xref: /openbmc/linux/drivers/gpu/drm/i915/gt/intel_rc6.c (revision adb19164)
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 	 * Wa_16011777198 and 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_METEORLAKE(gt->i915) ||
127 	    IS_DG2_GRAPHICS_STEP(gt->i915, G10, STEP_A0, STEP_C0) ||
128 	    IS_DG2_GRAPHICS_STEP(gt->i915, G11, STEP_A0, STEP_B0))
129 		pg_enable =
130 			GEN9_MEDIA_PG_ENABLE |
131 			GEN11_MEDIA_SAMPLER_PG_ENABLE;
132 	else
133 		pg_enable =
134 			GEN9_RENDER_PG_ENABLE |
135 			GEN9_MEDIA_PG_ENABLE |
136 			GEN11_MEDIA_SAMPLER_PG_ENABLE;
137 
138 	if (GRAPHICS_VER(gt->i915) >= 12) {
139 		for (i = 0; i < I915_MAX_VCS; i++)
140 			if (HAS_ENGINE(gt, _VCS(i)))
141 				pg_enable |= (VDN_HCP_POWERGATE_ENABLE(i) |
142 					      VDN_MFX_POWERGATE_ENABLE(i));
143 	}
144 
145 	intel_uncore_write_fw(uncore, GEN9_PG_ENABLE, pg_enable);
146 }
147 
148 static void gen9_rc6_enable(struct intel_rc6 *rc6)
149 {
150 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
151 	struct intel_engine_cs *engine;
152 	enum intel_engine_id id;
153 
154 	/* 2b: Program RC6 thresholds.*/
155 	if (GRAPHICS_VER(rc6_to_i915(rc6)) >= 11) {
156 		intel_uncore_write_fw(uncore, GEN6_RC6_WAKE_RATE_LIMIT, 54 << 16 | 85);
157 		intel_uncore_write_fw(uncore, GEN10_MEDIA_WAKE_RATE_LIMIT, 150);
158 	} else if (IS_SKYLAKE(rc6_to_i915(rc6))) {
159 		/*
160 		 * WaRsDoubleRc6WrlWithCoarsePowerGating:skl Doubling WRL only
161 		 * when CPG is enabled
162 		 */
163 		intel_uncore_write_fw(uncore, GEN6_RC6_WAKE_RATE_LIMIT, 108 << 16);
164 	} else {
165 		intel_uncore_write_fw(uncore, GEN6_RC6_WAKE_RATE_LIMIT, 54 << 16);
166 	}
167 
168 	intel_uncore_write_fw(uncore, GEN6_RC_EVALUATION_INTERVAL, 125000); /* 12500 * 1280ns */
169 	intel_uncore_write_fw(uncore, GEN6_RC_IDLE_HYSTERSIS, 25); /* 25 * 1280ns */
170 	for_each_engine(engine, rc6_to_gt(rc6), id)
171 		intel_uncore_write_fw(uncore, RING_MAX_IDLE(engine->mmio_base), 10);
172 
173 	intel_uncore_write_fw(uncore, GUC_MAX_IDLE_COUNT, 0xA);
174 
175 	intel_uncore_write_fw(uncore, GEN6_RC_SLEEP, 0);
176 
177 	/*
178 	 * 2c: Program Coarse Power Gating Policies.
179 	 *
180 	 * Bspec's guidance is to use 25us (really 25 * 1280ns) here. What we
181 	 * use instead is a more conservative estimate for the maximum time
182 	 * it takes us to service a CS interrupt and submit a new ELSP - that
183 	 * is the time which the GPU is idle waiting for the CPU to select the
184 	 * next request to execute. If the idle hysteresis is less than that
185 	 * interrupt service latency, the hardware will automatically gate
186 	 * the power well and we will then incur the wake up cost on top of
187 	 * the service latency. A similar guide from plane_state is that we
188 	 * do not want the enable hysteresis to less than the wakeup latency.
189 	 *
190 	 * igt/gem_exec_nop/sequential provides a rough estimate for the
191 	 * service latency, and puts it around 10us for Broadwell (and other
192 	 * big core) and around 40us for Broxton (and other low power cores).
193 	 * [Note that for legacy ringbuffer submission, this is less than 1us!]
194 	 * However, the wakeup latency on Broxton is closer to 100us. To be
195 	 * conservative, we have to factor in a context switch on top (due
196 	 * to ksoftirqd).
197 	 */
198 	intel_uncore_write_fw(uncore, GEN9_MEDIA_PG_IDLE_HYSTERESIS, 250);
199 	intel_uncore_write_fw(uncore, GEN9_RENDER_PG_IDLE_HYSTERESIS, 250);
200 
201 	/* 3a: Enable RC6 */
202 	intel_uncore_write_fw(uncore, GEN6_RC6_THRESHOLD, 37500); /* 37.5/125ms per EI */
203 
204 	rc6->ctl_enable =
205 		GEN6_RC_CTL_HW_ENABLE |
206 		GEN6_RC_CTL_RC6_ENABLE |
207 		GEN6_RC_CTL_EI_MODE(1);
208 
209 	/*
210 	 * WaRsDisableCoarsePowerGating:skl,cnl
211 	 *   - Render/Media PG need to be disabled with RC6.
212 	 */
213 	if (!NEEDS_WaRsDisableCoarsePowerGating(rc6_to_i915(rc6)))
214 		intel_uncore_write_fw(uncore, GEN9_PG_ENABLE,
215 				      GEN9_RENDER_PG_ENABLE | GEN9_MEDIA_PG_ENABLE);
216 }
217 
218 static void gen8_rc6_enable(struct intel_rc6 *rc6)
219 {
220 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
221 	struct intel_engine_cs *engine;
222 	enum intel_engine_id id;
223 
224 	/* 2b: Program RC6 thresholds.*/
225 	intel_uncore_write_fw(uncore, GEN6_RC6_WAKE_RATE_LIMIT, 40 << 16);
226 	intel_uncore_write_fw(uncore, GEN6_RC_EVALUATION_INTERVAL, 125000); /* 12500 * 1280ns */
227 	intel_uncore_write_fw(uncore, GEN6_RC_IDLE_HYSTERSIS, 25); /* 25 * 1280ns */
228 	for_each_engine(engine, rc6_to_gt(rc6), id)
229 		intel_uncore_write_fw(uncore, RING_MAX_IDLE(engine->mmio_base), 10);
230 	intel_uncore_write_fw(uncore, GEN6_RC_SLEEP, 0);
231 	intel_uncore_write_fw(uncore, GEN6_RC6_THRESHOLD, 625); /* 800us/1.28 for TO */
232 
233 	/* 3: Enable RC6 */
234 	rc6->ctl_enable =
235 	    GEN6_RC_CTL_HW_ENABLE |
236 	    GEN7_RC_CTL_TO_MODE |
237 	    GEN6_RC_CTL_RC6_ENABLE;
238 }
239 
240 static void gen6_rc6_enable(struct intel_rc6 *rc6)
241 {
242 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
243 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
244 	struct intel_engine_cs *engine;
245 	enum intel_engine_id id;
246 	u32 rc6vids, rc6_mask;
247 	int ret;
248 
249 	intel_uncore_write_fw(uncore, GEN6_RC1_WAKE_RATE_LIMIT, 1000 << 16);
250 	intel_uncore_write_fw(uncore, GEN6_RC6_WAKE_RATE_LIMIT, 40 << 16 | 30);
251 	intel_uncore_write_fw(uncore, GEN6_RC6pp_WAKE_RATE_LIMIT, 30);
252 	intel_uncore_write_fw(uncore, GEN6_RC_EVALUATION_INTERVAL, 125000);
253 	intel_uncore_write_fw(uncore, GEN6_RC_IDLE_HYSTERSIS, 25);
254 
255 	for_each_engine(engine, rc6_to_gt(rc6), id)
256 		intel_uncore_write_fw(uncore, RING_MAX_IDLE(engine->mmio_base), 10);
257 
258 	intel_uncore_write_fw(uncore, GEN6_RC_SLEEP, 0);
259 	intel_uncore_write_fw(uncore, GEN6_RC1e_THRESHOLD, 1000);
260 	intel_uncore_write_fw(uncore, GEN6_RC6_THRESHOLD, 50000);
261 	intel_uncore_write_fw(uncore, GEN6_RC6p_THRESHOLD, 150000);
262 	intel_uncore_write_fw(uncore, GEN6_RC6pp_THRESHOLD, 64000); /* unused */
263 
264 	/* We don't use those on Haswell */
265 	rc6_mask = GEN6_RC_CTL_RC6_ENABLE;
266 	if (HAS_RC6p(i915))
267 		rc6_mask |= GEN6_RC_CTL_RC6p_ENABLE;
268 	if (HAS_RC6pp(i915))
269 		rc6_mask |= GEN6_RC_CTL_RC6pp_ENABLE;
270 	rc6->ctl_enable =
271 	    rc6_mask |
272 	    GEN6_RC_CTL_EI_MODE(1) |
273 	    GEN6_RC_CTL_HW_ENABLE;
274 
275 	rc6vids = 0;
276 	ret = snb_pcode_read(rc6_to_gt(rc6)->uncore, GEN6_PCODE_READ_RC6VIDS, &rc6vids, NULL);
277 	if (GRAPHICS_VER(i915) == 6 && ret) {
278 		drm_dbg(&i915->drm, "Couldn't check for BIOS workaround\n");
279 	} else if (GRAPHICS_VER(i915) == 6 &&
280 		   (GEN6_DECODE_RC6_VID(rc6vids & 0xff) < 450)) {
281 		drm_dbg(&i915->drm,
282 			"You should update your BIOS. Correcting minimum rc6 voltage (%dmV->%dmV)\n",
283 			GEN6_DECODE_RC6_VID(rc6vids & 0xff), 450);
284 		rc6vids &= 0xffff00;
285 		rc6vids |= GEN6_ENCODE_RC6_VID(450);
286 		ret = snb_pcode_write(rc6_to_gt(rc6)->uncore, GEN6_PCODE_WRITE_RC6VIDS, rc6vids);
287 		if (ret)
288 			drm_err(&i915->drm,
289 				"Couldn't fix incorrect rc6 voltage\n");
290 	}
291 }
292 
293 /* Check that the pcbr address is not empty. */
294 static int chv_rc6_init(struct intel_rc6 *rc6)
295 {
296 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
297 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
298 	resource_size_t pctx_paddr, paddr;
299 	resource_size_t pctx_size = 32 * SZ_1K;
300 	u32 pcbr;
301 
302 	pcbr = intel_uncore_read(uncore, VLV_PCBR);
303 	if ((pcbr >> VLV_PCBR_ADDR_SHIFT) == 0) {
304 		drm_dbg(&i915->drm, "BIOS didn't set up PCBR, fixing up\n");
305 		paddr = i915->dsm.stolen.end + 1 - pctx_size;
306 		GEM_BUG_ON(paddr > U32_MAX);
307 
308 		pctx_paddr = (paddr & ~4095);
309 		intel_uncore_write(uncore, VLV_PCBR, pctx_paddr);
310 	}
311 
312 	return 0;
313 }
314 
315 static int vlv_rc6_init(struct intel_rc6 *rc6)
316 {
317 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
318 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
319 	struct drm_i915_gem_object *pctx;
320 	resource_size_t pctx_paddr;
321 	resource_size_t pctx_size = 24 * SZ_1K;
322 	u32 pcbr;
323 
324 	pcbr = intel_uncore_read(uncore, VLV_PCBR);
325 	if (pcbr) {
326 		/* BIOS set it up already, grab the pre-alloc'd space */
327 		resource_size_t pcbr_offset;
328 
329 		pcbr_offset = (pcbr & ~4095) - i915->dsm.stolen.start;
330 		pctx = i915_gem_object_create_region_at(i915->mm.stolen_region,
331 							pcbr_offset,
332 							pctx_size,
333 							0);
334 		if (IS_ERR(pctx))
335 			return PTR_ERR(pctx);
336 
337 		goto out;
338 	}
339 
340 	drm_dbg(&i915->drm, "BIOS didn't set up PCBR, fixing up\n");
341 
342 	/*
343 	 * From the Gunit register HAS:
344 	 * The Gfx driver is expected to program this register and ensure
345 	 * proper allocation within Gfx stolen memory.  For example, this
346 	 * register should be programmed such than the PCBR range does not
347 	 * overlap with other ranges, such as the frame buffer, protected
348 	 * memory, or any other relevant ranges.
349 	 */
350 	pctx = i915_gem_object_create_stolen(i915, pctx_size);
351 	if (IS_ERR(pctx)) {
352 		drm_dbg(&i915->drm,
353 			"not enough stolen space for PCTX, disabling\n");
354 		return PTR_ERR(pctx);
355 	}
356 
357 	GEM_BUG_ON(range_overflows_end_t(u64,
358 					 i915->dsm.stolen.start,
359 					 pctx->stolen->start,
360 					 U32_MAX));
361 	pctx_paddr = i915->dsm.stolen.start + pctx->stolen->start;
362 	intel_uncore_write(uncore, VLV_PCBR, pctx_paddr);
363 
364 out:
365 	rc6->pctx = pctx;
366 	return 0;
367 }
368 
369 static void chv_rc6_enable(struct intel_rc6 *rc6)
370 {
371 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
372 	struct intel_engine_cs *engine;
373 	enum intel_engine_id id;
374 
375 	/* 2a: Program RC6 thresholds.*/
376 	intel_uncore_write_fw(uncore, GEN6_RC6_WAKE_RATE_LIMIT, 40 << 16);
377 	intel_uncore_write_fw(uncore, GEN6_RC_EVALUATION_INTERVAL, 125000); /* 12500 * 1280ns */
378 	intel_uncore_write_fw(uncore, GEN6_RC_IDLE_HYSTERSIS, 25); /* 25 * 1280ns */
379 
380 	for_each_engine(engine, rc6_to_gt(rc6), id)
381 		intel_uncore_write_fw(uncore, RING_MAX_IDLE(engine->mmio_base), 10);
382 	intel_uncore_write_fw(uncore, GEN6_RC_SLEEP, 0);
383 
384 	/* TO threshold set to 500 us (0x186 * 1.28 us) */
385 	intel_uncore_write_fw(uncore, GEN6_RC6_THRESHOLD, 0x186);
386 
387 	/* Allows RC6 residency counter to work */
388 	intel_uncore_write_fw(uncore, VLV_COUNTER_CONTROL,
389 			      _MASKED_BIT_ENABLE(VLV_COUNT_RANGE_HIGH |
390 						 VLV_MEDIA_RC6_COUNT_EN |
391 						 VLV_RENDER_RC6_COUNT_EN));
392 
393 	/* 3: Enable RC6 */
394 	rc6->ctl_enable = GEN7_RC_CTL_TO_MODE;
395 }
396 
397 static void vlv_rc6_enable(struct intel_rc6 *rc6)
398 {
399 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
400 	struct intel_engine_cs *engine;
401 	enum intel_engine_id id;
402 
403 	intel_uncore_write_fw(uncore, GEN6_RC6_WAKE_RATE_LIMIT, 0x00280000);
404 	intel_uncore_write_fw(uncore, GEN6_RC_EVALUATION_INTERVAL, 125000);
405 	intel_uncore_write_fw(uncore, GEN6_RC_IDLE_HYSTERSIS, 25);
406 
407 	for_each_engine(engine, rc6_to_gt(rc6), id)
408 		intel_uncore_write_fw(uncore, RING_MAX_IDLE(engine->mmio_base), 10);
409 
410 	intel_uncore_write_fw(uncore, GEN6_RC6_THRESHOLD, 0x557);
411 
412 	/* Allows RC6 residency counter to work */
413 	intel_uncore_write_fw(uncore, VLV_COUNTER_CONTROL,
414 			      _MASKED_BIT_ENABLE(VLV_COUNT_RANGE_HIGH |
415 						 VLV_MEDIA_RC0_COUNT_EN |
416 						 VLV_RENDER_RC0_COUNT_EN |
417 						 VLV_MEDIA_RC6_COUNT_EN |
418 						 VLV_RENDER_RC6_COUNT_EN));
419 
420 	rc6->ctl_enable =
421 	    GEN7_RC_CTL_TO_MODE | VLV_RC_CTL_CTX_RST_PARALLEL;
422 }
423 
424 bool intel_check_bios_c6_setup(struct intel_rc6 *rc6)
425 {
426 	if (!rc6->bios_state_captured) {
427 		struct intel_uncore *uncore = rc6_to_uncore(rc6);
428 		intel_wakeref_t wakeref;
429 
430 		with_intel_runtime_pm(uncore->rpm, wakeref)
431 			rc6->bios_rc_state = intel_uncore_read(uncore, GEN6_RC_STATE);
432 
433 		rc6->bios_state_captured = true;
434 	}
435 
436 	return rc6->bios_rc_state & RC_SW_TARGET_STATE_MASK;
437 }
438 
439 static bool bxt_check_bios_rc6_setup(struct intel_rc6 *rc6)
440 {
441 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
442 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
443 	u32 rc6_ctx_base, rc_ctl, rc_sw_target;
444 	bool enable_rc6 = true;
445 
446 	rc_ctl = intel_uncore_read(uncore, GEN6_RC_CONTROL);
447 	rc_sw_target = intel_uncore_read(uncore, GEN6_RC_STATE);
448 	rc_sw_target &= RC_SW_TARGET_STATE_MASK;
449 	rc_sw_target >>= RC_SW_TARGET_STATE_SHIFT;
450 	drm_dbg(&i915->drm, "BIOS enabled RC states: "
451 			 "HW_CTRL %s HW_RC6 %s SW_TARGET_STATE %x\n",
452 			 str_on_off(rc_ctl & GEN6_RC_CTL_HW_ENABLE),
453 			 str_on_off(rc_ctl & GEN6_RC_CTL_RC6_ENABLE),
454 			 rc_sw_target);
455 
456 	if (!(intel_uncore_read(uncore, RC6_LOCATION) & RC6_CTX_IN_DRAM)) {
457 		drm_dbg(&i915->drm, "RC6 Base location not set properly.\n");
458 		enable_rc6 = false;
459 	}
460 
461 	/*
462 	 * The exact context size is not known for BXT, so assume a page size
463 	 * for this check.
464 	 */
465 	rc6_ctx_base =
466 		intel_uncore_read(uncore, RC6_CTX_BASE) & RC6_CTX_BASE_MASK;
467 	if (!(rc6_ctx_base >= i915->dsm.reserved.start &&
468 	      rc6_ctx_base + PAGE_SIZE < i915->dsm.reserved.end)) {
469 		drm_dbg(&i915->drm, "RC6 Base address not as expected.\n");
470 		enable_rc6 = false;
471 	}
472 
473 	if (!((intel_uncore_read(uncore, PWRCTX_MAXCNT(RENDER_RING_BASE)) & IDLE_TIME_MASK) > 1 &&
474 	      (intel_uncore_read(uncore, PWRCTX_MAXCNT(GEN6_BSD_RING_BASE)) & IDLE_TIME_MASK) > 1 &&
475 	      (intel_uncore_read(uncore, PWRCTX_MAXCNT(BLT_RING_BASE)) & IDLE_TIME_MASK) > 1 &&
476 	      (intel_uncore_read(uncore, PWRCTX_MAXCNT(VEBOX_RING_BASE)) & IDLE_TIME_MASK) > 1)) {
477 		drm_dbg(&i915->drm,
478 			"Engine Idle wait time not set properly.\n");
479 		enable_rc6 = false;
480 	}
481 
482 	if (!intel_uncore_read(uncore, GEN8_PUSHBUS_CONTROL) ||
483 	    !intel_uncore_read(uncore, GEN8_PUSHBUS_ENABLE) ||
484 	    !intel_uncore_read(uncore, GEN8_PUSHBUS_SHIFT)) {
485 		drm_dbg(&i915->drm, "Pushbus not setup properly.\n");
486 		enable_rc6 = false;
487 	}
488 
489 	if (!intel_uncore_read(uncore, GEN6_GFXPAUSE)) {
490 		drm_dbg(&i915->drm, "GFX pause not setup properly.\n");
491 		enable_rc6 = false;
492 	}
493 
494 	if (!intel_uncore_read(uncore, GEN8_MISC_CTRL0)) {
495 		drm_dbg(&i915->drm, "GPM control not setup properly.\n");
496 		enable_rc6 = false;
497 	}
498 
499 	return enable_rc6;
500 }
501 
502 static bool rc6_supported(struct intel_rc6 *rc6)
503 {
504 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
505 	struct intel_gt *gt = rc6_to_gt(rc6);
506 
507 	if (!HAS_RC6(i915))
508 		return false;
509 
510 	if (intel_vgpu_active(i915))
511 		return false;
512 
513 	if (is_mock_gt(rc6_to_gt(rc6)))
514 		return false;
515 
516 	if (IS_GEN9_LP(i915) && !bxt_check_bios_rc6_setup(rc6)) {
517 		drm_notice(&i915->drm,
518 			   "RC6 and powersaving disabled by BIOS\n");
519 		return false;
520 	}
521 
522 	if (IS_METEORLAKE(gt->i915) &&
523 	    !intel_check_bios_c6_setup(rc6)) {
524 		drm_notice(&i915->drm,
525 			   "C6 disabled by BIOS\n");
526 		return false;
527 	}
528 
529 	if (IS_MTL_MEDIA_STEP(gt->i915, STEP_A0, STEP_B0) &&
530 	    gt->type == GT_MEDIA) {
531 		drm_notice(&i915->drm,
532 			   "Media RC6 disabled on A step\n");
533 		return false;
534 	}
535 
536 	return true;
537 }
538 
539 static void rpm_get(struct intel_rc6 *rc6)
540 {
541 	GEM_BUG_ON(rc6->wakeref);
542 	pm_runtime_get_sync(rc6_to_i915(rc6)->drm.dev);
543 	rc6->wakeref = true;
544 }
545 
546 static void rpm_put(struct intel_rc6 *rc6)
547 {
548 	GEM_BUG_ON(!rc6->wakeref);
549 	pm_runtime_put(rc6_to_i915(rc6)->drm.dev);
550 	rc6->wakeref = false;
551 }
552 
553 static bool pctx_corrupted(struct intel_rc6 *rc6)
554 {
555 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
556 
557 	if (!NEEDS_RC6_CTX_CORRUPTION_WA(i915))
558 		return false;
559 
560 	if (intel_uncore_read(rc6_to_uncore(rc6), GEN8_RC6_CTX_INFO))
561 		return false;
562 
563 	drm_notice(&i915->drm,
564 		   "RC6 context corruption, disabling runtime power management\n");
565 	return true;
566 }
567 
568 static void __intel_rc6_disable(struct intel_rc6 *rc6)
569 {
570 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
571 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
572 	struct intel_gt *gt = rc6_to_gt(rc6);
573 
574 	/* Take control of RC6 back from GuC */
575 	intel_guc_rc_disable(&gt->uc.guc);
576 
577 	intel_uncore_forcewake_get(uncore, FORCEWAKE_ALL);
578 	if (GRAPHICS_VER(i915) >= 9)
579 		intel_uncore_write_fw(uncore, GEN9_PG_ENABLE, 0);
580 	intel_uncore_write_fw(uncore, GEN6_RC_CONTROL, 0);
581 	intel_uncore_write_fw(uncore, GEN6_RC_STATE, 0);
582 	intel_uncore_forcewake_put(uncore, FORCEWAKE_ALL);
583 }
584 
585 static void rc6_res_reg_init(struct intel_rc6 *rc6)
586 {
587 	i915_reg_t res_reg[INTEL_RC6_RES_MAX] = {
588 		[0 ... INTEL_RC6_RES_MAX - 1] = INVALID_MMIO_REG,
589 	};
590 
591 	switch (rc6_to_gt(rc6)->type) {
592 	case GT_MEDIA:
593 		res_reg[INTEL_RC6_RES_RC6] = MTL_MEDIA_MC6;
594 		break;
595 	default:
596 		res_reg[INTEL_RC6_RES_RC6_LOCKED] = GEN6_GT_GFX_RC6_LOCKED;
597 		res_reg[INTEL_RC6_RES_RC6] = GEN6_GT_GFX_RC6;
598 		res_reg[INTEL_RC6_RES_RC6p] = GEN6_GT_GFX_RC6p;
599 		res_reg[INTEL_RC6_RES_RC6pp] = GEN6_GT_GFX_RC6pp;
600 		break;
601 	}
602 
603 	memcpy(rc6->res_reg, res_reg, sizeof(res_reg));
604 }
605 
606 void intel_rc6_init(struct intel_rc6 *rc6)
607 {
608 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
609 	int err;
610 
611 	/* Disable runtime-pm until we can save the GPU state with rc6 pctx */
612 	rpm_get(rc6);
613 
614 	if (!rc6_supported(rc6))
615 		return;
616 
617 	rc6_res_reg_init(rc6);
618 
619 	if (IS_CHERRYVIEW(i915))
620 		err = chv_rc6_init(rc6);
621 	else if (IS_VALLEYVIEW(i915))
622 		err = vlv_rc6_init(rc6);
623 	else
624 		err = 0;
625 
626 	/* Sanitize rc6, ensure it is disabled before we are ready. */
627 	__intel_rc6_disable(rc6);
628 
629 	rc6->supported = err == 0;
630 }
631 
632 void intel_rc6_sanitize(struct intel_rc6 *rc6)
633 {
634 	memset(rc6->prev_hw_residency, 0, sizeof(rc6->prev_hw_residency));
635 
636 	if (rc6->enabled) { /* unbalanced suspend/resume */
637 		rpm_get(rc6);
638 		rc6->enabled = false;
639 	}
640 
641 	if (rc6->supported)
642 		__intel_rc6_disable(rc6);
643 }
644 
645 void intel_rc6_enable(struct intel_rc6 *rc6)
646 {
647 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
648 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
649 
650 	if (!rc6->supported)
651 		return;
652 
653 	GEM_BUG_ON(rc6->enabled);
654 
655 	intel_uncore_forcewake_get(uncore, FORCEWAKE_ALL);
656 
657 	if (IS_CHERRYVIEW(i915))
658 		chv_rc6_enable(rc6);
659 	else if (IS_VALLEYVIEW(i915))
660 		vlv_rc6_enable(rc6);
661 	else if (GRAPHICS_VER(i915) >= 11)
662 		gen11_rc6_enable(rc6);
663 	else if (GRAPHICS_VER(i915) >= 9)
664 		gen9_rc6_enable(rc6);
665 	else if (IS_BROADWELL(i915))
666 		gen8_rc6_enable(rc6);
667 	else if (GRAPHICS_VER(i915) >= 6)
668 		gen6_rc6_enable(rc6);
669 
670 	rc6->manual = rc6->ctl_enable & GEN6_RC_CTL_RC6_ENABLE;
671 	if (NEEDS_RC6_CTX_CORRUPTION_WA(i915))
672 		rc6->ctl_enable = 0;
673 
674 	intel_uncore_forcewake_put(uncore, FORCEWAKE_ALL);
675 
676 	if (unlikely(pctx_corrupted(rc6)))
677 		return;
678 
679 	/* rc6 is ready, runtime-pm is go! */
680 	rpm_put(rc6);
681 	rc6->enabled = true;
682 }
683 
684 void intel_rc6_unpark(struct intel_rc6 *rc6)
685 {
686 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
687 
688 	if (!rc6->enabled)
689 		return;
690 
691 	/* Restore HW timers for automatic RC6 entry while busy */
692 	intel_uncore_write_fw(uncore, GEN6_RC_CONTROL, rc6->ctl_enable);
693 }
694 
695 void intel_rc6_park(struct intel_rc6 *rc6)
696 {
697 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
698 	unsigned int target;
699 
700 	if (!rc6->enabled)
701 		return;
702 
703 	if (unlikely(pctx_corrupted(rc6))) {
704 		intel_rc6_disable(rc6);
705 		return;
706 	}
707 
708 	if (!rc6->manual)
709 		return;
710 
711 	/* Turn off the HW timers and go directly to rc6 */
712 	intel_uncore_write_fw(uncore, GEN6_RC_CONTROL, GEN6_RC_CTL_RC6_ENABLE);
713 
714 	if (HAS_RC6pp(rc6_to_i915(rc6)))
715 		target = 0x6; /* deepest rc6 */
716 	else if (HAS_RC6p(rc6_to_i915(rc6)))
717 		target = 0x5; /* deep rc6 */
718 	else
719 		target = 0x4; /* normal rc6 */
720 	intel_uncore_write_fw(uncore, GEN6_RC_STATE, target << RC_SW_TARGET_STATE_SHIFT);
721 }
722 
723 void intel_rc6_disable(struct intel_rc6 *rc6)
724 {
725 	if (!rc6->enabled)
726 		return;
727 
728 	rpm_get(rc6);
729 	rc6->enabled = false;
730 
731 	__intel_rc6_disable(rc6);
732 }
733 
734 void intel_rc6_fini(struct intel_rc6 *rc6)
735 {
736 	struct drm_i915_gem_object *pctx;
737 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
738 
739 	intel_rc6_disable(rc6);
740 
741 	/* We want the BIOS C6 state preserved across loads for MTL */
742 	if (IS_METEORLAKE(rc6_to_i915(rc6)) && rc6->bios_state_captured)
743 		intel_uncore_write_fw(uncore, GEN6_RC_STATE, rc6->bios_rc_state);
744 
745 	pctx = fetch_and_zero(&rc6->pctx);
746 	if (pctx)
747 		i915_gem_object_put(pctx);
748 
749 	if (rc6->wakeref)
750 		rpm_put(rc6);
751 }
752 
753 static u64 vlv_residency_raw(struct intel_uncore *uncore, const i915_reg_t reg)
754 {
755 	u32 lower, upper, tmp;
756 	int loop = 2;
757 
758 	/*
759 	 * The register accessed do not need forcewake. We borrow
760 	 * uncore lock to prevent concurrent access to range reg.
761 	 */
762 	lockdep_assert_held(&uncore->lock);
763 
764 	/*
765 	 * vlv and chv residency counters are 40 bits in width.
766 	 * With a control bit, we can choose between upper or lower
767 	 * 32bit window into this counter.
768 	 *
769 	 * Although we always use the counter in high-range mode elsewhere,
770 	 * userspace may attempt to read the value before rc6 is initialised,
771 	 * before we have set the default VLV_COUNTER_CONTROL value. So always
772 	 * set the high bit to be safe.
773 	 */
774 	intel_uncore_write_fw(uncore, VLV_COUNTER_CONTROL,
775 			      _MASKED_BIT_ENABLE(VLV_COUNT_RANGE_HIGH));
776 	upper = intel_uncore_read_fw(uncore, reg);
777 	do {
778 		tmp = upper;
779 
780 		intel_uncore_write_fw(uncore, VLV_COUNTER_CONTROL,
781 				      _MASKED_BIT_DISABLE(VLV_COUNT_RANGE_HIGH));
782 		lower = intel_uncore_read_fw(uncore, reg);
783 
784 		intel_uncore_write_fw(uncore, VLV_COUNTER_CONTROL,
785 				      _MASKED_BIT_ENABLE(VLV_COUNT_RANGE_HIGH));
786 		upper = intel_uncore_read_fw(uncore, reg);
787 	} while (upper != tmp && --loop);
788 
789 	/*
790 	 * Everywhere else we always use VLV_COUNTER_CONTROL with the
791 	 * VLV_COUNT_RANGE_HIGH bit set - so it is safe to leave it set
792 	 * now.
793 	 */
794 
795 	return lower | (u64)upper << 8;
796 }
797 
798 u64 intel_rc6_residency_ns(struct intel_rc6 *rc6, enum intel_rc6_res_type id)
799 {
800 	struct drm_i915_private *i915 = rc6_to_i915(rc6);
801 	struct intel_uncore *uncore = rc6_to_uncore(rc6);
802 	u64 time_hw, prev_hw, overflow_hw;
803 	i915_reg_t reg = rc6->res_reg[id];
804 	unsigned int fw_domains;
805 	unsigned long flags;
806 	u32 mul, div;
807 
808 	if (!rc6->supported)
809 		return 0;
810 
811 	fw_domains = intel_uncore_forcewake_for_reg(uncore, reg, FW_REG_READ);
812 
813 	spin_lock_irqsave(&uncore->lock, flags);
814 	intel_uncore_forcewake_get__locked(uncore, fw_domains);
815 
816 	/* On VLV and CHV, residency time is in CZ units rather than 1.28us */
817 	if (IS_VALLEYVIEW(i915) || IS_CHERRYVIEW(i915)) {
818 		mul = 1000000;
819 		div = i915->czclk_freq;
820 		overflow_hw = BIT_ULL(40);
821 		time_hw = vlv_residency_raw(uncore, reg);
822 	} else {
823 		/* 833.33ns units on Gen9LP, 1.28us elsewhere. */
824 		if (IS_GEN9_LP(i915)) {
825 			mul = 10000;
826 			div = 12;
827 		} else {
828 			mul = 1280;
829 			div = 1;
830 		}
831 
832 		overflow_hw = BIT_ULL(32);
833 		time_hw = intel_uncore_read_fw(uncore, reg);
834 	}
835 
836 	/*
837 	 * Counter wrap handling.
838 	 *
839 	 * Store previous hw counter values for counter wrap-around handling. But
840 	 * relying on a sufficient frequency of queries otherwise counters can still wrap.
841 	 */
842 	prev_hw = rc6->prev_hw_residency[id];
843 	rc6->prev_hw_residency[id] = time_hw;
844 
845 	/* RC6 delta from last sample. */
846 	if (time_hw >= prev_hw)
847 		time_hw -= prev_hw;
848 	else
849 		time_hw += overflow_hw - prev_hw;
850 
851 	/* Add delta to RC6 extended raw driver copy. */
852 	time_hw += rc6->cur_residency[id];
853 	rc6->cur_residency[id] = time_hw;
854 
855 	intel_uncore_forcewake_put__locked(uncore, fw_domains);
856 	spin_unlock_irqrestore(&uncore->lock, flags);
857 
858 	return mul_u64_u32_div(time_hw, mul, div);
859 }
860 
861 u64 intel_rc6_residency_us(struct intel_rc6 *rc6, enum intel_rc6_res_type id)
862 {
863 	return DIV_ROUND_UP_ULL(intel_rc6_residency_ns(rc6, id), 1000);
864 }
865 
866 void intel_rc6_print_residency(struct seq_file *m, const char *title,
867 			       enum intel_rc6_res_type id)
868 {
869 	struct intel_gt *gt = m->private;
870 	i915_reg_t reg = gt->rc6.res_reg[id];
871 	intel_wakeref_t wakeref;
872 
873 	with_intel_runtime_pm(gt->uncore->rpm, wakeref)
874 		seq_printf(m, "%s %u (%llu us)\n", title,
875 			   intel_uncore_read(gt->uncore, reg),
876 			   intel_rc6_residency_us(&gt->rc6, id));
877 }
878 
879 #if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
880 #include "selftest_rc6.c"
881 #endif
882