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1 /*
2  * SPDX-License-Identifier: MIT
3  *
4  * Copyright © 2019 Intel Corporation
5  */
6 
7 #include "intel_context.h"
8 #include "intel_engine_pm.h"
9 #include "intel_gt_requests.h"
10 #include "intel_ring.h"
11 #include "selftest_rc6.h"
12 
13 #include "selftests/i915_random.h"
14 #include "selftests/librapl.h"
15 
rc6_residency(struct intel_rc6 * rc6)16 static u64 rc6_residency(struct intel_rc6 *rc6)
17 {
18 	u64 result;
19 
20 	/* XXX VLV_GT_MEDIA_RC6? */
21 
22 	result = intel_rc6_residency_ns(rc6, GEN6_GT_GFX_RC6);
23 	if (HAS_RC6p(rc6_to_i915(rc6)))
24 		result += intel_rc6_residency_ns(rc6, GEN6_GT_GFX_RC6p);
25 	if (HAS_RC6pp(rc6_to_i915(rc6)))
26 		result += intel_rc6_residency_ns(rc6, GEN6_GT_GFX_RC6pp);
27 
28 	return result;
29 }
30 
live_rc6_manual(void * arg)31 int live_rc6_manual(void *arg)
32 {
33 	struct intel_gt *gt = arg;
34 	struct intel_rc6 *rc6 = &gt->rc6;
35 	u64 rc0_power, rc6_power;
36 	intel_wakeref_t wakeref;
37 	ktime_t dt;
38 	u64 res[2];
39 	int err = 0;
40 
41 	/*
42 	 * Our claim is that we can "encourage" the GPU to enter rc6 at will.
43 	 * Let's try it!
44 	 */
45 
46 	if (!rc6->enabled)
47 		return 0;
48 
49 	/* bsw/byt use a PCU and decouple RC6 from our manual control */
50 	if (IS_VALLEYVIEW(gt->i915) || IS_CHERRYVIEW(gt->i915))
51 		return 0;
52 
53 	wakeref = intel_runtime_pm_get(gt->uncore->rpm);
54 
55 	/* Force RC6 off for starters */
56 	__intel_rc6_disable(rc6);
57 	msleep(1); /* wakeup is not immediate, takes about 100us on icl */
58 
59 	res[0] = rc6_residency(rc6);
60 
61 	dt = ktime_get();
62 	rc0_power = librapl_energy_uJ();
63 	msleep(250);
64 	rc0_power = librapl_energy_uJ() - rc0_power;
65 	dt = ktime_sub(ktime_get(), dt);
66 	res[1] = rc6_residency(rc6);
67 	if ((res[1] - res[0]) >> 10) {
68 		pr_err("RC6 residency increased by %lldus while disabled for 250ms!\n",
69 		       (res[1] - res[0]) >> 10);
70 		err = -EINVAL;
71 		goto out_unlock;
72 	}
73 
74 	rc0_power = div64_u64(NSEC_PER_SEC * rc0_power, ktime_to_ns(dt));
75 	if (!rc0_power) {
76 		pr_err("No power measured while in RC0\n");
77 		err = -EINVAL;
78 		goto out_unlock;
79 	}
80 
81 	/* Manually enter RC6 */
82 	intel_rc6_park(rc6);
83 
84 	res[0] = rc6_residency(rc6);
85 	intel_uncore_forcewake_flush(rc6_to_uncore(rc6), FORCEWAKE_ALL);
86 	dt = ktime_get();
87 	rc6_power = librapl_energy_uJ();
88 	msleep(100);
89 	rc6_power = librapl_energy_uJ() - rc6_power;
90 	dt = ktime_sub(ktime_get(), dt);
91 	res[1] = rc6_residency(rc6);
92 	if (res[1] == res[0]) {
93 		pr_err("Did not enter RC6! RC6_STATE=%08x, RC6_CONTROL=%08x, residency=%lld\n",
94 		       intel_uncore_read_fw(gt->uncore, GEN6_RC_STATE),
95 		       intel_uncore_read_fw(gt->uncore, GEN6_RC_CONTROL),
96 		       res[0]);
97 		err = -EINVAL;
98 	}
99 
100 	rc6_power = div64_u64(NSEC_PER_SEC * rc6_power, ktime_to_ns(dt));
101 	pr_info("GPU consumed %llduW in RC0 and %llduW in RC6\n",
102 		rc0_power, rc6_power);
103 	if (2 * rc6_power > rc0_power) {
104 		pr_err("GPU leaked energy while in RC6!\n");
105 		err = -EINVAL;
106 		goto out_unlock;
107 	}
108 
109 	/* Restore what should have been the original state! */
110 	intel_rc6_unpark(rc6);
111 
112 out_unlock:
113 	intel_runtime_pm_put(gt->uncore->rpm, wakeref);
114 	return err;
115 }
116 
__live_rc6_ctx(struct intel_context * ce)117 static const u32 *__live_rc6_ctx(struct intel_context *ce)
118 {
119 	struct i915_request *rq;
120 	const u32 *result;
121 	u32 cmd;
122 	u32 *cs;
123 
124 	rq = intel_context_create_request(ce);
125 	if (IS_ERR(rq))
126 		return ERR_CAST(rq);
127 
128 	cs = intel_ring_begin(rq, 4);
129 	if (IS_ERR(cs)) {
130 		i915_request_add(rq);
131 		return cs;
132 	}
133 
134 	cmd = MI_STORE_REGISTER_MEM | MI_USE_GGTT;
135 	if (INTEL_GEN(rq->engine->i915) >= 8)
136 		cmd++;
137 
138 	*cs++ = cmd;
139 	*cs++ = i915_mmio_reg_offset(GEN8_RC6_CTX_INFO);
140 	*cs++ = ce->timeline->hwsp_offset + 8;
141 	*cs++ = 0;
142 	intel_ring_advance(rq, cs);
143 
144 	result = rq->hwsp_seqno + 2;
145 	i915_request_add(rq);
146 
147 	return result;
148 }
149 
150 static struct intel_engine_cs **
randomised_engines(struct intel_gt * gt,struct rnd_state * prng,unsigned int * count)151 randomised_engines(struct intel_gt *gt,
152 		   struct rnd_state *prng,
153 		   unsigned int *count)
154 {
155 	struct intel_engine_cs *engine, **engines;
156 	enum intel_engine_id id;
157 	int n;
158 
159 	n = 0;
160 	for_each_engine(engine, gt, id)
161 		n++;
162 	if (!n)
163 		return NULL;
164 
165 	engines = kmalloc_array(n, sizeof(*engines), GFP_KERNEL);
166 	if (!engines)
167 		return NULL;
168 
169 	n = 0;
170 	for_each_engine(engine, gt, id)
171 		engines[n++] = engine;
172 
173 	i915_prandom_shuffle(engines, sizeof(*engines), n, prng);
174 
175 	*count = n;
176 	return engines;
177 }
178 
live_rc6_ctx_wa(void * arg)179 int live_rc6_ctx_wa(void *arg)
180 {
181 	struct intel_gt *gt = arg;
182 	struct intel_engine_cs **engines;
183 	unsigned int n, count;
184 	I915_RND_STATE(prng);
185 	int err = 0;
186 
187 	/* A read of CTX_INFO upsets rc6. Poke the bear! */
188 	if (INTEL_GEN(gt->i915) < 8)
189 		return 0;
190 
191 	engines = randomised_engines(gt, &prng, &count);
192 	if (!engines)
193 		return 0;
194 
195 	for (n = 0; n < count; n++) {
196 		struct intel_engine_cs *engine = engines[n];
197 		int pass;
198 
199 		for (pass = 0; pass < 2; pass++) {
200 			struct i915_gpu_error *error = &gt->i915->gpu_error;
201 			struct intel_context *ce;
202 			unsigned int resets =
203 				i915_reset_engine_count(error, engine);
204 			const u32 *res;
205 
206 			/* Use a sacrifical context */
207 			ce = intel_context_create(engine);
208 			if (IS_ERR(ce)) {
209 				err = PTR_ERR(ce);
210 				goto out;
211 			}
212 
213 			intel_engine_pm_get(engine);
214 			res = __live_rc6_ctx(ce);
215 			intel_engine_pm_put(engine);
216 			intel_context_put(ce);
217 			if (IS_ERR(res)) {
218 				err = PTR_ERR(res);
219 				goto out;
220 			}
221 
222 			if (intel_gt_wait_for_idle(gt, HZ / 5) == -ETIME) {
223 				intel_gt_set_wedged(gt);
224 				err = -ETIME;
225 				goto out;
226 			}
227 
228 			intel_gt_pm_wait_for_idle(gt);
229 			pr_debug("%s: CTX_INFO=%0x\n",
230 				 engine->name, READ_ONCE(*res));
231 
232 			if (resets !=
233 			    i915_reset_engine_count(error, engine)) {
234 				pr_err("%s: GPU reset required\n",
235 				       engine->name);
236 				add_taint_for_CI(gt->i915, TAINT_WARN);
237 				err = -EIO;
238 				goto out;
239 			}
240 		}
241 	}
242 
243 out:
244 	kfree(engines);
245 	return err;
246 }
247