1 // SPDX-License-Identifier: MIT
2 #include <linux/pci.h>
3 #include <linux/acpi.h>
4 #include <linux/slab.h>
5 #include <linux/mxm-wmi.h>
6 #include <linux/vga_switcheroo.h>
7 #include <drm/drm_edid.h>
8 #include <acpi/video.h>
9 
10 #include "nouveau_drv.h"
11 #include "nouveau_acpi.h"
12 
13 #define NOUVEAU_DSM_LED 0x02
14 #define NOUVEAU_DSM_LED_STATE 0x00
15 #define NOUVEAU_DSM_LED_OFF 0x10
16 #define NOUVEAU_DSM_LED_STAMINA 0x11
17 #define NOUVEAU_DSM_LED_SPEED 0x12
18 
19 #define NOUVEAU_DSM_POWER 0x03
20 #define NOUVEAU_DSM_POWER_STATE 0x00
21 #define NOUVEAU_DSM_POWER_SPEED 0x01
22 #define NOUVEAU_DSM_POWER_STAMINA 0x02
23 
24 #define NOUVEAU_DSM_OPTIMUS_CAPS 0x1A
25 #define NOUVEAU_DSM_OPTIMUS_FLAGS 0x1B
26 
27 #define NOUVEAU_DSM_OPTIMUS_POWERDOWN_PS3 (3 << 24)
28 #define NOUVEAU_DSM_OPTIMUS_NO_POWERDOWN_PS3 (2 << 24)
29 #define NOUVEAU_DSM_OPTIMUS_FLAGS_CHANGED (1)
30 
31 #define NOUVEAU_DSM_OPTIMUS_SET_POWERDOWN (NOUVEAU_DSM_OPTIMUS_POWERDOWN_PS3 | NOUVEAU_DSM_OPTIMUS_FLAGS_CHANGED)
32 
33 /* result of the optimus caps function */
34 #define OPTIMUS_ENABLED (1 << 0)
35 #define OPTIMUS_STATUS_MASK (3 << 3)
36 #define OPTIMUS_STATUS_OFF  (0 << 3)
37 #define OPTIMUS_STATUS_ON_ENABLED  (1 << 3)
38 #define OPTIMUS_STATUS_PWR_STABLE  (3 << 3)
39 #define OPTIMUS_DISPLAY_HOTPLUG (1 << 6)
40 #define OPTIMUS_CAPS_MASK (7 << 24)
41 #define OPTIMUS_DYNAMIC_PWR_CAP (1 << 24)
42 
43 #define OPTIMUS_AUDIO_CAPS_MASK (3 << 27)
44 #define OPTIMUS_HDA_CODEC_MASK (2 << 27) /* hda bios control */
45 
46 static struct nouveau_dsm_priv {
47 	bool dsm_detected;
48 	bool optimus_detected;
49 	bool optimus_flags_detected;
50 	bool optimus_skip_dsm;
51 	acpi_handle dhandle;
52 	acpi_handle rom_handle;
53 } nouveau_dsm_priv;
54 
55 bool nouveau_is_optimus(void) {
56 	return nouveau_dsm_priv.optimus_detected;
57 }
58 
59 bool nouveau_is_v1_dsm(void) {
60 	return nouveau_dsm_priv.dsm_detected;
61 }
62 
63 #ifdef CONFIG_VGA_SWITCHEROO
64 static const guid_t nouveau_dsm_muid =
65 	GUID_INIT(0x9D95A0A0, 0x0060, 0x4D48,
66 		  0xB3, 0x4D, 0x7E, 0x5F, 0xEA, 0x12, 0x9F, 0xD4);
67 
68 static const guid_t nouveau_op_dsm_muid =
69 	GUID_INIT(0xA486D8F8, 0x0BDA, 0x471B,
70 		  0xA7, 0x2B, 0x60, 0x42, 0xA6, 0xB5, 0xBE, 0xE0);
71 
72 static int nouveau_optimus_dsm(acpi_handle handle, int func, int arg, uint32_t *result)
73 {
74 	int i;
75 	union acpi_object *obj;
76 	char args_buff[4];
77 	union acpi_object argv4 = {
78 		.buffer.type = ACPI_TYPE_BUFFER,
79 		.buffer.length = 4,
80 		.buffer.pointer = args_buff
81 	};
82 
83 	/* ACPI is little endian, AABBCCDD becomes {DD,CC,BB,AA} */
84 	for (i = 0; i < 4; i++)
85 		args_buff[i] = (arg >> i * 8) & 0xFF;
86 
87 	*result = 0;
88 	obj = acpi_evaluate_dsm_typed(handle, &nouveau_op_dsm_muid, 0x00000100,
89 				      func, &argv4, ACPI_TYPE_BUFFER);
90 	if (!obj) {
91 		acpi_handle_info(handle, "failed to evaluate _DSM\n");
92 		return AE_ERROR;
93 	} else {
94 		if (obj->buffer.length == 4) {
95 			*result |= obj->buffer.pointer[0];
96 			*result |= (obj->buffer.pointer[1] << 8);
97 			*result |= (obj->buffer.pointer[2] << 16);
98 			*result |= (obj->buffer.pointer[3] << 24);
99 		}
100 		ACPI_FREE(obj);
101 	}
102 
103 	return 0;
104 }
105 
106 /*
107  * On some platforms, _DSM(nouveau_op_dsm_muid, func0) has special
108  * requirements on the fourth parameter, so a private implementation
109  * instead of using acpi_check_dsm().
110  */
111 static int nouveau_dsm_get_optimus_functions(acpi_handle handle)
112 {
113 	int result;
114 
115 	/*
116 	 * Function 0 returns a Buffer containing available functions.
117 	 * The args parameter is ignored for function 0, so just put 0 in it
118 	 */
119 	if (nouveau_optimus_dsm(handle, 0, 0, &result))
120 		return 0;
121 
122 	/*
123 	 * ACPI Spec v4 9.14.1: if bit 0 is zero, no function is supported.
124 	 * If the n-th bit is enabled, function n is supported
125 	 */
126 	if (result & 1 && result & (1 << NOUVEAU_DSM_OPTIMUS_CAPS))
127 		return result;
128 	return 0;
129 }
130 
131 static int nouveau_dsm(acpi_handle handle, int func, int arg)
132 {
133 	int ret = 0;
134 	union acpi_object *obj;
135 	union acpi_object argv4 = {
136 		.integer.type = ACPI_TYPE_INTEGER,
137 		.integer.value = arg,
138 	};
139 
140 	obj = acpi_evaluate_dsm_typed(handle, &nouveau_dsm_muid, 0x00000102,
141 				      func, &argv4, ACPI_TYPE_INTEGER);
142 	if (!obj) {
143 		acpi_handle_info(handle, "failed to evaluate _DSM\n");
144 		return AE_ERROR;
145 	} else {
146 		if (obj->integer.value == 0x80000002)
147 			ret = -ENODEV;
148 		ACPI_FREE(obj);
149 	}
150 
151 	return ret;
152 }
153 
154 static int nouveau_dsm_switch_mux(acpi_handle handle, int mux_id)
155 {
156 	mxm_wmi_call_mxmx(mux_id == NOUVEAU_DSM_LED_STAMINA ? MXM_MXDS_ADAPTER_IGD : MXM_MXDS_ADAPTER_0);
157 	mxm_wmi_call_mxds(mux_id == NOUVEAU_DSM_LED_STAMINA ? MXM_MXDS_ADAPTER_IGD : MXM_MXDS_ADAPTER_0);
158 	return nouveau_dsm(handle, NOUVEAU_DSM_LED, mux_id);
159 }
160 
161 static int nouveau_dsm_set_discrete_state(acpi_handle handle, enum vga_switcheroo_state state)
162 {
163 	int arg;
164 	if (state == VGA_SWITCHEROO_ON)
165 		arg = NOUVEAU_DSM_POWER_SPEED;
166 	else
167 		arg = NOUVEAU_DSM_POWER_STAMINA;
168 	nouveau_dsm(handle, NOUVEAU_DSM_POWER, arg);
169 	return 0;
170 }
171 
172 static int nouveau_dsm_switchto(enum vga_switcheroo_client_id id)
173 {
174 	if (!nouveau_dsm_priv.dsm_detected)
175 		return 0;
176 	if (id == VGA_SWITCHEROO_IGD)
177 		return nouveau_dsm_switch_mux(nouveau_dsm_priv.dhandle, NOUVEAU_DSM_LED_STAMINA);
178 	else
179 		return nouveau_dsm_switch_mux(nouveau_dsm_priv.dhandle, NOUVEAU_DSM_LED_SPEED);
180 }
181 
182 static int nouveau_dsm_power_state(enum vga_switcheroo_client_id id,
183 				   enum vga_switcheroo_state state)
184 {
185 	if (id == VGA_SWITCHEROO_IGD)
186 		return 0;
187 
188 	/* Optimus laptops have the card already disabled in
189 	 * nouveau_switcheroo_set_state */
190 	if (!nouveau_dsm_priv.dsm_detected)
191 		return 0;
192 
193 	return nouveau_dsm_set_discrete_state(nouveau_dsm_priv.dhandle, state);
194 }
195 
196 static enum vga_switcheroo_client_id nouveau_dsm_get_client_id(struct pci_dev *pdev)
197 {
198 	/* easy option one - intel vendor ID means Integrated */
199 	if (pdev->vendor == PCI_VENDOR_ID_INTEL)
200 		return VGA_SWITCHEROO_IGD;
201 
202 	/* is this device on Bus 0? - this may need improving */
203 	if (pdev->bus->number == 0)
204 		return VGA_SWITCHEROO_IGD;
205 
206 	return VGA_SWITCHEROO_DIS;
207 }
208 
209 static const struct vga_switcheroo_handler nouveau_dsm_handler = {
210 	.switchto = nouveau_dsm_switchto,
211 	.power_state = nouveau_dsm_power_state,
212 	.get_client_id = nouveau_dsm_get_client_id,
213 };
214 
215 /*
216  * Firmware supporting Windows 8 or later do not use _DSM to put the device into
217  * D3cold, they instead rely on disabling power resources on the parent.
218  */
219 static bool nouveau_pr3_present(struct pci_dev *pdev)
220 {
221 	struct pci_dev *parent_pdev = pci_upstream_bridge(pdev);
222 	struct acpi_device *parent_adev;
223 
224 	if (!parent_pdev)
225 		return false;
226 
227 	if (!parent_pdev->bridge_d3) {
228 		/*
229 		 * Parent PCI bridge is currently not power managed.
230 		 * Since userspace can change these afterwards to be on
231 		 * the safe side we stick with _DSM and prevent usage of
232 		 * _PR3 from the bridge.
233 		 */
234 		pci_d3cold_disable(pdev);
235 		return false;
236 	}
237 
238 	parent_adev = ACPI_COMPANION(&parent_pdev->dev);
239 	if (!parent_adev)
240 		return false;
241 
242 	return parent_adev->power.flags.power_resources &&
243 		acpi_has_method(parent_adev->handle, "_PR3");
244 }
245 
246 static void nouveau_dsm_pci_probe(struct pci_dev *pdev, acpi_handle *dhandle_out,
247 				  bool *has_mux, bool *has_opt,
248 				  bool *has_opt_flags, bool *has_pr3)
249 {
250 	acpi_handle dhandle;
251 	bool supports_mux;
252 	int optimus_funcs;
253 
254 	dhandle = ACPI_HANDLE(&pdev->dev);
255 	if (!dhandle)
256 		return;
257 
258 	if (!acpi_has_method(dhandle, "_DSM"))
259 		return;
260 
261 	supports_mux = acpi_check_dsm(dhandle, &nouveau_dsm_muid, 0x00000102,
262 				      1 << NOUVEAU_DSM_POWER);
263 	optimus_funcs = nouveau_dsm_get_optimus_functions(dhandle);
264 
265 	/* Does not look like a Nvidia device. */
266 	if (!supports_mux && !optimus_funcs)
267 		return;
268 
269 	*dhandle_out = dhandle;
270 	*has_mux = supports_mux;
271 	*has_opt = !!optimus_funcs;
272 	*has_opt_flags = optimus_funcs & (1 << NOUVEAU_DSM_OPTIMUS_FLAGS);
273 	*has_pr3 = false;
274 
275 	if (optimus_funcs) {
276 		uint32_t result;
277 		nouveau_optimus_dsm(dhandle, NOUVEAU_DSM_OPTIMUS_CAPS, 0,
278 				    &result);
279 		dev_info(&pdev->dev, "optimus capabilities: %s, status %s%s\n",
280 			 (result & OPTIMUS_ENABLED) ? "enabled" : "disabled",
281 			 (result & OPTIMUS_DYNAMIC_PWR_CAP) ? "dynamic power, " : "",
282 			 (result & OPTIMUS_HDA_CODEC_MASK) ? "hda bios codec supported" : "");
283 
284 		*has_pr3 = nouveau_pr3_present(pdev);
285 	}
286 }
287 
288 static bool nouveau_dsm_detect(void)
289 {
290 	char acpi_method_name[255] = { 0 };
291 	struct acpi_buffer buffer = {sizeof(acpi_method_name), acpi_method_name};
292 	struct pci_dev *pdev = NULL;
293 	acpi_handle dhandle = NULL;
294 	bool has_mux = false;
295 	bool has_optimus = false;
296 	bool has_optimus_flags = false;
297 	bool has_power_resources = false;
298 	int vga_count = 0;
299 	bool guid_valid;
300 	bool ret = false;
301 
302 	/* lookup the MXM GUID */
303 	guid_valid = mxm_wmi_supported();
304 
305 	if (guid_valid)
306 		printk("MXM: GUID detected in BIOS\n");
307 
308 	/* now do DSM detection */
309 	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
310 		vga_count++;
311 
312 		nouveau_dsm_pci_probe(pdev, &dhandle, &has_mux, &has_optimus,
313 				      &has_optimus_flags, &has_power_resources);
314 	}
315 
316 	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_3D << 8, pdev)) != NULL) {
317 		vga_count++;
318 
319 		nouveau_dsm_pci_probe(pdev, &dhandle, &has_mux, &has_optimus,
320 				      &has_optimus_flags, &has_power_resources);
321 	}
322 
323 	/* find the optimus DSM or the old v1 DSM */
324 	if (has_optimus) {
325 		nouveau_dsm_priv.dhandle = dhandle;
326 		acpi_get_name(nouveau_dsm_priv.dhandle, ACPI_FULL_PATHNAME,
327 			&buffer);
328 		pr_info("VGA switcheroo: detected Optimus DSM method %s handle\n",
329 			acpi_method_name);
330 		if (has_power_resources)
331 			pr_info("nouveau: detected PR support, will not use DSM\n");
332 		nouveau_dsm_priv.optimus_detected = true;
333 		nouveau_dsm_priv.optimus_flags_detected = has_optimus_flags;
334 		nouveau_dsm_priv.optimus_skip_dsm = has_power_resources;
335 		ret = true;
336 	} else if (vga_count == 2 && has_mux && guid_valid) {
337 		nouveau_dsm_priv.dhandle = dhandle;
338 		acpi_get_name(nouveau_dsm_priv.dhandle, ACPI_FULL_PATHNAME,
339 			&buffer);
340 		pr_info("VGA switcheroo: detected DSM switching method %s handle\n",
341 			acpi_method_name);
342 		nouveau_dsm_priv.dsm_detected = true;
343 		ret = true;
344 	}
345 
346 
347 	return ret;
348 }
349 
350 void nouveau_register_dsm_handler(void)
351 {
352 	bool r;
353 
354 	r = nouveau_dsm_detect();
355 	if (!r)
356 		return;
357 
358 	vga_switcheroo_register_handler(&nouveau_dsm_handler, 0);
359 }
360 
361 /* Must be called for Optimus models before the card can be turned off */
362 void nouveau_switcheroo_optimus_dsm(void)
363 {
364 	u32 result = 0;
365 	if (!nouveau_dsm_priv.optimus_detected || nouveau_dsm_priv.optimus_skip_dsm)
366 		return;
367 
368 	if (nouveau_dsm_priv.optimus_flags_detected)
369 		nouveau_optimus_dsm(nouveau_dsm_priv.dhandle, NOUVEAU_DSM_OPTIMUS_FLAGS,
370 				    0x3, &result);
371 
372 	nouveau_optimus_dsm(nouveau_dsm_priv.dhandle, NOUVEAU_DSM_OPTIMUS_CAPS,
373 		NOUVEAU_DSM_OPTIMUS_SET_POWERDOWN, &result);
374 
375 }
376 
377 void nouveau_unregister_dsm_handler(void)
378 {
379 	if (nouveau_dsm_priv.optimus_detected || nouveau_dsm_priv.dsm_detected)
380 		vga_switcheroo_unregister_handler();
381 }
382 #else
383 void nouveau_register_dsm_handler(void) {}
384 void nouveau_unregister_dsm_handler(void) {}
385 void nouveau_switcheroo_optimus_dsm(void) {}
386 #endif
387 
388 /* retrieve the ROM in 4k blocks */
389 static int nouveau_rom_call(acpi_handle rom_handle, uint8_t *bios,
390 			    int offset, int len)
391 {
392 	acpi_status status;
393 	union acpi_object rom_arg_elements[2], *obj;
394 	struct acpi_object_list rom_arg;
395 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL};
396 
397 	rom_arg.count = 2;
398 	rom_arg.pointer = &rom_arg_elements[0];
399 
400 	rom_arg_elements[0].type = ACPI_TYPE_INTEGER;
401 	rom_arg_elements[0].integer.value = offset;
402 
403 	rom_arg_elements[1].type = ACPI_TYPE_INTEGER;
404 	rom_arg_elements[1].integer.value = len;
405 
406 	status = acpi_evaluate_object(rom_handle, NULL, &rom_arg, &buffer);
407 	if (ACPI_FAILURE(status)) {
408 		pr_info("failed to evaluate ROM got %s\n",
409 			acpi_format_exception(status));
410 		return -ENODEV;
411 	}
412 	obj = (union acpi_object *)buffer.pointer;
413 	len = min(len, (int)obj->buffer.length);
414 	memcpy(bios+offset, obj->buffer.pointer, len);
415 	kfree(buffer.pointer);
416 	return len;
417 }
418 
419 bool nouveau_acpi_rom_supported(struct device *dev)
420 {
421 	acpi_status status;
422 	acpi_handle dhandle, rom_handle;
423 
424 	dhandle = ACPI_HANDLE(dev);
425 	if (!dhandle)
426 		return false;
427 
428 	status = acpi_get_handle(dhandle, "_ROM", &rom_handle);
429 	if (ACPI_FAILURE(status))
430 		return false;
431 
432 	nouveau_dsm_priv.rom_handle = rom_handle;
433 	return true;
434 }
435 
436 int nouveau_acpi_get_bios_chunk(uint8_t *bios, int offset, int len)
437 {
438 	return nouveau_rom_call(nouveau_dsm_priv.rom_handle, bios, offset, len);
439 }
440 
441 void *
442 nouveau_acpi_edid(struct drm_device *dev, struct drm_connector *connector)
443 {
444 	struct acpi_device *acpidev;
445 	acpi_handle handle;
446 	int type, ret;
447 	void *edid;
448 
449 	switch (connector->connector_type) {
450 	case DRM_MODE_CONNECTOR_LVDS:
451 	case DRM_MODE_CONNECTOR_eDP:
452 		type = ACPI_VIDEO_DISPLAY_LCD;
453 		break;
454 	default:
455 		return NULL;
456 	}
457 
458 	handle = ACPI_HANDLE(&dev->pdev->dev);
459 	if (!handle)
460 		return NULL;
461 
462 	ret = acpi_bus_get_device(handle, &acpidev);
463 	if (ret)
464 		return NULL;
465 
466 	ret = acpi_video_get_edid(acpidev, type, -1, &edid);
467 	if (ret < 0)
468 		return NULL;
469 
470 	return kmemdup(edid, EDID_LENGTH, GFP_KERNEL);
471 }
472