xref: /linux/drivers/gpu/drm/i915/gt/selftest_gt_pm.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2019 Intel Corporation
4  */
5 
6 #include <linux/sort.h>
7 
8 #include "intel_engine_regs.h"
9 #include "intel_gt_clock_utils.h"
10 
11 #include "selftest_llc.h"
12 #include "selftest_rc6.h"
13 #include "selftest_rps.h"
14 
15 static int cmp_u64(const void *A, const void *B)
16 {
17 	const u64 *a = A, *b = B;
18 
19 	if (a < b)
20 		return -1;
21 	else if (a > b)
22 		return 1;
23 	else
24 		return 0;
25 }
26 
27 static int cmp_u32(const void *A, const void *B)
28 {
29 	const u32 *a = A, *b = B;
30 
31 	if (a < b)
32 		return -1;
33 	else if (a > b)
34 		return 1;
35 	else
36 		return 0;
37 }
38 
39 static u32 read_timestamp(struct intel_engine_cs *engine)
40 {
41 	struct drm_i915_private *i915 = engine->i915;
42 
43 	/* On i965 the first read tends to give a stale value */
44 	ENGINE_READ_FW(engine, RING_TIMESTAMP);
45 
46 	if (GRAPHICS_VER(i915) == 5 || IS_G4X(i915))
47 		return ENGINE_READ_FW(engine, RING_TIMESTAMP_UDW);
48 	else
49 		return ENGINE_READ_FW(engine, RING_TIMESTAMP);
50 }
51 
52 static void measure_clocks(struct intel_engine_cs *engine,
53 			   u32 *out_cycles, ktime_t *out_dt)
54 {
55 	ktime_t dt[5];
56 	u32 cycles[5];
57 	int i;
58 
59 	for (i = 0; i < 5; i++) {
60 		local_irq_disable();
61 		cycles[i] = -read_timestamp(engine);
62 		dt[i] = ktime_get();
63 
64 		udelay(1000);
65 
66 		cycles[i] += read_timestamp(engine);
67 		dt[i] = ktime_sub(ktime_get(), dt[i]);
68 		local_irq_enable();
69 	}
70 
71 	/* Use the median of both cycle/dt; close enough */
72 	sort(cycles, 5, sizeof(*cycles), cmp_u32, NULL);
73 	*out_cycles = (cycles[1] + 2 * cycles[2] + cycles[3]) / 4;
74 
75 	sort(dt, 5, sizeof(*dt), cmp_u64, NULL);
76 	*out_dt = div_u64(dt[1] + 2 * dt[2] + dt[3], 4);
77 }
78 
79 static int live_gt_clocks(void *arg)
80 {
81 	struct intel_gt *gt = arg;
82 	struct intel_engine_cs *engine;
83 	enum intel_engine_id id;
84 	intel_wakeref_t wakeref;
85 	int err = 0;
86 
87 	if (!gt->clock_frequency) { /* unknown */
88 		pr_info("CS_TIMESTAMP frequency unknown\n");
89 		return 0;
90 	}
91 
92 	if (GRAPHICS_VER(gt->i915) < 4) /* Any CS_TIMESTAMP? */
93 		return 0;
94 
95 	wakeref = intel_gt_pm_get(gt);
96 	intel_uncore_forcewake_get(gt->uncore, FORCEWAKE_ALL);
97 
98 	for_each_engine(engine, gt, id) {
99 		u32 cycles;
100 		u32 expected;
101 		u64 time;
102 		u64 dt;
103 
104 		if (GRAPHICS_VER(engine->i915) < 7 && engine->id != RCS0)
105 			continue;
106 
107 		measure_clocks(engine, &cycles, &dt);
108 
109 		time = intel_gt_clock_interval_to_ns(engine->gt, cycles);
110 		expected = intel_gt_ns_to_clock_interval(engine->gt, dt);
111 
112 		pr_info("%s: TIMESTAMP %d cycles [%lldns] in %lldns [%d cycles], using CS clock frequency of %uKHz\n",
113 			engine->name, cycles, time, dt, expected,
114 			engine->gt->clock_frequency / 1000);
115 
116 		if (9 * time < 8 * dt || 8 * time > 9 * dt) {
117 			pr_err("%s: CS ticks did not match walltime!\n",
118 			       engine->name);
119 			err = -EINVAL;
120 			break;
121 		}
122 
123 		if (9 * expected < 8 * cycles || 8 * expected > 9 * cycles) {
124 			pr_err("%s: walltime did not match CS ticks!\n",
125 			       engine->name);
126 			err = -EINVAL;
127 			break;
128 		}
129 	}
130 
131 	intel_uncore_forcewake_put(gt->uncore, FORCEWAKE_ALL);
132 	intel_gt_pm_put(gt, wakeref);
133 
134 	return err;
135 }
136 
137 static int live_gt_resume(void *arg)
138 {
139 	struct intel_gt *gt = arg;
140 	IGT_TIMEOUT(end_time);
141 	int err;
142 
143 	/* Do several suspend/resume cycles to check we don't explode! */
144 	do {
145 		intel_gt_suspend_prepare(gt);
146 		intel_gt_suspend_late(gt);
147 
148 		if (gt->rc6.enabled) {
149 			pr_err("rc6 still enabled after suspend!\n");
150 			intel_gt_set_wedged_on_init(gt);
151 			err = -EINVAL;
152 			break;
153 		}
154 
155 		err = intel_gt_resume(gt);
156 		if (err)
157 			break;
158 
159 		if (gt->rc6.supported && !gt->rc6.enabled) {
160 			pr_err("rc6 not enabled upon resume!\n");
161 			intel_gt_set_wedged_on_init(gt);
162 			err = -EINVAL;
163 			break;
164 		}
165 
166 		err = st_llc_verify(&gt->llc);
167 		if (err) {
168 			pr_err("llc state not restored upon resume!\n");
169 			intel_gt_set_wedged_on_init(gt);
170 			break;
171 		}
172 	} while (!__igt_timeout(end_time, NULL));
173 
174 	return err;
175 }
176 
177 int intel_gt_pm_live_selftests(struct drm_i915_private *i915)
178 {
179 	static const struct i915_subtest tests[] = {
180 		SUBTEST(live_gt_clocks),
181 		SUBTEST(live_rc6_manual),
182 		SUBTEST(live_rps_clock_interval),
183 		SUBTEST(live_rps_control),
184 		SUBTEST(live_rps_frequency_cs),
185 		SUBTEST(live_rps_frequency_srm),
186 		SUBTEST(live_rps_power),
187 		SUBTEST(live_rps_interrupt),
188 		SUBTEST(live_rps_dynamic),
189 		SUBTEST(live_gt_resume),
190 	};
191 
192 	if (intel_gt_is_wedged(to_gt(i915)))
193 		return 0;
194 
195 	return intel_gt_live_subtests(tests, to_gt(i915));
196 }
197 
198 int intel_gt_pm_late_selftests(struct drm_i915_private *i915)
199 {
200 	static const struct i915_subtest tests[] = {
201 		/*
202 		 * These tests may leave the system in an undesirable state.
203 		 * They are intended to be run last in CI and the system
204 		 * rebooted afterwards.
205 		 */
206 		SUBTEST(live_rc6_ctx_wa),
207 	};
208 
209 	if (intel_gt_is_wedged(to_gt(i915)))
210 		return 0;
211 
212 	return intel_gt_live_subtests(tests, to_gt(i915));
213 }
214