xref: /openbmc/linux/drivers/gpu/drm/i915/gt/intel_rc6.c (revision 78560d41)
1 /*
2  * SPDX-License-Identifier: MIT
3  *
4  * Copyright © 2019 Intel Corporation
5  */
6 
7 #include <linux/pm_runtime.h>
8 
9 #include "i915_drv.h"
10 #include "intel_gt.h"
11 #include "intel_gt_pm.h"
12 #include "intel_rc6.h"
13 #include "intel_sideband.h"
14 
15 /**
16  * DOC: RC6
17  *
18  * RC6 is a special power stage which allows the GPU to enter an very
19  * low-voltage mode when idle, using down to 0V while at this stage.  This
20  * stage is entered automatically when the GPU is idle when RC6 support is
21  * enabled, and as soon as new workload arises GPU wakes up automatically as
22  * well.
23  *
24  * There are different RC6 modes available in Intel GPU, which differentiate
25  * among each other with the latency required to enter and leave RC6 and
26  * voltage consumed by the GPU in different states.
27  *
28  * The combination of the following flags define which states GPU is allowed
29  * to enter, while RC6 is the normal RC6 state, RC6p is the deep RC6, and
30  * RC6pp is deepest RC6. Their support by hardware varies according to the
31  * GPU, BIOS, chipset and platform. RC6 is usually the safest one and the one
32  * which brings the most power savings; deeper states save more power, but
33  * require higher latency to switch to and wake up.
34  */
35 
36 static struct intel_gt *rc6_to_gt(struct intel_rc6 *rc6)
37 {
38 	return container_of(rc6, struct intel_gt, rc6);
39 }
40 
41 static struct intel_uncore *rc6_to_uncore(struct intel_rc6 *rc)
42 {
43 	return rc6_to_gt(rc)->uncore;
44 }
45 
46 static struct drm_i915_private *rc6_to_i915(struct intel_rc6 *rc)
47 {
48 	return rc6_to_gt(rc)->i915;
49 }
50 
51 static inline void set(struct intel_uncore *uncore, i915_reg_t reg, u32 val)
52 {
53 	intel_uncore_write_fw(uncore, reg, val);
54 }
55 
56 static void gen11_rc6_enable(struct intel_rc6 *rc6)
57 {
58 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
59 	struct intel_engine_cs *engine;
60 	enum intel_engine_id id;
61 
62 	/* 2b: Program RC6 thresholds.*/
63 	set(uncore, GEN6_RC6_WAKE_RATE_LIMIT, 54 << 16 | 85);
64 	set(uncore, GEN10_MEDIA_WAKE_RATE_LIMIT, 150);
65 
66 	set(uncore, GEN6_RC_EVALUATION_INTERVAL, 125000); /* 12500 * 1280ns */
67 	set(uncore, GEN6_RC_IDLE_HYSTERSIS, 25); /* 25 * 1280ns */
68 	for_each_engine(engine, rc6_to_gt(rc6), id)
69 		set(uncore, RING_MAX_IDLE(engine->mmio_base), 10);
70 
71 	set(uncore, GUC_MAX_IDLE_COUNT, 0xA);
72 
73 	set(uncore, GEN6_RC_SLEEP, 0);
74 
75 	set(uncore, GEN6_RC6_THRESHOLD, 50000); /* 50/125ms per EI */
76 
77 	/*
78 	 * 2c: Program Coarse Power Gating Policies.
79 	 *
80 	 * Bspec's guidance is to use 25us (really 25 * 1280ns) here. What we
81 	 * use instead is a more conservative estimate for the maximum time
82 	 * it takes us to service a CS interrupt and submit a new ELSP - that
83 	 * is the time which the GPU is idle waiting for the CPU to select the
84 	 * next request to execute. If the idle hysteresis is less than that
85 	 * interrupt service latency, the hardware will automatically gate
86 	 * the power well and we will then incur the wake up cost on top of
87 	 * the service latency. A similar guide from plane_state is that we
88 	 * do not want the enable hysteresis to less than the wakeup latency.
89 	 *
90 	 * igt/gem_exec_nop/sequential provides a rough estimate for the
91 	 * service latency, and puts it under 10us for Icelake, similar to
92 	 * Broadwell+, To be conservative, we want to factor in a context
93 	 * switch on top (due to ksoftirqd).
94 	 */
95 	set(uncore, GEN9_MEDIA_PG_IDLE_HYSTERESIS, 60);
96 	set(uncore, GEN9_RENDER_PG_IDLE_HYSTERESIS, 60);
97 
98 	/* 3a: Enable RC6 */
99 	rc6->ctl_enable =
100 		GEN6_RC_CTL_HW_ENABLE |
101 		GEN6_RC_CTL_RC6_ENABLE |
102 		GEN6_RC_CTL_EI_MODE(1);
103 
104 	set(uncore, GEN9_PG_ENABLE,
105 	    GEN9_RENDER_PG_ENABLE |
106 	    GEN9_MEDIA_PG_ENABLE |
107 	    GEN11_MEDIA_SAMPLER_PG_ENABLE);
108 }
109 
110 static void gen9_rc6_enable(struct intel_rc6 *rc6)
111 {
112 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
113 	struct intel_engine_cs *engine;
114 	enum intel_engine_id id;
115 	u32 rc6_mode;
116 
117 	/* 2b: Program RC6 thresholds.*/
118 	if (INTEL_GEN(rc6_to_i915(rc6)) >= 10) {
119 		set(uncore, GEN6_RC6_WAKE_RATE_LIMIT, 54 << 16 | 85);
120 		set(uncore, GEN10_MEDIA_WAKE_RATE_LIMIT, 150);
121 	} else if (IS_SKYLAKE(rc6_to_i915(rc6))) {
122 		/*
123 		 * WaRsDoubleRc6WrlWithCoarsePowerGating:skl Doubling WRL only
124 		 * when CPG is enabled
125 		 */
126 		set(uncore, GEN6_RC6_WAKE_RATE_LIMIT, 108 << 16);
127 	} else {
128 		set(uncore, GEN6_RC6_WAKE_RATE_LIMIT, 54 << 16);
129 	}
130 
131 	set(uncore, GEN6_RC_EVALUATION_INTERVAL, 125000); /* 12500 * 1280ns */
132 	set(uncore, GEN6_RC_IDLE_HYSTERSIS, 25); /* 25 * 1280ns */
133 	for_each_engine(engine, rc6_to_gt(rc6), id)
134 		set(uncore, RING_MAX_IDLE(engine->mmio_base), 10);
135 
136 	set(uncore, GUC_MAX_IDLE_COUNT, 0xA);
137 
138 	set(uncore, GEN6_RC_SLEEP, 0);
139 
140 	/*
141 	 * 2c: Program Coarse Power Gating Policies.
142 	 *
143 	 * Bspec's guidance is to use 25us (really 25 * 1280ns) here. What we
144 	 * use instead is a more conservative estimate for the maximum time
145 	 * it takes us to service a CS interrupt and submit a new ELSP - that
146 	 * is the time which the GPU is idle waiting for the CPU to select the
147 	 * next request to execute. If the idle hysteresis is less than that
148 	 * interrupt service latency, the hardware will automatically gate
149 	 * the power well and we will then incur the wake up cost on top of
150 	 * the service latency. A similar guide from plane_state is that we
151 	 * do not want the enable hysteresis to less than the wakeup latency.
152 	 *
153 	 * igt/gem_exec_nop/sequential provides a rough estimate for the
154 	 * service latency, and puts it around 10us for Broadwell (and other
155 	 * big core) and around 40us for Broxton (and other low power cores).
156 	 * [Note that for legacy ringbuffer submission, this is less than 1us!]
157 	 * However, the wakeup latency on Broxton is closer to 100us. To be
158 	 * conservative, we have to factor in a context switch on top (due
159 	 * to ksoftirqd).
160 	 */
161 	set(uncore, GEN9_MEDIA_PG_IDLE_HYSTERESIS, 250);
162 	set(uncore, GEN9_RENDER_PG_IDLE_HYSTERESIS, 250);
163 
164 	/* 3a: Enable RC6 */
165 	set(uncore, GEN6_RC6_THRESHOLD, 37500); /* 37.5/125ms per EI */
166 
167 	/* WaRsUseTimeoutMode:cnl (pre-prod) */
168 	if (IS_CNL_REVID(rc6_to_i915(rc6), CNL_REVID_A0, CNL_REVID_C0))
169 		rc6_mode = GEN7_RC_CTL_TO_MODE;
170 	else
171 		rc6_mode = GEN6_RC_CTL_EI_MODE(1);
172 
173 	rc6->ctl_enable =
174 		GEN6_RC_CTL_HW_ENABLE |
175 		GEN6_RC_CTL_RC6_ENABLE |
176 		rc6_mode;
177 
178 	/*
179 	 * WaRsDisableCoarsePowerGating:skl,cnl
180 	 *   - Render/Media PG need to be disabled with RC6.
181 	 */
182 	if (!NEEDS_WaRsDisableCoarsePowerGating(rc6_to_i915(rc6)))
183 		set(uncore, GEN9_PG_ENABLE,
184 		    GEN9_RENDER_PG_ENABLE | GEN9_MEDIA_PG_ENABLE);
185 }
186 
187 static void gen8_rc6_enable(struct intel_rc6 *rc6)
188 {
189 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
190 	struct intel_engine_cs *engine;
191 	enum intel_engine_id id;
192 
193 	/* 2b: Program RC6 thresholds.*/
194 	set(uncore, GEN6_RC6_WAKE_RATE_LIMIT, 40 << 16);
195 	set(uncore, GEN6_RC_EVALUATION_INTERVAL, 125000); /* 12500 * 1280ns */
196 	set(uncore, GEN6_RC_IDLE_HYSTERSIS, 25); /* 25 * 1280ns */
197 	for_each_engine(engine, rc6_to_gt(rc6), id)
198 		set(uncore, RING_MAX_IDLE(engine->mmio_base), 10);
199 	set(uncore, GEN6_RC_SLEEP, 0);
200 	set(uncore, GEN6_RC6_THRESHOLD, 625); /* 800us/1.28 for TO */
201 
202 	/* 3: Enable RC6 */
203 	rc6->ctl_enable =
204 	    GEN6_RC_CTL_HW_ENABLE |
205 	    GEN7_RC_CTL_TO_MODE |
206 	    GEN6_RC_CTL_RC6_ENABLE;
207 }
208 
209 static void gen6_rc6_enable(struct intel_rc6 *rc6)
210 {
211 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
212 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
213 	struct intel_engine_cs *engine;
214 	enum intel_engine_id id;
215 	u32 rc6vids, rc6_mask;
216 	int ret;
217 
218 	set(uncore, GEN6_RC1_WAKE_RATE_LIMIT, 1000 << 16);
219 	set(uncore, GEN6_RC6_WAKE_RATE_LIMIT, 40 << 16 | 30);
220 	set(uncore, GEN6_RC6pp_WAKE_RATE_LIMIT, 30);
221 	set(uncore, GEN6_RC_EVALUATION_INTERVAL, 125000);
222 	set(uncore, GEN6_RC_IDLE_HYSTERSIS, 25);
223 
224 	for_each_engine(engine, rc6_to_gt(rc6), id)
225 		set(uncore, RING_MAX_IDLE(engine->mmio_base), 10);
226 
227 	set(uncore, GEN6_RC_SLEEP, 0);
228 	set(uncore, GEN6_RC1e_THRESHOLD, 1000);
229 	if (IS_IVYBRIDGE(i915))
230 		set(uncore, GEN6_RC6_THRESHOLD, 125000);
231 	else
232 		set(uncore, GEN6_RC6_THRESHOLD, 50000);
233 	set(uncore, GEN6_RC6p_THRESHOLD, 150000);
234 	set(uncore, GEN6_RC6pp_THRESHOLD, 64000); /* unused */
235 
236 	/* We don't use those on Haswell */
237 	rc6_mask = GEN6_RC_CTL_RC6_ENABLE;
238 	if (HAS_RC6p(i915))
239 		rc6_mask |= GEN6_RC_CTL_RC6p_ENABLE;
240 	if (HAS_RC6pp(i915))
241 		rc6_mask |= GEN6_RC_CTL_RC6pp_ENABLE;
242 	rc6->ctl_enable =
243 	    rc6_mask |
244 	    GEN6_RC_CTL_EI_MODE(1) |
245 	    GEN6_RC_CTL_HW_ENABLE;
246 
247 	rc6vids = 0;
248 	ret = sandybridge_pcode_read(i915, GEN6_PCODE_READ_RC6VIDS,
249 				     &rc6vids, NULL);
250 	if (IS_GEN(i915, 6) && ret) {
251 		DRM_DEBUG_DRIVER("Couldn't check for BIOS workaround\n");
252 	} else if (IS_GEN(i915, 6) &&
253 		   (GEN6_DECODE_RC6_VID(rc6vids & 0xff) < 450)) {
254 		DRM_DEBUG_DRIVER("You should update your BIOS. Correcting minimum rc6 voltage (%dmV->%dmV)\n",
255 				 GEN6_DECODE_RC6_VID(rc6vids & 0xff), 450);
256 		rc6vids &= 0xffff00;
257 		rc6vids |= GEN6_ENCODE_RC6_VID(450);
258 		ret = sandybridge_pcode_write(i915, GEN6_PCODE_WRITE_RC6VIDS, rc6vids);
259 		if (ret)
260 			DRM_ERROR("Couldn't fix incorrect rc6 voltage\n");
261 	}
262 }
263 
264 /* Check that the pcbr address is not empty. */
265 static int chv_rc6_init(struct intel_rc6 *rc6)
266 {
267 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
268 	resource_size_t pctx_paddr, paddr;
269 	resource_size_t pctx_size = 32 * SZ_1K;
270 	u32 pcbr;
271 
272 	pcbr = intel_uncore_read(uncore, VLV_PCBR);
273 	if ((pcbr >> VLV_PCBR_ADDR_SHIFT) == 0) {
274 		DRM_DEBUG_DRIVER("BIOS didn't set up PCBR, fixing up\n");
275 		paddr = rc6_to_i915(rc6)->dsm.end + 1 - pctx_size;
276 		GEM_BUG_ON(paddr > U32_MAX);
277 
278 		pctx_paddr = (paddr & ~4095);
279 		intel_uncore_write(uncore, VLV_PCBR, pctx_paddr);
280 	}
281 
282 	return 0;
283 }
284 
285 static int vlv_rc6_init(struct intel_rc6 *rc6)
286 {
287 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
288 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
289 	struct drm_i915_gem_object *pctx;
290 	resource_size_t pctx_paddr;
291 	resource_size_t pctx_size = 24 * SZ_1K;
292 	u32 pcbr;
293 
294 	pcbr = intel_uncore_read(uncore, VLV_PCBR);
295 	if (pcbr) {
296 		/* BIOS set it up already, grab the pre-alloc'd space */
297 		resource_size_t pcbr_offset;
298 
299 		pcbr_offset = (pcbr & ~4095) - i915->dsm.start;
300 		pctx = i915_gem_object_create_stolen_for_preallocated(i915,
301 								      pcbr_offset,
302 								      I915_GTT_OFFSET_NONE,
303 								      pctx_size);
304 		if (IS_ERR(pctx))
305 			return PTR_ERR(pctx);
306 
307 		goto out;
308 	}
309 
310 	DRM_DEBUG_DRIVER("BIOS didn't set up PCBR, fixing up\n");
311 
312 	/*
313 	 * From the Gunit register HAS:
314 	 * The Gfx driver is expected to program this register and ensure
315 	 * proper allocation within Gfx stolen memory.  For example, this
316 	 * register should be programmed such than the PCBR range does not
317 	 * overlap with other ranges, such as the frame buffer, protected
318 	 * memory, or any other relevant ranges.
319 	 */
320 	pctx = i915_gem_object_create_stolen(i915, pctx_size);
321 	if (IS_ERR(pctx)) {
322 		DRM_DEBUG("not enough stolen space for PCTX, disabling\n");
323 		return PTR_ERR(pctx);
324 	}
325 
326 	GEM_BUG_ON(range_overflows_t(u64,
327 				     i915->dsm.start,
328 				     pctx->stolen->start,
329 				     U32_MAX));
330 	pctx_paddr = i915->dsm.start + pctx->stolen->start;
331 	intel_uncore_write(uncore, VLV_PCBR, pctx_paddr);
332 
333 out:
334 	rc6->pctx = pctx;
335 	return 0;
336 }
337 
338 static void chv_rc6_enable(struct intel_rc6 *rc6)
339 {
340 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
341 	struct intel_engine_cs *engine;
342 	enum intel_engine_id id;
343 
344 	/* 2a: Program RC6 thresholds.*/
345 	set(uncore, GEN6_RC6_WAKE_RATE_LIMIT, 40 << 16);
346 	set(uncore, GEN6_RC_EVALUATION_INTERVAL, 125000); /* 12500 * 1280ns */
347 	set(uncore, GEN6_RC_IDLE_HYSTERSIS, 25); /* 25 * 1280ns */
348 
349 	for_each_engine(engine, rc6_to_gt(rc6), id)
350 		set(uncore, RING_MAX_IDLE(engine->mmio_base), 10);
351 	set(uncore, GEN6_RC_SLEEP, 0);
352 
353 	/* TO threshold set to 500 us (0x186 * 1.28 us) */
354 	set(uncore, GEN6_RC6_THRESHOLD, 0x186);
355 
356 	/* Allows RC6 residency counter to work */
357 	set(uncore, VLV_COUNTER_CONTROL,
358 	    _MASKED_BIT_ENABLE(VLV_COUNT_RANGE_HIGH |
359 			       VLV_MEDIA_RC6_COUNT_EN |
360 			       VLV_RENDER_RC6_COUNT_EN));
361 
362 	/* 3: Enable RC6 */
363 	rc6->ctl_enable = GEN7_RC_CTL_TO_MODE;
364 }
365 
366 static void vlv_rc6_enable(struct intel_rc6 *rc6)
367 {
368 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
369 	struct intel_engine_cs *engine;
370 	enum intel_engine_id id;
371 
372 	set(uncore, GEN6_RC6_WAKE_RATE_LIMIT, 0x00280000);
373 	set(uncore, GEN6_RC_EVALUATION_INTERVAL, 125000);
374 	set(uncore, GEN6_RC_IDLE_HYSTERSIS, 25);
375 
376 	for_each_engine(engine, rc6_to_gt(rc6), id)
377 		set(uncore, RING_MAX_IDLE(engine->mmio_base), 10);
378 
379 	set(uncore, GEN6_RC6_THRESHOLD, 0x557);
380 
381 	/* Allows RC6 residency counter to work */
382 	set(uncore, VLV_COUNTER_CONTROL,
383 	    _MASKED_BIT_ENABLE(VLV_COUNT_RANGE_HIGH |
384 			       VLV_MEDIA_RC0_COUNT_EN |
385 			       VLV_RENDER_RC0_COUNT_EN |
386 			       VLV_MEDIA_RC6_COUNT_EN |
387 			       VLV_RENDER_RC6_COUNT_EN));
388 
389 	rc6->ctl_enable =
390 	    GEN7_RC_CTL_TO_MODE | VLV_RC_CTL_CTX_RST_PARALLEL;
391 }
392 
393 static bool bxt_check_bios_rc6_setup(struct intel_rc6 *rc6)
394 {
395 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
396 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
397 	u32 rc6_ctx_base, rc_ctl, rc_sw_target;
398 	bool enable_rc6 = true;
399 
400 	rc_ctl = intel_uncore_read(uncore, GEN6_RC_CONTROL);
401 	rc_sw_target = intel_uncore_read(uncore, GEN6_RC_STATE);
402 	rc_sw_target &= RC_SW_TARGET_STATE_MASK;
403 	rc_sw_target >>= RC_SW_TARGET_STATE_SHIFT;
404 	DRM_DEBUG_DRIVER("BIOS enabled RC states: "
405 			 "HW_CTRL %s HW_RC6 %s SW_TARGET_STATE %x\n",
406 			 onoff(rc_ctl & GEN6_RC_CTL_HW_ENABLE),
407 			 onoff(rc_ctl & GEN6_RC_CTL_RC6_ENABLE),
408 			 rc_sw_target);
409 
410 	if (!(intel_uncore_read(uncore, RC6_LOCATION) & RC6_CTX_IN_DRAM)) {
411 		DRM_DEBUG_DRIVER("RC6 Base location not set properly.\n");
412 		enable_rc6 = false;
413 	}
414 
415 	/*
416 	 * The exact context size is not known for BXT, so assume a page size
417 	 * for this check.
418 	 */
419 	rc6_ctx_base =
420 		intel_uncore_read(uncore, RC6_CTX_BASE) & RC6_CTX_BASE_MASK;
421 	if (!(rc6_ctx_base >= i915->dsm_reserved.start &&
422 	      rc6_ctx_base + PAGE_SIZE < i915->dsm_reserved.end)) {
423 		DRM_DEBUG_DRIVER("RC6 Base address not as expected.\n");
424 		enable_rc6 = false;
425 	}
426 
427 	if (!((intel_uncore_read(uncore, PWRCTX_MAXCNT_RCSUNIT) & IDLE_TIME_MASK) > 1 &&
428 	      (intel_uncore_read(uncore, PWRCTX_MAXCNT_VCSUNIT0) & IDLE_TIME_MASK) > 1 &&
429 	      (intel_uncore_read(uncore, PWRCTX_MAXCNT_BCSUNIT) & IDLE_TIME_MASK) > 1 &&
430 	      (intel_uncore_read(uncore, PWRCTX_MAXCNT_VECSUNIT) & IDLE_TIME_MASK) > 1)) {
431 		DRM_DEBUG_DRIVER("Engine Idle wait time not set properly.\n");
432 		enable_rc6 = false;
433 	}
434 
435 	if (!intel_uncore_read(uncore, GEN8_PUSHBUS_CONTROL) ||
436 	    !intel_uncore_read(uncore, GEN8_PUSHBUS_ENABLE) ||
437 	    !intel_uncore_read(uncore, GEN8_PUSHBUS_SHIFT)) {
438 		DRM_DEBUG_DRIVER("Pushbus not setup properly.\n");
439 		enable_rc6 = false;
440 	}
441 
442 	if (!intel_uncore_read(uncore, GEN6_GFXPAUSE)) {
443 		DRM_DEBUG_DRIVER("GFX pause not setup properly.\n");
444 		enable_rc6 = false;
445 	}
446 
447 	if (!intel_uncore_read(uncore, GEN8_MISC_CTRL0)) {
448 		DRM_DEBUG_DRIVER("GPM control not setup properly.\n");
449 		enable_rc6 = false;
450 	}
451 
452 	return enable_rc6;
453 }
454 
455 static bool rc6_supported(struct intel_rc6 *rc6)
456 {
457 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
458 
459 	if (!HAS_RC6(i915))
460 		return false;
461 
462 	if (intel_vgpu_active(i915))
463 		return false;
464 
465 	if (is_mock_gt(rc6_to_gt(rc6)))
466 		return false;
467 
468 	if (IS_GEN9_LP(i915) && !bxt_check_bios_rc6_setup(rc6)) {
469 		dev_notice(i915->drm.dev,
470 			   "RC6 and powersaving disabled by BIOS\n");
471 		return false;
472 	}
473 
474 	return true;
475 }
476 
477 static void rpm_get(struct intel_rc6 *rc6)
478 {
479 	GEM_BUG_ON(rc6->wakeref);
480 	pm_runtime_get_sync(&rc6_to_i915(rc6)->drm.pdev->dev);
481 	rc6->wakeref = true;
482 }
483 
484 static void rpm_put(struct intel_rc6 *rc6)
485 {
486 	GEM_BUG_ON(!rc6->wakeref);
487 	pm_runtime_put(&rc6_to_i915(rc6)->drm.pdev->dev);
488 	rc6->wakeref = false;
489 }
490 
491 static bool pctx_corrupted(struct intel_rc6 *rc6)
492 {
493 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
494 
495 	if (!NEEDS_RC6_CTX_CORRUPTION_WA(i915))
496 		return false;
497 
498 	if (intel_uncore_read(rc6_to_uncore(rc6), GEN8_RC6_CTX_INFO))
499 		return false;
500 
501 	dev_notice(i915->drm.dev,
502 		   "RC6 context corruption, disabling runtime power management\n");
503 	return true;
504 }
505 
506 static void __intel_rc6_disable(struct intel_rc6 *rc6)
507 {
508 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
509 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
510 
511 	intel_uncore_forcewake_get(uncore, FORCEWAKE_ALL);
512 	if (INTEL_GEN(i915) >= 9)
513 		set(uncore, GEN9_PG_ENABLE, 0);
514 	set(uncore, GEN6_RC_CONTROL, 0);
515 	set(uncore, GEN6_RC_STATE, 0);
516 	intel_uncore_forcewake_put(uncore, FORCEWAKE_ALL);
517 }
518 
519 void intel_rc6_init(struct intel_rc6 *rc6)
520 {
521 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
522 	int err;
523 
524 	/* Disable runtime-pm until we can save the GPU state with rc6 pctx */
525 	rpm_get(rc6);
526 
527 	if (!rc6_supported(rc6))
528 		return;
529 
530 	if (IS_CHERRYVIEW(i915))
531 		err = chv_rc6_init(rc6);
532 	else if (IS_VALLEYVIEW(i915))
533 		err = vlv_rc6_init(rc6);
534 	else
535 		err = 0;
536 
537 	/* Sanitize rc6, ensure it is disabled before we are ready. */
538 	__intel_rc6_disable(rc6);
539 
540 	rc6->supported = err == 0;
541 }
542 
543 void intel_rc6_sanitize(struct intel_rc6 *rc6)
544 {
545 	if (rc6->enabled) { /* unbalanced suspend/resume */
546 		rpm_get(rc6);
547 		rc6->enabled = false;
548 	}
549 
550 	if (rc6->supported)
551 		__intel_rc6_disable(rc6);
552 }
553 
554 void intel_rc6_enable(struct intel_rc6 *rc6)
555 {
556 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
557 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
558 
559 	if (!rc6->supported)
560 		return;
561 
562 	GEM_BUG_ON(rc6->enabled);
563 
564 	intel_uncore_forcewake_get(uncore, FORCEWAKE_ALL);
565 
566 	if (IS_CHERRYVIEW(i915))
567 		chv_rc6_enable(rc6);
568 	else if (IS_VALLEYVIEW(i915))
569 		vlv_rc6_enable(rc6);
570 	else if (INTEL_GEN(i915) >= 11)
571 		gen11_rc6_enable(rc6);
572 	else if (INTEL_GEN(i915) >= 9)
573 		gen9_rc6_enable(rc6);
574 	else if (IS_BROADWELL(i915))
575 		gen8_rc6_enable(rc6);
576 	else if (INTEL_GEN(i915) >= 6)
577 		gen6_rc6_enable(rc6);
578 
579 	rc6->manual = rc6->ctl_enable & GEN6_RC_CTL_RC6_ENABLE;
580 	if (NEEDS_RC6_CTX_CORRUPTION_WA(i915))
581 		rc6->ctl_enable = 0;
582 
583 	intel_uncore_forcewake_put(uncore, FORCEWAKE_ALL);
584 
585 	if (unlikely(pctx_corrupted(rc6)))
586 		return;
587 
588 	/* rc6 is ready, runtime-pm is go! */
589 	rpm_put(rc6);
590 	rc6->enabled = true;
591 }
592 
593 void intel_rc6_unpark(struct intel_rc6 *rc6)
594 {
595 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
596 
597 	if (!rc6->enabled)
598 		return;
599 
600 	/* Restore HW timers for automatic RC6 entry while busy */
601 	set(uncore, GEN6_RC_CONTROL, rc6->ctl_enable);
602 }
603 
604 void intel_rc6_park(struct intel_rc6 *rc6)
605 {
606 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
607 
608 	if (!rc6->enabled)
609 		return;
610 
611 	if (unlikely(pctx_corrupted(rc6))) {
612 		intel_rc6_disable(rc6);
613 		return;
614 	}
615 
616 	if (!rc6->manual)
617 		return;
618 
619 	/* Turn off the HW timers and go directly to rc6 */
620 	set(uncore, GEN6_RC_CONTROL, GEN6_RC_CTL_RC6_ENABLE);
621 	set(uncore, GEN6_RC_STATE, 0x4 << RC_SW_TARGET_STATE_SHIFT);
622 }
623 
624 void intel_rc6_disable(struct intel_rc6 *rc6)
625 {
626 	if (!rc6->enabled)
627 		return;
628 
629 	rpm_get(rc6);
630 	rc6->enabled = false;
631 
632 	__intel_rc6_disable(rc6);
633 }
634 
635 void intel_rc6_fini(struct intel_rc6 *rc6)
636 {
637 	struct drm_i915_gem_object *pctx;
638 
639 	intel_rc6_disable(rc6);
640 
641 	pctx = fetch_and_zero(&rc6->pctx);
642 	if (pctx)
643 		i915_gem_object_put(pctx);
644 
645 	if (rc6->wakeref)
646 		rpm_put(rc6);
647 }
648 
649 static u64 vlv_residency_raw(struct intel_uncore *uncore, const i915_reg_t reg)
650 {
651 	u32 lower, upper, tmp;
652 	int loop = 2;
653 
654 	/*
655 	 * The register accessed do not need forcewake. We borrow
656 	 * uncore lock to prevent concurrent access to range reg.
657 	 */
658 	lockdep_assert_held(&uncore->lock);
659 
660 	/*
661 	 * vlv and chv residency counters are 40 bits in width.
662 	 * With a control bit, we can choose between upper or lower
663 	 * 32bit window into this counter.
664 	 *
665 	 * Although we always use the counter in high-range mode elsewhere,
666 	 * userspace may attempt to read the value before rc6 is initialised,
667 	 * before we have set the default VLV_COUNTER_CONTROL value. So always
668 	 * set the high bit to be safe.
669 	 */
670 	set(uncore, VLV_COUNTER_CONTROL,
671 	    _MASKED_BIT_ENABLE(VLV_COUNT_RANGE_HIGH));
672 	upper = intel_uncore_read_fw(uncore, reg);
673 	do {
674 		tmp = upper;
675 
676 		set(uncore, VLV_COUNTER_CONTROL,
677 		    _MASKED_BIT_DISABLE(VLV_COUNT_RANGE_HIGH));
678 		lower = intel_uncore_read_fw(uncore, reg);
679 
680 		set(uncore, VLV_COUNTER_CONTROL,
681 		    _MASKED_BIT_ENABLE(VLV_COUNT_RANGE_HIGH));
682 		upper = intel_uncore_read_fw(uncore, reg);
683 	} while (upper != tmp && --loop);
684 
685 	/*
686 	 * Everywhere else we always use VLV_COUNTER_CONTROL with the
687 	 * VLV_COUNT_RANGE_HIGH bit set - so it is safe to leave it set
688 	 * now.
689 	 */
690 
691 	return lower | (u64)upper << 8;
692 }
693 
694 u64 intel_rc6_residency_ns(struct intel_rc6 *rc6, const i915_reg_t reg)
695 {
696 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
697 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
698 	u64 time_hw, prev_hw, overflow_hw;
699 	unsigned int fw_domains;
700 	unsigned long flags;
701 	unsigned int i;
702 	u32 mul, div;
703 
704 	if (!rc6->supported)
705 		return 0;
706 
707 	/*
708 	 * Store previous hw counter values for counter wrap-around handling.
709 	 *
710 	 * There are only four interesting registers and they live next to each
711 	 * other so we can use the relative address, compared to the smallest
712 	 * one as the index into driver storage.
713 	 */
714 	i = (i915_mmio_reg_offset(reg) -
715 	     i915_mmio_reg_offset(GEN6_GT_GFX_RC6_LOCKED)) / sizeof(u32);
716 	if (WARN_ON_ONCE(i >= ARRAY_SIZE(rc6->cur_residency)))
717 		return 0;
718 
719 	fw_domains = intel_uncore_forcewake_for_reg(uncore, reg, FW_REG_READ);
720 
721 	spin_lock_irqsave(&uncore->lock, flags);
722 	intel_uncore_forcewake_get__locked(uncore, fw_domains);
723 
724 	/* On VLV and CHV, residency time is in CZ units rather than 1.28us */
725 	if (IS_VALLEYVIEW(i915) || IS_CHERRYVIEW(i915)) {
726 		mul = 1000000;
727 		div = i915->czclk_freq;
728 		overflow_hw = BIT_ULL(40);
729 		time_hw = vlv_residency_raw(uncore, reg);
730 	} else {
731 		/* 833.33ns units on Gen9LP, 1.28us elsewhere. */
732 		if (IS_GEN9_LP(i915)) {
733 			mul = 10000;
734 			div = 12;
735 		} else {
736 			mul = 1280;
737 			div = 1;
738 		}
739 
740 		overflow_hw = BIT_ULL(32);
741 		time_hw = intel_uncore_read_fw(uncore, reg);
742 	}
743 
744 	/*
745 	 * Counter wrap handling.
746 	 *
747 	 * But relying on a sufficient frequency of queries otherwise counters
748 	 * can still wrap.
749 	 */
750 	prev_hw = rc6->prev_hw_residency[i];
751 	rc6->prev_hw_residency[i] = time_hw;
752 
753 	/* RC6 delta from last sample. */
754 	if (time_hw >= prev_hw)
755 		time_hw -= prev_hw;
756 	else
757 		time_hw += overflow_hw - prev_hw;
758 
759 	/* Add delta to RC6 extended raw driver copy. */
760 	time_hw += rc6->cur_residency[i];
761 	rc6->cur_residency[i] = time_hw;
762 
763 	intel_uncore_forcewake_put__locked(uncore, fw_domains);
764 	spin_unlock_irqrestore(&uncore->lock, flags);
765 
766 	return mul_u64_u32_div(time_hw, mul, div);
767 }
768 
769 u64 intel_rc6_residency_us(struct intel_rc6 *rc6, i915_reg_t reg)
770 {
771 	return DIV_ROUND_UP_ULL(intel_rc6_residency_ns(rc6, reg), 1000);
772 }
773 
774 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
775 #include "selftest_rc6.c"
776 #endif
777