xref: /openbmc/linux/drivers/gpu/drm/i915/gt/intel_gt_pm.c (revision 8781e5df)
1 /*
2  * SPDX-License-Identifier: MIT
3  *
4  * Copyright © 2019 Intel Corporation
5  */
6 
7 #include "i915_drv.h"
8 #include "i915_globals.h"
9 #include "i915_params.h"
10 #include "intel_context.h"
11 #include "intel_engine_pm.h"
12 #include "intel_gt.h"
13 #include "intel_gt_pm.h"
14 #include "intel_gt_requests.h"
15 #include "intel_llc.h"
16 #include "intel_pm.h"
17 #include "intel_rc6.h"
18 #include "intel_rps.h"
19 #include "intel_wakeref.h"
20 
21 static int __gt_unpark(struct intel_wakeref *wf)
22 {
23 	struct intel_gt *gt = container_of(wf, typeof(*gt), wakeref);
24 	struct drm_i915_private *i915 = gt->i915;
25 
26 	GEM_TRACE("\n");
27 
28 	i915_globals_unpark();
29 
30 	/*
31 	 * It seems that the DMC likes to transition between the DC states a lot
32 	 * when there are no connected displays (no active power domains) during
33 	 * command submission.
34 	 *
35 	 * This activity has negative impact on the performance of the chip with
36 	 * huge latencies observed in the interrupt handler and elsewhere.
37 	 *
38 	 * Work around it by grabbing a GT IRQ power domain whilst there is any
39 	 * GT activity, preventing any DC state transitions.
40 	 */
41 	gt->awake = intel_display_power_get(i915, POWER_DOMAIN_GT_IRQ);
42 	GEM_BUG_ON(!gt->awake);
43 
44 	intel_rps_unpark(&gt->rps);
45 	i915_pmu_gt_unparked(i915);
46 
47 	intel_gt_unpark_requests(gt);
48 
49 	return 0;
50 }
51 
52 static int __gt_park(struct intel_wakeref *wf)
53 {
54 	struct intel_gt *gt = container_of(wf, typeof(*gt), wakeref);
55 	intel_wakeref_t wakeref = fetch_and_zero(&gt->awake);
56 	struct drm_i915_private *i915 = gt->i915;
57 
58 	GEM_TRACE("\n");
59 
60 	intel_gt_park_requests(gt);
61 
62 	i915_vma_parked(gt);
63 	i915_pmu_gt_parked(i915);
64 	intel_rps_park(&gt->rps);
65 
66 	/* Everything switched off, flush any residual interrupt just in case */
67 	intel_synchronize_irq(i915);
68 
69 	GEM_BUG_ON(!wakeref);
70 	intel_display_power_put(i915, POWER_DOMAIN_GT_IRQ, wakeref);
71 
72 	i915_globals_park();
73 
74 	return 0;
75 }
76 
77 static const struct intel_wakeref_ops wf_ops = {
78 	.get = __gt_unpark,
79 	.put = __gt_park,
80 	.flags = INTEL_WAKEREF_PUT_ASYNC,
81 };
82 
83 void intel_gt_pm_init_early(struct intel_gt *gt)
84 {
85 	intel_wakeref_init(&gt->wakeref, gt->uncore->rpm, &wf_ops);
86 }
87 
88 void intel_gt_pm_init(struct intel_gt *gt)
89 {
90 	/*
91 	 * Enabling power-management should be "self-healing". If we cannot
92 	 * enable a feature, simply leave it disabled with a notice to the
93 	 * user.
94 	 */
95 	intel_rc6_init(&gt->rc6);
96 	intel_rps_init(&gt->rps);
97 }
98 
99 static bool reset_engines(struct intel_gt *gt)
100 {
101 	if (INTEL_INFO(gt->i915)->gpu_reset_clobbers_display)
102 		return false;
103 
104 	return __intel_gt_reset(gt, ALL_ENGINES) == 0;
105 }
106 
107 /**
108  * intel_gt_sanitize: called after the GPU has lost power
109  * @gt: the i915 GT container
110  * @force: ignore a failed reset and sanitize engine state anyway
111  *
112  * Anytime we reset the GPU, either with an explicit GPU reset or through a
113  * PCI power cycle, the GPU loses state and we must reset our state tracking
114  * to match. Note that calling intel_gt_sanitize() if the GPU has not
115  * been reset results in much confusion!
116  */
117 void intel_gt_sanitize(struct intel_gt *gt, bool force)
118 {
119 	struct intel_engine_cs *engine;
120 	enum intel_engine_id id;
121 
122 	GEM_TRACE("\n");
123 
124 	intel_uc_sanitize(&gt->uc);
125 
126 	for_each_engine(engine, gt, id)
127 		if (engine->reset.prepare)
128 			engine->reset.prepare(engine);
129 
130 	if (reset_engines(gt) || force) {
131 		for_each_engine(engine, gt, id)
132 			__intel_engine_reset(engine, false);
133 	}
134 
135 	for_each_engine(engine, gt, id)
136 		if (engine->reset.finish)
137 			engine->reset.finish(engine);
138 }
139 
140 void intel_gt_pm_fini(struct intel_gt *gt)
141 {
142 	intel_rc6_fini(&gt->rc6);
143 }
144 
145 int intel_gt_resume(struct intel_gt *gt)
146 {
147 	struct intel_engine_cs *engine;
148 	enum intel_engine_id id;
149 	int err = 0;
150 
151 	/*
152 	 * After resume, we may need to poke into the pinned kernel
153 	 * contexts to paper over any damage caused by the sudden suspend.
154 	 * Only the kernel contexts should remain pinned over suspend,
155 	 * allowing us to fixup the user contexts on their first pin.
156 	 */
157 	intel_gt_pm_get(gt);
158 
159 	intel_uncore_forcewake_get(gt->uncore, FORCEWAKE_ALL);
160 	intel_rc6_sanitize(&gt->rc6);
161 
162 	intel_rps_enable(&gt->rps);
163 	intel_llc_enable(&gt->llc);
164 
165 	for_each_engine(engine, gt, id) {
166 		struct intel_context *ce;
167 
168 		intel_engine_pm_get(engine);
169 
170 		ce = engine->kernel_context;
171 		if (ce) {
172 			GEM_BUG_ON(!intel_context_is_pinned(ce));
173 			ce->ops->reset(ce);
174 		}
175 
176 		engine->serial++; /* kernel context lost */
177 		err = engine->resume(engine);
178 
179 		intel_engine_pm_put(engine);
180 		if (err) {
181 			dev_err(gt->i915->drm.dev,
182 				"Failed to restart %s (%d)\n",
183 				engine->name, err);
184 			break;
185 		}
186 	}
187 
188 	intel_rc6_enable(&gt->rc6);
189 	intel_uncore_forcewake_put(gt->uncore, FORCEWAKE_ALL);
190 	intel_gt_pm_put(gt);
191 
192 	return err;
193 }
194 
195 static void wait_for_idle(struct intel_gt *gt)
196 {
197 	if (intel_gt_wait_for_idle(gt, I915_GEM_IDLE_TIMEOUT) == -ETIME) {
198 		/*
199 		 * Forcibly cancel outstanding work and leave
200 		 * the gpu quiet.
201 		 */
202 		intel_gt_set_wedged(gt);
203 	}
204 
205 	intel_gt_pm_wait_for_idle(gt);
206 }
207 
208 void intel_gt_suspend(struct intel_gt *gt)
209 {
210 	intel_wakeref_t wakeref;
211 
212 	/* We expect to be idle already; but also want to be independent */
213 	wait_for_idle(gt);
214 
215 	with_intel_runtime_pm(gt->uncore->rpm, wakeref) {
216 		intel_rps_disable(&gt->rps);
217 		intel_rc6_disable(&gt->rc6);
218 		intel_llc_disable(&gt->llc);
219 	}
220 }
221 
222 void intel_gt_runtime_suspend(struct intel_gt *gt)
223 {
224 	intel_uc_runtime_suspend(&gt->uc);
225 }
226 
227 int intel_gt_runtime_resume(struct intel_gt *gt)
228 {
229 	intel_gt_init_swizzling(gt);
230 
231 	return intel_uc_runtime_resume(&gt->uc);
232 }
233 
234 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
235 #include "selftest_gt_pm.c"
236 #endif
237