xref: /openbmc/linux/drivers/gpu/drm/i915/gt/intel_mocs.c (revision b593bce5)
1 /*
2  * Copyright (c) 2015 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  * The above copyright notice and this permission notice (including the next
11  * paragraph) shall be included in all copies or substantial portions of the
12  * Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
20  * SOFTWARE.
21  */
22 
23 #include "i915_drv.h"
24 
25 #include "intel_engine.h"
26 #include "intel_gt.h"
27 #include "intel_mocs.h"
28 #include "intel_lrc.h"
29 
30 /* structures required */
31 struct drm_i915_mocs_entry {
32 	u32 control_value;
33 	u16 l3cc_value;
34 	u16 used;
35 };
36 
37 struct drm_i915_mocs_table {
38 	unsigned int size;
39 	unsigned int n_entries;
40 	const struct drm_i915_mocs_entry *table;
41 };
42 
43 /* Defines for the tables (XXX_MOCS_0 - XXX_MOCS_63) */
44 #define _LE_CACHEABILITY(value)	((value) << 0)
45 #define _LE_TGT_CACHE(value)	((value) << 2)
46 #define LE_LRUM(value)		((value) << 4)
47 #define LE_AOM(value)		((value) << 6)
48 #define LE_RSC(value)		((value) << 7)
49 #define LE_SCC(value)		((value) << 8)
50 #define LE_PFM(value)		((value) << 11)
51 #define LE_SCF(value)		((value) << 14)
52 #define LE_COS(value)		((value) << 15)
53 #define LE_SSE(value)		((value) << 17)
54 
55 /* Defines for the tables (LNCFMOCS0 - LNCFMOCS31) - two entries per word */
56 #define L3_ESC(value)		((value) << 0)
57 #define L3_SCC(value)		((value) << 1)
58 #define _L3_CACHEABILITY(value)	((value) << 4)
59 
60 /* Helper defines */
61 #define GEN9_NUM_MOCS_ENTRIES	62  /* 62 out of 64 - 63 & 64 are reserved. */
62 #define GEN11_NUM_MOCS_ENTRIES	64  /* 63-64 are reserved, but configured. */
63 
64 /* (e)LLC caching options */
65 #define LE_0_PAGETABLE		_LE_CACHEABILITY(0)
66 #define LE_1_UC			_LE_CACHEABILITY(1)
67 #define LE_2_WT			_LE_CACHEABILITY(2)
68 #define LE_3_WB			_LE_CACHEABILITY(3)
69 
70 /* Target cache */
71 #define LE_TC_0_PAGETABLE	_LE_TGT_CACHE(0)
72 #define LE_TC_1_LLC		_LE_TGT_CACHE(1)
73 #define LE_TC_2_LLC_ELLC	_LE_TGT_CACHE(2)
74 #define LE_TC_3_LLC_ELLC_ALT	_LE_TGT_CACHE(3)
75 
76 /* L3 caching options */
77 #define L3_0_DIRECT		_L3_CACHEABILITY(0)
78 #define L3_1_UC			_L3_CACHEABILITY(1)
79 #define L3_2_RESERVED		_L3_CACHEABILITY(2)
80 #define L3_3_WB			_L3_CACHEABILITY(3)
81 
82 #define MOCS_ENTRY(__idx, __control_value, __l3cc_value) \
83 	[__idx] = { \
84 		.control_value = __control_value, \
85 		.l3cc_value = __l3cc_value, \
86 		.used = 1, \
87 	}
88 
89 /*
90  * MOCS tables
91  *
92  * These are the MOCS tables that are programmed across all the rings.
93  * The control value is programmed to all the rings that support the
94  * MOCS registers. While the l3cc_values are only programmed to the
95  * LNCFCMOCS0 - LNCFCMOCS32 registers.
96  *
97  * These tables are intended to be kept reasonably consistent across
98  * HW platforms, and for ICL+, be identical across OSes. To achieve
99  * that, for Icelake and above, list of entries is published as part
100  * of bspec.
101  *
102  * Entries not part of the following tables are undefined as far as
103  * userspace is concerned and shouldn't be relied upon.  For the time
104  * being they will be initialized to PTE.
105  *
106  * The last two entries are reserved by the hardware. For ICL+ they
107  * should be initialized according to bspec and never used, for older
108  * platforms they should never be written to.
109  *
110  * NOTE: These tables are part of bspec and defined as part of hardware
111  *       interface for ICL+. For older platforms, they are part of kernel
112  *       ABI. It is expected that, for specific hardware platform, existing
113  *       entries will remain constant and the table will only be updated by
114  *       adding new entries, filling unused positions.
115  */
116 #define GEN9_MOCS_ENTRIES \
117 	MOCS_ENTRY(I915_MOCS_UNCACHED, \
118 		   LE_1_UC | LE_TC_2_LLC_ELLC, \
119 		   L3_1_UC), \
120 	MOCS_ENTRY(I915_MOCS_PTE, \
121 		   LE_0_PAGETABLE | LE_TC_2_LLC_ELLC | LE_LRUM(3), \
122 		   L3_3_WB)
123 
124 static const struct drm_i915_mocs_entry skylake_mocs_table[] = {
125 	GEN9_MOCS_ENTRIES,
126 	MOCS_ENTRY(I915_MOCS_CACHED,
127 		   LE_3_WB | LE_TC_2_LLC_ELLC | LE_LRUM(3),
128 		   L3_3_WB)
129 };
130 
131 /* NOTE: the LE_TGT_CACHE is not used on Broxton */
132 static const struct drm_i915_mocs_entry broxton_mocs_table[] = {
133 	GEN9_MOCS_ENTRIES,
134 	MOCS_ENTRY(I915_MOCS_CACHED,
135 		   LE_1_UC | LE_TC_2_LLC_ELLC | LE_LRUM(3),
136 		   L3_3_WB)
137 };
138 
139 #define GEN11_MOCS_ENTRIES \
140 	/* Base - Uncached (Deprecated) */ \
141 	MOCS_ENTRY(I915_MOCS_UNCACHED, \
142 		   LE_1_UC | LE_TC_1_LLC, \
143 		   L3_1_UC), \
144 	/* Base - L3 + LeCC:PAT (Deprecated) */ \
145 	MOCS_ENTRY(I915_MOCS_PTE, \
146 		   LE_0_PAGETABLE | LE_TC_1_LLC, \
147 		   L3_3_WB), \
148 	/* Base - L3 + LLC */ \
149 	MOCS_ENTRY(2, \
150 		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3), \
151 		   L3_3_WB), \
152 	/* Base - Uncached */ \
153 	MOCS_ENTRY(3, \
154 		   LE_1_UC | LE_TC_1_LLC, \
155 		   L3_1_UC), \
156 	/* Base - L3 */ \
157 	MOCS_ENTRY(4, \
158 		   LE_1_UC | LE_TC_1_LLC, \
159 		   L3_3_WB), \
160 	/* Base - LLC */ \
161 	MOCS_ENTRY(5, \
162 		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3), \
163 		   L3_1_UC), \
164 	/* Age 0 - LLC */ \
165 	MOCS_ENTRY(6, \
166 		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(1), \
167 		   L3_1_UC), \
168 	/* Age 0 - L3 + LLC */ \
169 	MOCS_ENTRY(7, \
170 		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(1), \
171 		   L3_3_WB), \
172 	/* Age: Don't Chg. - LLC */ \
173 	MOCS_ENTRY(8, \
174 		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(2), \
175 		   L3_1_UC), \
176 	/* Age: Don't Chg. - L3 + LLC */ \
177 	MOCS_ENTRY(9, \
178 		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(2), \
179 		   L3_3_WB), \
180 	/* No AOM - LLC */ \
181 	MOCS_ENTRY(10, \
182 		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3) | LE_AOM(1), \
183 		   L3_1_UC), \
184 	/* No AOM - L3 + LLC */ \
185 	MOCS_ENTRY(11, \
186 		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3) | LE_AOM(1), \
187 		   L3_3_WB), \
188 	/* No AOM; Age 0 - LLC */ \
189 	MOCS_ENTRY(12, \
190 		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(1) | LE_AOM(1), \
191 		   L3_1_UC), \
192 	/* No AOM; Age 0 - L3 + LLC */ \
193 	MOCS_ENTRY(13, \
194 		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(1) | LE_AOM(1), \
195 		   L3_3_WB), \
196 	/* No AOM; Age:DC - LLC */ \
197 	MOCS_ENTRY(14, \
198 		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(2) | LE_AOM(1), \
199 		   L3_1_UC), \
200 	/* No AOM; Age:DC - L3 + LLC */ \
201 	MOCS_ENTRY(15, \
202 		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(2) | LE_AOM(1), \
203 		   L3_3_WB), \
204 	/* Bypass LLC - Uncached (EHL+) */ \
205 	MOCS_ENTRY(16, \
206 		   LE_1_UC | LE_TC_1_LLC | LE_SCF(1), \
207 		   L3_1_UC), \
208 	/* Bypass LLC - L3 (Read-Only) (EHL+) */ \
209 	MOCS_ENTRY(17, \
210 		   LE_1_UC | LE_TC_1_LLC | LE_SCF(1), \
211 		   L3_3_WB), \
212 	/* Self-Snoop - L3 + LLC */ \
213 	MOCS_ENTRY(18, \
214 		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3) | LE_SSE(3), \
215 		   L3_3_WB), \
216 	/* Skip Caching - L3 + LLC(12.5%) */ \
217 	MOCS_ENTRY(19, \
218 		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3) | LE_SCC(7), \
219 		   L3_3_WB), \
220 	/* Skip Caching - L3 + LLC(25%) */ \
221 	MOCS_ENTRY(20, \
222 		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3) | LE_SCC(3), \
223 		   L3_3_WB), \
224 	/* Skip Caching - L3 + LLC(50%) */ \
225 	MOCS_ENTRY(21, \
226 		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3) | LE_SCC(1), \
227 		   L3_3_WB), \
228 	/* Skip Caching - L3 + LLC(75%) */ \
229 	MOCS_ENTRY(22, \
230 		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3) | LE_RSC(1) | LE_SCC(3), \
231 		   L3_3_WB), \
232 	/* Skip Caching - L3 + LLC(87.5%) */ \
233 	MOCS_ENTRY(23, \
234 		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3) | LE_RSC(1) | LE_SCC(7), \
235 		   L3_3_WB), \
236 	/* HW Reserved - SW program but never use */ \
237 	MOCS_ENTRY(62, \
238 		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3), \
239 		   L3_1_UC), \
240 	/* HW Reserved - SW program but never use */ \
241 	MOCS_ENTRY(63, \
242 		   LE_3_WB | LE_TC_1_LLC | LE_LRUM(3), \
243 		   L3_1_UC)
244 
245 static const struct drm_i915_mocs_entry icelake_mocs_table[] = {
246 	GEN11_MOCS_ENTRIES
247 };
248 
249 /**
250  * get_mocs_settings()
251  * @gt:		gt device
252  * @table:      Output table that will be made to point at appropriate
253  *	      MOCS values for the device.
254  *
255  * This function will return the values of the MOCS table that needs to
256  * be programmed for the platform. It will return the values that need
257  * to be programmed and if they need to be programmed.
258  *
259  * Return: true if there are applicable MOCS settings for the device.
260  */
261 static bool get_mocs_settings(struct intel_gt *gt,
262 			      struct drm_i915_mocs_table *table)
263 {
264 	struct drm_i915_private *i915 = gt->i915;
265 	bool result = false;
266 
267 	if (INTEL_GEN(i915) >= 11) {
268 		table->size  = ARRAY_SIZE(icelake_mocs_table);
269 		table->table = icelake_mocs_table;
270 		table->n_entries = GEN11_NUM_MOCS_ENTRIES;
271 		result = true;
272 	} else if (IS_GEN9_BC(i915) || IS_CANNONLAKE(i915)) {
273 		table->size  = ARRAY_SIZE(skylake_mocs_table);
274 		table->n_entries = GEN9_NUM_MOCS_ENTRIES;
275 		table->table = skylake_mocs_table;
276 		result = true;
277 	} else if (IS_GEN9_LP(i915)) {
278 		table->size  = ARRAY_SIZE(broxton_mocs_table);
279 		table->n_entries = GEN9_NUM_MOCS_ENTRIES;
280 		table->table = broxton_mocs_table;
281 		result = true;
282 	} else {
283 		WARN_ONCE(INTEL_GEN(i915) >= 9,
284 			  "Platform that should have a MOCS table does not.\n");
285 	}
286 
287 	/* WaDisableSkipCaching:skl,bxt,kbl,glk */
288 	if (IS_GEN(i915, 9)) {
289 		int i;
290 
291 		for (i = 0; i < table->size; i++)
292 			if (WARN_ON(table->table[i].l3cc_value &
293 				    (L3_ESC(1) | L3_SCC(0x7))))
294 				return false;
295 	}
296 
297 	return result;
298 }
299 
300 static i915_reg_t mocs_register(enum intel_engine_id engine_id, int index)
301 {
302 	switch (engine_id) {
303 	case RCS0:
304 		return GEN9_GFX_MOCS(index);
305 	case VCS0:
306 		return GEN9_MFX0_MOCS(index);
307 	case BCS0:
308 		return GEN9_BLT_MOCS(index);
309 	case VECS0:
310 		return GEN9_VEBOX_MOCS(index);
311 	case VCS1:
312 		return GEN9_MFX1_MOCS(index);
313 	case VCS2:
314 		return GEN11_MFX2_MOCS(index);
315 	default:
316 		MISSING_CASE(engine_id);
317 		return INVALID_MMIO_REG;
318 	}
319 }
320 
321 /*
322  * Get control_value from MOCS entry taking into account when it's not used:
323  * I915_MOCS_PTE's value is returned in this case.
324  */
325 static u32 get_entry_control(const struct drm_i915_mocs_table *table,
326 			     unsigned int index)
327 {
328 	if (table->table[index].used)
329 		return table->table[index].control_value;
330 
331 	return table->table[I915_MOCS_PTE].control_value;
332 }
333 
334 /**
335  * intel_mocs_init_engine() - emit the mocs control table
336  * @engine:	The engine for whom to emit the registers.
337  *
338  * This function simply emits a MI_LOAD_REGISTER_IMM command for the
339  * given table starting at the given address.
340  */
341 void intel_mocs_init_engine(struct intel_engine_cs *engine)
342 {
343 	struct intel_gt *gt = engine->gt;
344 	struct intel_uncore *uncore = gt->uncore;
345 	struct drm_i915_mocs_table table;
346 	unsigned int index;
347 	u32 unused_value;
348 
349 	/* Called under a blanket forcewake */
350 	assert_forcewakes_active(uncore, FORCEWAKE_ALL);
351 
352 	if (!get_mocs_settings(gt, &table))
353 		return;
354 
355 	/* Set unused values to PTE */
356 	unused_value = table.table[I915_MOCS_PTE].control_value;
357 
358 	for (index = 0; index < table.size; index++) {
359 		u32 value = get_entry_control(&table, index);
360 
361 		intel_uncore_write_fw(uncore,
362 				      mocs_register(engine->id, index),
363 				      value);
364 	}
365 
366 	/* All remaining entries are also unused */
367 	for (; index < table.n_entries; index++)
368 		intel_uncore_write_fw(uncore,
369 				      mocs_register(engine->id, index),
370 				      unused_value);
371 }
372 
373 /**
374  * emit_mocs_control_table() - emit the mocs control table
375  * @rq:	Request to set up the MOCS table for.
376  * @table:	The values to program into the control regs.
377  *
378  * This function simply emits a MI_LOAD_REGISTER_IMM command for the
379  * given table starting at the given address.
380  *
381  * Return: 0 on success, otherwise the error status.
382  */
383 static int emit_mocs_control_table(struct i915_request *rq,
384 				   const struct drm_i915_mocs_table *table)
385 {
386 	enum intel_engine_id engine = rq->engine->id;
387 	unsigned int index;
388 	u32 unused_value;
389 	u32 *cs;
390 
391 	if (GEM_WARN_ON(table->size > table->n_entries))
392 		return -ENODEV;
393 
394 	/* Set unused values to PTE */
395 	unused_value = table->table[I915_MOCS_PTE].control_value;
396 
397 	cs = intel_ring_begin(rq, 2 + 2 * table->n_entries);
398 	if (IS_ERR(cs))
399 		return PTR_ERR(cs);
400 
401 	*cs++ = MI_LOAD_REGISTER_IMM(table->n_entries);
402 
403 	for (index = 0; index < table->size; index++) {
404 		u32 value = get_entry_control(table, index);
405 
406 		*cs++ = i915_mmio_reg_offset(mocs_register(engine, index));
407 		*cs++ = value;
408 	}
409 
410 	/* All remaining entries are also unused */
411 	for (; index < table->n_entries; index++) {
412 		*cs++ = i915_mmio_reg_offset(mocs_register(engine, index));
413 		*cs++ = unused_value;
414 	}
415 
416 	*cs++ = MI_NOOP;
417 	intel_ring_advance(rq, cs);
418 
419 	return 0;
420 }
421 
422 /*
423  * Get l3cc_value from MOCS entry taking into account when it's not used:
424  * I915_MOCS_PTE's value is returned in this case.
425  */
426 static u16 get_entry_l3cc(const struct drm_i915_mocs_table *table,
427 			  unsigned int index)
428 {
429 	if (table->table[index].used)
430 		return table->table[index].l3cc_value;
431 
432 	return table->table[I915_MOCS_PTE].l3cc_value;
433 }
434 
435 static inline u32 l3cc_combine(const struct drm_i915_mocs_table *table,
436 			       u16 low,
437 			       u16 high)
438 {
439 	return low | high << 16;
440 }
441 
442 /**
443  * emit_mocs_l3cc_table() - emit the mocs control table
444  * @rq:	Request to set up the MOCS table for.
445  * @table:	The values to program into the control regs.
446  *
447  * This function simply emits a MI_LOAD_REGISTER_IMM command for the
448  * given table starting at the given address. This register set is
449  * programmed in pairs.
450  *
451  * Return: 0 on success, otherwise the error status.
452  */
453 static int emit_mocs_l3cc_table(struct i915_request *rq,
454 				const struct drm_i915_mocs_table *table)
455 {
456 	u16 unused_value;
457 	unsigned int i;
458 	u32 *cs;
459 
460 	if (GEM_WARN_ON(table->size > table->n_entries))
461 		return -ENODEV;
462 
463 	/* Set unused values to PTE */
464 	unused_value = table->table[I915_MOCS_PTE].l3cc_value;
465 
466 	cs = intel_ring_begin(rq, 2 + table->n_entries);
467 	if (IS_ERR(cs))
468 		return PTR_ERR(cs);
469 
470 	*cs++ = MI_LOAD_REGISTER_IMM(table->n_entries / 2);
471 
472 	for (i = 0; i < table->size / 2; i++) {
473 		u16 low = get_entry_l3cc(table, 2 * i);
474 		u16 high = get_entry_l3cc(table, 2 * i + 1);
475 
476 		*cs++ = i915_mmio_reg_offset(GEN9_LNCFCMOCS(i));
477 		*cs++ = l3cc_combine(table, low, high);
478 	}
479 
480 	/* Odd table size - 1 left over */
481 	if (table->size & 0x01) {
482 		u16 low = get_entry_l3cc(table, 2 * i);
483 
484 		*cs++ = i915_mmio_reg_offset(GEN9_LNCFCMOCS(i));
485 		*cs++ = l3cc_combine(table, low, unused_value);
486 		i++;
487 	}
488 
489 	/* All remaining entries are also unused */
490 	for (; i < table->n_entries / 2; i++) {
491 		*cs++ = i915_mmio_reg_offset(GEN9_LNCFCMOCS(i));
492 		*cs++ = l3cc_combine(table, unused_value, unused_value);
493 	}
494 
495 	*cs++ = MI_NOOP;
496 	intel_ring_advance(rq, cs);
497 
498 	return 0;
499 }
500 
501 /**
502  * intel_mocs_init_l3cc_table() - program the mocs control table
503  * @gt: the intel_gt container
504  *
505  * This function simply programs the mocs registers for the given table
506  * starting at the given address. This register set is  programmed in pairs.
507  *
508  * These registers may get programmed more than once, it is simpler to
509  * re-program 32 registers than maintain the state of when they were programmed.
510  * We are always reprogramming with the same values and this only on context
511  * start.
512  *
513  * Return: Nothing.
514  */
515 void intel_mocs_init_l3cc_table(struct intel_gt *gt)
516 {
517 	struct intel_uncore *uncore = gt->uncore;
518 	struct drm_i915_mocs_table table;
519 	unsigned int i;
520 	u16 unused_value;
521 
522 	if (!get_mocs_settings(gt, &table))
523 		return;
524 
525 	/* Set unused values to PTE */
526 	unused_value = table.table[I915_MOCS_PTE].l3cc_value;
527 
528 	for (i = 0; i < table.size / 2; i++) {
529 		u16 low = get_entry_l3cc(&table, 2 * i);
530 		u16 high = get_entry_l3cc(&table, 2 * i + 1);
531 
532 		intel_uncore_write(uncore,
533 				   GEN9_LNCFCMOCS(i),
534 				   l3cc_combine(&table, low, high));
535 	}
536 
537 	/* Odd table size - 1 left over */
538 	if (table.size & 0x01) {
539 		u16 low = get_entry_l3cc(&table, 2 * i);
540 
541 		intel_uncore_write(uncore,
542 				   GEN9_LNCFCMOCS(i),
543 				   l3cc_combine(&table, low, unused_value));
544 		i++;
545 	}
546 
547 	/* All remaining entries are also unused */
548 	for (; i < table.n_entries / 2; i++)
549 		intel_uncore_write(uncore,
550 				   GEN9_LNCFCMOCS(i),
551 				   l3cc_combine(&table, unused_value,
552 						unused_value));
553 }
554 
555 /**
556  * intel_rcs_context_init_mocs() - program the MOCS register.
557  * @rq:	Request to set up the MOCS tables for.
558  *
559  * This function will emit a batch buffer with the values required for
560  * programming the MOCS register values for all the currently supported
561  * rings.
562  *
563  * These registers are partially stored in the RCS context, so they are
564  * emitted at the same time so that when a context is created these registers
565  * are set up. These registers have to be emitted into the start of the
566  * context as setting the ELSP will re-init some of these registers back
567  * to the hw values.
568  *
569  * Return: 0 on success, otherwise the error status.
570  */
571 int intel_mocs_emit(struct i915_request *rq)
572 {
573 	struct drm_i915_mocs_table t;
574 	int ret;
575 
576 	if (rq->engine->class != RENDER_CLASS)
577 		return 0;
578 
579 	if (get_mocs_settings(rq->engine->gt, &t)) {
580 		/* Program the RCS control registers */
581 		ret = emit_mocs_control_table(rq, &t);
582 		if (ret)
583 			return ret;
584 
585 		/* Now program the l3cc registers */
586 		ret = emit_mocs_l3cc_table(rq, &t);
587 		if (ret)
588 			return ret;
589 	}
590 
591 	return 0;
592 }
593