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1 /* Driver for Intel Xeon Phi "Knights Corner" PMU */
2 
3 #include <linux/perf_event.h>
4 #include <linux/types.h>
5 
6 #include <asm/hardirq.h>
7 
8 #include "perf_event.h"
9 
10 static const u64 knc_perfmon_event_map[] =
11 {
12   [PERF_COUNT_HW_CPU_CYCLES]		= 0x002a,
13   [PERF_COUNT_HW_INSTRUCTIONS]		= 0x0016,
14   [PERF_COUNT_HW_CACHE_REFERENCES]	= 0x0028,
15   [PERF_COUNT_HW_CACHE_MISSES]		= 0x0029,
16   [PERF_COUNT_HW_BRANCH_INSTRUCTIONS]	= 0x0012,
17   [PERF_COUNT_HW_BRANCH_MISSES]		= 0x002b,
18 };
19 
20 static const u64 __initconst knc_hw_cache_event_ids
21 				[PERF_COUNT_HW_CACHE_MAX]
22 				[PERF_COUNT_HW_CACHE_OP_MAX]
23 				[PERF_COUNT_HW_CACHE_RESULT_MAX] =
24 {
25  [ C(L1D) ] = {
26 	[ C(OP_READ) ] = {
27 		/* On Xeon Phi event "0" is a valid DATA_READ          */
28 		/*   (L1 Data Cache Reads) Instruction.                */
29 		/* We code this as ARCH_PERFMON_EVENTSEL_INT as this   */
30 		/* bit will always be set in x86_pmu_hw_config().      */
31 		[ C(RESULT_ACCESS) ] = ARCH_PERFMON_EVENTSEL_INT,
32 						/* DATA_READ           */
33 		[ C(RESULT_MISS)   ] = 0x0003,	/* DATA_READ_MISS      */
34 	},
35 	[ C(OP_WRITE) ] = {
36 		[ C(RESULT_ACCESS) ] = 0x0001,	/* DATA_WRITE          */
37 		[ C(RESULT_MISS)   ] = 0x0004,	/* DATA_WRITE_MISS     */
38 	},
39 	[ C(OP_PREFETCH) ] = {
40 		[ C(RESULT_ACCESS) ] = 0x0011,	/* L1_DATA_PF1         */
41 		[ C(RESULT_MISS)   ] = 0x001c,	/* L1_DATA_PF1_MISS    */
42 	},
43  },
44  [ C(L1I ) ] = {
45 	[ C(OP_READ) ] = {
46 		[ C(RESULT_ACCESS) ] = 0x000c,	/* CODE_READ          */
47 		[ C(RESULT_MISS)   ] = 0x000e,	/* CODE_CACHE_MISS    */
48 	},
49 	[ C(OP_WRITE) ] = {
50 		[ C(RESULT_ACCESS) ] = -1,
51 		[ C(RESULT_MISS)   ] = -1,
52 	},
53 	[ C(OP_PREFETCH) ] = {
54 		[ C(RESULT_ACCESS) ] = 0x0,
55 		[ C(RESULT_MISS)   ] = 0x0,
56 	},
57  },
58  [ C(LL  ) ] = {
59 	[ C(OP_READ) ] = {
60 		[ C(RESULT_ACCESS) ] = 0,
61 		[ C(RESULT_MISS)   ] = 0x10cb,	/* L2_READ_MISS */
62 	},
63 	[ C(OP_WRITE) ] = {
64 		[ C(RESULT_ACCESS) ] = 0x10cc,	/* L2_WRITE_HIT */
65 		[ C(RESULT_MISS)   ] = 0,
66 	},
67 	[ C(OP_PREFETCH) ] = {
68 		[ C(RESULT_ACCESS) ] = 0x10fc,	/* L2_DATA_PF2      */
69 		[ C(RESULT_MISS)   ] = 0x10fe,	/* L2_DATA_PF2_MISS */
70 	},
71  },
72  [ C(DTLB) ] = {
73 	[ C(OP_READ) ] = {
74 		[ C(RESULT_ACCESS) ] = ARCH_PERFMON_EVENTSEL_INT,
75 						/* DATA_READ */
76 						/* see note on L1 OP_READ */
77 		[ C(RESULT_MISS)   ] = 0x0002,	/* DATA_PAGE_WALK */
78 	},
79 	[ C(OP_WRITE) ] = {
80 		[ C(RESULT_ACCESS) ] = 0x0001,	/* DATA_WRITE */
81 		[ C(RESULT_MISS)   ] = 0x0002,	/* DATA_PAGE_WALK */
82 	},
83 	[ C(OP_PREFETCH) ] = {
84 		[ C(RESULT_ACCESS) ] = 0x0,
85 		[ C(RESULT_MISS)   ] = 0x0,
86 	},
87  },
88  [ C(ITLB) ] = {
89 	[ C(OP_READ) ] = {
90 		[ C(RESULT_ACCESS) ] = 0x000c,	/* CODE_READ */
91 		[ C(RESULT_MISS)   ] = 0x000d,	/* CODE_PAGE_WALK */
92 	},
93 	[ C(OP_WRITE) ] = {
94 		[ C(RESULT_ACCESS) ] = -1,
95 		[ C(RESULT_MISS)   ] = -1,
96 	},
97 	[ C(OP_PREFETCH) ] = {
98 		[ C(RESULT_ACCESS) ] = -1,
99 		[ C(RESULT_MISS)   ] = -1,
100 	},
101  },
102  [ C(BPU ) ] = {
103 	[ C(OP_READ) ] = {
104 		[ C(RESULT_ACCESS) ] = 0x0012,	/* BRANCHES */
105 		[ C(RESULT_MISS)   ] = 0x002b,	/* BRANCHES_MISPREDICTED */
106 	},
107 	[ C(OP_WRITE) ] = {
108 		[ C(RESULT_ACCESS) ] = -1,
109 		[ C(RESULT_MISS)   ] = -1,
110 	},
111 	[ C(OP_PREFETCH) ] = {
112 		[ C(RESULT_ACCESS) ] = -1,
113 		[ C(RESULT_MISS)   ] = -1,
114 	},
115  },
116 };
117 
118 
knc_pmu_event_map(int hw_event)119 static u64 knc_pmu_event_map(int hw_event)
120 {
121 	return knc_perfmon_event_map[hw_event];
122 }
123 
124 static struct event_constraint knc_event_constraints[] =
125 {
126 	INTEL_EVENT_CONSTRAINT(0xc3, 0x1),	/* HWP_L2HIT */
127 	INTEL_EVENT_CONSTRAINT(0xc4, 0x1),	/* HWP_L2MISS */
128 	INTEL_EVENT_CONSTRAINT(0xc8, 0x1),	/* L2_READ_HIT_E */
129 	INTEL_EVENT_CONSTRAINT(0xc9, 0x1),	/* L2_READ_HIT_M */
130 	INTEL_EVENT_CONSTRAINT(0xca, 0x1),	/* L2_READ_HIT_S */
131 	INTEL_EVENT_CONSTRAINT(0xcb, 0x1),	/* L2_READ_MISS */
132 	INTEL_EVENT_CONSTRAINT(0xcc, 0x1),	/* L2_WRITE_HIT */
133 	INTEL_EVENT_CONSTRAINT(0xce, 0x1),	/* L2_STRONGLY_ORDERED_STREAMING_VSTORES_MISS */
134 	INTEL_EVENT_CONSTRAINT(0xcf, 0x1),	/* L2_WEAKLY_ORDERED_STREAMING_VSTORE_MISS */
135 	INTEL_EVENT_CONSTRAINT(0xd7, 0x1),	/* L2_VICTIM_REQ_WITH_DATA */
136 	INTEL_EVENT_CONSTRAINT(0xe3, 0x1),	/* SNP_HITM_BUNIT */
137 	INTEL_EVENT_CONSTRAINT(0xe6, 0x1),	/* SNP_HIT_L2 */
138 	INTEL_EVENT_CONSTRAINT(0xe7, 0x1),	/* SNP_HITM_L2 */
139 	INTEL_EVENT_CONSTRAINT(0xf1, 0x1),	/* L2_DATA_READ_MISS_CACHE_FILL */
140 	INTEL_EVENT_CONSTRAINT(0xf2, 0x1),	/* L2_DATA_WRITE_MISS_CACHE_FILL */
141 	INTEL_EVENT_CONSTRAINT(0xf6, 0x1),	/* L2_DATA_READ_MISS_MEM_FILL */
142 	INTEL_EVENT_CONSTRAINT(0xf7, 0x1),	/* L2_DATA_WRITE_MISS_MEM_FILL */
143 	INTEL_EVENT_CONSTRAINT(0xfc, 0x1),	/* L2_DATA_PF2 */
144 	INTEL_EVENT_CONSTRAINT(0xfd, 0x1),	/* L2_DATA_PF2_DROP */
145 	INTEL_EVENT_CONSTRAINT(0xfe, 0x1),	/* L2_DATA_PF2_MISS */
146 	INTEL_EVENT_CONSTRAINT(0xff, 0x1),	/* L2_DATA_HIT_INFLIGHT_PF2 */
147 	EVENT_CONSTRAINT_END
148 };
149 
150 #define MSR_KNC_IA32_PERF_GLOBAL_STATUS		0x0000002d
151 #define MSR_KNC_IA32_PERF_GLOBAL_OVF_CONTROL	0x0000002e
152 #define MSR_KNC_IA32_PERF_GLOBAL_CTRL		0x0000002f
153 
154 #define KNC_ENABLE_COUNTER0			0x00000001
155 #define KNC_ENABLE_COUNTER1			0x00000002
156 
knc_pmu_disable_all(void)157 static void knc_pmu_disable_all(void)
158 {
159 	u64 val;
160 
161 	rdmsrl(MSR_KNC_IA32_PERF_GLOBAL_CTRL, val);
162 	val &= ~(KNC_ENABLE_COUNTER0|KNC_ENABLE_COUNTER1);
163 	wrmsrl(MSR_KNC_IA32_PERF_GLOBAL_CTRL, val);
164 }
165 
knc_pmu_enable_all(int added)166 static void knc_pmu_enable_all(int added)
167 {
168 	u64 val;
169 
170 	rdmsrl(MSR_KNC_IA32_PERF_GLOBAL_CTRL, val);
171 	val |= (KNC_ENABLE_COUNTER0|KNC_ENABLE_COUNTER1);
172 	wrmsrl(MSR_KNC_IA32_PERF_GLOBAL_CTRL, val);
173 }
174 
175 static inline void
knc_pmu_disable_event(struct perf_event * event)176 knc_pmu_disable_event(struct perf_event *event)
177 {
178 	struct hw_perf_event *hwc = &event->hw;
179 	u64 val;
180 
181 	val = hwc->config;
182 	val &= ~ARCH_PERFMON_EVENTSEL_ENABLE;
183 
184 	(void)wrmsrl_safe(hwc->config_base + hwc->idx, val);
185 }
186 
knc_pmu_enable_event(struct perf_event * event)187 static void knc_pmu_enable_event(struct perf_event *event)
188 {
189 	struct hw_perf_event *hwc = &event->hw;
190 	u64 val;
191 
192 	val = hwc->config;
193 	val |= ARCH_PERFMON_EVENTSEL_ENABLE;
194 
195 	(void)wrmsrl_safe(hwc->config_base + hwc->idx, val);
196 }
197 
knc_pmu_get_status(void)198 static inline u64 knc_pmu_get_status(void)
199 {
200 	u64 status;
201 
202 	rdmsrl(MSR_KNC_IA32_PERF_GLOBAL_STATUS, status);
203 
204 	return status;
205 }
206 
knc_pmu_ack_status(u64 ack)207 static inline void knc_pmu_ack_status(u64 ack)
208 {
209 	wrmsrl(MSR_KNC_IA32_PERF_GLOBAL_OVF_CONTROL, ack);
210 }
211 
knc_pmu_handle_irq(struct pt_regs * regs)212 static int knc_pmu_handle_irq(struct pt_regs *regs)
213 {
214 	struct perf_sample_data data;
215 	struct cpu_hw_events *cpuc;
216 	int handled = 0;
217 	int bit, loops;
218 	u64 status;
219 
220 	cpuc = this_cpu_ptr(&cpu_hw_events);
221 
222 	knc_pmu_disable_all();
223 
224 	status = knc_pmu_get_status();
225 	if (!status) {
226 		knc_pmu_enable_all(0);
227 		return handled;
228 	}
229 
230 	loops = 0;
231 again:
232 	knc_pmu_ack_status(status);
233 	if (++loops > 100) {
234 		WARN_ONCE(1, "perf: irq loop stuck!\n");
235 		perf_event_print_debug();
236 		goto done;
237 	}
238 
239 	inc_irq_stat(apic_perf_irqs);
240 
241 	for_each_set_bit(bit, (unsigned long *)&status, X86_PMC_IDX_MAX) {
242 		struct perf_event *event = cpuc->events[bit];
243 
244 		handled++;
245 
246 		if (!test_bit(bit, cpuc->active_mask))
247 			continue;
248 
249 		if (!intel_pmu_save_and_restart(event))
250 			continue;
251 
252 		perf_sample_data_init(&data, 0, event->hw.last_period);
253 
254 		if (perf_event_overflow(event, &data, regs))
255 			x86_pmu_stop(event, 0);
256 	}
257 
258 	/*
259 	 * Repeat if there is more work to be done:
260 	 */
261 	status = knc_pmu_get_status();
262 	if (status)
263 		goto again;
264 
265 done:
266 	/* Only restore PMU state when it's active. See x86_pmu_disable(). */
267 	if (cpuc->enabled)
268 		knc_pmu_enable_all(0);
269 
270 	return handled;
271 }
272 
273 
274 PMU_FORMAT_ATTR(event,	"config:0-7"	);
275 PMU_FORMAT_ATTR(umask,	"config:8-15"	);
276 PMU_FORMAT_ATTR(edge,	"config:18"	);
277 PMU_FORMAT_ATTR(inv,	"config:23"	);
278 PMU_FORMAT_ATTR(cmask,	"config:24-31"	);
279 
280 static struct attribute *intel_knc_formats_attr[] = {
281 	&format_attr_event.attr,
282 	&format_attr_umask.attr,
283 	&format_attr_edge.attr,
284 	&format_attr_inv.attr,
285 	&format_attr_cmask.attr,
286 	NULL,
287 };
288 
289 static const struct x86_pmu knc_pmu __initconst = {
290 	.name			= "knc",
291 	.handle_irq		= knc_pmu_handle_irq,
292 	.disable_all		= knc_pmu_disable_all,
293 	.enable_all		= knc_pmu_enable_all,
294 	.enable			= knc_pmu_enable_event,
295 	.disable		= knc_pmu_disable_event,
296 	.hw_config		= x86_pmu_hw_config,
297 	.schedule_events	= x86_schedule_events,
298 	.eventsel		= MSR_KNC_EVNTSEL0,
299 	.perfctr		= MSR_KNC_PERFCTR0,
300 	.event_map		= knc_pmu_event_map,
301 	.max_events             = ARRAY_SIZE(knc_perfmon_event_map),
302 	.apic			= 1,
303 	.max_period		= (1ULL << 39) - 1,
304 	.version		= 0,
305 	.num_counters		= 2,
306 	.cntval_bits		= 40,
307 	.cntval_mask		= (1ULL << 40) - 1,
308 	.get_event_constraints	= x86_get_event_constraints,
309 	.event_constraints	= knc_event_constraints,
310 	.format_attrs		= intel_knc_formats_attr,
311 };
312 
knc_pmu_init(void)313 __init int knc_pmu_init(void)
314 {
315 	x86_pmu = knc_pmu;
316 
317 	memcpy(hw_cache_event_ids, knc_hw_cache_event_ids,
318 		sizeof(hw_cache_event_ids));
319 
320 	return 0;
321 }
322