xref: /linux/drivers/gpu/drm/i915/gt/selftest_gt_pm.c (revision cbafa54aa2ae23939846e150ad4ba98c784f6395)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2019 Intel Corporation
4  */
5 
6 #include <linux/sort.h>
7 
8 #include "intel_gt_clock_utils.h"
9 
10 #include "selftest_llc.h"
11 #include "selftest_rc6.h"
12 #include "selftest_rps.h"
13 
14 static int cmp_u64(const void *A, const void *B)
15 {
16 	const u64 *a = A, *b = B;
17 
18 	if (a < b)
19 		return -1;
20 	else if (a > b)
21 		return 1;
22 	else
23 		return 0;
24 }
25 
26 static int cmp_u32(const void *A, const void *B)
27 {
28 	const u32 *a = A, *b = B;
29 
30 	if (a < b)
31 		return -1;
32 	else if (a > b)
33 		return 1;
34 	else
35 		return 0;
36 }
37 
38 static void measure_clocks(struct intel_engine_cs *engine,
39 			   u32 *out_cycles, ktime_t *out_dt)
40 {
41 	ktime_t dt[5];
42 	u32 cycles[5];
43 	int i;
44 
45 	for (i = 0; i < 5; i++) {
46 		preempt_disable();
47 		cycles[i] = -ENGINE_READ_FW(engine, RING_TIMESTAMP);
48 		dt[i] = ktime_get();
49 
50 		udelay(1000);
51 
52 		dt[i] = ktime_sub(ktime_get(), dt[i]);
53 		cycles[i] += ENGINE_READ_FW(engine, RING_TIMESTAMP);
54 		preempt_enable();
55 	}
56 
57 	/* Use the median of both cycle/dt; close enough */
58 	sort(cycles, 5, sizeof(*cycles), cmp_u32, NULL);
59 	*out_cycles = (cycles[1] + 2 * cycles[2] + cycles[3]) / 4;
60 
61 	sort(dt, 5, sizeof(*dt), cmp_u64, NULL);
62 	*out_dt = div_u64(dt[1] + 2 * dt[2] + dt[3], 4);
63 }
64 
65 static int live_gt_clocks(void *arg)
66 {
67 	struct intel_gt *gt = arg;
68 	struct intel_engine_cs *engine;
69 	enum intel_engine_id id;
70 	int err = 0;
71 
72 	if (!gt->clock_frequency) { /* unknown */
73 		pr_info("CS_TIMESTAMP frequency unknown\n");
74 		return 0;
75 	}
76 
77 	if (INTEL_GEN(gt->i915) < 4) /* Any CS_TIMESTAMP? */
78 		return 0;
79 
80 	if (IS_GEN(gt->i915, 5))
81 		/*
82 		 * XXX CS_TIMESTAMP low dword is dysfunctional?
83 		 *
84 		 * Ville's experiments indicate the high dword still works,
85 		 * but at a correspondingly reduced frequency.
86 		 */
87 		return 0;
88 
89 	if (IS_GEN(gt->i915, 4))
90 		/*
91 		 * XXX CS_TIMESTAMP appears gibberish
92 		 *
93 		 * Ville's experiments indicate that it mostly appears 'stuck'
94 		 * in that we see the register report the same cycle count
95 		 * for a couple of reads.
96 		 */
97 		return 0;
98 
99 	intel_gt_pm_get(gt);
100 	intel_uncore_forcewake_get(gt->uncore, FORCEWAKE_ALL);
101 
102 	for_each_engine(engine, gt, id) {
103 		u32 cycles;
104 		u32 expected;
105 		u64 time;
106 		u64 dt;
107 
108 		if (INTEL_GEN(engine->i915) < 7 && engine->id != RCS0)
109 			continue;
110 
111 		measure_clocks(engine, &cycles, &dt);
112 
113 		time = intel_gt_clock_interval_to_ns(engine->gt, cycles);
114 		expected = intel_gt_ns_to_clock_interval(engine->gt, dt);
115 
116 		pr_info("%s: TIMESTAMP %d cycles [%lldns] in %lldns [%d cycles], using CS clock frequency of %uKHz\n",
117 			engine->name, cycles, time, dt, expected,
118 			engine->gt->clock_frequency / 1000);
119 
120 		if (9 * time < 8 * dt || 8 * time > 9 * dt) {
121 			pr_err("%s: CS ticks did not match walltime!\n",
122 			       engine->name);
123 			err = -EINVAL;
124 			break;
125 		}
126 
127 		if (9 * expected < 8 * cycles || 8 * expected > 9 * cycles) {
128 			pr_err("%s: walltime did not match CS ticks!\n",
129 			       engine->name);
130 			err = -EINVAL;
131 			break;
132 		}
133 	}
134 
135 	intel_uncore_forcewake_put(gt->uncore, FORCEWAKE_ALL);
136 	intel_gt_pm_put(gt);
137 
138 	return err;
139 }
140 
141 static int live_gt_resume(void *arg)
142 {
143 	struct intel_gt *gt = arg;
144 	IGT_TIMEOUT(end_time);
145 	int err;
146 
147 	/* Do several suspend/resume cycles to check we don't explode! */
148 	do {
149 		intel_gt_suspend_prepare(gt);
150 		intel_gt_suspend_late(gt);
151 
152 		if (gt->rc6.enabled) {
153 			pr_err("rc6 still enabled after suspend!\n");
154 			intel_gt_set_wedged_on_init(gt);
155 			err = -EINVAL;
156 			break;
157 		}
158 
159 		err = intel_gt_resume(gt);
160 		if (err)
161 			break;
162 
163 		if (gt->rc6.supported && !gt->rc6.enabled) {
164 			pr_err("rc6 not enabled upon resume!\n");
165 			intel_gt_set_wedged_on_init(gt);
166 			err = -EINVAL;
167 			break;
168 		}
169 
170 		err = st_llc_verify(&gt->llc);
171 		if (err) {
172 			pr_err("llc state not restored upon resume!\n");
173 			intel_gt_set_wedged_on_init(gt);
174 			break;
175 		}
176 	} while (!__igt_timeout(end_time, NULL));
177 
178 	return err;
179 }
180 
181 int intel_gt_pm_live_selftests(struct drm_i915_private *i915)
182 {
183 	static const struct i915_subtest tests[] = {
184 		SUBTEST(live_gt_clocks),
185 		SUBTEST(live_rc6_manual),
186 		SUBTEST(live_rps_clock_interval),
187 		SUBTEST(live_rps_control),
188 		SUBTEST(live_rps_frequency_cs),
189 		SUBTEST(live_rps_frequency_srm),
190 		SUBTEST(live_rps_power),
191 		SUBTEST(live_rps_interrupt),
192 		SUBTEST(live_rps_dynamic),
193 		SUBTEST(live_gt_resume),
194 	};
195 
196 	if (intel_gt_is_wedged(&i915->gt))
197 		return 0;
198 
199 	return intel_gt_live_subtests(tests, &i915->gt);
200 }
201 
202 int intel_gt_pm_late_selftests(struct drm_i915_private *i915)
203 {
204 	static const struct i915_subtest tests[] = {
205 		/*
206 		 * These tests may leave the system in an undesirable state.
207 		 * They are intended to be run last in CI and the system
208 		 * rebooted afterwards.
209 		 */
210 		SUBTEST(live_rc6_ctx_wa),
211 	};
212 
213 	if (intel_gt_is_wedged(&i915->gt))
214 		return 0;
215 
216 	return intel_gt_live_subtests(tests, &i915->gt);
217 }
218