1 /*
2  * Copyright © 2014 Intel Corporation
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice (including the next
12  * paragraph) shall be included in all copies or substantial portions of the
13  * Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21  * IN THE SOFTWARE.
22  *
23  */
24 
25 #include <linux/firmware.h>
26 
27 #include "i915_drv.h"
28 #include "i915_reg.h"
29 #include "intel_de.h"
30 #include "intel_dmc.h"
31 
32 /**
33  * DOC: DMC Firmware Support
34  *
35  * From gen9 onwards we have newly added DMC (Display microcontroller) in display
36  * engine to save and restore the state of display engine when it enter into
37  * low-power state and comes back to normal.
38  */
39 
40 #define DMC_PATH(platform, major, minor) \
41 	"i915/"				 \
42 	__stringify(platform) "_dmc_ver" \
43 	__stringify(major) "_"		 \
44 	__stringify(minor) ".bin"
45 
46 #define DISPLAY_VER13_DMC_MAX_FW_SIZE	0x20000
47 
48 #define DISPLAY_VER12_DMC_MAX_FW_SIZE	ICL_DMC_MAX_FW_SIZE
49 
50 #define ADLP_DMC_PATH			DMC_PATH(adlp, 2, 14)
51 #define ADLP_DMC_VERSION_REQUIRED	DMC_VERSION(2, 14)
52 MODULE_FIRMWARE(ADLP_DMC_PATH);
53 
54 #define ADLS_DMC_PATH			DMC_PATH(adls, 2, 01)
55 #define ADLS_DMC_VERSION_REQUIRED	DMC_VERSION(2, 1)
56 MODULE_FIRMWARE(ADLS_DMC_PATH);
57 
58 #define DG1_DMC_PATH			DMC_PATH(dg1, 2, 02)
59 #define DG1_DMC_VERSION_REQUIRED	DMC_VERSION(2, 2)
60 MODULE_FIRMWARE(DG1_DMC_PATH);
61 
62 #define RKL_DMC_PATH			DMC_PATH(rkl, 2, 03)
63 #define RKL_DMC_VERSION_REQUIRED	DMC_VERSION(2, 3)
64 MODULE_FIRMWARE(RKL_DMC_PATH);
65 
66 #define TGL_DMC_PATH			DMC_PATH(tgl, 2, 12)
67 #define TGL_DMC_VERSION_REQUIRED	DMC_VERSION(2, 12)
68 MODULE_FIRMWARE(TGL_DMC_PATH);
69 
70 #define ICL_DMC_PATH			DMC_PATH(icl, 1, 09)
71 #define ICL_DMC_VERSION_REQUIRED	DMC_VERSION(1, 9)
72 #define ICL_DMC_MAX_FW_SIZE		0x6000
73 MODULE_FIRMWARE(ICL_DMC_PATH);
74 
75 #define GLK_DMC_PATH			DMC_PATH(glk, 1, 04)
76 #define GLK_DMC_VERSION_REQUIRED	DMC_VERSION(1, 4)
77 #define GLK_DMC_MAX_FW_SIZE		0x4000
78 MODULE_FIRMWARE(GLK_DMC_PATH);
79 
80 #define KBL_DMC_PATH			DMC_PATH(kbl, 1, 04)
81 #define KBL_DMC_VERSION_REQUIRED	DMC_VERSION(1, 4)
82 #define KBL_DMC_MAX_FW_SIZE		BXT_DMC_MAX_FW_SIZE
83 MODULE_FIRMWARE(KBL_DMC_PATH);
84 
85 #define SKL_DMC_PATH			DMC_PATH(skl, 1, 27)
86 #define SKL_DMC_VERSION_REQUIRED	DMC_VERSION(1, 27)
87 #define SKL_DMC_MAX_FW_SIZE		BXT_DMC_MAX_FW_SIZE
88 MODULE_FIRMWARE(SKL_DMC_PATH);
89 
90 #define BXT_DMC_PATH			DMC_PATH(bxt, 1, 07)
91 #define BXT_DMC_VERSION_REQUIRED	DMC_VERSION(1, 7)
92 #define BXT_DMC_MAX_FW_SIZE		0x3000
93 MODULE_FIRMWARE(BXT_DMC_PATH);
94 
95 #define DMC_DEFAULT_FW_OFFSET		0xFFFFFFFF
96 #define PACKAGE_MAX_FW_INFO_ENTRIES	20
97 #define PACKAGE_V2_MAX_FW_INFO_ENTRIES	32
98 #define DMC_V1_MAX_MMIO_COUNT		8
99 #define DMC_V3_MAX_MMIO_COUNT		20
100 #define DMC_V1_MMIO_START_RANGE		0x80000
101 
102 struct intel_css_header {
103 	/* 0x09 for DMC */
104 	u32 module_type;
105 
106 	/* Includes the DMC specific header in dwords */
107 	u32 header_len;
108 
109 	/* always value would be 0x10000 */
110 	u32 header_ver;
111 
112 	/* Not used */
113 	u32 module_id;
114 
115 	/* Not used */
116 	u32 module_vendor;
117 
118 	/* in YYYYMMDD format */
119 	u32 date;
120 
121 	/* Size in dwords (CSS_Headerlen + PackageHeaderLen + dmc FWsLen)/4 */
122 	u32 size;
123 
124 	/* Not used */
125 	u32 key_size;
126 
127 	/* Not used */
128 	u32 modulus_size;
129 
130 	/* Not used */
131 	u32 exponent_size;
132 
133 	/* Not used */
134 	u32 reserved1[12];
135 
136 	/* Major Minor */
137 	u32 version;
138 
139 	/* Not used */
140 	u32 reserved2[8];
141 
142 	/* Not used */
143 	u32 kernel_header_info;
144 } __packed;
145 
146 struct intel_fw_info {
147 	u8 reserved1;
148 
149 	/* reserved on package_header version 1, must be 0 on version 2 */
150 	u8 dmc_id;
151 
152 	/* Stepping (A, B, C, ..., *). * is a wildcard */
153 	char stepping;
154 
155 	/* Sub-stepping (0, 1, ..., *). * is a wildcard */
156 	char substepping;
157 
158 	u32 offset;
159 	u32 reserved2;
160 } __packed;
161 
162 struct intel_package_header {
163 	/* DMC container header length in dwords */
164 	u8 header_len;
165 
166 	/* 0x01, 0x02 */
167 	u8 header_ver;
168 
169 	u8 reserved[10];
170 
171 	/* Number of valid entries in the FWInfo array below */
172 	u32 num_entries;
173 } __packed;
174 
175 struct intel_dmc_header_base {
176 	/* always value would be 0x40403E3E */
177 	u32 signature;
178 
179 	/* DMC binary header length */
180 	u8 header_len;
181 
182 	/* 0x01 */
183 	u8 header_ver;
184 
185 	/* Reserved */
186 	u16 dmcc_ver;
187 
188 	/* Major, Minor */
189 	u32 project;
190 
191 	/* Firmware program size (excluding header) in dwords */
192 	u32 fw_size;
193 
194 	/* Major Minor version */
195 	u32 fw_version;
196 } __packed;
197 
198 struct intel_dmc_header_v1 {
199 	struct intel_dmc_header_base base;
200 
201 	/* Number of valid MMIO cycles present. */
202 	u32 mmio_count;
203 
204 	/* MMIO address */
205 	u32 mmioaddr[DMC_V1_MAX_MMIO_COUNT];
206 
207 	/* MMIO data */
208 	u32 mmiodata[DMC_V1_MAX_MMIO_COUNT];
209 
210 	/* FW filename  */
211 	char dfile[32];
212 
213 	u32 reserved1[2];
214 } __packed;
215 
216 struct intel_dmc_header_v3 {
217 	struct intel_dmc_header_base base;
218 
219 	/* DMC RAM start MMIO address */
220 	u32 start_mmioaddr;
221 
222 	u32 reserved[9];
223 
224 	/* FW filename */
225 	char dfile[32];
226 
227 	/* Number of valid MMIO cycles present. */
228 	u32 mmio_count;
229 
230 	/* MMIO address */
231 	u32 mmioaddr[DMC_V3_MAX_MMIO_COUNT];
232 
233 	/* MMIO data */
234 	u32 mmiodata[DMC_V3_MAX_MMIO_COUNT];
235 } __packed;
236 
237 struct stepping_info {
238 	char stepping;
239 	char substepping;
240 };
241 
242 bool intel_dmc_has_payload(struct drm_i915_private *i915)
243 {
244 	return i915->dmc.dmc_info[DMC_FW_MAIN].payload;
245 }
246 
247 static const struct stepping_info *
248 intel_get_stepping_info(struct drm_i915_private *i915,
249 			struct stepping_info *si)
250 {
251 	const char *step_name = intel_step_name(RUNTIME_INFO(i915)->step.display_step);
252 
253 	si->stepping = step_name[0];
254 	si->substepping = step_name[1];
255 	return si;
256 }
257 
258 static void gen9_set_dc_state_debugmask(struct drm_i915_private *dev_priv)
259 {
260 	/* The below bit doesn't need to be cleared ever afterwards */
261 	intel_de_rmw(dev_priv, DC_STATE_DEBUG, 0,
262 		     DC_STATE_DEBUG_MASK_CORES | DC_STATE_DEBUG_MASK_MEMORY_UP);
263 	intel_de_posting_read(dev_priv, DC_STATE_DEBUG);
264 }
265 
266 /**
267  * intel_dmc_load_program() - write the firmware from memory to register.
268  * @dev_priv: i915 drm device.
269  *
270  * DMC firmware is read from a .bin file and kept in internal memory one time.
271  * Everytime display comes back from low power state this function is called to
272  * copy the firmware from internal memory to registers.
273  */
274 void intel_dmc_load_program(struct drm_i915_private *dev_priv)
275 {
276 	struct intel_dmc *dmc = &dev_priv->dmc;
277 	u32 id, i;
278 
279 	if (!HAS_DMC(dev_priv)) {
280 		drm_err(&dev_priv->drm,
281 			"No DMC support available for this platform\n");
282 		return;
283 	}
284 
285 	if (!dev_priv->dmc.dmc_info[DMC_FW_MAIN].payload) {
286 		drm_err(&dev_priv->drm,
287 			"Tried to program CSR with empty payload\n");
288 		return;
289 	}
290 
291 	assert_rpm_wakelock_held(&dev_priv->runtime_pm);
292 
293 	preempt_disable();
294 
295 	for (id = 0; id < DMC_FW_MAX; id++) {
296 		for (i = 0; i < dmc->dmc_info[id].dmc_fw_size; i++) {
297 			intel_uncore_write_fw(&dev_priv->uncore,
298 					      DMC_PROGRAM(dmc->dmc_info[id].start_mmioaddr, i),
299 					      dmc->dmc_info[id].payload[i]);
300 		}
301 	}
302 
303 	preempt_enable();
304 
305 	for (id = 0; id < DMC_FW_MAX; id++) {
306 		for (i = 0; i < dmc->dmc_info[id].mmio_count; i++) {
307 			intel_de_write(dev_priv, dmc->dmc_info[id].mmioaddr[i],
308 				       dmc->dmc_info[id].mmiodata[i]);
309 		}
310 	}
311 
312 	dev_priv->dmc.dc_state = 0;
313 
314 	gen9_set_dc_state_debugmask(dev_priv);
315 }
316 
317 static bool fw_info_matches_stepping(const struct intel_fw_info *fw_info,
318 				     const struct stepping_info *si)
319 {
320 	if ((fw_info->substepping == '*' && si->stepping == fw_info->stepping) ||
321 	    (si->stepping == fw_info->stepping && si->substepping == fw_info->substepping) ||
322 	    /*
323 	     * If we don't find a more specific one from above two checks, we
324 	     * then check for the generic one to be sure to work even with
325 	     * "broken firmware"
326 	     */
327 	    (si->stepping == '*' && si->substepping == fw_info->substepping) ||
328 	    (fw_info->stepping == '*' && fw_info->substepping == '*'))
329 		return true;
330 
331 	return false;
332 }
333 
334 /*
335  * Search fw_info table for dmc_offset to find firmware binary: num_entries is
336  * already sanitized.
337  */
338 static void dmc_set_fw_offset(struct intel_dmc *dmc,
339 			      const struct intel_fw_info *fw_info,
340 			      unsigned int num_entries,
341 			      const struct stepping_info *si,
342 			      u8 package_ver)
343 {
344 	unsigned int i, id;
345 
346 	struct drm_i915_private *i915 = container_of(dmc, typeof(*i915), dmc);
347 
348 	for (i = 0; i < num_entries; i++) {
349 		id = package_ver <= 1 ? DMC_FW_MAIN : fw_info[i].dmc_id;
350 
351 		if (id >= DMC_FW_MAX) {
352 			drm_dbg(&i915->drm, "Unsupported firmware id: %u\n", id);
353 			continue;
354 		}
355 
356 		/* More specific versions come first, so we don't even have to
357 		 * check for the stepping since we already found a previous FW
358 		 * for this id.
359 		 */
360 		if (dmc->dmc_info[id].present)
361 			continue;
362 
363 		if (fw_info_matches_stepping(&fw_info[i], si)) {
364 			dmc->dmc_info[id].present = true;
365 			dmc->dmc_info[id].dmc_offset = fw_info[i].offset;
366 		}
367 	}
368 }
369 
370 static bool dmc_mmio_addr_sanity_check(struct intel_dmc *dmc,
371 				       const u32 *mmioaddr, u32 mmio_count,
372 				       int header_ver, u8 dmc_id)
373 {
374 	struct drm_i915_private *i915 = container_of(dmc, typeof(*i915), dmc);
375 	u32 start_range, end_range;
376 	int i;
377 
378 	if (dmc_id >= DMC_FW_MAX) {
379 		drm_warn(&i915->drm, "Unsupported firmware id %u\n", dmc_id);
380 		return false;
381 	}
382 
383 	if (header_ver == 1) {
384 		start_range = DMC_MMIO_START_RANGE;
385 		end_range = DMC_MMIO_END_RANGE;
386 	} else if (dmc_id == DMC_FW_MAIN) {
387 		start_range = TGL_MAIN_MMIO_START;
388 		end_range = TGL_MAIN_MMIO_END;
389 	} else if (DISPLAY_VER(i915) >= 13) {
390 		start_range = ADLP_PIPE_MMIO_START;
391 		end_range = ADLP_PIPE_MMIO_END;
392 	} else if (DISPLAY_VER(i915) >= 12) {
393 		start_range = TGL_PIPE_MMIO_START(dmc_id);
394 		end_range = TGL_PIPE_MMIO_END(dmc_id);
395 	} else {
396 		drm_warn(&i915->drm, "Unknown mmio range for sanity check");
397 		return false;
398 	}
399 
400 	for (i = 0; i < mmio_count; i++) {
401 		if (mmioaddr[i] < start_range || mmioaddr[i] > end_range)
402 			return false;
403 	}
404 
405 	return true;
406 }
407 
408 static u32 parse_dmc_fw_header(struct intel_dmc *dmc,
409 			       const struct intel_dmc_header_base *dmc_header,
410 			       size_t rem_size, u8 dmc_id)
411 {
412 	struct drm_i915_private *i915 = container_of(dmc, typeof(*i915), dmc);
413 	struct dmc_fw_info *dmc_info = &dmc->dmc_info[dmc_id];
414 	unsigned int header_len_bytes, dmc_header_size, payload_size, i;
415 	const u32 *mmioaddr, *mmiodata;
416 	u32 mmio_count, mmio_count_max, start_mmioaddr;
417 	u8 *payload;
418 
419 	BUILD_BUG_ON(ARRAY_SIZE(dmc_info->mmioaddr) < DMC_V3_MAX_MMIO_COUNT ||
420 		     ARRAY_SIZE(dmc_info->mmioaddr) < DMC_V1_MAX_MMIO_COUNT);
421 
422 	/*
423 	 * Check if we can access common fields, we will checkc again below
424 	 * after we have read the version
425 	 */
426 	if (rem_size < sizeof(struct intel_dmc_header_base))
427 		goto error_truncated;
428 
429 	/* Cope with small differences between v1 and v3 */
430 	if (dmc_header->header_ver == 3) {
431 		const struct intel_dmc_header_v3 *v3 =
432 			(const struct intel_dmc_header_v3 *)dmc_header;
433 
434 		if (rem_size < sizeof(struct intel_dmc_header_v3))
435 			goto error_truncated;
436 
437 		mmioaddr = v3->mmioaddr;
438 		mmiodata = v3->mmiodata;
439 		mmio_count = v3->mmio_count;
440 		mmio_count_max = DMC_V3_MAX_MMIO_COUNT;
441 		/* header_len is in dwords */
442 		header_len_bytes = dmc_header->header_len * 4;
443 		start_mmioaddr = v3->start_mmioaddr;
444 		dmc_header_size = sizeof(*v3);
445 	} else if (dmc_header->header_ver == 1) {
446 		const struct intel_dmc_header_v1 *v1 =
447 			(const struct intel_dmc_header_v1 *)dmc_header;
448 
449 		if (rem_size < sizeof(struct intel_dmc_header_v1))
450 			goto error_truncated;
451 
452 		mmioaddr = v1->mmioaddr;
453 		mmiodata = v1->mmiodata;
454 		mmio_count = v1->mmio_count;
455 		mmio_count_max = DMC_V1_MAX_MMIO_COUNT;
456 		header_len_bytes = dmc_header->header_len;
457 		start_mmioaddr = DMC_V1_MMIO_START_RANGE;
458 		dmc_header_size = sizeof(*v1);
459 	} else {
460 		drm_err(&i915->drm, "Unknown DMC fw header version: %u\n",
461 			dmc_header->header_ver);
462 		return 0;
463 	}
464 
465 	if (header_len_bytes != dmc_header_size) {
466 		drm_err(&i915->drm, "DMC firmware has wrong dmc header length "
467 			"(%u bytes)\n", header_len_bytes);
468 		return 0;
469 	}
470 
471 	/* Cache the dmc header info. */
472 	if (mmio_count > mmio_count_max) {
473 		drm_err(&i915->drm, "DMC firmware has wrong mmio count %u\n", mmio_count);
474 		return 0;
475 	}
476 
477 	if (!dmc_mmio_addr_sanity_check(dmc, mmioaddr, mmio_count,
478 					dmc_header->header_ver, dmc_id)) {
479 		drm_err(&i915->drm, "DMC firmware has Wrong MMIO Addresses\n");
480 		return 0;
481 	}
482 
483 	for (i = 0; i < mmio_count; i++) {
484 		dmc_info->mmioaddr[i] = _MMIO(mmioaddr[i]);
485 		dmc_info->mmiodata[i] = mmiodata[i];
486 	}
487 	dmc_info->mmio_count = mmio_count;
488 	dmc_info->start_mmioaddr = start_mmioaddr;
489 
490 	rem_size -= header_len_bytes;
491 
492 	/* fw_size is in dwords, so multiplied by 4 to convert into bytes. */
493 	payload_size = dmc_header->fw_size * 4;
494 	if (rem_size < payload_size)
495 		goto error_truncated;
496 
497 	if (payload_size > dmc->max_fw_size) {
498 		drm_err(&i915->drm, "DMC FW too big (%u bytes)\n", payload_size);
499 		return 0;
500 	}
501 	dmc_info->dmc_fw_size = dmc_header->fw_size;
502 
503 	dmc_info->payload = kmalloc(payload_size, GFP_KERNEL);
504 	if (!dmc_info->payload)
505 		return 0;
506 
507 	payload = (u8 *)(dmc_header) + header_len_bytes;
508 	memcpy(dmc_info->payload, payload, payload_size);
509 
510 	return header_len_bytes + payload_size;
511 
512 error_truncated:
513 	drm_err(&i915->drm, "Truncated DMC firmware, refusing.\n");
514 	return 0;
515 }
516 
517 static u32
518 parse_dmc_fw_package(struct intel_dmc *dmc,
519 		     const struct intel_package_header *package_header,
520 		     const struct stepping_info *si,
521 		     size_t rem_size)
522 {
523 	struct drm_i915_private *i915 = container_of(dmc, typeof(*i915), dmc);
524 	u32 package_size = sizeof(struct intel_package_header);
525 	u32 num_entries, max_entries;
526 	const struct intel_fw_info *fw_info;
527 
528 	if (rem_size < package_size)
529 		goto error_truncated;
530 
531 	if (package_header->header_ver == 1) {
532 		max_entries = PACKAGE_MAX_FW_INFO_ENTRIES;
533 	} else if (package_header->header_ver == 2) {
534 		max_entries = PACKAGE_V2_MAX_FW_INFO_ENTRIES;
535 	} else {
536 		drm_err(&i915->drm, "DMC firmware has unknown header version %u\n",
537 			package_header->header_ver);
538 		return 0;
539 	}
540 
541 	/*
542 	 * We should always have space for max_entries,
543 	 * even if not all are used
544 	 */
545 	package_size += max_entries * sizeof(struct intel_fw_info);
546 	if (rem_size < package_size)
547 		goto error_truncated;
548 
549 	if (package_header->header_len * 4 != package_size) {
550 		drm_err(&i915->drm, "DMC firmware has wrong package header length "
551 			"(%u bytes)\n", package_size);
552 		return 0;
553 	}
554 
555 	num_entries = package_header->num_entries;
556 	if (WARN_ON(package_header->num_entries > max_entries))
557 		num_entries = max_entries;
558 
559 	fw_info = (const struct intel_fw_info *)
560 		((u8 *)package_header + sizeof(*package_header));
561 	dmc_set_fw_offset(dmc, fw_info, num_entries, si,
562 			  package_header->header_ver);
563 
564 	/* dmc_offset is in dwords */
565 	return package_size;
566 
567 error_truncated:
568 	drm_err(&i915->drm, "Truncated DMC firmware, refusing.\n");
569 	return 0;
570 }
571 
572 /* Return number of bytes parsed or 0 on error */
573 static u32 parse_dmc_fw_css(struct intel_dmc *dmc,
574 			    struct intel_css_header *css_header,
575 			    size_t rem_size)
576 {
577 	struct drm_i915_private *i915 = container_of(dmc, typeof(*i915), dmc);
578 
579 	if (rem_size < sizeof(struct intel_css_header)) {
580 		drm_err(&i915->drm, "Truncated DMC firmware, refusing.\n");
581 		return 0;
582 	}
583 
584 	if (sizeof(struct intel_css_header) !=
585 	    (css_header->header_len * 4)) {
586 		drm_err(&i915->drm, "DMC firmware has wrong CSS header length "
587 			"(%u bytes)\n",
588 			(css_header->header_len * 4));
589 		return 0;
590 	}
591 
592 	if (dmc->required_version &&
593 	    css_header->version != dmc->required_version) {
594 		drm_info(&i915->drm, "Refusing to load DMC firmware v%u.%u,"
595 			 " please use v%u.%u\n",
596 			 DMC_VERSION_MAJOR(css_header->version),
597 			 DMC_VERSION_MINOR(css_header->version),
598 			 DMC_VERSION_MAJOR(dmc->required_version),
599 			 DMC_VERSION_MINOR(dmc->required_version));
600 		return 0;
601 	}
602 
603 	dmc->version = css_header->version;
604 
605 	return sizeof(struct intel_css_header);
606 }
607 
608 static void parse_dmc_fw(struct drm_i915_private *dev_priv,
609 			 const struct firmware *fw)
610 {
611 	struct intel_css_header *css_header;
612 	struct intel_package_header *package_header;
613 	struct intel_dmc_header_base *dmc_header;
614 	struct intel_dmc *dmc = &dev_priv->dmc;
615 	struct stepping_info display_info = { '*', '*'};
616 	const struct stepping_info *si = intel_get_stepping_info(dev_priv, &display_info);
617 	u32 readcount = 0;
618 	u32 r, offset;
619 	int id;
620 
621 	if (!fw)
622 		return;
623 
624 	/* Extract CSS Header information */
625 	css_header = (struct intel_css_header *)fw->data;
626 	r = parse_dmc_fw_css(dmc, css_header, fw->size);
627 	if (!r)
628 		return;
629 
630 	readcount += r;
631 
632 	/* Extract Package Header information */
633 	package_header = (struct intel_package_header *)&fw->data[readcount];
634 	r = parse_dmc_fw_package(dmc, package_header, si, fw->size - readcount);
635 	if (!r)
636 		return;
637 
638 	readcount += r;
639 
640 	for (id = 0; id < DMC_FW_MAX; id++) {
641 		if (!dev_priv->dmc.dmc_info[id].present)
642 			continue;
643 
644 		offset = readcount + dmc->dmc_info[id].dmc_offset * 4;
645 		if (offset > fw->size) {
646 			drm_err(&dev_priv->drm, "Reading beyond the fw_size\n");
647 			continue;
648 		}
649 
650 		dmc_header = (struct intel_dmc_header_base *)&fw->data[offset];
651 		parse_dmc_fw_header(dmc, dmc_header, fw->size - offset, id);
652 	}
653 }
654 
655 static void intel_dmc_runtime_pm_get(struct drm_i915_private *dev_priv)
656 {
657 	drm_WARN_ON(&dev_priv->drm, dev_priv->dmc.wakeref);
658 	dev_priv->dmc.wakeref =
659 		intel_display_power_get(dev_priv, POWER_DOMAIN_INIT);
660 }
661 
662 static void intel_dmc_runtime_pm_put(struct drm_i915_private *dev_priv)
663 {
664 	intel_wakeref_t wakeref __maybe_unused =
665 		fetch_and_zero(&dev_priv->dmc.wakeref);
666 
667 	intel_display_power_put(dev_priv, POWER_DOMAIN_INIT, wakeref);
668 }
669 
670 static void dmc_load_work_fn(struct work_struct *work)
671 {
672 	struct drm_i915_private *dev_priv;
673 	struct intel_dmc *dmc;
674 	const struct firmware *fw = NULL;
675 
676 	dev_priv = container_of(work, typeof(*dev_priv), dmc.work);
677 	dmc = &dev_priv->dmc;
678 
679 	request_firmware(&fw, dev_priv->dmc.fw_path, dev_priv->drm.dev);
680 	parse_dmc_fw(dev_priv, fw);
681 
682 	if (intel_dmc_has_payload(dev_priv)) {
683 		intel_dmc_load_program(dev_priv);
684 		intel_dmc_runtime_pm_put(dev_priv);
685 
686 		drm_info(&dev_priv->drm,
687 			 "Finished loading DMC firmware %s (v%u.%u)\n",
688 			 dev_priv->dmc.fw_path, DMC_VERSION_MAJOR(dmc->version),
689 			 DMC_VERSION_MINOR(dmc->version));
690 	} else {
691 		drm_notice(&dev_priv->drm,
692 			   "Failed to load DMC firmware %s."
693 			   " Disabling runtime power management.\n",
694 			   dmc->fw_path);
695 		drm_notice(&dev_priv->drm, "DMC firmware homepage: %s",
696 			   INTEL_UC_FIRMWARE_URL);
697 	}
698 
699 	release_firmware(fw);
700 }
701 
702 /**
703  * intel_dmc_ucode_init() - initialize the firmware loading.
704  * @dev_priv: i915 drm device.
705  *
706  * This function is called at the time of loading the display driver to read
707  * firmware from a .bin file and copied into a internal memory.
708  */
709 void intel_dmc_ucode_init(struct drm_i915_private *dev_priv)
710 {
711 	struct intel_dmc *dmc = &dev_priv->dmc;
712 
713 	INIT_WORK(&dev_priv->dmc.work, dmc_load_work_fn);
714 
715 	if (!HAS_DMC(dev_priv))
716 		return;
717 
718 	/*
719 	 * Obtain a runtime pm reference, until DMC is loaded, to avoid entering
720 	 * runtime-suspend.
721 	 *
722 	 * On error, we return with the rpm wakeref held to prevent runtime
723 	 * suspend as runtime suspend *requires* a working DMC for whatever
724 	 * reason.
725 	 */
726 	intel_dmc_runtime_pm_get(dev_priv);
727 
728 	if (IS_ALDERLAKE_P(dev_priv)) {
729 		dmc->fw_path = ADLP_DMC_PATH;
730 		dmc->required_version = ADLP_DMC_VERSION_REQUIRED;
731 		dmc->max_fw_size = DISPLAY_VER13_DMC_MAX_FW_SIZE;
732 	} else if (IS_ALDERLAKE_S(dev_priv)) {
733 		dmc->fw_path = ADLS_DMC_PATH;
734 		dmc->required_version = ADLS_DMC_VERSION_REQUIRED;
735 		dmc->max_fw_size = DISPLAY_VER12_DMC_MAX_FW_SIZE;
736 	} else if (IS_DG1(dev_priv)) {
737 		dmc->fw_path = DG1_DMC_PATH;
738 		dmc->required_version = DG1_DMC_VERSION_REQUIRED;
739 		dmc->max_fw_size = DISPLAY_VER12_DMC_MAX_FW_SIZE;
740 	} else if (IS_ROCKETLAKE(dev_priv)) {
741 		dmc->fw_path = RKL_DMC_PATH;
742 		dmc->required_version = RKL_DMC_VERSION_REQUIRED;
743 		dmc->max_fw_size = DISPLAY_VER12_DMC_MAX_FW_SIZE;
744 	} else if (DISPLAY_VER(dev_priv) >= 12) {
745 		dmc->fw_path = TGL_DMC_PATH;
746 		dmc->required_version = TGL_DMC_VERSION_REQUIRED;
747 		dmc->max_fw_size = DISPLAY_VER12_DMC_MAX_FW_SIZE;
748 	} else if (DISPLAY_VER(dev_priv) == 11) {
749 		dmc->fw_path = ICL_DMC_PATH;
750 		dmc->required_version = ICL_DMC_VERSION_REQUIRED;
751 		dmc->max_fw_size = ICL_DMC_MAX_FW_SIZE;
752 	} else if (IS_GEMINILAKE(dev_priv)) {
753 		dmc->fw_path = GLK_DMC_PATH;
754 		dmc->required_version = GLK_DMC_VERSION_REQUIRED;
755 		dmc->max_fw_size = GLK_DMC_MAX_FW_SIZE;
756 	} else if (IS_KABYLAKE(dev_priv) ||
757 		   IS_COFFEELAKE(dev_priv) ||
758 		   IS_COMETLAKE(dev_priv)) {
759 		dmc->fw_path = KBL_DMC_PATH;
760 		dmc->required_version = KBL_DMC_VERSION_REQUIRED;
761 		dmc->max_fw_size = KBL_DMC_MAX_FW_SIZE;
762 	} else if (IS_SKYLAKE(dev_priv)) {
763 		dmc->fw_path = SKL_DMC_PATH;
764 		dmc->required_version = SKL_DMC_VERSION_REQUIRED;
765 		dmc->max_fw_size = SKL_DMC_MAX_FW_SIZE;
766 	} else if (IS_BROXTON(dev_priv)) {
767 		dmc->fw_path = BXT_DMC_PATH;
768 		dmc->required_version = BXT_DMC_VERSION_REQUIRED;
769 		dmc->max_fw_size = BXT_DMC_MAX_FW_SIZE;
770 	}
771 
772 	if (dev_priv->params.dmc_firmware_path) {
773 		if (strlen(dev_priv->params.dmc_firmware_path) == 0) {
774 			dmc->fw_path = NULL;
775 			drm_info(&dev_priv->drm,
776 				 "Disabling DMC firmware and runtime PM\n");
777 			return;
778 		}
779 
780 		dmc->fw_path = dev_priv->params.dmc_firmware_path;
781 		/* Bypass version check for firmware override. */
782 		dmc->required_version = 0;
783 	}
784 
785 	if (!dmc->fw_path) {
786 		drm_dbg_kms(&dev_priv->drm,
787 			    "No known DMC firmware for platform, disabling runtime PM\n");
788 		return;
789 	}
790 
791 	drm_dbg_kms(&dev_priv->drm, "Loading %s\n", dmc->fw_path);
792 	schedule_work(&dev_priv->dmc.work);
793 }
794 
795 /**
796  * intel_dmc_ucode_suspend() - prepare DMC firmware before system suspend
797  * @dev_priv: i915 drm device
798  *
799  * Prepare the DMC firmware before entering system suspend. This includes
800  * flushing pending work items and releasing any resources acquired during
801  * init.
802  */
803 void intel_dmc_ucode_suspend(struct drm_i915_private *dev_priv)
804 {
805 	if (!HAS_DMC(dev_priv))
806 		return;
807 
808 	flush_work(&dev_priv->dmc.work);
809 
810 	/* Drop the reference held in case DMC isn't loaded. */
811 	if (!intel_dmc_has_payload(dev_priv))
812 		intel_dmc_runtime_pm_put(dev_priv);
813 }
814 
815 /**
816  * intel_dmc_ucode_resume() - init DMC firmware during system resume
817  * @dev_priv: i915 drm device
818  *
819  * Reinitialize the DMC firmware during system resume, reacquiring any
820  * resources released in intel_dmc_ucode_suspend().
821  */
822 void intel_dmc_ucode_resume(struct drm_i915_private *dev_priv)
823 {
824 	if (!HAS_DMC(dev_priv))
825 		return;
826 
827 	/*
828 	 * Reacquire the reference to keep RPM disabled in case DMC isn't
829 	 * loaded.
830 	 */
831 	if (!intel_dmc_has_payload(dev_priv))
832 		intel_dmc_runtime_pm_get(dev_priv);
833 }
834 
835 /**
836  * intel_dmc_ucode_fini() - unload the DMC firmware.
837  * @dev_priv: i915 drm device.
838  *
839  * Firmmware unloading includes freeing the internal memory and reset the
840  * firmware loading status.
841  */
842 void intel_dmc_ucode_fini(struct drm_i915_private *dev_priv)
843 {
844 	int id;
845 
846 	if (!HAS_DMC(dev_priv))
847 		return;
848 
849 	intel_dmc_ucode_suspend(dev_priv);
850 	drm_WARN_ON(&dev_priv->drm, dev_priv->dmc.wakeref);
851 
852 	for (id = 0; id < DMC_FW_MAX; id++)
853 		kfree(dev_priv->dmc.dmc_info[id].payload);
854 }
855