xref: /linux/drivers/gpu/drm/i915/gvt/mmio_context.c (revision 44f57d78)
1 /*
2  * Copyright(c) 2011-2016 Intel Corporation. All rights reserved.
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 FROM,
20  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
21  * SOFTWARE.
22  *
23  * Authors:
24  *    Eddie Dong <eddie.dong@intel.com>
25  *    Kevin Tian <kevin.tian@intel.com>
26  *
27  * Contributors:
28  *    Zhi Wang <zhi.a.wang@intel.com>
29  *    Changbin Du <changbin.du@intel.com>
30  *    Zhenyu Wang <zhenyuw@linux.intel.com>
31  *    Tina Zhang <tina.zhang@intel.com>
32  *    Bing Niu <bing.niu@intel.com>
33  *
34  */
35 
36 #include "i915_drv.h"
37 #include "gvt.h"
38 #include "trace.h"
39 
40 #define GEN9_MOCS_SIZE		64
41 
42 /* Raw offset is appened to each line for convenience. */
43 static struct engine_mmio gen8_engine_mmio_list[] __cacheline_aligned = {
44 	{RCS0, GFX_MODE_GEN7, 0xffff, false}, /* 0x229c */
45 	{RCS0, GEN9_CTX_PREEMPT_REG, 0x0, false}, /* 0x2248 */
46 	{RCS0, HWSTAM, 0x0, false}, /* 0x2098 */
47 	{RCS0, INSTPM, 0xffff, true}, /* 0x20c0 */
48 	{RCS0, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 0), 0, false}, /* 0x24d0 */
49 	{RCS0, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 1), 0, false}, /* 0x24d4 */
50 	{RCS0, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 2), 0, false}, /* 0x24d8 */
51 	{RCS0, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 3), 0, false}, /* 0x24dc */
52 	{RCS0, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 4), 0, false}, /* 0x24e0 */
53 	{RCS0, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 5), 0, false}, /* 0x24e4 */
54 	{RCS0, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 6), 0, false}, /* 0x24e8 */
55 	{RCS0, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 7), 0, false}, /* 0x24ec */
56 	{RCS0, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 8), 0, false}, /* 0x24f0 */
57 	{RCS0, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 9), 0, false}, /* 0x24f4 */
58 	{RCS0, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 10), 0, false}, /* 0x24f8 */
59 	{RCS0, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 11), 0, false}, /* 0x24fc */
60 	{RCS0, CACHE_MODE_1, 0xffff, true}, /* 0x7004 */
61 	{RCS0, GEN7_GT_MODE, 0xffff, true}, /* 0x7008 */
62 	{RCS0, CACHE_MODE_0_GEN7, 0xffff, true}, /* 0x7000 */
63 	{RCS0, GEN7_COMMON_SLICE_CHICKEN1, 0xffff, true}, /* 0x7010 */
64 	{RCS0, HDC_CHICKEN0, 0xffff, true}, /* 0x7300 */
65 	{RCS0, VF_GUARDBAND, 0xffff, true}, /* 0x83a4 */
66 
67 	{BCS0, RING_GFX_MODE(BLT_RING_BASE), 0xffff, false}, /* 0x2229c */
68 	{BCS0, RING_MI_MODE(BLT_RING_BASE), 0xffff, false}, /* 0x2209c */
69 	{BCS0, RING_INSTPM(BLT_RING_BASE), 0xffff, false}, /* 0x220c0 */
70 	{BCS0, RING_HWSTAM(BLT_RING_BASE), 0x0, false}, /* 0x22098 */
71 	{BCS0, RING_EXCC(BLT_RING_BASE), 0xffff, false}, /* 0x22028 */
72 	{RCS0, INVALID_MMIO_REG, 0, false } /* Terminated */
73 };
74 
75 static struct engine_mmio gen9_engine_mmio_list[] __cacheline_aligned = {
76 	{RCS0, GFX_MODE_GEN7, 0xffff, false}, /* 0x229c */
77 	{RCS0, GEN9_CTX_PREEMPT_REG, 0x0, false}, /* 0x2248 */
78 	{RCS0, HWSTAM, 0x0, false}, /* 0x2098 */
79 	{RCS0, INSTPM, 0xffff, true}, /* 0x20c0 */
80 	{RCS0, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 0), 0, false}, /* 0x24d0 */
81 	{RCS0, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 1), 0, false}, /* 0x24d4 */
82 	{RCS0, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 2), 0, false}, /* 0x24d8 */
83 	{RCS0, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 3), 0, false}, /* 0x24dc */
84 	{RCS0, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 4), 0, false}, /* 0x24e0 */
85 	{RCS0, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 5), 0, false}, /* 0x24e4 */
86 	{RCS0, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 6), 0, false}, /* 0x24e8 */
87 	{RCS0, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 7), 0, false}, /* 0x24ec */
88 	{RCS0, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 8), 0, false}, /* 0x24f0 */
89 	{RCS0, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 9), 0, false}, /* 0x24f4 */
90 	{RCS0, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 10), 0, false}, /* 0x24f8 */
91 	{RCS0, RING_FORCE_TO_NONPRIV(RENDER_RING_BASE, 11), 0, false}, /* 0x24fc */
92 	{RCS0, CACHE_MODE_1, 0xffff, true}, /* 0x7004 */
93 	{RCS0, GEN7_GT_MODE, 0xffff, true}, /* 0x7008 */
94 	{RCS0, CACHE_MODE_0_GEN7, 0xffff, true}, /* 0x7000 */
95 	{RCS0, GEN7_COMMON_SLICE_CHICKEN1, 0xffff, true}, /* 0x7010 */
96 	{RCS0, HDC_CHICKEN0, 0xffff, true}, /* 0x7300 */
97 	{RCS0, VF_GUARDBAND, 0xffff, true}, /* 0x83a4 */
98 
99 	{RCS0, GEN8_PRIVATE_PAT_LO, 0, false}, /* 0x40e0 */
100 	{RCS0, GEN8_PRIVATE_PAT_HI, 0, false}, /* 0x40e4 */
101 	{RCS0, GEN8_CS_CHICKEN1, 0xffff, true}, /* 0x2580 */
102 	{RCS0, COMMON_SLICE_CHICKEN2, 0xffff, true}, /* 0x7014 */
103 	{RCS0, GEN9_CS_DEBUG_MODE1, 0xffff, false}, /* 0x20ec */
104 	{RCS0, GEN8_L3SQCREG4, 0, false}, /* 0xb118 */
105 	{RCS0, GEN7_HALF_SLICE_CHICKEN1, 0xffff, true}, /* 0xe100 */
106 	{RCS0, HALF_SLICE_CHICKEN2, 0xffff, true}, /* 0xe180 */
107 	{RCS0, HALF_SLICE_CHICKEN3, 0xffff, true}, /* 0xe184 */
108 	{RCS0, GEN9_HALF_SLICE_CHICKEN5, 0xffff, true}, /* 0xe188 */
109 	{RCS0, GEN9_HALF_SLICE_CHICKEN7, 0xffff, true}, /* 0xe194 */
110 	{RCS0, GEN8_ROW_CHICKEN, 0xffff, true}, /* 0xe4f0 */
111 	{RCS0, TRVATTL3PTRDW(0), 0, true}, /* 0x4de0 */
112 	{RCS0, TRVATTL3PTRDW(1), 0, true}, /* 0x4de4 */
113 	{RCS0, TRNULLDETCT, 0, true}, /* 0x4de8 */
114 	{RCS0, TRINVTILEDETCT, 0, true}, /* 0x4dec */
115 	{RCS0, TRVADR, 0, true}, /* 0x4df0 */
116 	{RCS0, TRTTE, 0, true}, /* 0x4df4 */
117 	{RCS0, _MMIO(0x4dfc), 0, true},
118 
119 	{BCS0, RING_GFX_MODE(BLT_RING_BASE), 0xffff, false}, /* 0x2229c */
120 	{BCS0, RING_MI_MODE(BLT_RING_BASE), 0xffff, false}, /* 0x2209c */
121 	{BCS0, RING_INSTPM(BLT_RING_BASE), 0xffff, false}, /* 0x220c0 */
122 	{BCS0, RING_HWSTAM(BLT_RING_BASE), 0x0, false}, /* 0x22098 */
123 	{BCS0, RING_EXCC(BLT_RING_BASE), 0xffff, false}, /* 0x22028 */
124 
125 	{VCS1, RING_EXCC(GEN8_BSD2_RING_BASE), 0xffff, false}, /* 0x1c028 */
126 
127 	{VECS0, RING_EXCC(VEBOX_RING_BASE), 0xffff, false}, /* 0x1a028 */
128 
129 	{RCS0, GEN8_HDC_CHICKEN1, 0xffff, true}, /* 0x7304 */
130 	{RCS0, GEN9_CTX_PREEMPT_REG, 0x0, false}, /* 0x2248 */
131 	{RCS0, GEN7_UCGCTL4, 0x0, false}, /* 0x940c */
132 	{RCS0, GAMT_CHKN_BIT_REG, 0x0, false}, /* 0x4ab8 */
133 
134 	{RCS0, GEN9_GAMT_ECO_REG_RW_IA, 0x0, false}, /* 0x4ab0 */
135 	{RCS0, GEN9_CSFE_CHICKEN1_RCS, 0xffff, false}, /* 0x20d4 */
136 	{RCS0, _MMIO(0x20D8), 0xffff, true}, /* 0x20d8 */
137 
138 	{RCS0, GEN8_GARBCNTL, 0x0, false}, /* 0xb004 */
139 	{RCS0, GEN7_FF_THREAD_MODE, 0x0, false}, /* 0x20a0 */
140 	{RCS0, FF_SLICE_CS_CHICKEN2, 0xffff, false}, /* 0x20e4 */
141 	{RCS0, INVALID_MMIO_REG, 0, false } /* Terminated */
142 };
143 
144 static struct {
145 	bool initialized;
146 	u32 control_table[I915_NUM_ENGINES][GEN9_MOCS_SIZE];
147 	u32 l3cc_table[GEN9_MOCS_SIZE / 2];
148 } gen9_render_mocs;
149 
150 static void load_render_mocs(struct drm_i915_private *dev_priv)
151 {
152 	i915_reg_t offset;
153 	u32 regs[] = {
154 		[RCS0]  = 0xc800,
155 		[VCS0]  = 0xc900,
156 		[VCS1]  = 0xca00,
157 		[BCS0]  = 0xcc00,
158 		[VECS0] = 0xcb00,
159 	};
160 	int ring_id, i;
161 
162 	for (ring_id = 0; ring_id < ARRAY_SIZE(regs); ring_id++) {
163 		if (!HAS_ENGINE(dev_priv, ring_id))
164 			continue;
165 		offset.reg = regs[ring_id];
166 		for (i = 0; i < GEN9_MOCS_SIZE; i++) {
167 			gen9_render_mocs.control_table[ring_id][i] =
168 				I915_READ_FW(offset);
169 			offset.reg += 4;
170 		}
171 	}
172 
173 	offset.reg = 0xb020;
174 	for (i = 0; i < GEN9_MOCS_SIZE / 2; i++) {
175 		gen9_render_mocs.l3cc_table[i] =
176 			I915_READ_FW(offset);
177 		offset.reg += 4;
178 	}
179 	gen9_render_mocs.initialized = true;
180 }
181 
182 static int
183 restore_context_mmio_for_inhibit(struct intel_vgpu *vgpu,
184 				 struct i915_request *req)
185 {
186 	u32 *cs;
187 	int ret;
188 	struct engine_mmio *mmio;
189 	struct intel_gvt *gvt = vgpu->gvt;
190 	int ring_id = req->engine->id;
191 	int count = gvt->engine_mmio_list.ctx_mmio_count[ring_id];
192 
193 	if (count == 0)
194 		return 0;
195 
196 	ret = req->engine->emit_flush(req, EMIT_BARRIER);
197 	if (ret)
198 		return ret;
199 
200 	cs = intel_ring_begin(req, count * 2 + 2);
201 	if (IS_ERR(cs))
202 		return PTR_ERR(cs);
203 
204 	*cs++ = MI_LOAD_REGISTER_IMM(count);
205 	for (mmio = gvt->engine_mmio_list.mmio;
206 	     i915_mmio_reg_valid(mmio->reg); mmio++) {
207 		if (mmio->ring_id != ring_id ||
208 		    !mmio->in_context)
209 			continue;
210 
211 		*cs++ = i915_mmio_reg_offset(mmio->reg);
212 		*cs++ = vgpu_vreg_t(vgpu, mmio->reg) |
213 				(mmio->mask << 16);
214 		gvt_dbg_core("add lri reg pair 0x%x:0x%x in inhibit ctx, vgpu:%d, rind_id:%d\n",
215 			      *(cs-2), *(cs-1), vgpu->id, ring_id);
216 	}
217 
218 	*cs++ = MI_NOOP;
219 	intel_ring_advance(req, cs);
220 
221 	ret = req->engine->emit_flush(req, EMIT_BARRIER);
222 	if (ret)
223 		return ret;
224 
225 	return 0;
226 }
227 
228 static int
229 restore_render_mocs_control_for_inhibit(struct intel_vgpu *vgpu,
230 					struct i915_request *req)
231 {
232 	unsigned int index;
233 	u32 *cs;
234 
235 	cs = intel_ring_begin(req, 2 * GEN9_MOCS_SIZE + 2);
236 	if (IS_ERR(cs))
237 		return PTR_ERR(cs);
238 
239 	*cs++ = MI_LOAD_REGISTER_IMM(GEN9_MOCS_SIZE);
240 
241 	for (index = 0; index < GEN9_MOCS_SIZE; index++) {
242 		*cs++ = i915_mmio_reg_offset(GEN9_GFX_MOCS(index));
243 		*cs++ = vgpu_vreg_t(vgpu, GEN9_GFX_MOCS(index));
244 		gvt_dbg_core("add lri reg pair 0x%x:0x%x in inhibit ctx, vgpu:%d, rind_id:%d\n",
245 			      *(cs-2), *(cs-1), vgpu->id, req->engine->id);
246 
247 	}
248 
249 	*cs++ = MI_NOOP;
250 	intel_ring_advance(req, cs);
251 
252 	return 0;
253 }
254 
255 static int
256 restore_render_mocs_l3cc_for_inhibit(struct intel_vgpu *vgpu,
257 				     struct i915_request *req)
258 {
259 	unsigned int index;
260 	u32 *cs;
261 
262 	cs = intel_ring_begin(req, 2 * GEN9_MOCS_SIZE / 2 + 2);
263 	if (IS_ERR(cs))
264 		return PTR_ERR(cs);
265 
266 	*cs++ = MI_LOAD_REGISTER_IMM(GEN9_MOCS_SIZE / 2);
267 
268 	for (index = 0; index < GEN9_MOCS_SIZE / 2; index++) {
269 		*cs++ = i915_mmio_reg_offset(GEN9_LNCFCMOCS(index));
270 		*cs++ = vgpu_vreg_t(vgpu, GEN9_LNCFCMOCS(index));
271 		gvt_dbg_core("add lri reg pair 0x%x:0x%x in inhibit ctx, vgpu:%d, rind_id:%d\n",
272 			      *(cs-2), *(cs-1), vgpu->id, req->engine->id);
273 
274 	}
275 
276 	*cs++ = MI_NOOP;
277 	intel_ring_advance(req, cs);
278 
279 	return 0;
280 }
281 
282 /*
283  * Use lri command to initialize the mmio which is in context state image for
284  * inhibit context, it contains tracked engine mmio, render_mocs and
285  * render_mocs_l3cc.
286  */
287 int intel_vgpu_restore_inhibit_context(struct intel_vgpu *vgpu,
288 				       struct i915_request *req)
289 {
290 	int ret;
291 	u32 *cs;
292 
293 	cs = intel_ring_begin(req, 2);
294 	if (IS_ERR(cs))
295 		return PTR_ERR(cs);
296 
297 	*cs++ = MI_ARB_ON_OFF | MI_ARB_DISABLE;
298 	*cs++ = MI_NOOP;
299 	intel_ring_advance(req, cs);
300 
301 	ret = restore_context_mmio_for_inhibit(vgpu, req);
302 	if (ret)
303 		goto out;
304 
305 	/* no MOCS register in context except render engine */
306 	if (req->engine->id != RCS0)
307 		goto out;
308 
309 	ret = restore_render_mocs_control_for_inhibit(vgpu, req);
310 	if (ret)
311 		goto out;
312 
313 	ret = restore_render_mocs_l3cc_for_inhibit(vgpu, req);
314 	if (ret)
315 		goto out;
316 
317 out:
318 	cs = intel_ring_begin(req, 2);
319 	if (IS_ERR(cs))
320 		return PTR_ERR(cs);
321 
322 	*cs++ = MI_ARB_ON_OFF | MI_ARB_ENABLE;
323 	*cs++ = MI_NOOP;
324 	intel_ring_advance(req, cs);
325 
326 	return ret;
327 }
328 
329 static void handle_tlb_pending_event(struct intel_vgpu *vgpu, int ring_id)
330 {
331 	struct drm_i915_private *dev_priv = vgpu->gvt->dev_priv;
332 	struct intel_uncore *uncore = &dev_priv->uncore;
333 	struct intel_vgpu_submission *s = &vgpu->submission;
334 	enum forcewake_domains fw;
335 	i915_reg_t reg;
336 	u32 regs[] = {
337 		[RCS0]  = 0x4260,
338 		[VCS0]  = 0x4264,
339 		[VCS1]  = 0x4268,
340 		[BCS0]  = 0x426c,
341 		[VECS0] = 0x4270,
342 	};
343 
344 	if (WARN_ON(ring_id >= ARRAY_SIZE(regs)))
345 		return;
346 
347 	if (!test_and_clear_bit(ring_id, (void *)s->tlb_handle_pending))
348 		return;
349 
350 	reg = _MMIO(regs[ring_id]);
351 
352 	/* WaForceWakeRenderDuringMmioTLBInvalidate:skl
353 	 * we need to put a forcewake when invalidating RCS TLB caches,
354 	 * otherwise device can go to RC6 state and interrupt invalidation
355 	 * process
356 	 */
357 	fw = intel_uncore_forcewake_for_reg(uncore, reg,
358 					    FW_REG_READ | FW_REG_WRITE);
359 	if (ring_id == RCS0 && INTEL_GEN(dev_priv) >= 9)
360 		fw |= FORCEWAKE_RENDER;
361 
362 	intel_uncore_forcewake_get(uncore, fw);
363 
364 	intel_uncore_write_fw(uncore, reg, 0x1);
365 
366 	if (wait_for_atomic((intel_uncore_read_fw(uncore, reg) == 0), 50))
367 		gvt_vgpu_err("timeout in invalidate ring (%d) tlb\n", ring_id);
368 	else
369 		vgpu_vreg_t(vgpu, reg) = 0;
370 
371 	intel_uncore_forcewake_put(uncore, fw);
372 
373 	gvt_dbg_core("invalidate TLB for ring %d\n", ring_id);
374 }
375 
376 static void switch_mocs(struct intel_vgpu *pre, struct intel_vgpu *next,
377 			int ring_id)
378 {
379 	struct drm_i915_private *dev_priv;
380 	i915_reg_t offset, l3_offset;
381 	u32 old_v, new_v;
382 
383 	u32 regs[] = {
384 		[RCS0]  = 0xc800,
385 		[VCS0]  = 0xc900,
386 		[VCS1]  = 0xca00,
387 		[BCS0]  = 0xcc00,
388 		[VECS0] = 0xcb00,
389 	};
390 	int i;
391 
392 	dev_priv = pre ? pre->gvt->dev_priv : next->gvt->dev_priv;
393 	if (WARN_ON(ring_id >= ARRAY_SIZE(regs)))
394 		return;
395 
396 	if (ring_id == RCS0 && IS_GEN(dev_priv, 9))
397 		return;
398 
399 	if (!pre && !gen9_render_mocs.initialized)
400 		load_render_mocs(dev_priv);
401 
402 	offset.reg = regs[ring_id];
403 	for (i = 0; i < GEN9_MOCS_SIZE; i++) {
404 		if (pre)
405 			old_v = vgpu_vreg_t(pre, offset);
406 		else
407 			old_v = gen9_render_mocs.control_table[ring_id][i];
408 		if (next)
409 			new_v = vgpu_vreg_t(next, offset);
410 		else
411 			new_v = gen9_render_mocs.control_table[ring_id][i];
412 
413 		if (old_v != new_v)
414 			I915_WRITE_FW(offset, new_v);
415 
416 		offset.reg += 4;
417 	}
418 
419 	if (ring_id == RCS0) {
420 		l3_offset.reg = 0xb020;
421 		for (i = 0; i < GEN9_MOCS_SIZE / 2; i++) {
422 			if (pre)
423 				old_v = vgpu_vreg_t(pre, l3_offset);
424 			else
425 				old_v = gen9_render_mocs.l3cc_table[i];
426 			if (next)
427 				new_v = vgpu_vreg_t(next, l3_offset);
428 			else
429 				new_v = gen9_render_mocs.l3cc_table[i];
430 
431 			if (old_v != new_v)
432 				I915_WRITE_FW(l3_offset, new_v);
433 
434 			l3_offset.reg += 4;
435 		}
436 	}
437 }
438 
439 #define CTX_CONTEXT_CONTROL_VAL	0x03
440 
441 bool is_inhibit_context(struct intel_context *ce)
442 {
443 	const u32 *reg_state = ce->lrc_reg_state;
444 	u32 inhibit_mask =
445 		_MASKED_BIT_ENABLE(CTX_CTRL_ENGINE_CTX_RESTORE_INHIBIT);
446 
447 	return inhibit_mask ==
448 		(reg_state[CTX_CONTEXT_CONTROL_VAL] & inhibit_mask);
449 }
450 
451 /* Switch ring mmio values (context). */
452 static void switch_mmio(struct intel_vgpu *pre,
453 			struct intel_vgpu *next,
454 			int ring_id)
455 {
456 	struct drm_i915_private *dev_priv;
457 	struct intel_vgpu_submission *s;
458 	struct engine_mmio *mmio;
459 	u32 old_v, new_v;
460 
461 	dev_priv = pre ? pre->gvt->dev_priv : next->gvt->dev_priv;
462 	if (INTEL_GEN(dev_priv) >= 9)
463 		switch_mocs(pre, next, ring_id);
464 
465 	for (mmio = dev_priv->gvt->engine_mmio_list.mmio;
466 	     i915_mmio_reg_valid(mmio->reg); mmio++) {
467 		if (mmio->ring_id != ring_id)
468 			continue;
469 		/*
470 		 * No need to do save or restore of the mmio which is in context
471 		 * state image on gen9, it's initialized by lri command and
472 		 * save or restore with context together.
473 		 */
474 		if (IS_GEN(dev_priv, 9) && mmio->in_context)
475 			continue;
476 
477 		// save
478 		if (pre) {
479 			vgpu_vreg_t(pre, mmio->reg) = I915_READ_FW(mmio->reg);
480 			if (mmio->mask)
481 				vgpu_vreg_t(pre, mmio->reg) &=
482 						~(mmio->mask << 16);
483 			old_v = vgpu_vreg_t(pre, mmio->reg);
484 		} else
485 			old_v = mmio->value = I915_READ_FW(mmio->reg);
486 
487 		// restore
488 		if (next) {
489 			s = &next->submission;
490 			/*
491 			 * No need to restore the mmio which is in context state
492 			 * image if it's not inhibit context, it will restore
493 			 * itself.
494 			 */
495 			if (mmio->in_context &&
496 			    !is_inhibit_context(intel_context_lookup(s->shadow_ctx,
497 								     dev_priv->engine[ring_id])))
498 				continue;
499 
500 			if (mmio->mask)
501 				new_v = vgpu_vreg_t(next, mmio->reg) |
502 							(mmio->mask << 16);
503 			else
504 				new_v = vgpu_vreg_t(next, mmio->reg);
505 		} else {
506 			if (mmio->in_context)
507 				continue;
508 			if (mmio->mask)
509 				new_v = mmio->value | (mmio->mask << 16);
510 			else
511 				new_v = mmio->value;
512 		}
513 
514 		I915_WRITE_FW(mmio->reg, new_v);
515 
516 		trace_render_mmio(pre ? pre->id : 0,
517 				  next ? next->id : 0,
518 				  "switch",
519 				  i915_mmio_reg_offset(mmio->reg),
520 				  old_v, new_v);
521 	}
522 
523 	if (next)
524 		handle_tlb_pending_event(next, ring_id);
525 }
526 
527 /**
528  * intel_gvt_switch_render_mmio - switch mmio context of specific engine
529  * @pre: the last vGPU that own the engine
530  * @next: the vGPU to switch to
531  * @ring_id: specify the engine
532  *
533  * If pre is null indicates that host own the engine. If next is null
534  * indicates that we are switching to host workload.
535  */
536 void intel_gvt_switch_mmio(struct intel_vgpu *pre,
537 			   struct intel_vgpu *next, int ring_id)
538 {
539 	struct drm_i915_private *dev_priv;
540 
541 	if (WARN_ON(!pre && !next))
542 		return;
543 
544 	gvt_dbg_render("switch ring %d from %s to %s\n", ring_id,
545 		       pre ? "vGPU" : "host", next ? "vGPU" : "HOST");
546 
547 	dev_priv = pre ? pre->gvt->dev_priv : next->gvt->dev_priv;
548 
549 	/**
550 	 * We are using raw mmio access wrapper to improve the
551 	 * performace for batch mmio read/write, so we need
552 	 * handle forcewake mannually.
553 	 */
554 	intel_uncore_forcewake_get(&dev_priv->uncore, FORCEWAKE_ALL);
555 	switch_mmio(pre, next, ring_id);
556 	intel_uncore_forcewake_put(&dev_priv->uncore, FORCEWAKE_ALL);
557 }
558 
559 /**
560  * intel_gvt_init_engine_mmio_context - Initiate the engine mmio list
561  * @gvt: GVT device
562  *
563  */
564 void intel_gvt_init_engine_mmio_context(struct intel_gvt *gvt)
565 {
566 	struct engine_mmio *mmio;
567 
568 	if (INTEL_GEN(gvt->dev_priv) >= 9)
569 		gvt->engine_mmio_list.mmio = gen9_engine_mmio_list;
570 	else
571 		gvt->engine_mmio_list.mmio = gen8_engine_mmio_list;
572 
573 	for (mmio = gvt->engine_mmio_list.mmio;
574 	     i915_mmio_reg_valid(mmio->reg); mmio++) {
575 		if (mmio->in_context) {
576 			gvt->engine_mmio_list.ctx_mmio_count[mmio->ring_id]++;
577 			intel_gvt_mmio_set_in_ctx(gvt, mmio->reg.reg);
578 		}
579 	}
580 }
581