1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2019 Intel Corporation
4  */
5 
6 #include "intel_context.h"
7 #include "intel_engine_pm.h"
8 #include "intel_gpu_commands.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 
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 
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 	bool has_power;
38 	ktime_t dt;
39 	u64 res[2];
40 	int err = 0;
41 
42 	/*
43 	 * Our claim is that we can "encourage" the GPU to enter rc6 at will.
44 	 * Let's try it!
45 	 */
46 
47 	if (!rc6->enabled)
48 		return 0;
49 
50 	/* bsw/byt use a PCU and decouple RC6 from our manual control */
51 	if (IS_VALLEYVIEW(gt->i915) || IS_CHERRYVIEW(gt->i915))
52 		return 0;
53 
54 	has_power = librapl_supported(gt->i915);
55 	wakeref = intel_runtime_pm_get(gt->uncore->rpm);
56 
57 	/* Force RC6 off for starters */
58 	__intel_rc6_disable(rc6);
59 	msleep(1); /* wakeup is not immediate, takes about 100us on icl */
60 
61 	res[0] = rc6_residency(rc6);
62 
63 	dt = ktime_get();
64 	rc0_power = librapl_energy_uJ();
65 	msleep(250);
66 	rc0_power = librapl_energy_uJ() - rc0_power;
67 	dt = ktime_sub(ktime_get(), dt);
68 	res[1] = rc6_residency(rc6);
69 	if ((res[1] - res[0]) >> 10) {
70 		pr_err("RC6 residency increased by %lldus while disabled for 250ms!\n",
71 		       (res[1] - res[0]) >> 10);
72 		err = -EINVAL;
73 		goto out_unlock;
74 	}
75 
76 	if (has_power) {
77 		rc0_power = div64_u64(NSEC_PER_SEC * rc0_power,
78 				      ktime_to_ns(dt));
79 		if (!rc0_power) {
80 			pr_err("No power measured while in RC0\n");
81 			err = -EINVAL;
82 			goto out_unlock;
83 		}
84 	}
85 
86 	/* Manually enter RC6 */
87 	intel_rc6_park(rc6);
88 
89 	res[0] = rc6_residency(rc6);
90 	intel_uncore_forcewake_flush(rc6_to_uncore(rc6), FORCEWAKE_ALL);
91 	dt = ktime_get();
92 	rc6_power = librapl_energy_uJ();
93 	msleep(100);
94 	rc6_power = librapl_energy_uJ() - rc6_power;
95 	dt = ktime_sub(ktime_get(), dt);
96 	res[1] = rc6_residency(rc6);
97 	if (res[1] == res[0]) {
98 		pr_err("Did not enter RC6! RC6_STATE=%08x, RC6_CONTROL=%08x, residency=%lld\n",
99 		       intel_uncore_read_fw(gt->uncore, GEN6_RC_STATE),
100 		       intel_uncore_read_fw(gt->uncore, GEN6_RC_CONTROL),
101 		       res[0]);
102 		err = -EINVAL;
103 	}
104 
105 	if (has_power) {
106 		rc6_power = div64_u64(NSEC_PER_SEC * rc6_power,
107 				      ktime_to_ns(dt));
108 		pr_info("GPU consumed %llduW in RC0 and %llduW in RC6\n",
109 			rc0_power, rc6_power);
110 		if (2 * rc6_power > rc0_power) {
111 			pr_err("GPU leaked energy while in RC6!\n");
112 			err = -EINVAL;
113 			goto out_unlock;
114 		}
115 	}
116 
117 	/* Restore what should have been the original state! */
118 	intel_rc6_unpark(rc6);
119 
120 out_unlock:
121 	intel_runtime_pm_put(gt->uncore->rpm, wakeref);
122 	return err;
123 }
124 
125 static const u32 *__live_rc6_ctx(struct intel_context *ce)
126 {
127 	struct i915_request *rq;
128 	const u32 *result;
129 	u32 cmd;
130 	u32 *cs;
131 
132 	rq = intel_context_create_request(ce);
133 	if (IS_ERR(rq))
134 		return ERR_CAST(rq);
135 
136 	cs = intel_ring_begin(rq, 4);
137 	if (IS_ERR(cs)) {
138 		i915_request_add(rq);
139 		return cs;
140 	}
141 
142 	cmd = MI_STORE_REGISTER_MEM | MI_USE_GGTT;
143 	if (GRAPHICS_VER(rq->engine->i915) >= 8)
144 		cmd++;
145 
146 	*cs++ = cmd;
147 	*cs++ = i915_mmio_reg_offset(GEN8_RC6_CTX_INFO);
148 	*cs++ = ce->timeline->hwsp_offset + 8;
149 	*cs++ = 0;
150 	intel_ring_advance(rq, cs);
151 
152 	result = rq->hwsp_seqno + 2;
153 	i915_request_add(rq);
154 
155 	return result;
156 }
157 
158 static struct intel_engine_cs **
159 randomised_engines(struct intel_gt *gt,
160 		   struct rnd_state *prng,
161 		   unsigned int *count)
162 {
163 	struct intel_engine_cs *engine, **engines;
164 	enum intel_engine_id id;
165 	int n;
166 
167 	n = 0;
168 	for_each_engine(engine, gt, id)
169 		n++;
170 	if (!n)
171 		return NULL;
172 
173 	engines = kmalloc_array(n, sizeof(*engines), GFP_KERNEL);
174 	if (!engines)
175 		return NULL;
176 
177 	n = 0;
178 	for_each_engine(engine, gt, id)
179 		engines[n++] = engine;
180 
181 	i915_prandom_shuffle(engines, sizeof(*engines), n, prng);
182 
183 	*count = n;
184 	return engines;
185 }
186 
187 int live_rc6_ctx_wa(void *arg)
188 {
189 	struct intel_gt *gt = arg;
190 	struct intel_engine_cs **engines;
191 	unsigned int n, count;
192 	I915_RND_STATE(prng);
193 	int err = 0;
194 
195 	/* A read of CTX_INFO upsets rc6. Poke the bear! */
196 	if (GRAPHICS_VER(gt->i915) < 8)
197 		return 0;
198 
199 	engines = randomised_engines(gt, &prng, &count);
200 	if (!engines)
201 		return 0;
202 
203 	for (n = 0; n < count; n++) {
204 		struct intel_engine_cs *engine = engines[n];
205 		int pass;
206 
207 		for (pass = 0; pass < 2; pass++) {
208 			struct i915_gpu_error *error = &gt->i915->gpu_error;
209 			struct intel_context *ce;
210 			unsigned int resets =
211 				i915_reset_engine_count(error, engine);
212 			const u32 *res;
213 
214 			/* Use a sacrifical context */
215 			ce = intel_context_create(engine);
216 			if (IS_ERR(ce)) {
217 				err = PTR_ERR(ce);
218 				goto out;
219 			}
220 
221 			intel_engine_pm_get(engine);
222 			res = __live_rc6_ctx(ce);
223 			intel_engine_pm_put(engine);
224 			intel_context_put(ce);
225 			if (IS_ERR(res)) {
226 				err = PTR_ERR(res);
227 				goto out;
228 			}
229 
230 			if (intel_gt_wait_for_idle(gt, HZ / 5) == -ETIME) {
231 				intel_gt_set_wedged(gt);
232 				err = -ETIME;
233 				goto out;
234 			}
235 
236 			intel_gt_pm_wait_for_idle(gt);
237 			pr_debug("%s: CTX_INFO=%0x\n",
238 				 engine->name, READ_ONCE(*res));
239 
240 			if (resets !=
241 			    i915_reset_engine_count(error, engine)) {
242 				pr_err("%s: GPU reset required\n",
243 				       engine->name);
244 				add_taint_for_CI(gt->i915, TAINT_WARN);
245 				err = -EIO;
246 				goto out;
247 			}
248 		}
249 	}
250 
251 out:
252 	kfree(engines);
253 	return err;
254 }
255