1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2010 Red Hat Inc.
4 * Author : Dave Airlie <airlied@redhat.com>
5 *
6 * ATPX support for both Intel/ATI
7 */
8#include <linux/vga_switcheroo.h>
9#include <linux/slab.h>
10#include <linux/acpi.h>
11#include <linux/pci.h>
12#include <linux/delay.h>
13
14#include "amdgpu.h"
15#include "amd_acpi.h"
16
17#define AMDGPU_PX_QUIRK_FORCE_ATPX (1 << 0)
18
19struct amdgpu_px_quirk {
20 u32 chip_vendor;
21 u32 chip_device;
22 u32 subsys_vendor;
23 u32 subsys_device;
24 u32 px_quirk_flags;
25};
26
27struct amdgpu_atpx_functions {
28 bool px_params;
29 bool power_cntl;
30 bool disp_mux_cntl;
31 bool i2c_mux_cntl;
32 bool switch_start;
33 bool switch_end;
34 bool disp_connectors_mapping;
35 bool disp_detection_ports;
36};
37
38struct amdgpu_atpx {
39 acpi_handle handle;
40 struct amdgpu_atpx_functions functions;
41 bool is_hybrid;
42 bool dgpu_req_power_for_displays;
43};
44
45static struct amdgpu_atpx_priv {
46 bool atpx_detected;
47 bool bridge_pm_usable;
48 unsigned int quirks;
49 /* handle for device - and atpx */
50 acpi_handle dhandle;
51 acpi_handle other_handle;
52 struct amdgpu_atpx atpx;
53} amdgpu_atpx_priv;
54
55struct atpx_verify_interface {
56 u16 size; /* structure size in bytes (includes size field) */
57 u16 version; /* version */
58 u32 function_bits; /* supported functions bit vector */
59} __packed;
60
61struct atpx_px_params {
62 u16 size; /* structure size in bytes (includes size field) */
63 u32 valid_flags; /* which flags are valid */
64 u32 flags; /* flags */
65} __packed;
66
67struct atpx_power_control {
68 u16 size;
69 u8 dgpu_state;
70} __packed;
71
72struct atpx_mux {
73 u16 size;
74 u16 mux;
75} __packed;
76
77bool amdgpu_has_atpx(void)
78{
79 return amdgpu_atpx_priv.atpx_detected;
80}
81
82bool amdgpu_has_atpx_dgpu_power_cntl(void)
83{
84 return amdgpu_atpx_priv.atpx.functions.power_cntl;
85}
86
87bool amdgpu_is_atpx_hybrid(void)
88{
89 return amdgpu_atpx_priv.atpx.is_hybrid;
90}
91
92/**
93 * amdgpu_atpx_call - call an ATPX method
94 *
95 * @handle: acpi handle
96 * @function: the ATPX function to execute
97 * @params: ATPX function params
98 *
99 * Executes the requested ATPX function (all asics).
100 * Returns a pointer to the acpi output buffer.
101 */
102static union acpi_object *amdgpu_atpx_call(acpi_handle handle, int function,
103 struct acpi_buffer *params)
104{
105 acpi_status status;
106 union acpi_object atpx_arg_elements[2];
107 struct acpi_object_list atpx_arg;
108 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
109
110 atpx_arg.count = 2;
111 atpx_arg.pointer = &atpx_arg_elements[0];
112
113 atpx_arg_elements[0].type = ACPI_TYPE_INTEGER;
114 atpx_arg_elements[0].integer.value = function;
115
116 if (params) {
117 atpx_arg_elements[1].type = ACPI_TYPE_BUFFER;
118 atpx_arg_elements[1].buffer.length = params->length;
119 atpx_arg_elements[1].buffer.pointer = params->pointer;
120 } else {
121 /* We need a second fake parameter */
122 atpx_arg_elements[1].type = ACPI_TYPE_INTEGER;
123 atpx_arg_elements[1].integer.value = 0;
124 }
125
126 status = acpi_evaluate_object(object: handle, NULL, parameter_objects: &atpx_arg, return_object_buffer: &buffer);
127
128 /* Fail only if calling the method fails and ATPX is supported */
129 if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {
130 pr_err("failed to evaluate ATPX got %s\n",
131 acpi_format_exception(status));
132 kfree(objp: buffer.pointer);
133 return NULL;
134 }
135
136 return buffer.pointer;
137}
138
139/**
140 * amdgpu_atpx_parse_functions - parse supported functions
141 *
142 * @f: supported functions struct
143 * @mask: supported functions mask from ATPX
144 *
145 * Use the supported functions mask from ATPX function
146 * ATPX_FUNCTION_VERIFY_INTERFACE to determine what functions
147 * are supported (all asics).
148 */
149static void amdgpu_atpx_parse_functions(struct amdgpu_atpx_functions *f, u32 mask)
150{
151 f->px_params = mask & ATPX_GET_PX_PARAMETERS_SUPPORTED;
152 f->power_cntl = mask & ATPX_POWER_CONTROL_SUPPORTED;
153 f->disp_mux_cntl = mask & ATPX_DISPLAY_MUX_CONTROL_SUPPORTED;
154 f->i2c_mux_cntl = mask & ATPX_I2C_MUX_CONTROL_SUPPORTED;
155 f->switch_start = mask & ATPX_GRAPHICS_DEVICE_SWITCH_START_NOTIFICATION_SUPPORTED;
156 f->switch_end = mask & ATPX_GRAPHICS_DEVICE_SWITCH_END_NOTIFICATION_SUPPORTED;
157 f->disp_connectors_mapping = mask & ATPX_GET_DISPLAY_CONNECTORS_MAPPING_SUPPORTED;
158 f->disp_detection_ports = mask & ATPX_GET_DISPLAY_DETECTION_PORTS_SUPPORTED;
159}
160
161/**
162 * amdgpu_atpx_validate - validate ATPX functions
163 *
164 * @atpx: amdgpu atpx struct
165 *
166 * Validate that required functions are enabled (all asics).
167 * returns 0 on success, error on failure.
168 */
169static int amdgpu_atpx_validate(struct amdgpu_atpx *atpx)
170{
171 u32 valid_bits = 0;
172
173 if (atpx->functions.px_params) {
174 union acpi_object *info;
175 struct atpx_px_params output;
176 size_t size;
177
178 info = amdgpu_atpx_call(handle: atpx->handle, ATPX_FUNCTION_GET_PX_PARAMETERS, NULL);
179 if (!info)
180 return -EIO;
181
182 memset(&output, 0, sizeof(output));
183
184 size = *(u16 *) info->buffer.pointer;
185 if (size < 10) {
186 pr_err("ATPX buffer is too small: %zu\n", size);
187 kfree(objp: info);
188 return -EINVAL;
189 }
190 size = min(sizeof(output), size);
191
192 memcpy(&output, info->buffer.pointer, size);
193
194 valid_bits = output.flags & output.valid_flags;
195
196 kfree(objp: info);
197 }
198
199 /* if separate mux flag is set, mux controls are required */
200 if (valid_bits & ATPX_SEPARATE_MUX_FOR_I2C) {
201 atpx->functions.i2c_mux_cntl = true;
202 atpx->functions.disp_mux_cntl = true;
203 }
204 /* if any outputs are muxed, mux controls are required */
205 if (valid_bits & (ATPX_CRT1_RGB_SIGNAL_MUXED |
206 ATPX_TV_SIGNAL_MUXED |
207 ATPX_DFP_SIGNAL_MUXED))
208 atpx->functions.disp_mux_cntl = true;
209
210
211 /* some bioses set these bits rather than flagging power_cntl as supported */
212 if (valid_bits & (ATPX_DYNAMIC_PX_SUPPORTED |
213 ATPX_DYNAMIC_DGPU_POWER_OFF_SUPPORTED))
214 atpx->functions.power_cntl = true;
215
216 atpx->is_hybrid = false;
217 if (valid_bits & ATPX_MS_HYBRID_GFX_SUPPORTED) {
218 if (amdgpu_atpx_priv.quirks & AMDGPU_PX_QUIRK_FORCE_ATPX) {
219 pr_warn("ATPX Hybrid Graphics, forcing to ATPX\n");
220 atpx->functions.power_cntl = true;
221 atpx->is_hybrid = false;
222 } else {
223 pr_notice("ATPX Hybrid Graphics\n");
224 /*
225 * Disable legacy PM methods only when pcie port PM is usable,
226 * otherwise the device might fail to power off or power on.
227 */
228 atpx->functions.power_cntl = !amdgpu_atpx_priv.bridge_pm_usable;
229 atpx->is_hybrid = true;
230 }
231 }
232
233 atpx->dgpu_req_power_for_displays = false;
234 if (valid_bits & ATPX_DGPU_REQ_POWER_FOR_DISPLAYS)
235 atpx->dgpu_req_power_for_displays = true;
236
237 return 0;
238}
239
240/**
241 * amdgpu_atpx_verify_interface - verify ATPX
242 *
243 * @atpx: amdgpu atpx struct
244 *
245 * Execute the ATPX_FUNCTION_VERIFY_INTERFACE ATPX function
246 * to initialize ATPX and determine what features are supported
247 * (all asics).
248 * returns 0 on success, error on failure.
249 */
250static int amdgpu_atpx_verify_interface(struct amdgpu_atpx *atpx)
251{
252 union acpi_object *info;
253 struct atpx_verify_interface output;
254 size_t size;
255 int err = 0;
256
257 info = amdgpu_atpx_call(handle: atpx->handle, ATPX_FUNCTION_VERIFY_INTERFACE, NULL);
258 if (!info)
259 return -EIO;
260
261 memset(&output, 0, sizeof(output));
262
263 size = *(u16 *) info->buffer.pointer;
264 if (size < 8) {
265 pr_err("ATPX buffer is too small: %zu\n", size);
266 err = -EINVAL;
267 goto out;
268 }
269 size = min(sizeof(output), size);
270
271 memcpy(&output, info->buffer.pointer, size);
272
273 /* TODO: check version? */
274 pr_notice("ATPX version %u, functions 0x%08x\n",
275 output.version, output.function_bits);
276
277 amdgpu_atpx_parse_functions(f: &atpx->functions, mask: output.function_bits);
278
279out:
280 kfree(objp: info);
281 return err;
282}
283
284/**
285 * amdgpu_atpx_set_discrete_state - power up/down discrete GPU
286 *
287 * @atpx: atpx info struct
288 * @state: discrete GPU state (0 = power down, 1 = power up)
289 *
290 * Execute the ATPX_FUNCTION_POWER_CONTROL ATPX function to
291 * power down/up the discrete GPU (all asics).
292 * Returns 0 on success, error on failure.
293 */
294static int amdgpu_atpx_set_discrete_state(struct amdgpu_atpx *atpx, u8 state)
295{
296 struct acpi_buffer params;
297 union acpi_object *info;
298 struct atpx_power_control input;
299
300 if (atpx->functions.power_cntl) {
301 input.size = 3;
302 input.dgpu_state = state;
303 params.length = input.size;
304 params.pointer = &input;
305 info = amdgpu_atpx_call(handle: atpx->handle,
306 ATPX_FUNCTION_POWER_CONTROL,
307 params: &params);
308 if (!info)
309 return -EIO;
310 kfree(objp: info);
311
312 /* 200ms delay is required after off */
313 if (state == 0)
314 msleep(msecs: 200);
315 }
316 return 0;
317}
318
319/**
320 * amdgpu_atpx_switch_disp_mux - switch display mux
321 *
322 * @atpx: atpx info struct
323 * @mux_id: mux state (0 = integrated GPU, 1 = discrete GPU)
324 *
325 * Execute the ATPX_FUNCTION_DISPLAY_MUX_CONTROL ATPX function to
326 * switch the display mux between the discrete GPU and integrated GPU
327 * (all asics).
328 * Returns 0 on success, error on failure.
329 */
330static int amdgpu_atpx_switch_disp_mux(struct amdgpu_atpx *atpx, u16 mux_id)
331{
332 struct acpi_buffer params;
333 union acpi_object *info;
334 struct atpx_mux input;
335
336 if (atpx->functions.disp_mux_cntl) {
337 input.size = 4;
338 input.mux = mux_id;
339 params.length = input.size;
340 params.pointer = &input;
341 info = amdgpu_atpx_call(handle: atpx->handle,
342 ATPX_FUNCTION_DISPLAY_MUX_CONTROL,
343 params: &params);
344 if (!info)
345 return -EIO;
346 kfree(objp: info);
347 }
348 return 0;
349}
350
351/**
352 * amdgpu_atpx_switch_i2c_mux - switch i2c/hpd mux
353 *
354 * @atpx: atpx info struct
355 * @mux_id: mux state (0 = integrated GPU, 1 = discrete GPU)
356 *
357 * Execute the ATPX_FUNCTION_I2C_MUX_CONTROL ATPX function to
358 * switch the i2c/hpd mux between the discrete GPU and integrated GPU
359 * (all asics).
360 * Returns 0 on success, error on failure.
361 */
362static int amdgpu_atpx_switch_i2c_mux(struct amdgpu_atpx *atpx, u16 mux_id)
363{
364 struct acpi_buffer params;
365 union acpi_object *info;
366 struct atpx_mux input;
367
368 if (atpx->functions.i2c_mux_cntl) {
369 input.size = 4;
370 input.mux = mux_id;
371 params.length = input.size;
372 params.pointer = &input;
373 info = amdgpu_atpx_call(handle: atpx->handle,
374 ATPX_FUNCTION_I2C_MUX_CONTROL,
375 params: &params);
376 if (!info)
377 return -EIO;
378 kfree(objp: info);
379 }
380 return 0;
381}
382
383/**
384 * amdgpu_atpx_switch_start - notify the sbios of a GPU switch
385 *
386 * @atpx: atpx info struct
387 * @mux_id: mux state (0 = integrated GPU, 1 = discrete GPU)
388 *
389 * Execute the ATPX_FUNCTION_GRAPHICS_DEVICE_SWITCH_START_NOTIFICATION ATPX
390 * function to notify the sbios that a switch between the discrete GPU and
391 * integrated GPU has begun (all asics).
392 * Returns 0 on success, error on failure.
393 */
394static int amdgpu_atpx_switch_start(struct amdgpu_atpx *atpx, u16 mux_id)
395{
396 struct acpi_buffer params;
397 union acpi_object *info;
398 struct atpx_mux input;
399
400 if (atpx->functions.switch_start) {
401 input.size = 4;
402 input.mux = mux_id;
403 params.length = input.size;
404 params.pointer = &input;
405 info = amdgpu_atpx_call(handle: atpx->handle,
406 ATPX_FUNCTION_GRAPHICS_DEVICE_SWITCH_START_NOTIFICATION,
407 params: &params);
408 if (!info)
409 return -EIO;
410 kfree(objp: info);
411 }
412 return 0;
413}
414
415/**
416 * amdgpu_atpx_switch_end - notify the sbios of a GPU switch
417 *
418 * @atpx: atpx info struct
419 * @mux_id: mux state (0 = integrated GPU, 1 = discrete GPU)
420 *
421 * Execute the ATPX_FUNCTION_GRAPHICS_DEVICE_SWITCH_END_NOTIFICATION ATPX
422 * function to notify the sbios that a switch between the discrete GPU and
423 * integrated GPU has ended (all asics).
424 * Returns 0 on success, error on failure.
425 */
426static int amdgpu_atpx_switch_end(struct amdgpu_atpx *atpx, u16 mux_id)
427{
428 struct acpi_buffer params;
429 union acpi_object *info;
430 struct atpx_mux input;
431
432 if (atpx->functions.switch_end) {
433 input.size = 4;
434 input.mux = mux_id;
435 params.length = input.size;
436 params.pointer = &input;
437 info = amdgpu_atpx_call(handle: atpx->handle,
438 ATPX_FUNCTION_GRAPHICS_DEVICE_SWITCH_END_NOTIFICATION,
439 params: &params);
440 if (!info)
441 return -EIO;
442 kfree(objp: info);
443 }
444 return 0;
445}
446
447/**
448 * amdgpu_atpx_switchto - switch to the requested GPU
449 *
450 * @id: GPU to switch to
451 *
452 * Execute the necessary ATPX functions to switch between the discrete GPU and
453 * integrated GPU (all asics).
454 * Returns 0 on success, error on failure.
455 */
456static int amdgpu_atpx_switchto(enum vga_switcheroo_client_id id)
457{
458 u16 gpu_id;
459
460 if (id == VGA_SWITCHEROO_IGD)
461 gpu_id = ATPX_INTEGRATED_GPU;
462 else
463 gpu_id = ATPX_DISCRETE_GPU;
464
465 amdgpu_atpx_switch_start(atpx: &amdgpu_atpx_priv.atpx, mux_id: gpu_id);
466 amdgpu_atpx_switch_disp_mux(atpx: &amdgpu_atpx_priv.atpx, mux_id: gpu_id);
467 amdgpu_atpx_switch_i2c_mux(atpx: &amdgpu_atpx_priv.atpx, mux_id: gpu_id);
468 amdgpu_atpx_switch_end(atpx: &amdgpu_atpx_priv.atpx, mux_id: gpu_id);
469
470 return 0;
471}
472
473/**
474 * amdgpu_atpx_power_state - power down/up the requested GPU
475 *
476 * @id: GPU to power down/up
477 * @state: requested power state (0 = off, 1 = on)
478 *
479 * Execute the necessary ATPX function to power down/up the discrete GPU
480 * (all asics).
481 * Returns 0 on success, error on failure.
482 */
483static int amdgpu_atpx_power_state(enum vga_switcheroo_client_id id,
484 enum vga_switcheroo_state state)
485{
486 /* on w500 ACPI can't change intel gpu state */
487 if (id == VGA_SWITCHEROO_IGD)
488 return 0;
489
490 amdgpu_atpx_set_discrete_state(atpx: &amdgpu_atpx_priv.atpx, state);
491 return 0;
492}
493
494/**
495 * amdgpu_atpx_pci_probe_handle - look up the ATPX handle
496 *
497 * @pdev: pci device
498 *
499 * Look up the ATPX handles (all asics).
500 * Returns true if the handles are found, false if not.
501 */
502static bool amdgpu_atpx_pci_probe_handle(struct pci_dev *pdev)
503{
504 acpi_handle dhandle, atpx_handle;
505 acpi_status status;
506
507 dhandle = ACPI_HANDLE(&pdev->dev);
508 if (!dhandle)
509 return false;
510
511 status = acpi_get_handle(parent: dhandle, pathname: "ATPX", ret_handle: &atpx_handle);
512 if (ACPI_FAILURE(status)) {
513 amdgpu_atpx_priv.other_handle = dhandle;
514 return false;
515 }
516 amdgpu_atpx_priv.dhandle = dhandle;
517 amdgpu_atpx_priv.atpx.handle = atpx_handle;
518 return true;
519}
520
521/**
522 * amdgpu_atpx_init - verify the ATPX interface
523 *
524 * Verify the ATPX interface (all asics).
525 * Returns 0 on success, error on failure.
526 */
527static int amdgpu_atpx_init(void)
528{
529 int r;
530
531 /* set up the ATPX handle */
532 r = amdgpu_atpx_verify_interface(atpx: &amdgpu_atpx_priv.atpx);
533 if (r)
534 return r;
535
536 /* validate the atpx setup */
537 r = amdgpu_atpx_validate(atpx: &amdgpu_atpx_priv.atpx);
538 if (r)
539 return r;
540
541 return 0;
542}
543
544/**
545 * amdgpu_atpx_get_client_id - get the client id
546 *
547 * @pdev: pci device
548 *
549 * look up whether we are the integrated or discrete GPU (all asics).
550 * Returns the client id.
551 */
552static enum vga_switcheroo_client_id amdgpu_atpx_get_client_id(struct pci_dev *pdev)
553{
554 if (amdgpu_atpx_priv.dhandle == ACPI_HANDLE(&pdev->dev))
555 return VGA_SWITCHEROO_IGD;
556 else
557 return VGA_SWITCHEROO_DIS;
558}
559
560static const struct vga_switcheroo_handler amdgpu_atpx_handler = {
561 .switchto = amdgpu_atpx_switchto,
562 .power_state = amdgpu_atpx_power_state,
563 .get_client_id = amdgpu_atpx_get_client_id,
564};
565
566static const struct amdgpu_px_quirk amdgpu_px_quirk_list[] = {
567 /* HG _PR3 doesn't seem to work on this A+A weston board */
568 { 0x1002, 0x6900, 0x1002, 0x0124, AMDGPU_PX_QUIRK_FORCE_ATPX },
569 { 0x1002, 0x6900, 0x1028, 0x0812, AMDGPU_PX_QUIRK_FORCE_ATPX },
570 { 0x1002, 0x6900, 0x1028, 0x0813, AMDGPU_PX_QUIRK_FORCE_ATPX },
571 { 0x1002, 0x699f, 0x1028, 0x0814, AMDGPU_PX_QUIRK_FORCE_ATPX },
572 { 0x1002, 0x6900, 0x1025, 0x125A, AMDGPU_PX_QUIRK_FORCE_ATPX },
573 { 0x1002, 0x6900, 0x17AA, 0x3806, AMDGPU_PX_QUIRK_FORCE_ATPX },
574 { 0, 0, 0, 0, 0 },
575};
576
577static void amdgpu_atpx_get_quirks(struct pci_dev *pdev)
578{
579 const struct amdgpu_px_quirk *p = amdgpu_px_quirk_list;
580
581 /* Apply PX quirks */
582 while (p && p->chip_device != 0) {
583 if (pdev->vendor == p->chip_vendor &&
584 pdev->device == p->chip_device &&
585 pdev->subsystem_vendor == p->subsys_vendor &&
586 pdev->subsystem_device == p->subsys_device) {
587 amdgpu_atpx_priv.quirks |= p->px_quirk_flags;
588 break;
589 }
590 ++p;
591 }
592}
593
594/**
595 * amdgpu_atpx_detect - detect whether we have PX
596 *
597 * Check if we have a PX system (all asics).
598 * Returns true if we have a PX system, false if not.
599 */
600static bool amdgpu_atpx_detect(void)
601{
602 char acpi_method_name[255] = { 0 };
603 struct acpi_buffer buffer = {sizeof(acpi_method_name), acpi_method_name};
604 struct pci_dev *pdev = NULL;
605 bool has_atpx = false;
606 int vga_count = 0;
607 bool d3_supported = false;
608 struct pci_dev *parent_pdev;
609
610 while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, from: pdev)) != NULL) {
611 vga_count++;
612
613 has_atpx |= amdgpu_atpx_pci_probe_handle(pdev);
614
615 parent_pdev = pci_upstream_bridge(dev: pdev);
616 d3_supported |= parent_pdev && parent_pdev->bridge_d3;
617 amdgpu_atpx_get_quirks(pdev);
618 }
619
620 while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_OTHER << 8, from: pdev)) != NULL) {
621 vga_count++;
622
623 has_atpx |= amdgpu_atpx_pci_probe_handle(pdev);
624
625 parent_pdev = pci_upstream_bridge(dev: pdev);
626 d3_supported |= parent_pdev && parent_pdev->bridge_d3;
627 amdgpu_atpx_get_quirks(pdev);
628 }
629
630 if (has_atpx && vga_count == 2) {
631 acpi_get_name(object: amdgpu_atpx_priv.atpx.handle, ACPI_FULL_PATHNAME, ret_path_ptr: &buffer);
632 pr_info("vga_switcheroo: detected switching method %s handle\n",
633 acpi_method_name);
634 amdgpu_atpx_priv.atpx_detected = true;
635 amdgpu_atpx_priv.bridge_pm_usable = d3_supported;
636 amdgpu_atpx_init();
637 return true;
638 }
639 return false;
640}
641
642/**
643 * amdgpu_register_atpx_handler - register with vga_switcheroo
644 *
645 * Register the PX callbacks with vga_switcheroo (all asics).
646 */
647void amdgpu_register_atpx_handler(void)
648{
649 bool r;
650 enum vga_switcheroo_handler_flags_t handler_flags = 0;
651
652 /* detect if we have any ATPX + 2 VGA in the system */
653 r = amdgpu_atpx_detect();
654 if (!r)
655 return;
656
657 vga_switcheroo_register_handler(handler: &amdgpu_atpx_handler, handler_flags);
658}
659
660/**
661 * amdgpu_unregister_atpx_handler - unregister with vga_switcheroo
662 *
663 * Unregister the PX callbacks with vga_switcheroo (all asics).
664 */
665void amdgpu_unregister_atpx_handler(void)
666{
667 vga_switcheroo_unregister_handler();
668}
669

source code of linux/drivers/gpu/drm/amd/amdgpu/amdgpu_atpx_handler.c