->ecap) || ecap_slts(iommu->ecap))) {
1073 		pr_info("%s: No supported address widths. Not attempting DMA translation.\n",
1074 			iommu->name);
1075 		drhd->ignored = 1;
1076 	}
1077 
1078 	if (!drhd->ignored) {
1079 		agaw = iommu_calculate_agaw(iommu);
1080 		if (agaw < 0) {
1081 			pr_err("Cannot get a valid agaw for iommu (seq_id = %d)\n",
1082 			       iommu->seq_id);
1083 			drhd->ignored = 1;
1084 		}
1085 	}
1086 	if (!drhd->ignored) {
1087 		msagaw = iommu_calculate_max_sagaw(iommu);
1088 		if (msagaw < 0) {
1089 			pr_err("Cannot get a valid max agaw for iommu (seq_id = %d)\n",
1090 			       iommu->seq_id);
1091 			drhd->ignored = 1;
1092 			agaw = -1;
1093 		}
1094 	}
1095 	iommu->agaw = agaw;
1096 	iommu->msagaw = msagaw;
1097 	iommu->segment = drhd->segment;
1098 	iommu->device_rbtree = RB_ROOT;
1099 	spin_lock_init(&iommu->device_rbtree_lock);
1100 	mutex_init(&iommu->iopf_lock);
1101 	iommu->node = NUMA_NO_NODE;
1102 
1103 	ver = readl(iommu->reg + DMAR_VER_REG);
1104 	pr_info("%s: reg_base_addr %llx ver %d:%d cap %llx ecap %llx\n",
1105 		iommu->name,
1106 		(unsigned long long)drhd->reg_base_addr,
1107 		DMAR_VER_MAJOR(ver), DMAR_VER_MINOR(ver),
1108 		(unsigned long long)iommu->cap,
1109 		(unsigned long long)iommu->ecap);
1110 
1111 	/* Reflect status in gcmd */
1112 	sts = readl(iommu->reg + DMAR_GSTS_REG);
1113 	if (sts & DMA_GSTS_IRES)
1114 		iommu->gcmd |= DMA_GCMD_IRE;
1115 	if (sts & DMA_GSTS_TES)
1116 		iommu->gcmd |= DMA_GCMD_TE;
1117 	if (sts & DMA_GSTS_QIES)
1118 		iommu->gcmd |= DMA_GCMD_QIE;
1119 
1120 	if (alloc_iommu_pmu(iommu))
1121 		pr_debug("Cannot alloc PMU for iommu (seq_id = %d)\n", iommu->seq_id);
1122 
1123 	raw_spin_lock_init(&iommu->register_lock);
1124 
1125 	/*
1126 	 * A value of N in PSS field of eCap register indicates hardware
1127 	 * supports PASID field of N+1 bits.
1128 	 */
1129 	if (pasid_supported(iommu))
1130 		iommu->iommu.max_pasids = 2UL << ecap_pss(iommu->ecap);
1131 
1132 	/*
1133 	 * This is only for hotplug; at boot time intel_iommu_enabled won't
1134 	 * be set yet. When intel_iommu_init() runs, it registers the units
1135 	 * present at boot time, then sets intel_iommu_enabled.
1136 	 */
1137 	if (intel_iommu_enabled && !drhd->ignored) {
1138 		err = iommu_device_sysfs_add(&iommu->iommu, NULL,
1139 					     intel_iommu_groups,
1140 					     "%s", iommu->name);
1141 		if (err)
1142 			goto err_unmap;
1143 
1144 		err = iommu_device_register(&iommu->iommu, &intel_iommu_ops, NULL);
1145 		if (err)
1146 			goto err_sysfs;
1147 
1148 		iommu_pmu_register(iommu);
1149 	}
1150 
1151 	drhd->iommu = iommu;
1152 	iommu->drhd = drhd;
1153 
1154 	return 0;
1155 
1156 err_sysfs:
1157 	iommu_device_sysfs_remove(&iommu->iommu);
1158 err_unmap:
1159 	free_iommu_pmu(iommu);
1160 	unmap_iommu(iommu);
1161 error_free_seq_id:
1162 	ida_free(&dmar_seq_ids, iommu->seq_id);
1163 error:
1164 	kfree(iommu);
1165 	return err;
1166 }
1167 
1168 static void free_iommu(struct intel_iommu *iommu)
1169 {
1170 	if (intel_iommu_enabled && !iommu->drhd->ignored) {
1171 		iommu_pmu_unregister(iommu);
1172 		iommu_device_unregister(&iommu->iommu);
1173 		iommu_device_sysfs_remove(&iommu->iommu);
1174 	}
1175 
1176 	free_iommu_pmu(iommu);
1177 
1178 	if (iommu->irq) {
1179 		if (iommu->pr_irq) {
1180 			free_irq(iommu->pr_irq, iommu);
1181 			dmar_free_hwirq(iommu->pr_irq);
1182 			iommu->pr_irq = 0;
1183 		}
1184 		free_irq(iommu->irq, iommu);
1185 		dmar_free_hwirq(iommu->irq);
1186 		iommu->irq = 0;
1187 	}
1188 
1189 	if (iommu->qi) {
1190 		iommu_free_page(iommu->qi->desc);
1191 		kfree(iommu->qi->desc_status);
1192 		kfree(iommu->qi);
1193 	}
1194 
1195 	if (iommu->reg)
1196 		unmap_iommu(iommu);
1197 
1198 	ida_free(&dmar_seq_ids, iommu->seq_id);
1199 	kfree(iommu);
1200 }
1201 
1202 /*
1203  * Reclaim all the submitted descriptors which have completed its work.
1204  */
1205 static inline void reclaim_free_desc(struct q_inval *qi)
1206 {
1207 	while (qi->desc_status[qi->free_tail] == QI_FREE && qi->free_tail != qi->free_head) {
1208 		qi->free_tail = (qi->free_tail + 1) % QI_LENGTH;
1209 		qi->free_cnt++;
1210 	}
1211 }
1212 
1213 static const char *qi_type_string(u8 type)
1214 {
1215 	switch (type) {
1216 	case QI_CC_TYPE:
1217 		return "Context-cache Invalidation";
1218 	case QI_IOTLB_TYPE:
1219 		return "IOTLB Invalidation";
1220 	case QI_DIOTLB_TYPE:
1221 		return "Device-TLB Invalidation";
1222 	case QI_IEC_TYPE:
1223 		return "Interrupt Entry Cache Invalidation";
1224 	case QI_IWD_TYPE:
1225 		return "Invalidation Wait";
1226 	case QI_EIOTLB_TYPE:
1227 		return "PASID-based IOTLB Invalidation";
1228 	case QI_PC_TYPE:
1229 		return "PASID-cache Invalidation";
1230 	case QI_DEIOTLB_TYPE:
1231 		return "PASID-based Device-TLB Invalidation";
1232 	case QI_PGRP_RESP_TYPE:
1233 		return "Page Group Response";
1234 	default:
1235 		return "UNKNOWN";
1236 	}
1237 }
1238 
1239 static void qi_dump_fault(struct intel_iommu *iommu, u32 fault)
1240 {
1241 	unsigned int head = dmar_readl(iommu->reg + DMAR_IQH_REG);
1242 	u64 iqe_err = dmar_readq(iommu->reg + DMAR_IQER_REG);
1243 	struct qi_desc *desc = iommu->qi->desc + head;
1244 
1245 	if (fault & DMA_FSTS_IQE)
1246 		pr_err("VT-d detected Invalidation Queue Error: Reason %llx",
1247 		       DMAR_IQER_REG_IQEI(iqe_err));
1248 	if (fault & DMA_FSTS_ITE)
1249 		pr_err("VT-d detected Invalidation Time-out Error: SID %llx",
1250 		       DMAR_IQER_REG_ITESID(iqe_err));
1251 	if (fault & DMA_FSTS_ICE)
1252 		pr_err("VT-d detected Invalidation Completion Error: SID %llx",
1253 		       DMAR_IQER_REG_ICESID(iqe_err));
1254 
1255 	pr_err("QI HEAD: %s qw0 = 0x%llx, qw1 = 0x%llx\n",
1256 	       qi_type_string(desc->qw0 & 0xf),
1257 	       (unsigned long long)desc->qw0,
1258 	       (unsigned long long)desc->qw1);
1259 
1260 	head = ((head >> qi_shift(iommu)) + QI_LENGTH - 1) % QI_LENGTH;
1261 	head <<= qi_shift(iommu);
1262 	desc = iommu->qi->desc + head;
1263 
1264 	pr_err("QI PRIOR: %s qw0 = 0x%llx, qw1 = 0x%llx\n",
1265 	       qi_type_string(desc->qw0 & 0xf),
1266 	       (unsigned long long)desc->qw0,
1267 	       (unsigned long long)desc->qw1);
1268 }
1269 
1270 static int qi_check_fault(struct intel_iommu *iommu, int index, int wait_index)
1271 {
1272 	u32 fault;
1273 	int head, tail;
1274 	struct device *dev;
1275 	u64 iqe_err, ite_sid;
1276 	struct q_inval *qi = iommu->qi;
1277 	int shift = qi_shift(iommu);
1278 
1279 	if (qi->desc_status[wait_index] == QI_ABORT)
1280 		return -EAGAIN;
1281 
1282 	fault = readl(iommu->reg + DMAR_FSTS_REG);
1283 	if (fault & (DMA_FSTS_IQE | DMA_FSTS_ITE | DMA_FSTS_ICE))
1284 		qi_dump_fault(iommu, fault);
1285 
1286 	/*
1287 	 * If IQE happens, the head points to the descriptor associated
1288 	 * with the error. No new descriptors are fetched until the IQE
1289 	 * is cleared.
1290 	 */
1291 	if (fault & DMA_FSTS_IQE) {
1292 		head = readl(iommu->reg + DMAR_IQH_REG);
1293 		if ((head >> shift) == index) {
1294 			struct qi_desc *desc = qi->desc + head;
1295 
1296 			/*
1297 			 * desc->qw2 and desc->qw3 are either reserved or
1298 			 * used by software as private data. We won't print
1299 			 * out these two qw's for security consideration.
1300 			 */
1301 			memcpy(desc, qi->desc + (wait_index << shift),
1302 			       1 << shift);
1303 			writel(DMA_FSTS_IQE, iommu->reg + DMAR_FSTS_REG);
1304 			pr_info("Invalidation Queue Error (IQE) cleared\n");
1305 			return -EINVAL;
1306 		}
1307 	}
1308 
1309 	/*
1310 	 * If ITE happens, all pending wait_desc commands are aborted.
1311 	 * No new descriptors are fetched until the ITE is cleared.
1312 	 */
1313 	if (fault & DMA_FSTS_ITE) {
1314 		head = readl(iommu->reg + DMAR_IQH_REG);
1315 		head = ((head >> shift) - 1 + QI_LENGTH) % QI_LENGTH;
1316 		head |= 1;
1317 		tail = readl(iommu->reg + DMAR_IQT_REG);
1318 		tail = ((tail >> shift) - 1 + QI_LENGTH) % QI_LENGTH;
1319 
1320 		/*
1321 		 * SID field is valid only when the ITE field is Set in FSTS_REG
1322 		 * see Intel VT-d spec r4.1, section 11.4.9.9
1323 		 */
1324 		iqe_err = dmar_readq(iommu->reg + DMAR_IQER_REG);
1325 		ite_sid = DMAR_IQER_REG_ITESID(iqe_err);
1326 
1327 		writel(DMA_FSTS_ITE, iommu->reg + DMAR_FSTS_REG);
1328 		pr_info("Invalidation Time-out Error (ITE) cleared\n");
1329 
1330 		do {
1331 			if (qi->desc_status[head] == QI_IN_USE)
1332 				qi->desc_status[head] = QI_ABORT;
1333 			head = (head - 2 + QI_LENGTH) % QI_LENGTH;
1334 		} while (head != tail);
1335 
1336 		/*
1337 		 * If device was released or isn't present, no need to retry
1338 		 * the ATS invalidate request anymore.
1339 		 *
1340 		 * 0 value of ite_sid means old VT-d device, no ite_sid value.
1341 		 * see Intel VT-d spec r4.1, section 11.4.9.9
1342 		 */
1343 		if (ite_sid) {
1344 			dev = device_rbtree_find(iommu, ite_sid);
1345 			if (!dev || !dev_is_pci(dev) ||
1346 			    !pci_device_is_present(to_pci_dev(dev)))
1347 				return -ETIMEDOUT;
1348 		}
1349 		if (qi->desc_status[wait_index] == QI_ABORT)
1350 			return -EAGAIN;
1351 	}
1352 
1353 	if (fault & DMA_FSTS_ICE) {
1354 		writel(DMA_FSTS_ICE, iommu->reg + DMAR_FSTS_REG);
1355 		pr_info("Invalidation Completion Error (ICE) cleared\n");
1356 	}
1357 
1358 	return 0;
1359 }
1360 
1361 /*
1362  * Function to submit invalidation descriptors of all types to the queued
1363  * invalidation interface(QI). Multiple descriptors can be submitted at a
1364  * time, a wait descriptor will be appended to each submission to ensure
1365  * hardware has completed the invalidation before return. Wait descriptors
1366  * can be part of the submission but it will not be polled for completion.
1367  */
1368 int qi_submit_sync(struct intel_iommu *iommu, struct qi_desc *desc,
1369 		   unsigned int count, unsigned long options)
1370 {
1371 	struct q_inval *qi = iommu->qi;
1372 	s64 devtlb_start_ktime = 0;
1373 	s64 iotlb_start_ktime = 0;
1374 	s64 iec_start_ktime = 0;
1375 	struct qi_desc wait_desc;
1376 	int wait_index, index;
1377 	unsigned long flags;
1378 	int offset, shift;
1379 	int rc, i;
1380 	u64 type;
1381 
1382 	if (!qi)
1383 		return 0;
1384 
1385 	type = desc->qw0 & GENMASK_ULL(3, 0);
1386 
1387 	if ((type == QI_IOTLB_TYPE || type == QI_EIOTLB_TYPE) &&
1388 	    dmar_latency_enabled(iommu, DMAR_LATENCY_INV_IOTLB))
1389 		iotlb_start_ktime = ktime_to_ns(ktime_get());
1390 
1391 	if ((type == QI_DIOTLB_TYPE || type == QI_DEIOTLB_TYPE) &&
1392 	    dmar_latency_enabled(iommu, DMAR_LATENCY_INV_DEVTLB))
1393 		devtlb_start_ktime = ktime_to_ns(ktime_get());
1394 
1395 	if (type == QI_IEC_TYPE &&
1396 	    dmar_latency_enabled(iommu, DMAR_LATENCY_INV_IEC))
1397 		iec_start_ktime = ktime_to_ns(ktime_get());
1398 
1399 restart:
1400 	rc = 0;
1401 
1402 	raw_spin_lock_irqsave(&qi->q_lock, flags);
1403 	/*
1404 	 * Check if we have enough empty slots in the queue to submit,
1405 	 * the calculation is based on:
1406 	 * # of desc + 1 wait desc + 1 space between head and tail
1407 	 */
1408 	while (qi->free_cnt < count + 2) {
1409 		raw_spin_unlock_irqrestore(&qi->q_lock, flags);
1410 		cpu_relax();
1411 		raw_spin_lock_irqsave(&qi->q_lock, flags);
1412 	}
1413 
1414 	index = qi->free_head;
1415 	wait_index = (index + count) % QI_LENGTH;
1416 	shift = qi_shift(iommu);
1417 
1418 	for (i = 0; i < count; i++) {
1419 		offset = ((index + i) % QI_LENGTH) << shift;
1420 		memcpy(qi->desc + offset, &desc[i], 1 << shift);
1421 		qi->desc_status[(index + i) % QI_LENGTH] = QI_IN_USE;
1422 		trace_qi_submit(iommu, desc[i].qw0, desc[i].qw1,
1423 				desc[i].qw2, desc[i].qw3);
1424 	}
1425 	qi->desc_status[wait_index] = QI_IN_USE;
1426 
1427 	wait_desc.qw0 = QI_IWD_STATUS_DATA(QI_DONE) |
1428 			QI_IWD_STATUS_WRITE | QI_IWD_TYPE;
1429 	if (options & QI_OPT_WAIT_DRAIN)
1430 		wait_desc.qw0 |= QI_IWD_PRQ_DRAIN;
1431 	wait_desc.qw1 = virt_to_phys(&qi->desc_status[wait_index]);
1432 	wait_desc.qw2 = 0;
1433 	wait_desc.qw3 = 0;
1434 
1435 	offset = wait_index << shift;
1436 	memcpy(qi->desc + offset, &wait_desc, 1 << shift);
1437 
1438 	qi->free_head = (qi->free_head + count + 1) % QI_LENGTH;
1439 	qi->free_cnt -= count + 1;
1440 
1441 	/*
1442 	 * update the HW tail register indicating the presence of
1443 	 * new descriptors.
1444 	 */
1445 	writel(qi->free_head << shift, iommu->reg + DMAR_IQT_REG);
1446 
1447 	while (READ_ONCE(qi->desc_status[wait_index]) != QI_DONE) {
1448 		/*
1449 		 * We will leave the interrupts disabled, to prevent interrupt
1450 		 * context to queue another cmd while a cmd is already submitted
1451 		 * and waiting for completion on this cpu. This is to avoid
1452 		 * a deadlock where the interrupt context can wait indefinitely
1453 		 * for free slots in the queue.
1454 		 */
1455 		rc = qi_check_fault(iommu, index, wait_index);
1456 		if (rc)
1457 			break;
1458 
1459 		raw_spin_unlock(&qi->q_lock);
1460 		cpu_relax();
1461 		raw_spin_lock(&qi->q_lock);
1462 	}
1463 
1464 	/*
1465 	 * The reclaim code can free descriptors from multiple submissions
1466 	 * starting from the tail of the queue. When count == 0, the
1467 	 * status of the standalone wait descriptor at the tail of the queue
1468 	 * must be set to QI_FREE to allow the reclaim code to proceed.
1469 	 * It is also possible that descriptors from one of the previous
1470 	 * submissions has to be reclaimed by a subsequent submission.
1471 	 */
1472 	for (i = 0; i <= count; i++)
1473 		qi->desc_status[(index + i) % QI_LENGTH] = QI_FREE;
1474 
1475 	reclaim_free_desc(qi);
1476 	raw_spin_unlock_irqrestore(&qi->q_lock, flags);
1477 
1478 	if (rc == -EAGAIN)
1479 		goto restart;
1480 
1481 	if (iotlb_start_ktime)
1482 		dmar_latency_update(iommu, DMAR_LATENCY_INV_IOTLB,
1483 				ktime_to_ns(ktime_get()) - iotlb_start_ktime);
1484 
1485 	if (devtlb_start_ktime)
1486 		dmar_latency_update(iommu, DMAR_LATENCY_INV_DEVTLB,
1487 				ktime_to_ns(ktime_get()) - devtlb_start_ktime);
1488 
1489 	if (iec_start_ktime)
1490 		dmar_latency_update(iommu, DMAR_LATENCY_INV_IEC,
1491 				ktime_to_ns(ktime_get()) - iec_start_ktime);
1492 
1493 	return rc;
1494 }
1495 
1496 /*
1497  * Flush the global interrupt entry cache.
1498  */
1499 void qi_global_iec(struct intel_iommu *iommu)
1500 {
1501 	struct qi_desc desc;
1502 
1503 	desc.qw0 = QI_IEC_TYPE;
1504 	desc.qw1 = 0;
1505 	desc.qw2 = 0;
1506 	desc.qw3 = 0;
1507 
1508 	/* should never fail */
1509 	qi_submit_sync(iommu, &desc, 1, 0);
1510 }
1511 
1512 void qi_flush_context(struct intel_iommu *iommu, u16 did, u16 sid, u8 fm,
1513 		      u64 type)
1514 {
1515 	struct qi_desc desc;
1516 
1517 	desc.qw0 = QI_CC_FM(fm) | QI_CC_SID(sid) | QI_CC_DID(did)
1518 			| QI_CC_GRAN(type) | QI_CC_TYPE;
1519 	desc.qw1 = 0;
1520 	desc.qw2 = 0;
1521 	desc.qw3 = 0;
1522 
1523 	qi_submit_sync(iommu, &desc, 1, 0);
1524 }
1525 
1526 void qi_flush_iotlb(struct intel_iommu *iommu, u16 did, u64 addr,
1527 		    unsigned int size_order, u64 type)
1528 {
1529 	struct qi_desc desc;
1530 
1531 	qi_desc_iotlb(iommu, did, addr, size_order, type, &desc);
1532 	qi_submit_sync(iommu, &desc, 1, 0);
1533 }
1534 
1535 void qi_flush_dev_iotlb(struct intel_iommu *iommu, u16 sid, u16 pfsid,
1536 			u16 qdep, u64 addr, unsigned mask)
1537 {
1538 	struct qi_desc desc;
1539 
1540 	/*
1541 	 * VT-d spec, section 4.3:
1542 	 *
1543 	 * Software is recommended to not submit any Device-TLB invalidation
1544 	 * requests while address remapping hardware is disabled.
1545 	 */
1546 	if (!(iommu->gcmd & DMA_GCMD_TE))
1547 		return;
1548 
1549 	qi_desc_dev_iotlb(sid, pfsid, qdep, addr, mask, &desc);
1550 	qi_submit_sync(iommu, &desc, 1, 0);
1551 }
1552 
1553 /* PASID-based IOTLB invalidation */
1554 void qi_flush_piotlb(struct intel_iommu *iommu, u16 did, u32 pasid, u64 addr,
1555 		     unsigned long npages, bool ih)
1556 {
1557 	struct qi_desc desc = {.qw2 = 0, .qw3 = 0};
1558 
1559 	/*
1560 	 * npages == -1 means a PASID-selective invalidation, otherwise,
1561 	 * a positive value for Page-selective-within-PASID invalidation.
1562 	 * 0 is not a valid input.
1563 	 */
1564 	if (WARN_ON(!npages)) {
1565 		pr_err("Invalid input npages = %ld\n", npages);
1566 		return;
1567 	}
1568 
1569 	qi_desc_piotlb(did, pasid, addr, npages, ih, &desc);
1570 	qi_submit_sync(iommu, &desc, 1, 0);
1571 }
1572 
1573 /* PASID-based device IOTLB Invalidate */
1574 void qi_flush_dev_iotlb_pasid(struct intel_iommu *iommu, u16 sid, u16 pfsid,
1575 			      u32 pasid,  u16 qdep, u64 addr, unsigned int size_order)
1576 {
1577 	struct qi_desc desc = {.qw1 = 0, .qw2 = 0, .qw3 = 0};
1578 
1579 	/*
1580 	 * VT-d spec, section 4.3:
1581 	 *
1582 	 * Software is recommended to not submit any Device-TLB invalidation
1583 	 * requests while address remapping hardware is disabled.
1584 	 */
1585 	if (!(iommu->gcmd & DMA_GCMD_TE))
1586 		return;
1587 
1588 	qi_desc_dev_iotlb_pasid(sid, pfsid, pasid,
1589 				qdep, addr, size_order,
1590 				&desc);
1591 	qi_submit_sync(iommu, &desc, 1, 0);
1592 }
1593 
1594 void qi_flush_pasid_cache(struct intel_iommu *iommu, u16 did,
1595 			  u64 granu, u32 pasid)
1596 {
1597 	struct qi_desc desc = {.qw1 = 0, .qw2 = 0, .qw3 = 0};
1598 
1599 	desc.qw0 = QI_PC_PASID(pasid) | QI_PC_DID(did) |
1600 			QI_PC_GRAN(granu) | QI_PC_TYPE;
1601 	qi_submit_sync(iommu, &desc, 1, 0);
1602 }
1603 
1604 /*
1605  * Disable Queued Invalidation interface.
1606  */
1607 void dmar_disable_qi(struct intel_iommu *iommu)
1608 {
1609 	unsigned long flags;
1610 	u32 sts;
1611 	cycles_t start_time = get_cycles();
1612 
1613 	if (!ecap_qis(iommu->ecap))
1614 		return;
1615 
1616 	raw_spin_lock_irqsave(&iommu->register_lock, flags);
1617 
1618 	sts =  readl(iommu->reg + DMAR_GSTS_REG);
1619 	if (!(sts & DMA_GSTS_QIES))
1620 		goto end;
1621 
1622 	/*
1623 	 * Give a chance to HW to complete the pending invalidation requests.
1624 	 */
1625 	while ((readl(iommu->reg + DMAR_IQT_REG) !=
1626 		readl(iommu->reg + DMAR_IQH_REG)) &&
1627 		(DMAR_OPERATION_TIMEOUT > (get_cycles() - start_time)))
1628 		cpu_relax();
1629 
1630 	iommu->gcmd &= ~DMA_GCMD_QIE;
1631 	writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);
1632 
1633 	IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG, readl,
1634 		      !(sts & DMA_GSTS_QIES), sts);
1635 end:
1636 	raw_spin_unlock_irqrestore(&iommu->register_lock, flags);
1637 }
1638 
1639 /*
1640  * Enable queued invalidation.
1641  */
1642 static void __dmar_enable_qi(struct intel_iommu *iommu)
1643 {
1644 	u32 sts;
1645 	unsigned long flags;
1646 	struct q_inval *qi = iommu->qi;
1647 	u64 val = virt_to_phys(qi->desc);
1648 
1649 	qi->free_head = qi->free_tail = 0;
1650 	qi->free_cnt = QI_LENGTH;
1651 
1652 	/*
1653 	 * Set DW=1 and QS=1 in IQA_REG when Scalable Mode capability
1654 	 * is present.
1655 	 */
1656 	if (ecap_smts(iommu->ecap))
1657 		val |= BIT_ULL(11) | BIT_ULL(0);
1658 
1659 	raw_spin_lock_irqsave(&iommu->register_lock, flags);
1660 
1661 	/* write zero to the tail reg */
1662 	writel(0, iommu->reg + DMAR_IQT_REG);
1663 
1664 	dmar_writeq(iommu->reg + DMAR_IQA_REG, val);
1665 
1666 	iommu->gcmd |= DMA_GCMD_QIE;
1667 	writel(iommu->gcmd, iommu->reg + DMAR_GCMD_REG);
1668 
1669 	/* Make sure hardware complete it */
1670 	IOMMU_WAIT_OP(iommu, DMAR_GSTS_REG, readl, (sts & DMA_GSTS_QIES), sts);
1671 
1672 	raw_spin_unlock_irqrestore(&iommu->register_lock, flags);
1673 }
1674 
1675 /*
1676  * Enable Queued Invalidation interface. This is a must to support
1677  * interrupt-remapping. Also used by DMA-remapping, which replaces
1678  * register based IOTLB invalidation.
1679  */
1680 int dmar_enable_qi(struct intel_iommu *iommu)
1681 {
1682 	struct q_inval *qi;
1683 	void *desc;
1684 	int order;
1685 
1686 	if (!ecap_qis(iommu->ecap))
1687 		return -ENOENT;
1688 
1689 	/*
1690 	 * queued invalidation is already setup and enabled.
1691 	 */
1692 	if (iommu->qi)
1693 		return 0;
1694 
1695 	iommu->qi = kmalloc(sizeof(*qi), GFP_ATOMIC);
1696 	if (!iommu->qi)
1697 		return -ENOMEM;
1698 
1699 	qi = iommu->qi;
1700 
1701 	/*
1702 	 * Need two pages to accommodate 256 descriptors of 256 bits each
1703 	 * if the remapping hardware supports scalable mode translation.
1704 	 */
1705 	order = ecap_smts(iommu->ecap) ? 1 : 0;
1706 	desc = iommu_alloc_pages_node(iommu->node, GFP_ATOMIC, order);
1707 	if (!desc) {
1708 		kfree(qi);
1709 		iommu->qi = NULL;
1710 		return -ENOMEM;
1711 	}
1712 
1713 	qi->desc = desc;
1714 
1715 	qi->desc_status = kcalloc(QI_LENGTH, sizeof(int), GFP_ATOMIC);
1716 	if (!qi->desc_status) {
1717 		iommu_free_page(qi->desc);
1718 		kfree(qi);
1719 		iommu->qi = NULL;
1720 		return -ENOMEM;
1721 	}
1722 
1723 	raw_spin_lock_init(&qi->q_lock);
1724 
1725 	__dmar_enable_qi(iommu);
1726 
1727 	return 0;
1728 }
1729 
1730 /* iommu interrupt handling. Most stuff are MSI-like. */
1731 
1732 enum faulttype {
1733 	DMA_REMAP,
1734 	INTR_REMAP,
1735 	UNKNOWN,
1736 };
1737 
1738 static const char *dma_remap_fault_reasons[] =
1739 {
1740 	"Software",
1741 	"Present bit in root entry is clear",
1742 	"Present bit in context entry is clear",
1743 	"Invalid context entry",
1744 	"Access beyond MGAW",
1745 	"PTE Write access is not set",
1746 	"PTE Read access is not set",
1747 	"Next page table ptr is invalid",
1748 	"Root table address invalid",
1749 	"Context table ptr is invalid",
1750 	"non-zero reserved fields in RTP",
1751 	"non-zero reserved fields in CTP",
1752 	"non-zero reserved fields in PTE",
1753 	"PCE for translation request specifies blocking",
1754 };
1755 
1756 static const char * const dma_remap_sm_fault_reasons[] = {
1757 	"SM: Invalid Root Table Address",
1758 	"SM: TTM 0 for request with PASID",
1759 	"SM: TTM 0 for page group request",
1760 	"Unknown", "Unknown", "Unknown", "Unknown", "Unknown", /* 0x33-0x37 */
1761 	"SM: Error attempting to access Root Entry",
1762 	"SM: Present bit in Root Entry is clear",
1763 	"SM: Non-zero reserved field set in Root Entry",
1764 	"Unknown", "Unknown", "Unknown", "Unknown", "Unknown", /* 0x3B-0x3F */
1765 	"SM: Error attempting to access Context Entry",
1766 	"SM: Present bit in Context Entry is clear",
1767 	"SM: Non-zero reserved field set in the Context Entry",
1768 	"SM: Invalid Context Entry",
1769 	"SM: DTE field in Context Entry is clear",
1770 	"SM: PASID Enable field in Context Entry is clear",
1771 	"SM: PASID is larger than the max in Context Entry",
1772 	"SM: PRE field in Context-Entry is clear",
1773 	"SM: RID_PASID field error in Context-Entry",
1774 	"Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", /* 0x49-0x4F */
1775 	"SM: Error attempting to access the PASID Directory Entry",
1776 	"SM: Present bit in Directory Entry is clear",
1777 	"SM: Non-zero reserved field set in PASID Directory Entry",
1778 	"Unknown", "Unknown", "Unknown", "Unknown", "Unknown", /* 0x53-0x57 */
1779 	"SM: Error attempting to access PASID Table Entry",
1780 	"SM: Present bit in PASID Table Entry is clear",
1781 	"SM: Non-zero reserved field set in PASID Table Entry",
1782 	"SM: Invalid Scalable-Mode PASID Table Entry",
1783 	"SM: ERE field is clear in PASID Table Entry",
1784 	"SM: SRE field is clear in PASID Table Entry",
1785 	"Unknown", "Unknown",/* 0x5E-0x5F */
1786 	"Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", /* 0x60-0x67 */
1787 	"Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", /* 0x68-0x6F */
1788 	"SM: Error attempting to access first-level paging entry",
1789 	"SM: Present bit in first-level paging entry is clear",
1790 	"SM: Non-zero reserved field set in first-level paging entry",
1791 	"SM: Error attempting to access FL-PML4 entry",
1792 	"SM: First-level entry address beyond MGAW in Nested translation",
1793 	"SM: Read permission error in FL-PML4 entry in Nested translation",
1794 	"SM: Read permission error in first-level paging entry in Nested translation",
1795 	"SM: Write permission error in first-level paging entry in Nested translation",
1796 	"SM: Error attempting to access second-level paging entry",
1797 	"SM: Read/Write permission error in second-level paging entry",
1798 	"SM: Non-zero reserved field set in second-level paging entry",
1799 	"SM: Invalid second-level page table pointer",
1800 	"SM: A/D bit update needed in second-level entry when set up in no snoop",
1801 	"Unknown", "Unknown", "Unknown", /* 0x7D-0x7F */
1802 	"SM: Address in first-level translation is not canonical",
1803 	"SM: U/S set 0 for first-level translation with user privilege",
1804 	"SM: No execute permission for request with PASID and ER=1",
1805 	"SM: Address beyond the DMA hardware max",
1806 	"SM: Second-level entry address beyond the max",
1807 	"SM: No write permission for Write/AtomicOp request",
1808 	"SM: No read permission for Read/AtomicOp request",
1809 	"SM: Invalid address-interrupt address",
1810 	"Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", "Unknown", /* 0x88-0x8F */
1811 	"SM: A/D bit update needed in first-level entry when set up in no snoop",
1812 };
1813 
1814 static const char *irq_remap_fault_reasons[] =
1815 {
1816 	"Detected reserved fields in the decoded interrupt-remapped request",
1817 	"Interrupt index exceeded the interrupt-remapping table size",
1818 	"Present field in the IRTE entry is clear",
1819 	"Error accessing interrupt-remapping table pointed by IRTA_REG",
1820 	"Detected reserved fields in the IRTE entry",
1821 	"Blocked a compatibility format interrupt request",
1822 	"Blocked an interrupt request due to source-id verification failure",
1823 };
1824 
1825 static const char *dmar_get_fault_reason(u8 fault_reason, int *fault_type)
1826 {
1827 	if (fault_reason >= 0x20 && (fault_reason - 0x20 <
1828 					ARRAY_SIZE(irq_remap_fault_reasons))) {
1829 		*fault_type = INTR_REMAP;
1830 		return irq_remap_fault_reasons[fault_reason - 0x20];
1831 	} else if (fault_reason >= 0x30 && (fault_reason - 0x30 <
1832 			ARRAY_SIZE(dma_remap_sm_fault_reasons))) {
1833 		*fault_type = DMA_REMAP;
1834 		return dma_remap_sm_fault_reasons[fault_reason - 0x30];
1835 	} else if (fault_reason < ARRAY_SIZE(dma_remap_fault_reasons)) {
1836 		*fault_type = DMA_REMAP;
1837 		return dma_remap_fault_reasons[fault_reason];
1838 	} else {
1839 		*fault_type = UNKNOWN;
1840 		return "Unknown";
1841 	}
1842 }
1843 
1844 
1845 static inline int dmar_msi_reg(struct intel_iommu *iommu, int irq)
1846 {
1847 	if (iommu->irq == irq)
1848 		return DMAR_FECTL_REG;
1849 	else if (iommu->pr_irq == irq)
1850 		return DMAR_PECTL_REG;
1851 	else if (iommu->perf_irq == irq)
1852 		return DMAR_PERFINTRCTL_REG;
1853 	else
1854 		BUG();
1855 }
1856 
1857 void dmar_msi_unmask(struct irq_data *data)
1858 {
1859 	struct intel_iommu *iommu = irq_data_get_irq_handler_data(data);
1860 	int reg = dmar_msi_reg(iommu, data->irq);
1861 	unsigned long flag;
1862 
1863 	/* unmask it */
1864 	raw_spin_lock_irqsave(&iommu->register_lock, flag);
1865 	writel(0, iommu->reg + reg);
1866 	/* Read a reg to force flush the post write */
1867 	readl(iommu->reg + reg);
1868 	raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
1869 }
1870 
1871 void dmar_msi_mask(struct irq_data *data)
1872 {
1873 	struct intel_iommu *iommu = irq_data_get_irq_handler_data(data);
1874 	int reg = dmar_msi_reg(iommu, data->irq);
1875 	unsigned long flag;
1876 
1877 	/* mask it */
1878 	raw_spin_lock_irqsave(&iommu->register_lock, flag);
1879 	writel(DMA_FECTL_IM, iommu->reg + reg);
1880 	/* Read a reg to force flush the post write */
1881 	readl(iommu->reg + reg);
1882 	raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
1883 }
1884 
1885 void dmar_msi_write(int irq, struct msi_msg *msg)
1886 {
1887 	struct intel_iommu *iommu = irq_get_handler_data(irq);
1888 	int reg = dmar_msi_reg(iommu, irq);
1889 	unsigned long flag;
1890 
1891 	raw_spin_lock_irqsave(&iommu->register_lock, flag);
1892 	writel(msg->data, iommu->reg + reg + 4);
1893 	writel(msg->address_lo, iommu->reg + reg + 8);
1894 	writel(msg->address_hi, iommu->reg + reg + 12);
1895 	raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
1896 }
1897 
1898 static int dmar_fault_do_one(struct intel_iommu *iommu, int type,
1899 		u8 fault_reason, u32 pasid, u16 source_id,
1900 		unsigned long long addr)
1901 {
1902 	const char *reason;
1903 	int fault_type;
1904 
1905 	reason = dmar_get_fault_reason(fault_reason, &fault_type);
1906 
1907 	if (fault_type == INTR_REMAP) {
1908 		pr_err("[INTR-REMAP] Request device [%02x:%02x.%d] fault index 0x%llx [fault reason 0x%02x] %s\n",
1909 		       source_id >> 8, PCI_SLOT(source_id & 0xFF),
1910 		       PCI_FUNC(source_id & 0xFF), addr >> 48,
1911 		       fault_reason, reason);
1912 
1913 		return 0;
1914 	}
1915 
1916 	if (pasid == IOMMU_PASID_INVALID)
1917 		pr_err("[%s NO_PASID] Request device [%02x:%02x.%d] fault addr 0x%llx [fault reason 0x%02x] %s\n",
1918 		       type ? "DMA Read" : "DMA Write",
1919 		       source_id >> 8, PCI_SLOT(source_id & 0xFF),
1920 		       PCI_FUNC(source_id & 0xFF), addr,
1921 		       fault_reason, reason);
1922 	else
1923 		pr_err("[%s PASID 0x%x] Request device [%02x:%02x.%d] fault addr 0x%llx [fault reason 0x%02x] %s\n",
1924 		       type ? "DMA Read" : "DMA Write", pasid,
1925 		       source_id >> 8, PCI_SLOT(source_id & 0xFF),
1926 		       PCI_FUNC(source_id & 0xFF), addr,
1927 		       fault_reason, reason);
1928 
1929 	dmar_fault_dump_ptes(iommu, source_id, addr, pasid);
1930 
1931 	return 0;
1932 }
1933 
1934 #define PRIMARY_FAULT_REG_LEN (16)
1935 irqreturn_t dmar_fault(int irq, void *dev_id)
1936 {
1937 	struct intel_iommu *iommu = dev_id;
1938 	int reg, fault_index;
1939 	u32 fault_status;
1940 	unsigned long flag;
1941 	static DEFINE_RATELIMIT_STATE(rs,
1942 				      DEFAULT_RATELIMIT_INTERVAL,
1943 				      DEFAULT_RATELIMIT_BURST);
1944 
1945 	raw_spin_lock_irqsave(&iommu->register_lock, flag);
1946 	fault_status = readl(iommu->reg + DMAR_FSTS_REG);
1947 	if (fault_status && __ratelimit(&rs))
1948 		pr_err("DRHD: handling fault status reg %x\n", fault_status);
1949 
1950 	/* TBD: ignore advanced fault log currently */
1951 	if (!(fault_status & DMA_FSTS_PPF))
1952 		goto unlock_exit;
1953 
1954 	fault_index = dma_fsts_fault_record_index(fault_status);
1955 	reg = cap_fault_reg_offset(iommu->cap);
1956 	while (1) {
1957 		/* Disable printing, simply clear the fault when ratelimited */
1958 		bool ratelimited = !__ratelimit(&rs);
1959 		u8 fault_reason;
1960 		u16 source_id;
1961 		u64 guest_addr;
1962 		u32 pasid;
1963 		int type;
1964 		u32 data;
1965 		bool pasid_present;
1966 
1967 		/* highest 32 bits */
1968 		data = readl(iommu->reg + reg +
1969 				fault_index * PRIMARY_FAULT_REG_LEN + 12);
1970 		if (!(data & DMA_FRCD_F))
1971 			break;
1972 
1973 		if (!ratelimited) {
1974 			fault_reason = dma_frcd_fault_reason(data);
1975 			type = dma_frcd_type(data);
1976 
1977 			pasid = dma_frcd_pasid_value(data);
1978 			data = readl(iommu->reg + reg +
1979 				     fault_index * PRIMARY_FAULT_REG_LEN + 8);
1980 			source_id = dma_frcd_source_id(data);
1981 
1982 			pasid_present = dma_frcd_pasid_present(data);
1983 			guest_addr = dmar_readq(iommu->reg + reg +
1984 					fault_index * PRIMARY_FAULT_REG_LEN);
1985 			guest_addr = dma_frcd_page_addr(guest_addr);
1986 		}
1987 
1988 		/* clear the fault */
1989 		writel(DMA_FRCD_F, iommu->reg + reg +
1990 			fault_index * PRIMARY_FAULT_REG_LEN + 12);
1991 
1992 		raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
1993 
1994 		if (!ratelimited)
1995 			/* Using pasid -1 if pasid is not present */
1996 			dmar_fault_do_one(iommu, type, fault_reason,
1997 					  pasid_present ? pasid : IOMMU_PASID_INVALID,
1998 					  source_id, guest_addr);
1999 
2000 		fault_index++;
2001 		if (fault_index >= cap_num_fault_regs(iommu->cap))
2002 			fault_index = 0;
2003 		raw_spin_lock_irqsave(&iommu->register_lock, flag);
2004 	}
2005 
2006 	writel(DMA_FSTS_PFO | DMA_FSTS_PPF | DMA_FSTS_PRO,
2007 	       iommu->reg + DMAR_FSTS_REG);
2008 
2009 unlock_exit:
2010 	raw_spin_unlock_irqrestore(&iommu->register_lock, flag);
2011 	return IRQ_HANDLED;
2012 }
2013 
2014 int dmar_set_interrupt(struct intel_iommu *iommu)
2015 {
2016 	int irq, ret;
2017 
2018 	/*
2019 	 * Check if the fault interrupt is already initialized.
2020 	 */
2021 	if (iommu->irq)
2022 		return 0;
2023 
2024 	irq = dmar_alloc_hwirq(iommu->seq_id, iommu->node, iommu);
2025 	if (irq > 0) {
2026 		iommu->irq = irq;
2027 	} else {
2028 		pr_err("No free IRQ vectors\n");
2029 		return -EINVAL;
2030 	}
2031 
2032 	ret = request_irq(irq, dmar_fault, IRQF_NO_THREAD, iommu->name, iommu);
2033 	if (ret)
2034 		pr_err("Can't request irq\n");
2035 	return ret;
2036 }
2037 
2038 int enable_drhd_fault_handling(unsigned int cpu)
2039 {
2040 	struct dmar_drhd_unit *drhd;
2041 	struct intel_iommu *iommu;
2042 
2043 	/*
2044 	 * Enable fault control interrupt.
2045 	 */
2046 	for_each_iommu(iommu, drhd) {
2047 		u32 fault_status;
2048 		int ret;
2049 
2050 		if (iommu->irq || iommu->node != cpu_to_node(cpu))
2051 			continue;
2052 
2053 		ret = dmar_set_interrupt(iommu);
2054 
2055 		if (ret) {
2056 			pr_err("DRHD %Lx: failed to enable fault, interrupt, ret %d\n",
2057 			       (unsigned long long)drhd->reg_base_addr, ret);
2058 			return -1;
2059 		}
2060 
2061 		/*
2062 		 * Clear any previous faults.
2063 		 */
2064 		dmar_fault(iommu->irq, iommu);
2065 		fault_status = readl(iommu->reg + DMAR_FSTS_REG);
2066 		writel(fault_status, iommu->reg + DMAR_FSTS_REG);
2067 	}
2068 
2069 	return 0;
2070 }
2071 
2072 /*
2073  * Re-enable Queued Invalidation interface.
2074  */
2075 int dmar_reenable_qi(struct intel_iommu *iommu)
2076 {
2077 	if (!ecap_qis(iommu->ecap))
2078 		return -ENOENT;
2079 
2080 	if (!iommu->qi)
2081 		return -ENOENT;
2082 
2083 	/*
2084 	 * First disable queued invalidation.
2085 	 */
2086 	dmar_disable_qi(iommu);
2087 	/*
2088 	 * Then enable queued invalidation again. Since there is no pending
2089 	 * invalidation requests now, it's safe to re-enable queued
2090 	 * invalidation.
2091 	 */
2092 	__dmar_enable_qi(iommu);
2093 
2094 	return 0;
2095 }
2096 
2097 /*
2098  * Check interrupt remapping support in DMAR table description.
2099  */
2100 int __init dmar_ir_support(void)
2101 {
2102 	struct acpi_table_dmar *dmar;
2103 	dmar = (struct acpi_table_dmar *)dmar_tbl;
2104 	if (!dmar)
2105 		return 0;
2106 	return dmar->flags & 0x1;
2107 }
2108 
2109 /* Check whether DMAR units are in use */
2110 static inline bool dmar_in_use(void)
2111 {
2112 	return irq_remapping_enabled || intel_iommu_enabled;
2113 }
2114 
2115 static int __init dmar_free_unused_resources(void)
2116 {
2117 	struct dmar_drhd_unit *dmaru, *dmaru_n;
2118 
2119 	if (dmar_in_use())
2120 		return 0;
2121 
2122 	if (dmar_dev_scope_status != 1 && !list_empty(&dmar_drhd_units))
2123 		bus_unregister_notifier(&pci_bus_type, &dmar_pci_bus_nb);
2124 
2125 	down_write(&dmar_global_lock);
2126 	list_for_each_entry_safe(dmaru, dmaru_n, &dmar_drhd_units, list) {
2127 		list_del(&dmaru->list);
2128 		dmar_free_drhd(dmaru);
2129 	}
2130 	up_write(&dmar_global_lock);
2131 
2132 	return 0;
2133 }
2134 
2135 late_initcall(dmar_free_unused_resources);
2136 
2137 /*
2138  * DMAR Hotplug Support
2139  * For more details, please refer to Intel(R) Virtualization Technology
2140  * for Directed-IO Architecture Specifiction, Rev 2.2, Section 8.8
2141  * "Remapping Hardware Unit Hot Plug".
2142  */
2143 static guid_t dmar_hp_guid =
2144 	GUID_INIT(0xD8C1A3A6, 0xBE9B, 0x4C9B,
2145 		  0x91, 0xBF, 0xC3, 0xCB, 0x81, 0xFC, 0x5D, 0xAF);
2146 
2147 /*
2148  * Currently there's only one revision and BIOS will not check the revision id,
2149  * so use 0 for safety.
2150  */
2151 #define	DMAR_DSM_REV_ID			0
2152 #define	DMAR_DSM_FUNC_DRHD		1
2153 #define	DMAR_DSM_FUNC_ATSR		2
2154 #define	DMAR_DSM_FUNC_RHSA		3
2155 #define	DMAR_DSM_FUNC_SATC		4
2156 
2157 static inline bool dmar_detect_dsm(acpi_handle handle, int func)
2158 {
2159 	return acpi_check_dsm(handle, &dmar_hp_guid, DMAR_DSM_REV_ID, 1 << func);
2160 }
2161 
2162 static int dmar_walk_dsm_resource(acpi_handle handle, int func,
2163 				  dmar_res_handler_t handler, void *arg)
2164 {
2165 	int ret = -ENODEV;
2166 	union acpi_object *obj;
2167 	struct acpi_dmar_header *start;
2168 	struct dmar_res_callback callback;
2169 	static int res_type[] = {
2170 		[DMAR_DSM_FUNC_DRHD] = ACPI_DMAR_TYPE_HARDWARE_UNIT,
2171 		[DMAR_DSM_FUNC_ATSR] = ACPI_DMAR_TYPE_ROOT_ATS,
2172 		[DMAR_DSM_FUNC_RHSA] = ACPI_DMAR_TYPE_HARDWARE_AFFINITY,
2173 		[DMAR_DSM_FUNC_SATC] = ACPI_DMAR_TYPE_SATC,
2174 	};
2175 
2176 	if (!dmar_detect_dsm(handle, func))
2177 		return 0;
2178 
2179 	obj = acpi_evaluate_dsm_typed(handle, &dmar_hp_guid, DMAR_DSM_REV_ID,
2180 				      func, NULL, ACPI_TYPE_BUFFER);
2181 	if (!obj)
2182 		return -ENODEV;
2183 
2184 	memset(&callback, 0, sizeof(callback));
2185 	callback.cb[res_type[func]] = handler;
2186 	callback.arg[res_type[func]] = arg;
2187 	start = (struct acpi_dmar_header *)obj->buffer.pointer;
2188 	ret = dmar_walk_remapping_entries(start, obj->buffer.length, &callback);
2189 
2190 	ACPI_FREE(obj);
2191 
2192 	return ret;
2193 }
2194 
2195 static int dmar_hp_add_drhd(struct acpi_dmar_header *header, void *arg)
2196 {
2197 	int ret;
2198 	struct dmar_drhd_unit *dmaru;
2199 
2200 	dmaru = dmar_find_dmaru((struct acpi_dmar_hardware_unit *)header);
2201 	if (!dmaru)
2202 		return -ENODEV;
2203 
2204 	ret = dmar_ir_hotplug(dmaru, true);
2205 	if (ret == 0)
2206 		ret = dmar_iommu_hotplug(dmaru, true);
2207 
2208 	return ret;
2209 }
2210 
2211 static int dmar_hp_remove_drhd(struct acpi_dmar_header *header, void *arg)
2212 {
2213 	int i, ret;
2214 	struct device *dev;
2215 	struct dmar_drhd_unit *dmaru;
2216 
2217 	dmaru = dmar_find_dmaru((struct acpi_dmar_hardware_unit *)header);
2218 	if (!dmaru)
2219 		return 0;
2220 
2221 	/*
2222 	 * All PCI devices managed by this unit should have been destroyed.
2223 	 */
2224 	if (!dmaru->include_all && dmaru->devices && dmaru->devices_cnt) {
2225 		for_each_active_dev_scope(dmaru->devices,
2226 					  dmaru->devices_cnt, i, dev)
2227 			return -EBUSY;
2228 	}
2229 
2230 	ret = dmar_ir_hotplug(dmaru, false);
2231 	if (ret == 0)
2232 		ret = dmar_iommu_hotplug(dmaru, false);
2233 
2234 	return ret;
2235 }
2236 
2237 static int dmar_hp_release_drhd(struct acpi_dmar_header *header, void *arg)
2238 {
2239 	struct dmar_drhd_unit *dmaru;
2240 
2241 	dmaru = dmar_find_dmaru((struct acpi_dmar_hardware_unit *)header);
2242 	if (dmaru) {
2243 		list_del_rcu(&dmaru->list);
2244 		synchronize_rcu();
2245 		dmar_free_drhd(dmaru);
2246 	}
2247 
2248 	return 0;
2249 }
2250 
2251 static int dmar_hotplug_insert(acpi_handle handle)
2252 {
2253 	int ret;
2254 	int drhd_count = 0;
2255 
2256 	ret = dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_DRHD,
2257 				     &dmar_validate_one_drhd, (void *)1);
2258 	if (ret)
2259 		goto out;
2260 
2261 	ret = dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_DRHD,
2262 				     &dmar_parse_one_drhd, (void *)&drhd_count);
2263 	if (ret == 0 && drhd_count == 0) {
2264 		pr_warn(FW_BUG "No DRHD structures in buffer returned by _DSM method\n");
2265 		goto out;
2266 	} else if (ret) {
2267 		goto release_drhd;
2268 	}
2269 
2270 	ret = dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_RHSA,
2271 				     &dmar_parse_one_rhsa, NULL);
2272 	if (ret)
2273 		goto release_drhd;
2274 
2275 	ret = dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_ATSR,
2276 				     &dmar_parse_one_atsr, NULL);
2277 	if (ret)
2278 		goto release_atsr;
2279 
2280 	ret = dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_DRHD,
2281 				     &dmar_hp_add_drhd, NULL);
2282 	if (!ret)
2283 		return 0;
2284 
2285 	dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_DRHD,
2286 			       &dmar_hp_remove_drhd, NULL);
2287 release_atsr:
2288 	dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_ATSR,
2289 			       &dmar_release_one_atsr, NULL);
2290 release_drhd:
2291 	dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_DRHD,
2292 			       &dmar_hp_release_drhd, NULL);
2293 out:
2294 	return ret;
2295 }
2296 
2297 static int dmar_hotplug_remove(acpi_handle handle)
2298 {
2299 	int ret;
2300 
2301 	ret = dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_ATSR,
2302 				     &dmar_check_one_atsr, NULL);
2303 	if (ret)
2304 		return ret;
2305 
2306 	ret = dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_DRHD,
2307 				     &dmar_hp_remove_drhd, NULL);
2308 	if (ret == 0) {
2309 		WARN_ON(dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_ATSR,
2310 					       &dmar_release_one_atsr, NULL));
2311 		WARN_ON(dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_DRHD,
2312 					       &dmar_hp_release_drhd, NULL));
2313 	} else {
2314 		dmar_walk_dsm_resource(handle, DMAR_DSM_FUNC_DRHD,
2315 				       &dmar_hp_add_drhd, NULL);
2316 	}
2317 
2318 	return ret;
2319 }
2320 
2321 static acpi_status dmar_get_dsm_handle(acpi_handle handle, u32 lvl,
2322 				       void *context, void **retval)
2323 {
2324 	acpi_handle *phdl = retval;
2325 
2326 	if (dmar_detect_dsm(handle, DMAR_DSM_FUNC_DRHD)) {
2327 		*phdl = handle;
2328 		return AE_CTRL_TERMINATE;
2329 	}
2330 
2331 	return AE_OK;
2332 }
2333 
2334 static int dmar_device_hotplug(acpi_handle handle, bool insert)
2335 {
2336 	int ret;
2337 	acpi_handle tmp = NULL;
2338 	acpi_status status;
2339 
2340 	if (!dmar_in_use())
2341 		return 0;
2342 
2343 	if (dmar_detect_dsm(handle, DMAR_DSM_FUNC_DRHD)) {
2344 		tmp = handle;
2345 	} else {
2346 		status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle,
2347 					     ACPI_UINT32_MAX,
2348 					     dmar_get_dsm_handle,
2349 					     NULL, NULL, &tmp);
2350 		if (ACPI_FAILURE(status)) {
2351 			pr_warn("Failed to locate _DSM method.\n");
2352 			return -ENXIO;
2353 		}
2354 	}
2355 	if (tmp == NULL)
2356 		return 0;
2357 
2358 	down_write(&dmar_global_lock);
2359 	if (insert)
2360 		ret = dmar_hotplug_insert(tmp);
2361 	else
2362 		ret = dmar_hotplug_remove(tmp);
2363 	up_write(&dmar_global_lock);
2364 
2365 	return ret;
2366 }
2367 
2368 int dmar_device_add(acpi_handle handle)
2369 {
2370 	return dmar_device_hotplug(handle, true);
2371 }
2372 
2373 int dmar_device_remove(acpi_handle handle)
2374 {
2375 	return dmar_device_hotplug(handle, false);
2376 }
2377 
2378 /*
2379  * dmar_platform_optin - Is %DMA_CTRL_PLATFORM_OPT_IN_FLAG set in DMAR table
2380  *
2381  * Returns true if the platform has %DMA_CTRL_PLATFORM_OPT_IN_FLAG set in
2382  * the ACPI DMAR table. This means that the platform boot firmware has made
2383  * sure no device can issue DMA outside of RMRR regions.
2384  */
2385 bool dmar_platform_optin(void)
2386 {
2387 	struct acpi_table_dmar *dmar;
2388 	acpi_status status;
2389 	bool ret;
2390 
2391 	status = acpi_get_table(ACPI_SIG_DMAR, 0,
2392 				(struct acpi_table_header **)&dmar);
2393 	if (ACPI_FAILURE(status))
2394 		return false;
2395 
2396 	ret = !!(dmar->flags & DMAR_PLATFORM_OPT_IN);
2397 	acpi_put_table((struct acpi_table_header *)dmar);
2398 
2399 	return ret;
2400 }
2401 EXPORT_SYMBOL_GPL(dmar_platform_optin);
2402