xref: /linux/drivers/gpu/drm/i915/gt/intel_rc6.c (revision be239684b18e1cdcafcf8c7face4a2f562c745ad)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2019 Intel Corporation
4  */
5 
6 #include <linux/pm_runtime.h>
7 #include <linux/string_helpers.h>
8 
9 #include "gem/i915_gem_region.h"
10 #include "i915_drv.h"
11 #include "i915_reg.h"
12 #include "i915_vgpu.h"
13 #include "intel_engine_regs.h"
14 #include "intel_gt.h"
15 #include "intel_gt_pm.h"
16 #include "intel_gt_regs.h"
17 #include "intel_pcode.h"
18 #include "intel_rc6.h"
19 
20 /**
21  * DOC: RC6
22  *
23  * RC6 is a special power stage which allows the GPU to enter an very
24  * low-voltage mode when idle, using down to 0V while at this stage.  This
25  * stage is entered automatically when the GPU is idle when RC6 support is
26  * enabled, and as soon as new workload arises GPU wakes up automatically as
27  * well.
28  *
29  * There are different RC6 modes available in Intel GPU, which differentiate
30  * among each other with the latency required to enter and leave RC6 and
31  * voltage consumed by the GPU in different states.
32  *
33  * The combination of the following flags define which states GPU is allowed
34  * to enter, while RC6 is the normal RC6 state, RC6p is the deep RC6, and
35  * RC6pp is deepest RC6. Their support by hardware varies according to the
36  * GPU, BIOS, chipset and platform. RC6 is usually the safest one and the one
37  * which brings the most power savings; deeper states save more power, but
38  * require higher latency to switch to and wake up.
39  */
40 
41 static struct intel_gt *rc6_to_gt(struct intel_rc6 *rc6)
42 {
43 	return container_of(rc6, struct intel_gt, rc6);
44 }
45 
46 static struct intel_uncore *rc6_to_uncore(struct intel_rc6 *rc)
47 {
48 	return rc6_to_gt(rc)->uncore;
49 }
50 
51 static struct drm_i915_private *rc6_to_i915(struct intel_rc6 *rc)
52 {
53 	return rc6_to_gt(rc)->i915;
54 }
55 
56 static void gen11_rc6_enable(struct intel_rc6 *rc6)
57 {
58 	struct intel_gt *gt = rc6_to_gt(rc6);
59 	struct intel_uncore *uncore = gt->uncore;
60 	struct intel_engine_cs *engine;
61 	enum intel_engine_id id;
62 	u32 pg_enable;
63 	int i;
64 
65 	/*
66 	 * With GuCRC, these parameters are set by GuC
67 	 */
68 	if (!intel_uc_uses_guc_rc(&gt->uc)) {
69 		/* 2b: Program RC6 thresholds.*/
70 		intel_uncore_write_fw(uncore, GEN6_RC6_WAKE_RATE_LIMIT, 54 << 16 | 85);
71 		intel_uncore_write_fw(uncore, GEN10_MEDIA_WAKE_RATE_LIMIT, 150);
72 
73 		intel_uncore_write_fw(uncore, GEN6_RC_EVALUATION_INTERVAL, 125000); /* 12500 * 1280ns */
74 		intel_uncore_write_fw(uncore, GEN6_RC_IDLE_HYSTERSIS, 25); /* 25 * 1280ns */
75 		for_each_engine(engine, rc6_to_gt(rc6), id)
76 			intel_uncore_write_fw(uncore, RING_MAX_IDLE(engine->mmio_base), 10);
77 
78 		intel_uncore_write_fw(uncore, GUC_MAX_IDLE_COUNT, 0xA);
79 
80 		intel_uncore_write_fw(uncore, GEN6_RC_SLEEP, 0);
81 
82 		intel_uncore_write_fw(uncore, GEN6_RC6_THRESHOLD, 50000); /* 50/125ms per EI */
83 	}
84 
85 	/*
86 	 * 2c: Program Coarse Power Gating Policies.
87 	 *
88 	 * Bspec's guidance is to use 25us (really 25 * 1280ns) here. What we
89 	 * use instead is a more conservative estimate for the maximum time
90 	 * it takes us to service a CS interrupt and submit a new ELSP - that
91 	 * is the time which the GPU is idle waiting for the CPU to select the
92 	 * next request to execute. If the idle hysteresis is less than that
93 	 * interrupt service latency, the hardware will automatically gate
94 	 * the power well and we will then incur the wake up cost on top of
95 	 * the service latency. A similar guide from plane_state is that we
96 	 * do not want the enable hysteresis to less than the wakeup latency.
97 	 *
98 	 * igt/gem_exec_nop/sequential provides a rough estimate for the
99 	 * service latency, and puts it under 10us for Icelake, similar to
100 	 * Broadwell+, To be conservative, we want to factor in a context
101 	 * switch on top (due to ksoftirqd).
102 	 */
103 	intel_uncore_write_fw(uncore, GEN9_MEDIA_PG_IDLE_HYSTERESIS, 60);
104 	intel_uncore_write_fw(uncore, GEN9_RENDER_PG_IDLE_HYSTERESIS, 60);
105 
106 	/* 3a: Enable RC6
107 	 *
108 	 * With GuCRC, we do not enable bit 31 of RC_CTL,
109 	 * thus allowing GuC to control RC6 entry/exit fully instead.
110 	 * We will not set the HW ENABLE and EI bits
111 	 */
112 	if (!intel_guc_rc_enable(&gt->uc.guc))
113 		rc6->ctl_enable = GEN6_RC_CTL_RC6_ENABLE;
114 	else
115 		rc6->ctl_enable =
116 			GEN6_RC_CTL_HW_ENABLE |
117 			GEN6_RC_CTL_RC6_ENABLE |
118 			GEN6_RC_CTL_EI_MODE(1);
119 
120 	/*
121 	 * BSpec 52698 - Render powergating must be off.
122 	 * FIXME BSpec is outdated, disabling powergating for MTL is just
123 	 * temporary wa and should be removed after fixing real cause
124 	 * of forcewake timeouts.
125 	 */
126 	if (IS_GFX_GT_IP_RANGE(gt, IP_VER(12, 70), IP_VER(12, 74)))
127 		pg_enable =
128 			GEN9_MEDIA_PG_ENABLE |
129 			GEN11_MEDIA_SAMPLER_PG_ENABLE;
130 	else
131 		pg_enable =
132 			GEN9_RENDER_PG_ENABLE |
133 			GEN9_MEDIA_PG_ENABLE |
134 			GEN11_MEDIA_SAMPLER_PG_ENABLE;
135 
136 	if (GRAPHICS_VER(gt->i915) >= 12) {
137 		for (i = 0; i < I915_MAX_VCS; i++)
138 			if (HAS_ENGINE(gt, _VCS(i)))
139 				pg_enable |= (VDN_HCP_POWERGATE_ENABLE(i) |
140 					      VDN_MFX_POWERGATE_ENABLE(i));
141 	}
142 
143 	intel_uncore_write_fw(uncore, GEN9_PG_ENABLE, pg_enable);
144 }
145 
146 static void gen9_rc6_enable(struct intel_rc6 *rc6)
147 {
148 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
149 	struct intel_engine_cs *engine;
150 	enum intel_engine_id id;
151 
152 	/* 2b: Program RC6 thresholds.*/
153 	if (GRAPHICS_VER(rc6_to_i915(rc6)) >= 11) {
154 		intel_uncore_write_fw(uncore, GEN6_RC6_WAKE_RATE_LIMIT, 54 << 16 | 85);
155 		intel_uncore_write_fw(uncore, GEN10_MEDIA_WAKE_RATE_LIMIT, 150);
156 	} else if (IS_SKYLAKE(rc6_to_i915(rc6))) {
157 		/*
158 		 * WaRsDoubleRc6WrlWithCoarsePowerGating:skl Doubling WRL only
159 		 * when CPG is enabled
160 		 */
161 		intel_uncore_write_fw(uncore, GEN6_RC6_WAKE_RATE_LIMIT, 108 << 16);
162 	} else {
163 		intel_uncore_write_fw(uncore, GEN6_RC6_WAKE_RATE_LIMIT, 54 << 16);
164 	}
165 
166 	intel_uncore_write_fw(uncore, GEN6_RC_EVALUATION_INTERVAL, 125000); /* 12500 * 1280ns */
167 	intel_uncore_write_fw(uncore, GEN6_RC_IDLE_HYSTERSIS, 25); /* 25 * 1280ns */
168 	for_each_engine(engine, rc6_to_gt(rc6), id)
169 		intel_uncore_write_fw(uncore, RING_MAX_IDLE(engine->mmio_base), 10);
170 
171 	intel_uncore_write_fw(uncore, GUC_MAX_IDLE_COUNT, 0xA);
172 
173 	intel_uncore_write_fw(uncore, GEN6_RC_SLEEP, 0);
174 
175 	/*
176 	 * 2c: Program Coarse Power Gating Policies.
177 	 *
178 	 * Bspec's guidance is to use 25us (really 25 * 1280ns) here. What we
179 	 * use instead is a more conservative estimate for the maximum time
180 	 * it takes us to service a CS interrupt and submit a new ELSP - that
181 	 * is the time which the GPU is idle waiting for the CPU to select the
182 	 * next request to execute. If the idle hysteresis is less than that
183 	 * interrupt service latency, the hardware will automatically gate
184 	 * the power well and we will then incur the wake up cost on top of
185 	 * the service latency. A similar guide from plane_state is that we
186 	 * do not want the enable hysteresis to less than the wakeup latency.
187 	 *
188 	 * igt/gem_exec_nop/sequential provides a rough estimate for the
189 	 * service latency, and puts it around 10us for Broadwell (and other
190 	 * big core) and around 40us for Broxton (and other low power cores).
191 	 * [Note that for legacy ringbuffer submission, this is less than 1us!]
192 	 * However, the wakeup latency on Broxton is closer to 100us. To be
193 	 * conservative, we have to factor in a context switch on top (due
194 	 * to ksoftirqd).
195 	 */
196 	intel_uncore_write_fw(uncore, GEN9_MEDIA_PG_IDLE_HYSTERESIS, 250);
197 	intel_uncore_write_fw(uncore, GEN9_RENDER_PG_IDLE_HYSTERESIS, 250);
198 
199 	/* 3a: Enable RC6 */
200 	intel_uncore_write_fw(uncore, GEN6_RC6_THRESHOLD, 37500); /* 37.5/125ms per EI */
201 
202 	rc6->ctl_enable =
203 		GEN6_RC_CTL_HW_ENABLE |
204 		GEN6_RC_CTL_RC6_ENABLE |
205 		GEN6_RC_CTL_EI_MODE(1);
206 
207 	/*
208 	 * WaRsDisableCoarsePowerGating:skl,cnl
209 	 *   - Render/Media PG need to be disabled with RC6.
210 	 */
211 	if (!NEEDS_WaRsDisableCoarsePowerGating(rc6_to_i915(rc6)))
212 		intel_uncore_write_fw(uncore, GEN9_PG_ENABLE,
213 				      GEN9_RENDER_PG_ENABLE | GEN9_MEDIA_PG_ENABLE);
214 }
215 
216 static void gen8_rc6_enable(struct intel_rc6 *rc6)
217 {
218 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
219 	struct intel_engine_cs *engine;
220 	enum intel_engine_id id;
221 
222 	/* 2b: Program RC6 thresholds.*/
223 	intel_uncore_write_fw(uncore, GEN6_RC6_WAKE_RATE_LIMIT, 40 << 16);
224 	intel_uncore_write_fw(uncore, GEN6_RC_EVALUATION_INTERVAL, 125000); /* 12500 * 1280ns */
225 	intel_uncore_write_fw(uncore, GEN6_RC_IDLE_HYSTERSIS, 25); /* 25 * 1280ns */
226 	for_each_engine(engine, rc6_to_gt(rc6), id)
227 		intel_uncore_write_fw(uncore, RING_MAX_IDLE(engine->mmio_base), 10);
228 	intel_uncore_write_fw(uncore, GEN6_RC_SLEEP, 0);
229 	intel_uncore_write_fw(uncore, GEN6_RC6_THRESHOLD, 625); /* 800us/1.28 for TO */
230 
231 	/* 3: Enable RC6 */
232 	rc6->ctl_enable =
233 	    GEN6_RC_CTL_HW_ENABLE |
234 	    GEN7_RC_CTL_TO_MODE |
235 	    GEN6_RC_CTL_RC6_ENABLE;
236 }
237 
238 static void gen6_rc6_enable(struct intel_rc6 *rc6)
239 {
240 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
241 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
242 	struct intel_engine_cs *engine;
243 	enum intel_engine_id id;
244 	u32 rc6vids, rc6_mask;
245 	int ret;
246 
247 	intel_uncore_write_fw(uncore, GEN6_RC1_WAKE_RATE_LIMIT, 1000 << 16);
248 	intel_uncore_write_fw(uncore, GEN6_RC6_WAKE_RATE_LIMIT, 40 << 16 | 30);
249 	intel_uncore_write_fw(uncore, GEN6_RC6pp_WAKE_RATE_LIMIT, 30);
250 	intel_uncore_write_fw(uncore, GEN6_RC_EVALUATION_INTERVAL, 125000);
251 	intel_uncore_write_fw(uncore, GEN6_RC_IDLE_HYSTERSIS, 25);
252 
253 	for_each_engine(engine, rc6_to_gt(rc6), id)
254 		intel_uncore_write_fw(uncore, RING_MAX_IDLE(engine->mmio_base), 10);
255 
256 	intel_uncore_write_fw(uncore, GEN6_RC_SLEEP, 0);
257 	intel_uncore_write_fw(uncore, GEN6_RC1e_THRESHOLD, 1000);
258 	intel_uncore_write_fw(uncore, GEN6_RC6_THRESHOLD, 50000);
259 	intel_uncore_write_fw(uncore, GEN6_RC6p_THRESHOLD, 150000);
260 	intel_uncore_write_fw(uncore, GEN6_RC6pp_THRESHOLD, 64000); /* unused */
261 
262 	/* We don't use those on Haswell */
263 	rc6_mask = GEN6_RC_CTL_RC6_ENABLE;
264 	if (HAS_RC6p(i915))
265 		rc6_mask |= GEN6_RC_CTL_RC6p_ENABLE;
266 	if (HAS_RC6pp(i915))
267 		rc6_mask |= GEN6_RC_CTL_RC6pp_ENABLE;
268 	rc6->ctl_enable =
269 	    rc6_mask |
270 	    GEN6_RC_CTL_EI_MODE(1) |
271 	    GEN6_RC_CTL_HW_ENABLE;
272 
273 	rc6vids = 0;
274 	ret = snb_pcode_read(rc6_to_gt(rc6)->uncore, GEN6_PCODE_READ_RC6VIDS, &rc6vids, NULL);
275 	if (GRAPHICS_VER(i915) == 6 && ret) {
276 		drm_dbg(&i915->drm, "Couldn't check for BIOS workaround\n");
277 	} else if (GRAPHICS_VER(i915) == 6 &&
278 		   (GEN6_DECODE_RC6_VID(rc6vids & 0xff) < 450)) {
279 		drm_dbg(&i915->drm,
280 			"You should update your BIOS. Correcting minimum rc6 voltage (%dmV->%dmV)\n",
281 			GEN6_DECODE_RC6_VID(rc6vids & 0xff), 450);
282 		rc6vids &= 0xffff00;
283 		rc6vids |= GEN6_ENCODE_RC6_VID(450);
284 		ret = snb_pcode_write(rc6_to_gt(rc6)->uncore, GEN6_PCODE_WRITE_RC6VIDS, rc6vids);
285 		if (ret)
286 			drm_err(&i915->drm,
287 				"Couldn't fix incorrect rc6 voltage\n");
288 	}
289 }
290 
291 /* Check that the pcbr address is not empty. */
292 static int chv_rc6_init(struct intel_rc6 *rc6)
293 {
294 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
295 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
296 	resource_size_t pctx_paddr, paddr;
297 	resource_size_t pctx_size = 32 * SZ_1K;
298 	u32 pcbr;
299 
300 	pcbr = intel_uncore_read(uncore, VLV_PCBR);
301 	if ((pcbr >> VLV_PCBR_ADDR_SHIFT) == 0) {
302 		drm_dbg(&i915->drm, "BIOS didn't set up PCBR, fixing up\n");
303 		paddr = i915->dsm.stolen.end + 1 - pctx_size;
304 		GEM_BUG_ON(paddr > U32_MAX);
305 
306 		pctx_paddr = (paddr & ~4095);
307 		intel_uncore_write(uncore, VLV_PCBR, pctx_paddr);
308 	}
309 
310 	return 0;
311 }
312 
313 static int vlv_rc6_init(struct intel_rc6 *rc6)
314 {
315 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
316 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
317 	struct drm_i915_gem_object *pctx;
318 	resource_size_t pctx_paddr;
319 	resource_size_t pctx_size = 24 * SZ_1K;
320 	u32 pcbr;
321 
322 	pcbr = intel_uncore_read(uncore, VLV_PCBR);
323 	if (pcbr) {
324 		/* BIOS set it up already, grab the pre-alloc'd space */
325 		resource_size_t pcbr_offset;
326 
327 		pcbr_offset = (pcbr & ~4095) - i915->dsm.stolen.start;
328 		pctx = i915_gem_object_create_region_at(i915->mm.stolen_region,
329 							pcbr_offset,
330 							pctx_size,
331 							0);
332 		if (IS_ERR(pctx))
333 			return PTR_ERR(pctx);
334 
335 		goto out;
336 	}
337 
338 	drm_dbg(&i915->drm, "BIOS didn't set up PCBR, fixing up\n");
339 
340 	/*
341 	 * From the Gunit register HAS:
342 	 * The Gfx driver is expected to program this register and ensure
343 	 * proper allocation within Gfx stolen memory.  For example, this
344 	 * register should be programmed such than the PCBR range does not
345 	 * overlap with other ranges, such as the frame buffer, protected
346 	 * memory, or any other relevant ranges.
347 	 */
348 	pctx = i915_gem_object_create_stolen(i915, pctx_size);
349 	if (IS_ERR(pctx)) {
350 		drm_dbg(&i915->drm,
351 			"not enough stolen space for PCTX, disabling\n");
352 		return PTR_ERR(pctx);
353 	}
354 
355 	GEM_BUG_ON(range_overflows_end_t(u64,
356 					 i915->dsm.stolen.start,
357 					 pctx->stolen->start,
358 					 U32_MAX));
359 	pctx_paddr = i915->dsm.stolen.start + pctx->stolen->start;
360 	intel_uncore_write(uncore, VLV_PCBR, pctx_paddr);
361 
362 out:
363 	rc6->pctx = pctx;
364 	return 0;
365 }
366 
367 static void chv_rc6_enable(struct intel_rc6 *rc6)
368 {
369 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
370 	struct intel_engine_cs *engine;
371 	enum intel_engine_id id;
372 
373 	/* 2a: Program RC6 thresholds.*/
374 	intel_uncore_write_fw(uncore, GEN6_RC6_WAKE_RATE_LIMIT, 40 << 16);
375 	intel_uncore_write_fw(uncore, GEN6_RC_EVALUATION_INTERVAL, 125000); /* 12500 * 1280ns */
376 	intel_uncore_write_fw(uncore, GEN6_RC_IDLE_HYSTERSIS, 25); /* 25 * 1280ns */
377 
378 	for_each_engine(engine, rc6_to_gt(rc6), id)
379 		intel_uncore_write_fw(uncore, RING_MAX_IDLE(engine->mmio_base), 10);
380 	intel_uncore_write_fw(uncore, GEN6_RC_SLEEP, 0);
381 
382 	/* TO threshold set to 500 us (0x186 * 1.28 us) */
383 	intel_uncore_write_fw(uncore, GEN6_RC6_THRESHOLD, 0x186);
384 
385 	/* Allows RC6 residency counter to work */
386 	intel_uncore_write_fw(uncore, VLV_COUNTER_CONTROL,
387 			      _MASKED_BIT_ENABLE(VLV_COUNT_RANGE_HIGH |
388 						 VLV_MEDIA_RC6_COUNT_EN |
389 						 VLV_RENDER_RC6_COUNT_EN));
390 
391 	/* 3: Enable RC6 */
392 	rc6->ctl_enable = GEN7_RC_CTL_TO_MODE;
393 }
394 
395 static void vlv_rc6_enable(struct intel_rc6 *rc6)
396 {
397 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
398 	struct intel_engine_cs *engine;
399 	enum intel_engine_id id;
400 
401 	intel_uncore_write_fw(uncore, GEN6_RC6_WAKE_RATE_LIMIT, 0x00280000);
402 	intel_uncore_write_fw(uncore, GEN6_RC_EVALUATION_INTERVAL, 125000);
403 	intel_uncore_write_fw(uncore, GEN6_RC_IDLE_HYSTERSIS, 25);
404 
405 	for_each_engine(engine, rc6_to_gt(rc6), id)
406 		intel_uncore_write_fw(uncore, RING_MAX_IDLE(engine->mmio_base), 10);
407 
408 	intel_uncore_write_fw(uncore, GEN6_RC6_THRESHOLD, 0x557);
409 
410 	/* Allows RC6 residency counter to work */
411 	intel_uncore_write_fw(uncore, VLV_COUNTER_CONTROL,
412 			      _MASKED_BIT_ENABLE(VLV_COUNT_RANGE_HIGH |
413 						 VLV_MEDIA_RC0_COUNT_EN |
414 						 VLV_RENDER_RC0_COUNT_EN |
415 						 VLV_MEDIA_RC6_COUNT_EN |
416 						 VLV_RENDER_RC6_COUNT_EN));
417 
418 	rc6->ctl_enable =
419 	    GEN7_RC_CTL_TO_MODE | VLV_RC_CTL_CTX_RST_PARALLEL;
420 }
421 
422 bool intel_check_bios_c6_setup(struct intel_rc6 *rc6)
423 {
424 	if (!rc6->bios_state_captured) {
425 		struct intel_uncore *uncore = rc6_to_uncore(rc6);
426 		intel_wakeref_t wakeref;
427 
428 		with_intel_runtime_pm(uncore->rpm, wakeref)
429 			rc6->bios_rc_state = intel_uncore_read(uncore, GEN6_RC_STATE);
430 
431 		rc6->bios_state_captured = true;
432 	}
433 
434 	return rc6->bios_rc_state & RC_SW_TARGET_STATE_MASK;
435 }
436 
437 static bool bxt_check_bios_rc6_setup(struct intel_rc6 *rc6)
438 {
439 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
440 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
441 	u32 rc6_ctx_base, rc_ctl, rc_sw_target;
442 	bool enable_rc6 = true;
443 
444 	rc_ctl = intel_uncore_read(uncore, GEN6_RC_CONTROL);
445 	rc_sw_target = intel_uncore_read(uncore, GEN6_RC_STATE);
446 	rc_sw_target &= RC_SW_TARGET_STATE_MASK;
447 	rc_sw_target >>= RC_SW_TARGET_STATE_SHIFT;
448 	drm_dbg(&i915->drm, "BIOS enabled RC states: "
449 			 "HW_CTRL %s HW_RC6 %s SW_TARGET_STATE %x\n",
450 			 str_on_off(rc_ctl & GEN6_RC_CTL_HW_ENABLE),
451 			 str_on_off(rc_ctl & GEN6_RC_CTL_RC6_ENABLE),
452 			 rc_sw_target);
453 
454 	if (!(intel_uncore_read(uncore, RC6_LOCATION) & RC6_CTX_IN_DRAM)) {
455 		drm_dbg(&i915->drm, "RC6 Base location not set properly.\n");
456 		enable_rc6 = false;
457 	}
458 
459 	/*
460 	 * The exact context size is not known for BXT, so assume a page size
461 	 * for this check.
462 	 */
463 	rc6_ctx_base =
464 		intel_uncore_read(uncore, RC6_CTX_BASE) & RC6_CTX_BASE_MASK;
465 	if (!(rc6_ctx_base >= i915->dsm.reserved.start &&
466 	      rc6_ctx_base + PAGE_SIZE < i915->dsm.reserved.end)) {
467 		drm_dbg(&i915->drm, "RC6 Base address not as expected.\n");
468 		enable_rc6 = false;
469 	}
470 
471 	if (!((intel_uncore_read(uncore, PWRCTX_MAXCNT(RENDER_RING_BASE)) & IDLE_TIME_MASK) > 1 &&
472 	      (intel_uncore_read(uncore, PWRCTX_MAXCNT(GEN6_BSD_RING_BASE)) & IDLE_TIME_MASK) > 1 &&
473 	      (intel_uncore_read(uncore, PWRCTX_MAXCNT(BLT_RING_BASE)) & IDLE_TIME_MASK) > 1 &&
474 	      (intel_uncore_read(uncore, PWRCTX_MAXCNT(VEBOX_RING_BASE)) & IDLE_TIME_MASK) > 1)) {
475 		drm_dbg(&i915->drm,
476 			"Engine Idle wait time not set properly.\n");
477 		enable_rc6 = false;
478 	}
479 
480 	if (!intel_uncore_read(uncore, GEN8_PUSHBUS_CONTROL) ||
481 	    !intel_uncore_read(uncore, GEN8_PUSHBUS_ENABLE) ||
482 	    !intel_uncore_read(uncore, GEN8_PUSHBUS_SHIFT)) {
483 		drm_dbg(&i915->drm, "Pushbus not setup properly.\n");
484 		enable_rc6 = false;
485 	}
486 
487 	if (!intel_uncore_read(uncore, GEN6_GFXPAUSE)) {
488 		drm_dbg(&i915->drm, "GFX pause not setup properly.\n");
489 		enable_rc6 = false;
490 	}
491 
492 	if (!intel_uncore_read(uncore, GEN8_MISC_CTRL0)) {
493 		drm_dbg(&i915->drm, "GPM control not setup properly.\n");
494 		enable_rc6 = false;
495 	}
496 
497 	return enable_rc6;
498 }
499 
500 static bool rc6_supported(struct intel_rc6 *rc6)
501 {
502 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
503 	struct intel_gt *gt = rc6_to_gt(rc6);
504 
505 	if (!HAS_RC6(i915))
506 		return false;
507 
508 	if (intel_vgpu_active(i915))
509 		return false;
510 
511 	if (is_mock_gt(rc6_to_gt(rc6)))
512 		return false;
513 
514 	if (IS_GEN9_LP(i915) && !bxt_check_bios_rc6_setup(rc6)) {
515 		drm_notice(&i915->drm,
516 			   "RC6 and powersaving disabled by BIOS\n");
517 		return false;
518 	}
519 
520 	if (IS_METEORLAKE(gt->i915) &&
521 	    !intel_check_bios_c6_setup(rc6)) {
522 		drm_notice(&i915->drm,
523 			   "C6 disabled by BIOS\n");
524 		return false;
525 	}
526 
527 	if (IS_MEDIA_GT_IP_STEP(gt, IP_VER(13, 0), STEP_A0, STEP_B0)) {
528 		drm_notice(&i915->drm,
529 			   "Media RC6 disabled on A step\n");
530 		return false;
531 	}
532 
533 	return true;
534 }
535 
536 static void rpm_get(struct intel_rc6 *rc6)
537 {
538 	GEM_BUG_ON(rc6->wakeref);
539 	pm_runtime_get_sync(rc6_to_i915(rc6)->drm.dev);
540 	rc6->wakeref = true;
541 }
542 
543 static void rpm_put(struct intel_rc6 *rc6)
544 {
545 	GEM_BUG_ON(!rc6->wakeref);
546 	pm_runtime_put(rc6_to_i915(rc6)->drm.dev);
547 	rc6->wakeref = false;
548 }
549 
550 static bool pctx_corrupted(struct intel_rc6 *rc6)
551 {
552 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
553 
554 	if (!NEEDS_RC6_CTX_CORRUPTION_WA(i915))
555 		return false;
556 
557 	if (intel_uncore_read(rc6_to_uncore(rc6), GEN8_RC6_CTX_INFO))
558 		return false;
559 
560 	drm_notice(&i915->drm,
561 		   "RC6 context corruption, disabling runtime power management\n");
562 	return true;
563 }
564 
565 static void __intel_rc6_disable(struct intel_rc6 *rc6)
566 {
567 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
568 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
569 	struct intel_gt *gt = rc6_to_gt(rc6);
570 
571 	/* Take control of RC6 back from GuC */
572 	intel_guc_rc_disable(&gt->uc.guc);
573 
574 	intel_uncore_forcewake_get(uncore, FORCEWAKE_ALL);
575 	if (GRAPHICS_VER(i915) >= 9)
576 		intel_uncore_write_fw(uncore, GEN9_PG_ENABLE, 0);
577 	intel_uncore_write_fw(uncore, GEN6_RC_CONTROL, 0);
578 	intel_uncore_write_fw(uncore, GEN6_RC_STATE, 0);
579 	intel_uncore_forcewake_put(uncore, FORCEWAKE_ALL);
580 }
581 
582 static void rc6_res_reg_init(struct intel_rc6 *rc6)
583 {
584 	i915_reg_t res_reg[INTEL_RC6_RES_MAX] = {
585 		[0 ... INTEL_RC6_RES_MAX - 1] = INVALID_MMIO_REG,
586 	};
587 
588 	switch (rc6_to_gt(rc6)->type) {
589 	case GT_MEDIA:
590 		res_reg[INTEL_RC6_RES_RC6] = MTL_MEDIA_MC6;
591 		break;
592 	default:
593 		res_reg[INTEL_RC6_RES_RC6_LOCKED] = GEN6_GT_GFX_RC6_LOCKED;
594 		res_reg[INTEL_RC6_RES_RC6] = GEN6_GT_GFX_RC6;
595 		res_reg[INTEL_RC6_RES_RC6p] = GEN6_GT_GFX_RC6p;
596 		res_reg[INTEL_RC6_RES_RC6pp] = GEN6_GT_GFX_RC6pp;
597 		break;
598 	}
599 
600 	memcpy(rc6->res_reg, res_reg, sizeof(res_reg));
601 }
602 
603 void intel_rc6_init(struct intel_rc6 *rc6)
604 {
605 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
606 	int err;
607 
608 	/* Disable runtime-pm until we can save the GPU state with rc6 pctx */
609 	rpm_get(rc6);
610 
611 	if (!rc6_supported(rc6))
612 		return;
613 
614 	rc6_res_reg_init(rc6);
615 
616 	if (IS_CHERRYVIEW(i915))
617 		err = chv_rc6_init(rc6);
618 	else if (IS_VALLEYVIEW(i915))
619 		err = vlv_rc6_init(rc6);
620 	else
621 		err = 0;
622 
623 	/* Sanitize rc6, ensure it is disabled before we are ready. */
624 	__intel_rc6_disable(rc6);
625 
626 	rc6->supported = err == 0;
627 }
628 
629 void intel_rc6_sanitize(struct intel_rc6 *rc6)
630 {
631 	memset(rc6->prev_hw_residency, 0, sizeof(rc6->prev_hw_residency));
632 
633 	if (rc6->enabled) { /* unbalanced suspend/resume */
634 		rpm_get(rc6);
635 		rc6->enabled = false;
636 	}
637 
638 	if (rc6->supported)
639 		__intel_rc6_disable(rc6);
640 }
641 
642 void intel_rc6_enable(struct intel_rc6 *rc6)
643 {
644 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
645 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
646 
647 	if (!rc6->supported)
648 		return;
649 
650 	GEM_BUG_ON(rc6->enabled);
651 
652 	intel_uncore_forcewake_get(uncore, FORCEWAKE_ALL);
653 
654 	if (IS_CHERRYVIEW(i915))
655 		chv_rc6_enable(rc6);
656 	else if (IS_VALLEYVIEW(i915))
657 		vlv_rc6_enable(rc6);
658 	else if (GRAPHICS_VER(i915) >= 11)
659 		gen11_rc6_enable(rc6);
660 	else if (GRAPHICS_VER(i915) >= 9)
661 		gen9_rc6_enable(rc6);
662 	else if (IS_BROADWELL(i915))
663 		gen8_rc6_enable(rc6);
664 	else if (GRAPHICS_VER(i915) >= 6)
665 		gen6_rc6_enable(rc6);
666 
667 	rc6->manual = rc6->ctl_enable & GEN6_RC_CTL_RC6_ENABLE;
668 	if (NEEDS_RC6_CTX_CORRUPTION_WA(i915))
669 		rc6->ctl_enable = 0;
670 
671 	intel_uncore_forcewake_put(uncore, FORCEWAKE_ALL);
672 
673 	if (unlikely(pctx_corrupted(rc6)))
674 		return;
675 
676 	/* rc6 is ready, runtime-pm is go! */
677 	rpm_put(rc6);
678 	rc6->enabled = true;
679 }
680 
681 void intel_rc6_unpark(struct intel_rc6 *rc6)
682 {
683 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
684 
685 	if (!rc6->enabled)
686 		return;
687 
688 	/* Restore HW timers for automatic RC6 entry while busy */
689 	intel_uncore_write_fw(uncore, GEN6_RC_CONTROL, rc6->ctl_enable);
690 }
691 
692 void intel_rc6_park(struct intel_rc6 *rc6)
693 {
694 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
695 	unsigned int target;
696 
697 	if (!rc6->enabled)
698 		return;
699 
700 	if (unlikely(pctx_corrupted(rc6))) {
701 		intel_rc6_disable(rc6);
702 		return;
703 	}
704 
705 	if (!rc6->manual)
706 		return;
707 
708 	/* Turn off the HW timers and go directly to rc6 */
709 	intel_uncore_write_fw(uncore, GEN6_RC_CONTROL, GEN6_RC_CTL_RC6_ENABLE);
710 
711 	if (HAS_RC6pp(rc6_to_i915(rc6)))
712 		target = 0x6; /* deepest rc6 */
713 	else if (HAS_RC6p(rc6_to_i915(rc6)))
714 		target = 0x5; /* deep rc6 */
715 	else
716 		target = 0x4; /* normal rc6 */
717 	intel_uncore_write_fw(uncore, GEN6_RC_STATE, target << RC_SW_TARGET_STATE_SHIFT);
718 }
719 
720 void intel_rc6_disable(struct intel_rc6 *rc6)
721 {
722 	if (!rc6->enabled)
723 		return;
724 
725 	rpm_get(rc6);
726 	rc6->enabled = false;
727 
728 	__intel_rc6_disable(rc6);
729 }
730 
731 void intel_rc6_fini(struct intel_rc6 *rc6)
732 {
733 	struct drm_i915_gem_object *pctx;
734 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
735 
736 	intel_rc6_disable(rc6);
737 
738 	/* We want the BIOS C6 state preserved across loads for MTL */
739 	if (IS_METEORLAKE(rc6_to_i915(rc6)) && rc6->bios_state_captured)
740 		intel_uncore_write_fw(uncore, GEN6_RC_STATE, rc6->bios_rc_state);
741 
742 	pctx = fetch_and_zero(&rc6->pctx);
743 	if (pctx)
744 		i915_gem_object_put(pctx);
745 
746 	if (rc6->wakeref)
747 		rpm_put(rc6);
748 }
749 
750 static u64 vlv_residency_raw(struct intel_uncore *uncore, const i915_reg_t reg)
751 {
752 	u32 lower, upper, tmp;
753 	int loop = 2;
754 
755 	/*
756 	 * The register accessed do not need forcewake. We borrow
757 	 * uncore lock to prevent concurrent access to range reg.
758 	 */
759 	lockdep_assert_held(&uncore->lock);
760 
761 	/*
762 	 * vlv and chv residency counters are 40 bits in width.
763 	 * With a control bit, we can choose between upper or lower
764 	 * 32bit window into this counter.
765 	 *
766 	 * Although we always use the counter in high-range mode elsewhere,
767 	 * userspace may attempt to read the value before rc6 is initialised,
768 	 * before we have set the default VLV_COUNTER_CONTROL value. So always
769 	 * set the high bit to be safe.
770 	 */
771 	intel_uncore_write_fw(uncore, VLV_COUNTER_CONTROL,
772 			      _MASKED_BIT_ENABLE(VLV_COUNT_RANGE_HIGH));
773 	upper = intel_uncore_read_fw(uncore, reg);
774 	do {
775 		tmp = upper;
776 
777 		intel_uncore_write_fw(uncore, VLV_COUNTER_CONTROL,
778 				      _MASKED_BIT_DISABLE(VLV_COUNT_RANGE_HIGH));
779 		lower = intel_uncore_read_fw(uncore, reg);
780 
781 		intel_uncore_write_fw(uncore, VLV_COUNTER_CONTROL,
782 				      _MASKED_BIT_ENABLE(VLV_COUNT_RANGE_HIGH));
783 		upper = intel_uncore_read_fw(uncore, reg);
784 	} while (upper != tmp && --loop);
785 
786 	/*
787 	 * Everywhere else we always use VLV_COUNTER_CONTROL with the
788 	 * VLV_COUNT_RANGE_HIGH bit set - so it is safe to leave it set
789 	 * now.
790 	 */
791 
792 	return lower | (u64)upper << 8;
793 }
794 
795 u64 intel_rc6_residency_ns(struct intel_rc6 *rc6, enum intel_rc6_res_type id)
796 {
797 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
798 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
799 	u64 time_hw, prev_hw, overflow_hw;
800 	i915_reg_t reg = rc6->res_reg[id];
801 	unsigned int fw_domains;
802 	unsigned long flags;
803 	u32 mul, div;
804 
805 	if (!rc6->supported)
806 		return 0;
807 
808 	fw_domains = intel_uncore_forcewake_for_reg(uncore, reg, FW_REG_READ);
809 
810 	spin_lock_irqsave(&uncore->lock, flags);
811 	intel_uncore_forcewake_get__locked(uncore, fw_domains);
812 
813 	/* On VLV and CHV, residency time is in CZ units rather than 1.28us */
814 	if (IS_VALLEYVIEW(i915) || IS_CHERRYVIEW(i915)) {
815 		mul = 1000000;
816 		div = i915->czclk_freq;
817 		overflow_hw = BIT_ULL(40);
818 		time_hw = vlv_residency_raw(uncore, reg);
819 	} else {
820 		/* 833.33ns units on Gen9LP, 1.28us elsewhere. */
821 		if (IS_GEN9_LP(i915)) {
822 			mul = 10000;
823 			div = 12;
824 		} else {
825 			mul = 1280;
826 			div = 1;
827 		}
828 
829 		overflow_hw = BIT_ULL(32);
830 		time_hw = intel_uncore_read_fw(uncore, reg);
831 	}
832 
833 	/*
834 	 * Counter wrap handling.
835 	 *
836 	 * Store previous hw counter values for counter wrap-around handling. But
837 	 * relying on a sufficient frequency of queries otherwise counters can still wrap.
838 	 */
839 	prev_hw = rc6->prev_hw_residency[id];
840 	rc6->prev_hw_residency[id] = time_hw;
841 
842 	/* RC6 delta from last sample. */
843 	if (time_hw >= prev_hw)
844 		time_hw -= prev_hw;
845 	else
846 		time_hw += overflow_hw - prev_hw;
847 
848 	/* Add delta to RC6 extended raw driver copy. */
849 	time_hw += rc6->cur_residency[id];
850 	rc6->cur_residency[id] = time_hw;
851 
852 	intel_uncore_forcewake_put__locked(uncore, fw_domains);
853 	spin_unlock_irqrestore(&uncore->lock, flags);
854 
855 	return mul_u64_u32_div(time_hw, mul, div);
856 }
857 
858 u64 intel_rc6_residency_us(struct intel_rc6 *rc6, enum intel_rc6_res_type id)
859 {
860 	return DIV_ROUND_UP_ULL(intel_rc6_residency_ns(rc6, id), 1000);
861 }
862 
863 void intel_rc6_print_residency(struct seq_file *m, const char *title,
864 			       enum intel_rc6_res_type id)
865 {
866 	struct intel_gt *gt = m->private;
867 	i915_reg_t reg = gt->rc6.res_reg[id];
868 	intel_wakeref_t wakeref;
869 
870 	with_intel_runtime_pm(gt->uncore->rpm, wakeref)
871 		seq_printf(m, "%s %u (%llu us)\n", title,
872 			   intel_uncore_read(gt->uncore, reg),
873 			   intel_rc6_residency_us(&gt->rc6, id));
874 }
875 
876 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
877 #include "selftest_rc6.c"
878 #endif
879