xref: /linux/arch/x86/events/amd/iommu.c (revision f3a8b6645dc2e60d11f20c1c23afd964ff4e55ae) 
1 /*
2  * Copyright (C) 2013 Advanced Micro Devices, Inc.
3  *
4  * Author: Steven Kinney <Steven.Kinney@amd.com>
5  * Author: Suravee Suthikulpanit <Suraveee.Suthikulpanit@amd.com>
6  *
7  * Perf: amd_iommu - AMD IOMMU Performance Counter PMU implementation
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  */
13 
14 #include <linux/perf_event.h>
15 #include <linux/init.h>
16 #include <linux/cpumask.h>
17 #include <linux/slab.h>
18 
19 #include "../perf_event.h"
20 #include "iommu.h"
21 
22 #define COUNTER_SHIFT		16
23 
24 #define _GET_BANK(ev)       ((u8)(ev->hw.extra_reg.reg >> 8))
25 #define _GET_CNTR(ev)       ((u8)(ev->hw.extra_reg.reg))
26 
27 /* iommu pmu config masks */
28 #define _GET_CSOURCE(ev)    ((ev->hw.config & 0xFFULL))
29 #define _GET_DEVID(ev)      ((ev->hw.config >> 8)  & 0xFFFFULL)
30 #define _GET_PASID(ev)      ((ev->hw.config >> 24) & 0xFFFFULL)
31 #define _GET_DOMID(ev)      ((ev->hw.config >> 40) & 0xFFFFULL)
32 #define _GET_DEVID_MASK(ev) ((ev->hw.extra_reg.config)  & 0xFFFFULL)
33 #define _GET_PASID_MASK(ev) ((ev->hw.extra_reg.config >> 16) & 0xFFFFULL)
34 #define _GET_DOMID_MASK(ev) ((ev->hw.extra_reg.config >> 32) & 0xFFFFULL)
35 
36 static struct perf_amd_iommu __perf_iommu;
37 
38 struct perf_amd_iommu {
39 	struct pmu pmu;
40 	u8 max_banks;
41 	u8 max_counters;
42 	u64 cntr_assign_mask;
43 	raw_spinlock_t lock;
44 	const struct attribute_group *attr_groups[4];
45 };
46 
47 #define format_group	attr_groups[0]
48 #define cpumask_group	attr_groups[1]
49 #define events_group	attr_groups[2]
50 #define null_group	attr_groups[3]
51 
52 /*---------------------------------------------
53  * sysfs format attributes
54  *---------------------------------------------*/
55 PMU_FORMAT_ATTR(csource,    "config:0-7");
56 PMU_FORMAT_ATTR(devid,      "config:8-23");
57 PMU_FORMAT_ATTR(pasid,      "config:24-39");
58 PMU_FORMAT_ATTR(domid,      "config:40-55");
59 PMU_FORMAT_ATTR(devid_mask, "config1:0-15");
60 PMU_FORMAT_ATTR(pasid_mask, "config1:16-31");
61 PMU_FORMAT_ATTR(domid_mask, "config1:32-47");
62 
63 static struct attribute *iommu_format_attrs[] = {
64 	&format_attr_csource.attr,
65 	&format_attr_devid.attr,
66 	&format_attr_pasid.attr,
67 	&format_attr_domid.attr,
68 	&format_attr_devid_mask.attr,
69 	&format_attr_pasid_mask.attr,
70 	&format_attr_domid_mask.attr,
71 	NULL,
72 };
73 
74 static struct attribute_group amd_iommu_format_group = {
75 	.name = "format",
76 	.attrs = iommu_format_attrs,
77 };
78 
79 /*---------------------------------------------
80  * sysfs events attributes
81  *---------------------------------------------*/
82 struct amd_iommu_event_desc {
83 	struct kobj_attribute attr;
84 	const char *event;
85 };
86 
87 static ssize_t _iommu_event_show(struct kobject *kobj,
88 				struct kobj_attribute *attr, char *buf)
89 {
90 	struct amd_iommu_event_desc *event =
91 		container_of(attr, struct amd_iommu_event_desc, attr);
92 	return sprintf(buf, "%s\n", event->event);
93 }
94 
95 #define AMD_IOMMU_EVENT_DESC(_name, _event)			\
96 {								\
97 	.attr  = __ATTR(_name, 0444, _iommu_event_show, NULL),	\
98 	.event = _event,					\
99 }
100 
101 static struct amd_iommu_event_desc amd_iommu_v2_event_descs[] = {
102 	AMD_IOMMU_EVENT_DESC(mem_pass_untrans,        "csource=0x01"),
103 	AMD_IOMMU_EVENT_DESC(mem_pass_pretrans,       "csource=0x02"),
104 	AMD_IOMMU_EVENT_DESC(mem_pass_excl,           "csource=0x03"),
105 	AMD_IOMMU_EVENT_DESC(mem_target_abort,        "csource=0x04"),
106 	AMD_IOMMU_EVENT_DESC(mem_trans_total,         "csource=0x05"),
107 	AMD_IOMMU_EVENT_DESC(mem_iommu_tlb_pte_hit,   "csource=0x06"),
108 	AMD_IOMMU_EVENT_DESC(mem_iommu_tlb_pte_mis,   "csource=0x07"),
109 	AMD_IOMMU_EVENT_DESC(mem_iommu_tlb_pde_hit,   "csource=0x08"),
110 	AMD_IOMMU_EVENT_DESC(mem_iommu_tlb_pde_mis,   "csource=0x09"),
111 	AMD_IOMMU_EVENT_DESC(mem_dte_hit,             "csource=0x0a"),
112 	AMD_IOMMU_EVENT_DESC(mem_dte_mis,             "csource=0x0b"),
113 	AMD_IOMMU_EVENT_DESC(page_tbl_read_tot,       "csource=0x0c"),
114 	AMD_IOMMU_EVENT_DESC(page_tbl_read_nst,       "csource=0x0d"),
115 	AMD_IOMMU_EVENT_DESC(page_tbl_read_gst,       "csource=0x0e"),
116 	AMD_IOMMU_EVENT_DESC(int_dte_hit,             "csource=0x0f"),
117 	AMD_IOMMU_EVENT_DESC(int_dte_mis,             "csource=0x10"),
118 	AMD_IOMMU_EVENT_DESC(cmd_processed,           "csource=0x11"),
119 	AMD_IOMMU_EVENT_DESC(cmd_processed_inv,       "csource=0x12"),
120 	AMD_IOMMU_EVENT_DESC(tlb_inv,                 "csource=0x13"),
121 	AMD_IOMMU_EVENT_DESC(ign_rd_wr_mmio_1ff8h,    "csource=0x14"),
122 	AMD_IOMMU_EVENT_DESC(vapic_int_non_guest,     "csource=0x15"),
123 	AMD_IOMMU_EVENT_DESC(vapic_int_guest,         "csource=0x16"),
124 	AMD_IOMMU_EVENT_DESC(smi_recv,                "csource=0x17"),
125 	AMD_IOMMU_EVENT_DESC(smi_blk,                 "csource=0x18"),
126 	{ /* end: all zeroes */ },
127 };
128 
129 /*---------------------------------------------
130  * sysfs cpumask attributes
131  *---------------------------------------------*/
132 static cpumask_t iommu_cpumask;
133 
134 static ssize_t _iommu_cpumask_show(struct device *dev,
135 				   struct device_attribute *attr,
136 				   char *buf)
137 {
138 	return cpumap_print_to_pagebuf(true, buf, &iommu_cpumask);
139 }
140 static DEVICE_ATTR(cpumask, S_IRUGO, _iommu_cpumask_show, NULL);
141 
142 static struct attribute *iommu_cpumask_attrs[] = {
143 	&dev_attr_cpumask.attr,
144 	NULL,
145 };
146 
147 static struct attribute_group amd_iommu_cpumask_group = {
148 	.attrs = iommu_cpumask_attrs,
149 };
150 
151 /*---------------------------------------------*/
152 
153 static int get_next_avail_iommu_bnk_cntr(struct perf_amd_iommu *perf_iommu)
154 {
155 	unsigned long flags;
156 	int shift, bank, cntr, retval;
157 	int max_banks = perf_iommu->max_banks;
158 	int max_cntrs = perf_iommu->max_counters;
159 
160 	raw_spin_lock_irqsave(&perf_iommu->lock, flags);
161 
162 	for (bank = 0, shift = 0; bank < max_banks; bank++) {
163 		for (cntr = 0; cntr < max_cntrs; cntr++) {
164 			shift = bank + (bank*3) + cntr;
165 			if (perf_iommu->cntr_assign_mask & (1ULL<<shift)) {
166 				continue;
167 			} else {
168 				perf_iommu->cntr_assign_mask |= (1ULL<<shift);
169 				retval = ((u16)((u16)bank<<8) | (u8)(cntr));
170 				goto out;
171 			}
172 		}
173 	}
174 	retval = -ENOSPC;
175 out:
176 	raw_spin_unlock_irqrestore(&perf_iommu->lock, flags);
177 	return retval;
178 }
179 
180 static int clear_avail_iommu_bnk_cntr(struct perf_amd_iommu *perf_iommu,
181 					u8 bank, u8 cntr)
182 {
183 	unsigned long flags;
184 	int max_banks, max_cntrs;
185 	int shift = 0;
186 
187 	max_banks = perf_iommu->max_banks;
188 	max_cntrs = perf_iommu->max_counters;
189 
190 	if ((bank > max_banks) || (cntr > max_cntrs))
191 		return -EINVAL;
192 
193 	shift = bank + cntr + (bank*3);
194 
195 	raw_spin_lock_irqsave(&perf_iommu->lock, flags);
196 	perf_iommu->cntr_assign_mask &= ~(1ULL<<shift);
197 	raw_spin_unlock_irqrestore(&perf_iommu->lock, flags);
198 
199 	return 0;
200 }
201 
202 static int perf_iommu_event_init(struct perf_event *event)
203 {
204 	struct hw_perf_event *hwc = &event->hw;
205 	struct perf_amd_iommu *perf_iommu;
206 	u64 config, config1;
207 
208 	/* test the event attr type check for PMU enumeration */
209 	if (event->attr.type != event->pmu->type)
210 		return -ENOENT;
211 
212 	/*
213 	 * IOMMU counters are shared across all cores.
214 	 * Therefore, it does not support per-process mode.
215 	 * Also, it does not support event sampling mode.
216 	 */
217 	if (is_sampling_event(event) || event->attach_state & PERF_ATTACH_TASK)
218 		return -EINVAL;
219 
220 	/* IOMMU counters do not have usr/os/guest/host bits */
221 	if (event->attr.exclude_user || event->attr.exclude_kernel ||
222 	    event->attr.exclude_host || event->attr.exclude_guest)
223 		return -EINVAL;
224 
225 	if (event->cpu < 0)
226 		return -EINVAL;
227 
228 	perf_iommu = &__perf_iommu;
229 
230 	if (event->pmu != &perf_iommu->pmu)
231 		return -ENOENT;
232 
233 	if (perf_iommu) {
234 		config = event->attr.config;
235 		config1 = event->attr.config1;
236 	} else {
237 		return -EINVAL;
238 	}
239 
240 	/* integrate with iommu base devid (0000), assume one iommu */
241 	perf_iommu->max_banks =
242 		amd_iommu_pc_get_max_banks(IOMMU_BASE_DEVID);
243 	perf_iommu->max_counters =
244 		amd_iommu_pc_get_max_counters(IOMMU_BASE_DEVID);
245 	if ((perf_iommu->max_banks == 0) || (perf_iommu->max_counters == 0))
246 		return -EINVAL;
247 
248 	/* update the hw_perf_event struct with the iommu config data */
249 	hwc->config = config;
250 	hwc->extra_reg.config = config1;
251 
252 	return 0;
253 }
254 
255 static void perf_iommu_enable_event(struct perf_event *ev)
256 {
257 	u8 csource = _GET_CSOURCE(ev);
258 	u16 devid = _GET_DEVID(ev);
259 	u64 reg = 0ULL;
260 
261 	reg = csource;
262 	amd_iommu_pc_get_set_reg_val(devid,
263 			_GET_BANK(ev), _GET_CNTR(ev) ,
264 			 IOMMU_PC_COUNTER_SRC_REG, &reg, true);
265 
266 	reg = 0ULL | devid | (_GET_DEVID_MASK(ev) << 32);
267 	if (reg)
268 		reg |= (1UL << 31);
269 	amd_iommu_pc_get_set_reg_val(devid,
270 			_GET_BANK(ev), _GET_CNTR(ev) ,
271 			 IOMMU_PC_DEVID_MATCH_REG, &reg, true);
272 
273 	reg = 0ULL | _GET_PASID(ev) | (_GET_PASID_MASK(ev) << 32);
274 	if (reg)
275 		reg |= (1UL << 31);
276 	amd_iommu_pc_get_set_reg_val(devid,
277 			_GET_BANK(ev), _GET_CNTR(ev) ,
278 			 IOMMU_PC_PASID_MATCH_REG, &reg, true);
279 
280 	reg = 0ULL | _GET_DOMID(ev) | (_GET_DOMID_MASK(ev) << 32);
281 	if (reg)
282 		reg |= (1UL << 31);
283 	amd_iommu_pc_get_set_reg_val(devid,
284 			_GET_BANK(ev), _GET_CNTR(ev) ,
285 			 IOMMU_PC_DOMID_MATCH_REG, &reg, true);
286 }
287 
288 static void perf_iommu_disable_event(struct perf_event *event)
289 {
290 	u64 reg = 0ULL;
291 
292 	amd_iommu_pc_get_set_reg_val(_GET_DEVID(event),
293 			_GET_BANK(event), _GET_CNTR(event),
294 			IOMMU_PC_COUNTER_SRC_REG, &reg, true);
295 }
296 
297 static void perf_iommu_start(struct perf_event *event, int flags)
298 {
299 	struct hw_perf_event *hwc = &event->hw;
300 
301 	pr_debug("perf: amd_iommu:perf_iommu_start\n");
302 	if (WARN_ON_ONCE(!(hwc->state & PERF_HES_STOPPED)))
303 		return;
304 
305 	WARN_ON_ONCE(!(hwc->state & PERF_HES_UPTODATE));
306 	hwc->state = 0;
307 
308 	if (flags & PERF_EF_RELOAD) {
309 		u64 prev_raw_count =  local64_read(&hwc->prev_count);
310 		amd_iommu_pc_get_set_reg_val(_GET_DEVID(event),
311 				_GET_BANK(event), _GET_CNTR(event),
312 				IOMMU_PC_COUNTER_REG, &prev_raw_count, true);
313 	}
314 
315 	perf_iommu_enable_event(event);
316 	perf_event_update_userpage(event);
317 
318 }
319 
320 static void perf_iommu_read(struct perf_event *event)
321 {
322 	u64 count = 0ULL;
323 	u64 prev_raw_count = 0ULL;
324 	u64 delta = 0ULL;
325 	struct hw_perf_event *hwc = &event->hw;
326 	pr_debug("perf: amd_iommu:perf_iommu_read\n");
327 
328 	amd_iommu_pc_get_set_reg_val(_GET_DEVID(event),
329 				_GET_BANK(event), _GET_CNTR(event),
330 				IOMMU_PC_COUNTER_REG, &count, false);
331 
332 	/* IOMMU pc counter register is only 48 bits */
333 	count &= 0xFFFFFFFFFFFFULL;
334 
335 	prev_raw_count =  local64_read(&hwc->prev_count);
336 	if (local64_cmpxchg(&hwc->prev_count, prev_raw_count,
337 					count) != prev_raw_count)
338 		return;
339 
340 	/* Handling 48-bit counter overflowing */
341 	delta = (count << COUNTER_SHIFT) - (prev_raw_count << COUNTER_SHIFT);
342 	delta >>= COUNTER_SHIFT;
343 	local64_add(delta, &event->count);
344 
345 }
346 
347 static void perf_iommu_stop(struct perf_event *event, int flags)
348 {
349 	struct hw_perf_event *hwc = &event->hw;
350 	u64 config;
351 
352 	pr_debug("perf: amd_iommu:perf_iommu_stop\n");
353 
354 	if (hwc->state & PERF_HES_UPTODATE)
355 		return;
356 
357 	perf_iommu_disable_event(event);
358 	WARN_ON_ONCE(hwc->state & PERF_HES_STOPPED);
359 	hwc->state |= PERF_HES_STOPPED;
360 
361 	if (hwc->state & PERF_HES_UPTODATE)
362 		return;
363 
364 	config = hwc->config;
365 	perf_iommu_read(event);
366 	hwc->state |= PERF_HES_UPTODATE;
367 }
368 
369 static int perf_iommu_add(struct perf_event *event, int flags)
370 {
371 	int retval;
372 	struct perf_amd_iommu *perf_iommu =
373 			container_of(event->pmu, struct perf_amd_iommu, pmu);
374 
375 	pr_debug("perf: amd_iommu:perf_iommu_add\n");
376 	event->hw.state = PERF_HES_UPTODATE | PERF_HES_STOPPED;
377 
378 	/* request an iommu bank/counter */
379 	retval = get_next_avail_iommu_bnk_cntr(perf_iommu);
380 	if (retval != -ENOSPC)
381 		event->hw.extra_reg.reg = (u16)retval;
382 	else
383 		return retval;
384 
385 	if (flags & PERF_EF_START)
386 		perf_iommu_start(event, PERF_EF_RELOAD);
387 
388 	return 0;
389 }
390 
391 static void perf_iommu_del(struct perf_event *event, int flags)
392 {
393 	struct perf_amd_iommu *perf_iommu =
394 			container_of(event->pmu, struct perf_amd_iommu, pmu);
395 
396 	pr_debug("perf: amd_iommu:perf_iommu_del\n");
397 	perf_iommu_stop(event, PERF_EF_UPDATE);
398 
399 	/* clear the assigned iommu bank/counter */
400 	clear_avail_iommu_bnk_cntr(perf_iommu,
401 				     _GET_BANK(event),
402 				     _GET_CNTR(event));
403 
404 	perf_event_update_userpage(event);
405 }
406 
407 static __init int _init_events_attrs(struct perf_amd_iommu *perf_iommu)
408 {
409 	struct attribute **attrs;
410 	struct attribute_group *attr_group;
411 	int i = 0, j;
412 
413 	while (amd_iommu_v2_event_descs[i].attr.attr.name)
414 		i++;
415 
416 	attr_group = kzalloc(sizeof(struct attribute *)
417 		* (i + 1) + sizeof(*attr_group), GFP_KERNEL);
418 	if (!attr_group)
419 		return -ENOMEM;
420 
421 	attrs = (struct attribute **)(attr_group + 1);
422 	for (j = 0; j < i; j++)
423 		attrs[j] = &amd_iommu_v2_event_descs[j].attr.attr;
424 
425 	attr_group->name = "events";
426 	attr_group->attrs = attrs;
427 	perf_iommu->events_group = attr_group;
428 
429 	return 0;
430 }
431 
432 static __init void amd_iommu_pc_exit(void)
433 {
434 	if (__perf_iommu.events_group != NULL) {
435 		kfree(__perf_iommu.events_group);
436 		__perf_iommu.events_group = NULL;
437 	}
438 }
439 
440 static __init int _init_perf_amd_iommu(
441 	struct perf_amd_iommu *perf_iommu, char *name)
442 {
443 	int ret;
444 
445 	raw_spin_lock_init(&perf_iommu->lock);
446 
447 	/* Init format attributes */
448 	perf_iommu->format_group = &amd_iommu_format_group;
449 
450 	/* Init cpumask attributes to only core 0 */
451 	cpumask_set_cpu(0, &iommu_cpumask);
452 	perf_iommu->cpumask_group = &amd_iommu_cpumask_group;
453 
454 	/* Init events attributes */
455 	if (_init_events_attrs(perf_iommu) != 0)
456 		pr_err("perf: amd_iommu: Only support raw events.\n");
457 
458 	/* Init null attributes */
459 	perf_iommu->null_group = NULL;
460 	perf_iommu->pmu.attr_groups = perf_iommu->attr_groups;
461 
462 	ret = perf_pmu_register(&perf_iommu->pmu, name, -1);
463 	if (ret) {
464 		pr_err("perf: amd_iommu: Failed to initialized.\n");
465 		amd_iommu_pc_exit();
466 	} else {
467 		pr_info("perf: amd_iommu: Detected. (%d banks, %d counters/bank)\n",
468 			amd_iommu_pc_get_max_banks(IOMMU_BASE_DEVID),
469 			amd_iommu_pc_get_max_counters(IOMMU_BASE_DEVID));
470 	}
471 
472 	return ret;
473 }
474 
475 static struct perf_amd_iommu __perf_iommu = {
476 	.pmu = {
477 		.task_ctx_nr    = perf_invalid_context,
478 		.event_init	= perf_iommu_event_init,
479 		.add		= perf_iommu_add,
480 		.del		= perf_iommu_del,
481 		.start		= perf_iommu_start,
482 		.stop		= perf_iommu_stop,
483 		.read		= perf_iommu_read,
484 	},
485 	.max_banks		= 0x00,
486 	.max_counters		= 0x00,
487 	.cntr_assign_mask	= 0ULL,
488 	.format_group		= NULL,
489 	.cpumask_group		= NULL,
490 	.events_group		= NULL,
491 	.null_group		= NULL,
492 };
493 
494 static __init int amd_iommu_pc_init(void)
495 {
496 	/* Make sure the IOMMU PC resource is available */
497 	if (!amd_iommu_pc_supported())
498 		return -ENODEV;
499 
500 	_init_perf_amd_iommu(&__perf_iommu, "amd_iommu");
501 
502 	return 0;
503 }
504 
505 device_initcall(amd_iommu_pc_init);
506