xref: /linux/drivers/gpu/drm/xe/xe_hwmon.c (revision 6c7353836a91b1479e6b81791cdc163fb04b4834)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2023 Intel Corporation
4  */
5 
6 #include <linux/hwmon-sysfs.h>
7 #include <linux/hwmon.h>
8 #include <linux/types.h>
9 
10 #include <drm/drm_managed.h>
11 #include "regs/xe_gt_regs.h"
12 #include "regs/xe_mchbar_regs.h"
13 #include "xe_device.h"
14 #include "xe_gt.h"
15 #include "xe_hwmon.h"
16 #include "xe_mmio.h"
17 #include "xe_pcode.h"
18 #include "xe_pcode_api.h"
19 
20 enum xe_hwmon_reg {
21 	REG_PKG_RAPL_LIMIT,
22 	REG_PKG_POWER_SKU,
23 	REG_PKG_POWER_SKU_UNIT,
24 	REG_GT_PERF_STATUS,
25 	REG_PKG_ENERGY_STATUS,
26 };
27 
28 enum xe_hwmon_reg_operation {
29 	REG_READ32,
30 	REG_RMW32,
31 	REG_READ64,
32 };
33 
34 /*
35  * SF_* - scale factors for particular quantities according to hwmon spec.
36  */
37 #define SF_POWER	1000000		/* microwatts */
38 #define SF_CURR		1000		/* milliamperes */
39 #define SF_VOLTAGE	1000		/* millivolts */
40 #define SF_ENERGY	1000000		/* microjoules */
41 #define SF_TIME		1000		/* milliseconds */
42 
43 /**
44  * struct xe_hwmon_energy_info - to accumulate energy
45  */
46 struct xe_hwmon_energy_info {
47 	/** @reg_val_prev: previous energy reg val */
48 	u32 reg_val_prev;
49 	/** @accum_energy: accumulated energy */
50 	long accum_energy;
51 };
52 
53 /**
54  * struct xe_hwmon - xe hwmon data structure
55  */
56 struct xe_hwmon {
57 	/** @hwmon_dev: hwmon device for xe */
58 	struct device *hwmon_dev;
59 	/** @gt: primary gt */
60 	struct xe_gt *gt;
61 	/** @hwmon_lock: lock for rw attributes*/
62 	struct mutex hwmon_lock;
63 	/** @scl_shift_power: pkg power unit */
64 	int scl_shift_power;
65 	/** @scl_shift_energy: pkg energy unit */
66 	int scl_shift_energy;
67 	/** @scl_shift_time: pkg time unit */
68 	int scl_shift_time;
69 	/** @ei: Energy info for energy1_input */
70 	struct xe_hwmon_energy_info ei;
71 };
72 
73 static u32 xe_hwmon_get_reg(struct xe_hwmon *hwmon, enum xe_hwmon_reg hwmon_reg)
74 {
75 	struct xe_device *xe = gt_to_xe(hwmon->gt);
76 	struct xe_reg reg = XE_REG(0);
77 
78 	switch (hwmon_reg) {
79 	case REG_PKG_RAPL_LIMIT:
80 		if (xe->info.platform == XE_DG2)
81 			reg = PCU_CR_PACKAGE_RAPL_LIMIT;
82 		else if (xe->info.platform == XE_PVC)
83 			reg = PVC_GT0_PACKAGE_RAPL_LIMIT;
84 		break;
85 	case REG_PKG_POWER_SKU:
86 		if (xe->info.platform == XE_DG2)
87 			reg = PCU_CR_PACKAGE_POWER_SKU;
88 		else if (xe->info.platform == XE_PVC)
89 			reg = PVC_GT0_PACKAGE_POWER_SKU;
90 		break;
91 	case REG_PKG_POWER_SKU_UNIT:
92 		if (xe->info.platform == XE_DG2)
93 			reg = PCU_CR_PACKAGE_POWER_SKU_UNIT;
94 		else if (xe->info.platform == XE_PVC)
95 			reg = PVC_GT0_PACKAGE_POWER_SKU_UNIT;
96 		break;
97 	case REG_GT_PERF_STATUS:
98 		if (xe->info.platform == XE_DG2)
99 			reg = GT_PERF_STATUS;
100 		break;
101 	case REG_PKG_ENERGY_STATUS:
102 		if (xe->info.platform == XE_DG2)
103 			reg = PCU_CR_PACKAGE_ENERGY_STATUS;
104 		else if (xe->info.platform == XE_PVC)
105 			reg = PVC_GT0_PLATFORM_ENERGY_STATUS;
106 		break;
107 	default:
108 		drm_warn(&xe->drm, "Unknown xe hwmon reg id: %d\n", hwmon_reg);
109 		break;
110 	}
111 
112 	return reg.raw;
113 }
114 
115 static void xe_hwmon_process_reg(struct xe_hwmon *hwmon, enum xe_hwmon_reg hwmon_reg,
116 				 enum xe_hwmon_reg_operation operation, u64 *value,
117 				 u32 clr, u32 set)
118 {
119 	struct xe_reg reg;
120 
121 	reg.raw = xe_hwmon_get_reg(hwmon, hwmon_reg);
122 
123 	if (!reg.raw)
124 		return;
125 
126 	switch (operation) {
127 	case REG_READ32:
128 		*value = xe_mmio_read32(hwmon->gt, reg);
129 		break;
130 	case REG_RMW32:
131 		*value = xe_mmio_rmw32(hwmon->gt, reg, clr, set);
132 		break;
133 	case REG_READ64:
134 		*value = xe_mmio_read64_2x32(hwmon->gt, reg);
135 		break;
136 	default:
137 		drm_warn(&gt_to_xe(hwmon->gt)->drm, "Invalid xe hwmon reg operation: %d\n",
138 			 operation);
139 		break;
140 	}
141 }
142 
143 #define PL1_DISABLE 0
144 
145 /*
146  * HW allows arbitrary PL1 limits to be set but silently clamps these values to
147  * "typical but not guaranteed" min/max values in REG_PKG_POWER_SKU. Follow the
148  * same pattern for sysfs, allow arbitrary PL1 limits to be set but display
149  * clamped values when read.
150  */
151 static void xe_hwmon_power_max_read(struct xe_hwmon *hwmon, long *value)
152 {
153 	u64 reg_val, min, max;
154 
155 	mutex_lock(&hwmon->hwmon_lock);
156 
157 	xe_hwmon_process_reg(hwmon, REG_PKG_RAPL_LIMIT, REG_READ32, &reg_val, 0, 0);
158 	/* Check if PL1 limit is disabled */
159 	if (!(reg_val & PKG_PWR_LIM_1_EN)) {
160 		*value = PL1_DISABLE;
161 		goto unlock;
162 	}
163 
164 	reg_val = REG_FIELD_GET(PKG_PWR_LIM_1, reg_val);
165 	*value = mul_u64_u32_shr(reg_val, SF_POWER, hwmon->scl_shift_power);
166 
167 	xe_hwmon_process_reg(hwmon, REG_PKG_POWER_SKU, REG_READ64, &reg_val, 0, 0);
168 	min = REG_FIELD_GET(PKG_MIN_PWR, reg_val);
169 	min = mul_u64_u32_shr(min, SF_POWER, hwmon->scl_shift_power);
170 	max = REG_FIELD_GET(PKG_MAX_PWR, reg_val);
171 	max = mul_u64_u32_shr(max, SF_POWER, hwmon->scl_shift_power);
172 
173 	if (min && max)
174 		*value = clamp_t(u64, *value, min, max);
175 unlock:
176 	mutex_unlock(&hwmon->hwmon_lock);
177 }
178 
179 static int xe_hwmon_power_max_write(struct xe_hwmon *hwmon, long value)
180 {
181 	int ret = 0;
182 	u64 reg_val;
183 
184 	mutex_lock(&hwmon->hwmon_lock);
185 
186 	/* Disable PL1 limit and verify, as limit cannot be disabled on all platforms */
187 	if (value == PL1_DISABLE) {
188 		xe_hwmon_process_reg(hwmon, REG_PKG_RAPL_LIMIT, REG_RMW32, &reg_val,
189 				     PKG_PWR_LIM_1_EN, 0);
190 		xe_hwmon_process_reg(hwmon, REG_PKG_RAPL_LIMIT, REG_READ32, &reg_val,
191 				     PKG_PWR_LIM_1_EN, 0);
192 
193 		if (reg_val & PKG_PWR_LIM_1_EN) {
194 			ret = -EOPNOTSUPP;
195 			goto unlock;
196 		}
197 	}
198 
199 	/* Computation in 64-bits to avoid overflow. Round to nearest. */
200 	reg_val = DIV_ROUND_CLOSEST_ULL((u64)value << hwmon->scl_shift_power, SF_POWER);
201 	reg_val = PKG_PWR_LIM_1_EN | REG_FIELD_PREP(PKG_PWR_LIM_1, reg_val);
202 
203 	xe_hwmon_process_reg(hwmon, REG_PKG_RAPL_LIMIT, REG_RMW32, &reg_val,
204 			     PKG_PWR_LIM_1_EN | PKG_PWR_LIM_1, reg_val);
205 unlock:
206 	mutex_unlock(&hwmon->hwmon_lock);
207 	return ret;
208 }
209 
210 static void xe_hwmon_power_rated_max_read(struct xe_hwmon *hwmon, long *value)
211 {
212 	u64 reg_val;
213 
214 	xe_hwmon_process_reg(hwmon, REG_PKG_POWER_SKU, REG_READ32, &reg_val, 0, 0);
215 	reg_val = REG_FIELD_GET(PKG_TDP, reg_val);
216 	*value = mul_u64_u32_shr(reg_val, SF_POWER, hwmon->scl_shift_power);
217 }
218 
219 /*
220  * xe_hwmon_energy_get - Obtain energy value
221  *
222  * The underlying energy hardware register is 32-bits and is subject to
223  * overflow. How long before overflow? For example, with an example
224  * scaling bit shift of 14 bits (see register *PACKAGE_POWER_SKU_UNIT) and
225  * a power draw of 1000 watts, the 32-bit counter will overflow in
226  * approximately 4.36 minutes.
227  *
228  * Examples:
229  *    1 watt:  (2^32 >> 14) /    1 W / (60 * 60 * 24) secs/day -> 3 days
230  * 1000 watts: (2^32 >> 14) / 1000 W / 60             secs/min -> 4.36 minutes
231  *
232  * The function significantly increases overflow duration (from 4.36
233  * minutes) by accumulating the energy register into a 'long' as allowed by
234  * the hwmon API. Using x86_64 128 bit arithmetic (see mul_u64_u32_shr()),
235  * a 'long' of 63 bits, SF_ENERGY of 1e6 (~20 bits) and
236  * hwmon->scl_shift_energy of 14 bits we have 57 (63 - 20 + 14) bits before
237  * energy1_input overflows. This at 1000 W is an overflow duration of 278 years.
238  */
239 static void
240 xe_hwmon_energy_get(struct xe_hwmon *hwmon, long *energy)
241 {
242 	struct xe_hwmon_energy_info *ei = &hwmon->ei;
243 	u64 reg_val;
244 
245 	xe_hwmon_process_reg(hwmon, REG_PKG_ENERGY_STATUS, REG_READ32,
246 			     &reg_val, 0, 0);
247 
248 	if (reg_val >= ei->reg_val_prev)
249 		ei->accum_energy += reg_val - ei->reg_val_prev;
250 	else
251 		ei->accum_energy += UINT_MAX - ei->reg_val_prev + reg_val;
252 
253 	ei->reg_val_prev = reg_val;
254 
255 	*energy = mul_u64_u32_shr(ei->accum_energy, SF_ENERGY,
256 				  hwmon->scl_shift_energy);
257 }
258 
259 static ssize_t
260 xe_hwmon_power1_max_interval_show(struct device *dev, struct device_attribute *attr,
261 				  char *buf)
262 {
263 	struct xe_hwmon *hwmon = dev_get_drvdata(dev);
264 	u32 x, y, x_w = 2; /* 2 bits */
265 	u64 r, tau4, out;
266 
267 	xe_device_mem_access_get(gt_to_xe(hwmon->gt));
268 
269 	mutex_lock(&hwmon->hwmon_lock);
270 
271 	xe_hwmon_process_reg(hwmon, REG_PKG_RAPL_LIMIT,
272 			     REG_READ32, &r, 0, 0);
273 
274 	mutex_unlock(&hwmon->hwmon_lock);
275 
276 	xe_device_mem_access_put(gt_to_xe(hwmon->gt));
277 
278 	x = REG_FIELD_GET(PKG_PWR_LIM_1_TIME_X, r);
279 	y = REG_FIELD_GET(PKG_PWR_LIM_1_TIME_Y, r);
280 
281 	/*
282 	 * tau = 1.x * power(2,y), x = bits(23:22), y = bits(21:17)
283 	 *     = (4 | x) << (y - 2)
284 	 *
285 	 * Here (y - 2) ensures a 1.x fixed point representation of 1.x
286 	 * As x is 2 bits so 1.x can be 1.0, 1.25, 1.50, 1.75
287 	 *
288 	 * As y can be < 2, we compute tau4 = (4 | x) << y
289 	 * and then add 2 when doing the final right shift to account for units
290 	 */
291 	tau4 = ((1 << x_w) | x) << y;
292 
293 	/* val in hwmon interface units (millisec) */
294 	out = mul_u64_u32_shr(tau4, SF_TIME, hwmon->scl_shift_time + x_w);
295 
296 	return sysfs_emit(buf, "%llu\n", out);
297 }
298 
299 static ssize_t
300 xe_hwmon_power1_max_interval_store(struct device *dev, struct device_attribute *attr,
301 				   const char *buf, size_t count)
302 {
303 	struct xe_hwmon *hwmon = dev_get_drvdata(dev);
304 	u32 x, y, rxy, x_w = 2; /* 2 bits */
305 	u64 tau4, r, max_win;
306 	unsigned long val;
307 	int ret;
308 
309 	ret = kstrtoul(buf, 0, &val);
310 	if (ret)
311 		return ret;
312 
313 	/*
314 	 * Max HW supported tau in '1.x * power(2,y)' format, x = 0, y = 0x12.
315 	 * The hwmon->scl_shift_time default of 0xa results in a max tau of 256 seconds.
316 	 *
317 	 * The ideal scenario is for PKG_MAX_WIN to be read from the PKG_PWR_SKU register.
318 	 * However, it is observed that existing discrete GPUs does not provide correct
319 	 * PKG_MAX_WIN value, therefore a using default constant value. For future discrete GPUs
320 	 * this may get resolved, in which case PKG_MAX_WIN should be obtained from PKG_PWR_SKU.
321 	 */
322 #define PKG_MAX_WIN_DEFAULT 0x12ull
323 
324 	/*
325 	 * val must be < max in hwmon interface units. The steps below are
326 	 * explained in xe_hwmon_power1_max_interval_show()
327 	 */
328 	r = FIELD_PREP(PKG_MAX_WIN, PKG_MAX_WIN_DEFAULT);
329 	x = REG_FIELD_GET(PKG_MAX_WIN_X, r);
330 	y = REG_FIELD_GET(PKG_MAX_WIN_Y, r);
331 	tau4 = ((1 << x_w) | x) << y;
332 	max_win = mul_u64_u32_shr(tau4, SF_TIME, hwmon->scl_shift_time + x_w);
333 
334 	if (val > max_win)
335 		return -EINVAL;
336 
337 	/* val in hw units */
338 	val = DIV_ROUND_CLOSEST_ULL((u64)val << hwmon->scl_shift_time, SF_TIME);
339 
340 	/*
341 	 * Convert val to 1.x * power(2,y)
342 	 * y = ilog2(val)
343 	 * x = (val - (1 << y)) >> (y - 2)
344 	 */
345 	if (!val) {
346 		y = 0;
347 		x = 0;
348 	} else {
349 		y = ilog2(val);
350 		x = (val - (1ul << y)) << x_w >> y;
351 	}
352 
353 	rxy = REG_FIELD_PREP(PKG_PWR_LIM_1_TIME_X, x) | REG_FIELD_PREP(PKG_PWR_LIM_1_TIME_Y, y);
354 
355 	xe_device_mem_access_get(gt_to_xe(hwmon->gt));
356 
357 	mutex_lock(&hwmon->hwmon_lock);
358 
359 	xe_hwmon_process_reg(hwmon, REG_PKG_RAPL_LIMIT, REG_RMW32, (u64 *)&r,
360 			     PKG_PWR_LIM_1_TIME, rxy);
361 
362 	mutex_unlock(&hwmon->hwmon_lock);
363 
364 	xe_device_mem_access_put(gt_to_xe(hwmon->gt));
365 
366 	return count;
367 }
368 
369 static SENSOR_DEVICE_ATTR(power1_max_interval, 0664,
370 			  xe_hwmon_power1_max_interval_show,
371 			  xe_hwmon_power1_max_interval_store, 0);
372 
373 static struct attribute *hwmon_attributes[] = {
374 	&sensor_dev_attr_power1_max_interval.dev_attr.attr,
375 	NULL
376 };
377 
378 static umode_t xe_hwmon_attributes_visible(struct kobject *kobj,
379 					   struct attribute *attr, int index)
380 {
381 	struct device *dev = kobj_to_dev(kobj);
382 	struct xe_hwmon *hwmon = dev_get_drvdata(dev);
383 	int ret = 0;
384 
385 	xe_device_mem_access_get(gt_to_xe(hwmon->gt));
386 
387 	if (attr == &sensor_dev_attr_power1_max_interval.dev_attr.attr)
388 		ret = xe_hwmon_get_reg(hwmon, REG_PKG_RAPL_LIMIT) ? attr->mode : 0;
389 
390 	xe_device_mem_access_put(gt_to_xe(hwmon->gt));
391 
392 	return ret;
393 }
394 
395 static const struct attribute_group hwmon_attrgroup = {
396 	.attrs = hwmon_attributes,
397 	.is_visible = xe_hwmon_attributes_visible,
398 };
399 
400 static const struct attribute_group *hwmon_groups[] = {
401 	&hwmon_attrgroup,
402 	NULL
403 };
404 
405 static const struct hwmon_channel_info *hwmon_info[] = {
406 	HWMON_CHANNEL_INFO(power, HWMON_P_MAX | HWMON_P_RATED_MAX | HWMON_P_CRIT),
407 	HWMON_CHANNEL_INFO(curr, HWMON_C_CRIT),
408 	HWMON_CHANNEL_INFO(in, HWMON_I_INPUT),
409 	HWMON_CHANNEL_INFO(energy, HWMON_E_INPUT),
410 	NULL
411 };
412 
413 /* I1 is exposed as power_crit or as curr_crit depending on bit 31 */
414 static int xe_hwmon_pcode_read_i1(struct xe_gt *gt, u32 *uval)
415 {
416 	/* Avoid Illegal Subcommand error */
417 	if (gt_to_xe(gt)->info.platform == XE_DG2)
418 		return -ENXIO;
419 
420 	return xe_pcode_read(gt, PCODE_MBOX(PCODE_POWER_SETUP,
421 			     POWER_SETUP_SUBCOMMAND_READ_I1, 0),
422 			     uval, 0);
423 }
424 
425 static int xe_hwmon_pcode_write_i1(struct xe_gt *gt, u32 uval)
426 {
427 	return xe_pcode_write(gt, PCODE_MBOX(PCODE_POWER_SETUP,
428 			      POWER_SETUP_SUBCOMMAND_WRITE_I1, 0),
429 			      uval);
430 }
431 
432 static int xe_hwmon_power_curr_crit_read(struct xe_hwmon *hwmon, long *value, u32 scale_factor)
433 {
434 	int ret;
435 	u32 uval;
436 
437 	mutex_lock(&hwmon->hwmon_lock);
438 
439 	ret = xe_hwmon_pcode_read_i1(hwmon->gt, &uval);
440 	if (ret)
441 		goto unlock;
442 
443 	*value = mul_u64_u32_shr(REG_FIELD_GET(POWER_SETUP_I1_DATA_MASK, uval),
444 				 scale_factor, POWER_SETUP_I1_SHIFT);
445 unlock:
446 	mutex_unlock(&hwmon->hwmon_lock);
447 	return ret;
448 }
449 
450 static int xe_hwmon_power_curr_crit_write(struct xe_hwmon *hwmon, long value, u32 scale_factor)
451 {
452 	int ret;
453 	u32 uval;
454 
455 	mutex_lock(&hwmon->hwmon_lock);
456 
457 	uval = DIV_ROUND_CLOSEST_ULL(value << POWER_SETUP_I1_SHIFT, scale_factor);
458 	ret = xe_hwmon_pcode_write_i1(hwmon->gt, uval);
459 
460 	mutex_unlock(&hwmon->hwmon_lock);
461 	return ret;
462 }
463 
464 static void xe_hwmon_get_voltage(struct xe_hwmon *hwmon, long *value)
465 {
466 	u64 reg_val;
467 
468 	xe_hwmon_process_reg(hwmon, REG_GT_PERF_STATUS,
469 			     REG_READ32, &reg_val, 0, 0);
470 	/* HW register value in units of 2.5 millivolt */
471 	*value = DIV_ROUND_CLOSEST(REG_FIELD_GET(VOLTAGE_MASK, reg_val) * 2500, SF_VOLTAGE);
472 }
473 
474 static umode_t
475 xe_hwmon_power_is_visible(struct xe_hwmon *hwmon, u32 attr, int chan)
476 {
477 	u32 uval;
478 
479 	switch (attr) {
480 	case hwmon_power_max:
481 		return xe_hwmon_get_reg(hwmon, REG_PKG_RAPL_LIMIT) ? 0664 : 0;
482 	case hwmon_power_rated_max:
483 		return xe_hwmon_get_reg(hwmon, REG_PKG_POWER_SKU) ? 0444 : 0;
484 	case hwmon_power_crit:
485 		return (xe_hwmon_pcode_read_i1(hwmon->gt, &uval) ||
486 			!(uval & POWER_SETUP_I1_WATTS)) ? 0 : 0644;
487 	default:
488 		return 0;
489 	}
490 }
491 
492 static int
493 xe_hwmon_power_read(struct xe_hwmon *hwmon, u32 attr, int chan, long *val)
494 {
495 	switch (attr) {
496 	case hwmon_power_max:
497 		xe_hwmon_power_max_read(hwmon, val);
498 		return 0;
499 	case hwmon_power_rated_max:
500 		xe_hwmon_power_rated_max_read(hwmon, val);
501 		return 0;
502 	case hwmon_power_crit:
503 		return xe_hwmon_power_curr_crit_read(hwmon, val, SF_POWER);
504 	default:
505 		return -EOPNOTSUPP;
506 	}
507 }
508 
509 static int
510 xe_hwmon_power_write(struct xe_hwmon *hwmon, u32 attr, int chan, long val)
511 {
512 	switch (attr) {
513 	case hwmon_power_max:
514 		return xe_hwmon_power_max_write(hwmon, val);
515 	case hwmon_power_crit:
516 		return xe_hwmon_power_curr_crit_write(hwmon, val, SF_POWER);
517 	default:
518 		return -EOPNOTSUPP;
519 	}
520 }
521 
522 static umode_t
523 xe_hwmon_curr_is_visible(const struct xe_hwmon *hwmon, u32 attr)
524 {
525 	u32 uval;
526 
527 	switch (attr) {
528 	case hwmon_curr_crit:
529 		return (xe_hwmon_pcode_read_i1(hwmon->gt, &uval) ||
530 			(uval & POWER_SETUP_I1_WATTS)) ? 0 : 0644;
531 	default:
532 		return 0;
533 	}
534 }
535 
536 static int
537 xe_hwmon_curr_read(struct xe_hwmon *hwmon, u32 attr, long *val)
538 {
539 	switch (attr) {
540 	case hwmon_curr_crit:
541 		return xe_hwmon_power_curr_crit_read(hwmon, val, SF_CURR);
542 	default:
543 		return -EOPNOTSUPP;
544 	}
545 }
546 
547 static int
548 xe_hwmon_curr_write(struct xe_hwmon *hwmon, u32 attr, long val)
549 {
550 	switch (attr) {
551 	case hwmon_curr_crit:
552 		return xe_hwmon_power_curr_crit_write(hwmon, val, SF_CURR);
553 	default:
554 		return -EOPNOTSUPP;
555 	}
556 }
557 
558 static umode_t
559 xe_hwmon_in_is_visible(struct xe_hwmon *hwmon, u32 attr)
560 {
561 	switch (attr) {
562 	case hwmon_in_input:
563 		return xe_hwmon_get_reg(hwmon, REG_GT_PERF_STATUS) ? 0444 : 0;
564 	default:
565 		return 0;
566 	}
567 }
568 
569 static int
570 xe_hwmon_in_read(struct xe_hwmon *hwmon, u32 attr, long *val)
571 {
572 	switch (attr) {
573 	case hwmon_in_input:
574 		xe_hwmon_get_voltage(hwmon, val);
575 		return 0;
576 	default:
577 		return -EOPNOTSUPP;
578 	}
579 }
580 
581 static umode_t
582 xe_hwmon_energy_is_visible(struct xe_hwmon *hwmon, u32 attr)
583 {
584 	switch (attr) {
585 	case hwmon_energy_input:
586 		return xe_hwmon_get_reg(hwmon, REG_PKG_ENERGY_STATUS) ? 0444 : 0;
587 	default:
588 		return 0;
589 	}
590 }
591 
592 static int
593 xe_hwmon_energy_read(struct xe_hwmon *hwmon, u32 attr, long *val)
594 {
595 	switch (attr) {
596 	case hwmon_energy_input:
597 		xe_hwmon_energy_get(hwmon, val);
598 		return 0;
599 	default:
600 		return -EOPNOTSUPP;
601 	}
602 }
603 
604 static umode_t
605 xe_hwmon_is_visible(const void *drvdata, enum hwmon_sensor_types type,
606 		    u32 attr, int channel)
607 {
608 	struct xe_hwmon *hwmon = (struct xe_hwmon *)drvdata;
609 	int ret;
610 
611 	xe_device_mem_access_get(gt_to_xe(hwmon->gt));
612 
613 	switch (type) {
614 	case hwmon_power:
615 		ret = xe_hwmon_power_is_visible(hwmon, attr, channel);
616 		break;
617 	case hwmon_curr:
618 		ret = xe_hwmon_curr_is_visible(hwmon, attr);
619 		break;
620 	case hwmon_in:
621 		ret = xe_hwmon_in_is_visible(hwmon, attr);
622 		break;
623 	case hwmon_energy:
624 		ret = xe_hwmon_energy_is_visible(hwmon, attr);
625 		break;
626 	default:
627 		ret = 0;
628 		break;
629 	}
630 
631 	xe_device_mem_access_put(gt_to_xe(hwmon->gt));
632 
633 	return ret;
634 }
635 
636 static int
637 xe_hwmon_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
638 	      int channel, long *val)
639 {
640 	struct xe_hwmon *hwmon = dev_get_drvdata(dev);
641 	int ret;
642 
643 	xe_device_mem_access_get(gt_to_xe(hwmon->gt));
644 
645 	switch (type) {
646 	case hwmon_power:
647 		ret = xe_hwmon_power_read(hwmon, attr, channel, val);
648 		break;
649 	case hwmon_curr:
650 		ret = xe_hwmon_curr_read(hwmon, attr, val);
651 		break;
652 	case hwmon_in:
653 		ret = xe_hwmon_in_read(hwmon, attr, val);
654 		break;
655 	case hwmon_energy:
656 		ret = xe_hwmon_energy_read(hwmon, attr, val);
657 		break;
658 	default:
659 		ret = -EOPNOTSUPP;
660 		break;
661 	}
662 
663 	xe_device_mem_access_put(gt_to_xe(hwmon->gt));
664 
665 	return ret;
666 }
667 
668 static int
669 xe_hwmon_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
670 	       int channel, long val)
671 {
672 	struct xe_hwmon *hwmon = dev_get_drvdata(dev);
673 	int ret;
674 
675 	xe_device_mem_access_get(gt_to_xe(hwmon->gt));
676 
677 	switch (type) {
678 	case hwmon_power:
679 		ret = xe_hwmon_power_write(hwmon, attr, channel, val);
680 		break;
681 	case hwmon_curr:
682 		ret = xe_hwmon_curr_write(hwmon, attr, val);
683 		break;
684 	default:
685 		ret = -EOPNOTSUPP;
686 		break;
687 	}
688 
689 	xe_device_mem_access_put(gt_to_xe(hwmon->gt));
690 
691 	return ret;
692 }
693 
694 static const struct hwmon_ops hwmon_ops = {
695 	.is_visible = xe_hwmon_is_visible,
696 	.read = xe_hwmon_read,
697 	.write = xe_hwmon_write,
698 };
699 
700 static const struct hwmon_chip_info hwmon_chip_info = {
701 	.ops = &hwmon_ops,
702 	.info = hwmon_info,
703 };
704 
705 static void
706 xe_hwmon_get_preregistration_info(struct xe_device *xe)
707 {
708 	struct xe_hwmon *hwmon = xe->hwmon;
709 	long energy;
710 	u64 val_sku_unit = 0;
711 
712 	/*
713 	 * The contents of register PKG_POWER_SKU_UNIT do not change,
714 	 * so read it once and store the shift values.
715 	 */
716 	if (xe_hwmon_get_reg(hwmon, REG_PKG_POWER_SKU_UNIT)) {
717 		xe_hwmon_process_reg(hwmon, REG_PKG_POWER_SKU_UNIT,
718 				     REG_READ32, &val_sku_unit, 0, 0);
719 		hwmon->scl_shift_power = REG_FIELD_GET(PKG_PWR_UNIT, val_sku_unit);
720 		hwmon->scl_shift_energy = REG_FIELD_GET(PKG_ENERGY_UNIT, val_sku_unit);
721 		hwmon->scl_shift_time = REG_FIELD_GET(PKG_TIME_UNIT, val_sku_unit);
722 	}
723 
724 	/*
725 	 * Initialize 'struct xe_hwmon_energy_info', i.e. set fields to the
726 	 * first value of the energy register read
727 	 */
728 	if (xe_hwmon_is_visible(hwmon, hwmon_energy, hwmon_energy_input, 0))
729 		xe_hwmon_energy_get(hwmon, &energy);
730 }
731 
732 static void xe_hwmon_mutex_destroy(void *arg)
733 {
734 	struct xe_hwmon *hwmon = arg;
735 
736 	mutex_destroy(&hwmon->hwmon_lock);
737 }
738 
739 void xe_hwmon_register(struct xe_device *xe)
740 {
741 	struct device *dev = xe->drm.dev;
742 	struct xe_hwmon *hwmon;
743 
744 	/* hwmon is available only for dGfx */
745 	if (!IS_DGFX(xe))
746 		return;
747 
748 	hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL);
749 	if (!hwmon)
750 		return;
751 
752 	xe->hwmon = hwmon;
753 
754 	mutex_init(&hwmon->hwmon_lock);
755 	if (devm_add_action_or_reset(dev, xe_hwmon_mutex_destroy, hwmon))
756 		return;
757 
758 	/* primary GT to access device level properties */
759 	hwmon->gt = xe->tiles[0].primary_gt;
760 
761 	xe_hwmon_get_preregistration_info(xe);
762 
763 	drm_dbg(&xe->drm, "Register xe hwmon interface\n");
764 
765 	/*  hwmon_dev points to device hwmon<i> */
766 	hwmon->hwmon_dev = devm_hwmon_device_register_with_info(dev, "xe", hwmon,
767 								&hwmon_chip_info,
768 								hwmon_groups);
769 
770 	if (IS_ERR(hwmon->hwmon_dev)) {
771 		drm_warn(&xe->drm, "Failed to register xe hwmon (%pe)\n", hwmon->hwmon_dev);
772 		xe->hwmon = NULL;
773 		return;
774 	}
775 }
776 
777