1 /*
2  * Copyright © 2013 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 #include "i915_drv.h"
25 #include "intel_drv.h"
26 
27 #define FORCEWAKE_ACK_TIMEOUT_MS 2
28 
29 #define __raw_i915_read8(dev_priv__, reg__) readb((dev_priv__)->regs + (reg__))
30 #define __raw_i915_write8(dev_priv__, reg__, val__) writeb(val__, (dev_priv__)->regs + (reg__))
31 
32 #define __raw_i915_read16(dev_priv__, reg__) readw((dev_priv__)->regs + (reg__))
33 #define __raw_i915_write16(dev_priv__, reg__, val__) writew(val__, (dev_priv__)->regs + (reg__))
34 
35 #define __raw_i915_read32(dev_priv__, reg__) readl((dev_priv__)->regs + (reg__))
36 #define __raw_i915_write32(dev_priv__, reg__, val__) writel(val__, (dev_priv__)->regs + (reg__))
37 
38 #define __raw_i915_read64(dev_priv__, reg__) readq((dev_priv__)->regs + (reg__))
39 #define __raw_i915_write64(dev_priv__, reg__, val__) writeq(val__, (dev_priv__)->regs + (reg__))
40 
41 #define __raw_posting_read(dev_priv__, reg__) (void)__raw_i915_read32(dev_priv__, reg__)
42 
43 
44 static void __gen6_gt_wait_for_thread_c0(struct drm_i915_private *dev_priv)
45 {
46 	u32 gt_thread_status_mask;
47 
48 	if (IS_HASWELL(dev_priv->dev))
49 		gt_thread_status_mask = GEN6_GT_THREAD_STATUS_CORE_MASK_HSW;
50 	else
51 		gt_thread_status_mask = GEN6_GT_THREAD_STATUS_CORE_MASK;
52 
53 	/* w/a for a sporadic read returning 0 by waiting for the GT
54 	 * thread to wake up.
55 	 */
56 	if (wait_for_atomic_us((__raw_i915_read32(dev_priv, GEN6_GT_THREAD_STATUS_REG) & gt_thread_status_mask) == 0, 500))
57 		DRM_ERROR("GT thread status wait timed out\n");
58 }
59 
60 static void __gen6_gt_force_wake_reset(struct drm_i915_private *dev_priv)
61 {
62 	__raw_i915_write32(dev_priv, FORCEWAKE, 0);
63 	/* something from same cacheline, but !FORCEWAKE */
64 	__raw_posting_read(dev_priv, ECOBUS);
65 }
66 
67 static void __gen6_gt_force_wake_get(struct drm_i915_private *dev_priv)
68 {
69 	if (wait_for_atomic((__raw_i915_read32(dev_priv, FORCEWAKE_ACK) & 1) == 0,
70 			    FORCEWAKE_ACK_TIMEOUT_MS))
71 		DRM_ERROR("Timed out waiting for forcewake old ack to clear.\n");
72 
73 	__raw_i915_write32(dev_priv, FORCEWAKE, 1);
74 	/* something from same cacheline, but !FORCEWAKE */
75 	__raw_posting_read(dev_priv, ECOBUS);
76 
77 	if (wait_for_atomic((__raw_i915_read32(dev_priv, FORCEWAKE_ACK) & 1),
78 			    FORCEWAKE_ACK_TIMEOUT_MS))
79 		DRM_ERROR("Timed out waiting for forcewake to ack request.\n");
80 
81 	/* WaRsForcewakeWaitTC0:snb */
82 	__gen6_gt_wait_for_thread_c0(dev_priv);
83 }
84 
85 static void __gen6_gt_force_wake_mt_reset(struct drm_i915_private *dev_priv)
86 {
87 	__raw_i915_write32(dev_priv, FORCEWAKE_MT, _MASKED_BIT_DISABLE(0xffff));
88 	/* something from same cacheline, but !FORCEWAKE_MT */
89 	__raw_posting_read(dev_priv, ECOBUS);
90 }
91 
92 static void __gen6_gt_force_wake_mt_get(struct drm_i915_private *dev_priv)
93 {
94 	u32 forcewake_ack;
95 
96 	if (IS_HASWELL(dev_priv->dev))
97 		forcewake_ack = FORCEWAKE_ACK_HSW;
98 	else
99 		forcewake_ack = FORCEWAKE_MT_ACK;
100 
101 	if (wait_for_atomic((__raw_i915_read32(dev_priv, forcewake_ack) & FORCEWAKE_KERNEL) == 0,
102 			    FORCEWAKE_ACK_TIMEOUT_MS))
103 		DRM_ERROR("Timed out waiting for forcewake old ack to clear.\n");
104 
105 	__raw_i915_write32(dev_priv, FORCEWAKE_MT,
106 			   _MASKED_BIT_ENABLE(FORCEWAKE_KERNEL));
107 	/* something from same cacheline, but !FORCEWAKE_MT */
108 	__raw_posting_read(dev_priv, ECOBUS);
109 
110 	if (wait_for_atomic((__raw_i915_read32(dev_priv, forcewake_ack) & FORCEWAKE_KERNEL),
111 			    FORCEWAKE_ACK_TIMEOUT_MS))
112 		DRM_ERROR("Timed out waiting for forcewake to ack request.\n");
113 
114 	/* WaRsForcewakeWaitTC0:ivb,hsw */
115 	__gen6_gt_wait_for_thread_c0(dev_priv);
116 }
117 
118 static void gen6_gt_check_fifodbg(struct drm_i915_private *dev_priv)
119 {
120 	u32 gtfifodbg;
121 
122 	gtfifodbg = __raw_i915_read32(dev_priv, GTFIFODBG);
123 	if (WARN(gtfifodbg & GT_FIFO_CPU_ERROR_MASK,
124 	     "MMIO read or write has been dropped %x\n", gtfifodbg))
125 		__raw_i915_write32(dev_priv, GTFIFODBG, GT_FIFO_CPU_ERROR_MASK);
126 }
127 
128 static void __gen6_gt_force_wake_put(struct drm_i915_private *dev_priv)
129 {
130 	__raw_i915_write32(dev_priv, FORCEWAKE, 0);
131 	/* something from same cacheline, but !FORCEWAKE */
132 	__raw_posting_read(dev_priv, ECOBUS);
133 	gen6_gt_check_fifodbg(dev_priv);
134 }
135 
136 static void __gen6_gt_force_wake_mt_put(struct drm_i915_private *dev_priv)
137 {
138 	__raw_i915_write32(dev_priv, FORCEWAKE_MT,
139 			   _MASKED_BIT_DISABLE(FORCEWAKE_KERNEL));
140 	/* something from same cacheline, but !FORCEWAKE_MT */
141 	__raw_posting_read(dev_priv, ECOBUS);
142 	gen6_gt_check_fifodbg(dev_priv);
143 }
144 
145 static int __gen6_gt_wait_for_fifo(struct drm_i915_private *dev_priv)
146 {
147 	int ret = 0;
148 
149 	if (dev_priv->uncore.fifo_count < GT_FIFO_NUM_RESERVED_ENTRIES) {
150 		int loop = 500;
151 		u32 fifo = __raw_i915_read32(dev_priv, GT_FIFO_FREE_ENTRIES);
152 		while (fifo <= GT_FIFO_NUM_RESERVED_ENTRIES && loop--) {
153 			udelay(10);
154 			fifo = __raw_i915_read32(dev_priv, GT_FIFO_FREE_ENTRIES);
155 		}
156 		if (WARN_ON(loop < 0 && fifo <= GT_FIFO_NUM_RESERVED_ENTRIES))
157 			++ret;
158 		dev_priv->uncore.fifo_count = fifo;
159 	}
160 	dev_priv->uncore.fifo_count--;
161 
162 	return ret;
163 }
164 
165 static void vlv_force_wake_reset(struct drm_i915_private *dev_priv)
166 {
167 	__raw_i915_write32(dev_priv, FORCEWAKE_VLV,
168 			   _MASKED_BIT_DISABLE(0xffff));
169 	/* something from same cacheline, but !FORCEWAKE_VLV */
170 	__raw_posting_read(dev_priv, FORCEWAKE_ACK_VLV);
171 }
172 
173 static void vlv_force_wake_get(struct drm_i915_private *dev_priv)
174 {
175 	if (wait_for_atomic((__raw_i915_read32(dev_priv, FORCEWAKE_ACK_VLV) & FORCEWAKE_KERNEL) == 0,
176 			    FORCEWAKE_ACK_TIMEOUT_MS))
177 		DRM_ERROR("Timed out waiting for forcewake old ack to clear.\n");
178 
179 	__raw_i915_write32(dev_priv, FORCEWAKE_VLV,
180 			   _MASKED_BIT_ENABLE(FORCEWAKE_KERNEL));
181 	__raw_i915_write32(dev_priv, FORCEWAKE_MEDIA_VLV,
182 			   _MASKED_BIT_ENABLE(FORCEWAKE_KERNEL));
183 
184 	if (wait_for_atomic((__raw_i915_read32(dev_priv, FORCEWAKE_ACK_VLV) & FORCEWAKE_KERNEL),
185 			    FORCEWAKE_ACK_TIMEOUT_MS))
186 		DRM_ERROR("Timed out waiting for GT to ack forcewake request.\n");
187 
188 	if (wait_for_atomic((__raw_i915_read32(dev_priv, FORCEWAKE_ACK_MEDIA_VLV) &
189 			     FORCEWAKE_KERNEL),
190 			    FORCEWAKE_ACK_TIMEOUT_MS))
191 		DRM_ERROR("Timed out waiting for media to ack forcewake request.\n");
192 
193 	/* WaRsForcewakeWaitTC0:vlv */
194 	__gen6_gt_wait_for_thread_c0(dev_priv);
195 }
196 
197 static void vlv_force_wake_put(struct drm_i915_private *dev_priv)
198 {
199 	__raw_i915_write32(dev_priv, FORCEWAKE_VLV,
200 			   _MASKED_BIT_DISABLE(FORCEWAKE_KERNEL));
201 	__raw_i915_write32(dev_priv, FORCEWAKE_MEDIA_VLV,
202 			   _MASKED_BIT_DISABLE(FORCEWAKE_KERNEL));
203 	/* The below doubles as a POSTING_READ */
204 	gen6_gt_check_fifodbg(dev_priv);
205 }
206 
207 void intel_uncore_early_sanitize(struct drm_device *dev)
208 {
209 	struct drm_i915_private *dev_priv = dev->dev_private;
210 
211 	if (HAS_FPGA_DBG_UNCLAIMED(dev))
212 		__raw_i915_write32(dev_priv, FPGA_DBG, FPGA_DBG_RM_NOCLAIM);
213 }
214 
215 void intel_uncore_init(struct drm_device *dev)
216 {
217 	struct drm_i915_private *dev_priv = dev->dev_private;
218 
219 	if (IS_VALLEYVIEW(dev)) {
220 		dev_priv->uncore.funcs.force_wake_get = vlv_force_wake_get;
221 		dev_priv->uncore.funcs.force_wake_put = vlv_force_wake_put;
222 	} else if (IS_HASWELL(dev)) {
223 		dev_priv->uncore.funcs.force_wake_get = __gen6_gt_force_wake_mt_get;
224 		dev_priv->uncore.funcs.force_wake_put = __gen6_gt_force_wake_mt_put;
225 	} else if (IS_IVYBRIDGE(dev)) {
226 		u32 ecobus;
227 
228 		/* IVB configs may use multi-threaded forcewake */
229 
230 		/* A small trick here - if the bios hasn't configured
231 		 * MT forcewake, and if the device is in RC6, then
232 		 * force_wake_mt_get will not wake the device and the
233 		 * ECOBUS read will return zero. Which will be
234 		 * (correctly) interpreted by the test below as MT
235 		 * forcewake being disabled.
236 		 */
237 		mutex_lock(&dev->struct_mutex);
238 		__gen6_gt_force_wake_mt_get(dev_priv);
239 		ecobus = __raw_i915_read32(dev_priv, ECOBUS);
240 		__gen6_gt_force_wake_mt_put(dev_priv);
241 		mutex_unlock(&dev->struct_mutex);
242 
243 		if (ecobus & FORCEWAKE_MT_ENABLE) {
244 			dev_priv->uncore.funcs.force_wake_get =
245 				__gen6_gt_force_wake_mt_get;
246 			dev_priv->uncore.funcs.force_wake_put =
247 				__gen6_gt_force_wake_mt_put;
248 		} else {
249 			DRM_INFO("No MT forcewake available on Ivybridge, this can result in issues\n");
250 			DRM_INFO("when using vblank-synced partial screen updates.\n");
251 			dev_priv->uncore.funcs.force_wake_get =
252 				__gen6_gt_force_wake_get;
253 			dev_priv->uncore.funcs.force_wake_put =
254 				__gen6_gt_force_wake_put;
255 		}
256 	} else if (IS_GEN6(dev)) {
257 		dev_priv->uncore.funcs.force_wake_get =
258 			__gen6_gt_force_wake_get;
259 		dev_priv->uncore.funcs.force_wake_put =
260 			__gen6_gt_force_wake_put;
261 	}
262 }
263 
264 static void intel_uncore_forcewake_reset(struct drm_device *dev)
265 {
266 	struct drm_i915_private *dev_priv = dev->dev_private;
267 
268 	if (IS_VALLEYVIEW(dev)) {
269 		vlv_force_wake_reset(dev_priv);
270 	} else if (INTEL_INFO(dev)->gen >= 6) {
271 		__gen6_gt_force_wake_reset(dev_priv);
272 		if (IS_IVYBRIDGE(dev) || IS_HASWELL(dev))
273 			__gen6_gt_force_wake_mt_reset(dev_priv);
274 	}
275 }
276 
277 void intel_uncore_sanitize(struct drm_device *dev)
278 {
279 	intel_uncore_forcewake_reset(dev);
280 
281 	/* BIOS often leaves RC6 enabled, but disable it for hw init */
282 	intel_disable_gt_powersave(dev);
283 }
284 
285 /*
286  * Generally this is called implicitly by the register read function. However,
287  * if some sequence requires the GT to not power down then this function should
288  * be called at the beginning of the sequence followed by a call to
289  * gen6_gt_force_wake_put() at the end of the sequence.
290  */
291 void gen6_gt_force_wake_get(struct drm_i915_private *dev_priv)
292 {
293 	unsigned long irqflags;
294 
295 	spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
296 	if (dev_priv->uncore.forcewake_count++ == 0)
297 		dev_priv->uncore.funcs.force_wake_get(dev_priv);
298 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
299 }
300 
301 /*
302  * see gen6_gt_force_wake_get()
303  */
304 void gen6_gt_force_wake_put(struct drm_i915_private *dev_priv)
305 {
306 	unsigned long irqflags;
307 
308 	spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
309 	if (--dev_priv->uncore.forcewake_count == 0)
310 		dev_priv->uncore.funcs.force_wake_put(dev_priv);
311 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
312 }
313 
314 /* We give fast paths for the really cool registers */
315 #define NEEDS_FORCE_WAKE(dev_priv, reg) \
316 	((HAS_FORCE_WAKE((dev_priv)->dev)) && \
317 	 ((reg) < 0x40000) &&            \
318 	 ((reg) != FORCEWAKE))
319 
320 static void
321 ilk_dummy_write(struct drm_i915_private *dev_priv)
322 {
323 	/* WaIssueDummyWriteToWakeupFromRC6:ilk Issue a dummy write to wake up
324 	 * the chip from rc6 before touching it for real. MI_MODE is masked,
325 	 * hence harmless to write 0 into. */
326 	__raw_i915_write32(dev_priv, MI_MODE, 0);
327 }
328 
329 static void
330 hsw_unclaimed_reg_clear(struct drm_i915_private *dev_priv, u32 reg)
331 {
332 	if (HAS_FPGA_DBG_UNCLAIMED(dev_priv->dev) &&
333 	    (__raw_i915_read32(dev_priv, FPGA_DBG) & FPGA_DBG_RM_NOCLAIM)) {
334 		DRM_ERROR("Unknown unclaimed register before writing to %x\n",
335 			  reg);
336 		__raw_i915_write32(dev_priv, FPGA_DBG, FPGA_DBG_RM_NOCLAIM);
337 	}
338 }
339 
340 static void
341 hsw_unclaimed_reg_check(struct drm_i915_private *dev_priv, u32 reg)
342 {
343 	if (HAS_FPGA_DBG_UNCLAIMED(dev_priv->dev) &&
344 	    (__raw_i915_read32(dev_priv, FPGA_DBG) & FPGA_DBG_RM_NOCLAIM)) {
345 		DRM_ERROR("Unclaimed write to %x\n", reg);
346 		__raw_i915_write32(dev_priv, FPGA_DBG, FPGA_DBG_RM_NOCLAIM);
347 	}
348 }
349 
350 #define __i915_read(x) \
351 u##x i915_read##x(struct drm_i915_private *dev_priv, u32 reg, bool trace) { \
352 	unsigned long irqflags; \
353 	u##x val = 0; \
354 	spin_lock_irqsave(&dev_priv->uncore.lock, irqflags); \
355 	if (dev_priv->info->gen == 5) \
356 		ilk_dummy_write(dev_priv); \
357 	if (NEEDS_FORCE_WAKE((dev_priv), (reg))) { \
358 		if (dev_priv->uncore.forcewake_count == 0) \
359 			dev_priv->uncore.funcs.force_wake_get(dev_priv); \
360 		val = __raw_i915_read##x(dev_priv, reg); \
361 		if (dev_priv->uncore.forcewake_count == 0) \
362 			dev_priv->uncore.funcs.force_wake_put(dev_priv); \
363 	} else { \
364 		val = __raw_i915_read##x(dev_priv, reg); \
365 	} \
366 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags); \
367 	trace_i915_reg_rw(false, reg, val, sizeof(val), trace); \
368 	return val; \
369 }
370 
371 __i915_read(8)
372 __i915_read(16)
373 __i915_read(32)
374 __i915_read(64)
375 #undef __i915_read
376 
377 #define __i915_write(x) \
378 void i915_write##x(struct drm_i915_private *dev_priv, u32 reg, u##x val, bool trace) { \
379 	unsigned long irqflags; \
380 	u32 __fifo_ret = 0; \
381 	trace_i915_reg_rw(true, reg, val, sizeof(val), trace); \
382 	spin_lock_irqsave(&dev_priv->uncore.lock, irqflags); \
383 	if (NEEDS_FORCE_WAKE((dev_priv), (reg))) { \
384 		__fifo_ret = __gen6_gt_wait_for_fifo(dev_priv); \
385 	} \
386 	if (dev_priv->info->gen == 5) \
387 		ilk_dummy_write(dev_priv); \
388 	hsw_unclaimed_reg_clear(dev_priv, reg); \
389 	__raw_i915_write##x(dev_priv, reg, val); \
390 	if (unlikely(__fifo_ret)) { \
391 		gen6_gt_check_fifodbg(dev_priv); \
392 	} \
393 	hsw_unclaimed_reg_check(dev_priv, reg); \
394 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags); \
395 }
396 __i915_write(8)
397 __i915_write(16)
398 __i915_write(32)
399 __i915_write(64)
400 #undef __i915_write
401 
402 static const struct register_whitelist {
403 	uint64_t offset;
404 	uint32_t size;
405 	uint32_t gen_bitmask; /* support gens, 0x10 for 4, 0x30 for 4 and 5, etc. */
406 } whitelist[] = {
407 	{ RING_TIMESTAMP(RENDER_RING_BASE), 8, 0xF0 },
408 };
409 
410 int i915_reg_read_ioctl(struct drm_device *dev,
411 			void *data, struct drm_file *file)
412 {
413 	struct drm_i915_private *dev_priv = dev->dev_private;
414 	struct drm_i915_reg_read *reg = data;
415 	struct register_whitelist const *entry = whitelist;
416 	int i;
417 
418 	for (i = 0; i < ARRAY_SIZE(whitelist); i++, entry++) {
419 		if (entry->offset == reg->offset &&
420 		    (1 << INTEL_INFO(dev)->gen & entry->gen_bitmask))
421 			break;
422 	}
423 
424 	if (i == ARRAY_SIZE(whitelist))
425 		return -EINVAL;
426 
427 	switch (entry->size) {
428 	case 8:
429 		reg->val = I915_READ64(reg->offset);
430 		break;
431 	case 4:
432 		reg->val = I915_READ(reg->offset);
433 		break;
434 	case 2:
435 		reg->val = I915_READ16(reg->offset);
436 		break;
437 	case 1:
438 		reg->val = I915_READ8(reg->offset);
439 		break;
440 	default:
441 		WARN_ON(1);
442 		return -EINVAL;
443 	}
444 
445 	return 0;
446 }
447 
448 static int i8xx_do_reset(struct drm_device *dev)
449 {
450 	struct drm_i915_private *dev_priv = dev->dev_private;
451 
452 	if (IS_I85X(dev))
453 		return -ENODEV;
454 
455 	I915_WRITE(D_STATE, I915_READ(D_STATE) | DSTATE_GFX_RESET_I830);
456 	POSTING_READ(D_STATE);
457 
458 	if (IS_I830(dev) || IS_845G(dev)) {
459 		I915_WRITE(DEBUG_RESET_I830,
460 			   DEBUG_RESET_DISPLAY |
461 			   DEBUG_RESET_RENDER |
462 			   DEBUG_RESET_FULL);
463 		POSTING_READ(DEBUG_RESET_I830);
464 		msleep(1);
465 
466 		I915_WRITE(DEBUG_RESET_I830, 0);
467 		POSTING_READ(DEBUG_RESET_I830);
468 	}
469 
470 	msleep(1);
471 
472 	I915_WRITE(D_STATE, I915_READ(D_STATE) & ~DSTATE_GFX_RESET_I830);
473 	POSTING_READ(D_STATE);
474 
475 	return 0;
476 }
477 
478 static int i965_reset_complete(struct drm_device *dev)
479 {
480 	u8 gdrst;
481 	pci_read_config_byte(dev->pdev, I965_GDRST, &gdrst);
482 	return (gdrst & GRDOM_RESET_ENABLE) == 0;
483 }
484 
485 static int i965_do_reset(struct drm_device *dev)
486 {
487 	int ret;
488 
489 	/*
490 	 * Set the domains we want to reset (GRDOM/bits 2 and 3) as
491 	 * well as the reset bit (GR/bit 0).  Setting the GR bit
492 	 * triggers the reset; when done, the hardware will clear it.
493 	 */
494 	pci_write_config_byte(dev->pdev, I965_GDRST,
495 			      GRDOM_RENDER | GRDOM_RESET_ENABLE);
496 	ret =  wait_for(i965_reset_complete(dev), 500);
497 	if (ret)
498 		return ret;
499 
500 	/* We can't reset render&media without also resetting display ... */
501 	pci_write_config_byte(dev->pdev, I965_GDRST,
502 			      GRDOM_MEDIA | GRDOM_RESET_ENABLE);
503 
504 	ret =  wait_for(i965_reset_complete(dev), 500);
505 	if (ret)
506 		return ret;
507 
508 	pci_write_config_byte(dev->pdev, I965_GDRST, 0);
509 
510 	return 0;
511 }
512 
513 static int ironlake_do_reset(struct drm_device *dev)
514 {
515 	struct drm_i915_private *dev_priv = dev->dev_private;
516 	u32 gdrst;
517 	int ret;
518 
519 	gdrst = I915_READ(MCHBAR_MIRROR_BASE + ILK_GDSR);
520 	gdrst &= ~GRDOM_MASK;
521 	I915_WRITE(MCHBAR_MIRROR_BASE + ILK_GDSR,
522 		   gdrst | GRDOM_RENDER | GRDOM_RESET_ENABLE);
523 	ret = wait_for(I915_READ(MCHBAR_MIRROR_BASE + ILK_GDSR) & 0x1, 500);
524 	if (ret)
525 		return ret;
526 
527 	/* We can't reset render&media without also resetting display ... */
528 	gdrst = I915_READ(MCHBAR_MIRROR_BASE + ILK_GDSR);
529 	gdrst &= ~GRDOM_MASK;
530 	I915_WRITE(MCHBAR_MIRROR_BASE + ILK_GDSR,
531 		   gdrst | GRDOM_MEDIA | GRDOM_RESET_ENABLE);
532 	return wait_for(I915_READ(MCHBAR_MIRROR_BASE + ILK_GDSR) & 0x1, 500);
533 }
534 
535 static int gen6_do_reset(struct drm_device *dev)
536 {
537 	struct drm_i915_private *dev_priv = dev->dev_private;
538 	int	ret;
539 	unsigned long irqflags;
540 
541 	/* Hold uncore.lock across reset to prevent any register access
542 	 * with forcewake not set correctly
543 	 */
544 	spin_lock_irqsave(&dev_priv->uncore.lock, irqflags);
545 
546 	/* Reset the chip */
547 
548 	/* GEN6_GDRST is not in the gt power well, no need to check
549 	 * for fifo space for the write or forcewake the chip for
550 	 * the read
551 	 */
552 	__raw_i915_write32(dev_priv, GEN6_GDRST, GEN6_GRDOM_FULL);
553 
554 	/* Spin waiting for the device to ack the reset request */
555 	ret = wait_for((__raw_i915_read32(dev_priv, GEN6_GDRST) & GEN6_GRDOM_FULL) == 0, 500);
556 
557 	intel_uncore_forcewake_reset(dev);
558 
559 	/* If reset with a user forcewake, try to restore, otherwise turn it off */
560 	if (dev_priv->uncore.forcewake_count)
561 		dev_priv->uncore.funcs.force_wake_get(dev_priv);
562 	else
563 		dev_priv->uncore.funcs.force_wake_put(dev_priv);
564 
565 	/* Restore fifo count */
566 	dev_priv->uncore.fifo_count = __raw_i915_read32(dev_priv, GT_FIFO_FREE_ENTRIES);
567 
568 	spin_unlock_irqrestore(&dev_priv->uncore.lock, irqflags);
569 	return ret;
570 }
571 
572 int intel_gpu_reset(struct drm_device *dev)
573 {
574 	switch (INTEL_INFO(dev)->gen) {
575 	case 7:
576 	case 6: return gen6_do_reset(dev);
577 	case 5: return ironlake_do_reset(dev);
578 	case 4: return i965_do_reset(dev);
579 	case 2: return i8xx_do_reset(dev);
580 	default: return -ENODEV;
581 	}
582 }
583 
584 void intel_uncore_clear_errors(struct drm_device *dev)
585 {
586 	struct drm_i915_private *dev_priv = dev->dev_private;
587 
588 	/* XXX needs spinlock around caller's grouping */
589 	if (HAS_FPGA_DBG_UNCLAIMED(dev))
590 		__raw_i915_write32(dev_priv, FPGA_DBG, FPGA_DBG_RM_NOCLAIM);
591 }
592 
593 void intel_uncore_check_errors(struct drm_device *dev)
594 {
595 	struct drm_i915_private *dev_priv = dev->dev_private;
596 
597 	if (HAS_FPGA_DBG_UNCLAIMED(dev) &&
598 	    (__raw_i915_read32(dev_priv, FPGA_DBG) & FPGA_DBG_RM_NOCLAIM)) {
599 		DRM_ERROR("Unclaimed register before interrupt\n");
600 		__raw_i915_write32(dev_priv, FPGA_DBG, FPGA_DBG_RM_NOCLAIM);
601 	}
602 }
603