1 /*
2  * Copyright 2008 Advanced Micro Devices, Inc.
3  * Copyright 2008 Red Hat Inc.
4  * Copyright 2009 Jerome Glisse.
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a
7  * copy of this software and associated documentation files (the "Software"),
8  * to deal in the Software without restriction, including without limitation
9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10  * and/or sell copies of the Software, and to permit persons to whom the
11  * Software is furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
19  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22  * OTHER DEALINGS IN THE SOFTWARE.
23  *
24  * Authors: Dave Airlie
25  *          Alex Deucher
26  *          Jerome Glisse
27  *          Christian König
28  */
29 #include <drm/drmP.h>
30 #include "radeon.h"
31 
32 /*
33  * Rings
34  * Most engines on the GPU are fed via ring buffers.  Ring
35  * buffers are areas of GPU accessible memory that the host
36  * writes commands into and the GPU reads commands out of.
37  * There is a rptr (read pointer) that determines where the
38  * GPU is currently reading, and a wptr (write pointer)
39  * which determines where the host has written.  When the
40  * pointers are equal, the ring is idle.  When the host
41  * writes commands to the ring buffer, it increments the
42  * wptr.  The GPU then starts fetching commands and executes
43  * them until the pointers are equal again.
44  */
45 static int radeon_debugfs_ring_init(struct radeon_device *rdev, struct radeon_ring *ring);
46 
47 /**
48  * radeon_ring_write - write a value to the ring
49  *
50  * @ring: radeon_ring structure holding ring information
51  * @v: dword (dw) value to write
52  *
53  * Write a value to the requested ring buffer (all asics).
54  */
55 void radeon_ring_write(struct radeon_ring *ring, uint32_t v)
56 {
57 #if DRM_DEBUG_CODE
58 	if (ring->count_dw <= 0) {
59 		DRM_ERROR("radeon: writing more dwords to the ring than expected!\n");
60 	}
61 #endif
62 	ring->ring[ring->wptr++] = v;
63 	ring->wptr &= ring->ptr_mask;
64 	ring->count_dw--;
65 	ring->ring_free_dw--;
66 }
67 
68 /**
69  * radeon_ring_supports_scratch_reg - check if the ring supports
70  * writing to scratch registers
71  *
72  * @rdev: radeon_device pointer
73  * @ring: radeon_ring structure holding ring information
74  *
75  * Check if a specific ring supports writing to scratch registers (all asics).
76  * Returns true if the ring supports writing to scratch regs, false if not.
77  */
78 bool radeon_ring_supports_scratch_reg(struct radeon_device *rdev,
79 				      struct radeon_ring *ring)
80 {
81 	switch (ring->idx) {
82 	case RADEON_RING_TYPE_GFX_INDEX:
83 	case CAYMAN_RING_TYPE_CP1_INDEX:
84 	case CAYMAN_RING_TYPE_CP2_INDEX:
85 		return true;
86 	default:
87 		return false;
88 	}
89 }
90 
91 /**
92  * radeon_ring_free_size - update the free size
93  *
94  * @rdev: radeon_device pointer
95  * @ring: radeon_ring structure holding ring information
96  *
97  * Update the free dw slots in the ring buffer (all asics).
98  */
99 void radeon_ring_free_size(struct radeon_device *rdev, struct radeon_ring *ring)
100 {
101 	uint32_t rptr = radeon_ring_get_rptr(rdev, ring);
102 
103 	/* This works because ring_size is a power of 2 */
104 	ring->ring_free_dw = rptr + (ring->ring_size / 4);
105 	ring->ring_free_dw -= ring->wptr;
106 	ring->ring_free_dw &= ring->ptr_mask;
107 	if (!ring->ring_free_dw) {
108 		/* this is an empty ring */
109 		ring->ring_free_dw = ring->ring_size / 4;
110 		/*  update lockup info to avoid false positive */
111 		radeon_ring_lockup_update(rdev, ring);
112 	}
113 }
114 
115 /**
116  * radeon_ring_alloc - allocate space on the ring buffer
117  *
118  * @rdev: radeon_device pointer
119  * @ring: radeon_ring structure holding ring information
120  * @ndw: number of dwords to allocate in the ring buffer
121  *
122  * Allocate @ndw dwords in the ring buffer (all asics).
123  * Returns 0 on success, error on failure.
124  */
125 int radeon_ring_alloc(struct radeon_device *rdev, struct radeon_ring *ring, unsigned ndw)
126 {
127 	int r;
128 
129 	/* make sure we aren't trying to allocate more space than there is on the ring */
130 	if (ndw > (ring->ring_size / 4))
131 		return -ENOMEM;
132 	/* Align requested size with padding so unlock_commit can
133 	 * pad safely */
134 	radeon_ring_free_size(rdev, ring);
135 	ndw = (ndw + ring->align_mask) & ~ring->align_mask;
136 	while (ndw > (ring->ring_free_dw - 1)) {
137 		radeon_ring_free_size(rdev, ring);
138 		if (ndw < ring->ring_free_dw) {
139 			break;
140 		}
141 		r = radeon_fence_wait_next(rdev, ring->idx);
142 		if (r)
143 			return r;
144 	}
145 	ring->count_dw = ndw;
146 	ring->wptr_old = ring->wptr;
147 	return 0;
148 }
149 
150 /**
151  * radeon_ring_lock - lock the ring and allocate space on it
152  *
153  * @rdev: radeon_device pointer
154  * @ring: radeon_ring structure holding ring information
155  * @ndw: number of dwords to allocate in the ring buffer
156  *
157  * Lock the ring and allocate @ndw dwords in the ring buffer
158  * (all asics).
159  * Returns 0 on success, error on failure.
160  */
161 int radeon_ring_lock(struct radeon_device *rdev, struct radeon_ring *ring, unsigned ndw)
162 {
163 	int r;
164 
165 	mutex_lock(&rdev->ring_lock);
166 	r = radeon_ring_alloc(rdev, ring, ndw);
167 	if (r) {
168 		mutex_unlock(&rdev->ring_lock);
169 		return r;
170 	}
171 	return 0;
172 }
173 
174 /**
175  * radeon_ring_commit - tell the GPU to execute the new
176  * commands on the ring buffer
177  *
178  * @rdev: radeon_device pointer
179  * @ring: radeon_ring structure holding ring information
180  *
181  * Update the wptr (write pointer) to tell the GPU to
182  * execute new commands on the ring buffer (all asics).
183  */
184 void radeon_ring_commit(struct radeon_device *rdev, struct radeon_ring *ring)
185 {
186 	/* If we are emitting the HDP flush via the ring buffer, we need to
187 	 * do it before padding.
188 	 */
189 	if (rdev->asic->ring[ring->idx]->hdp_flush)
190 		rdev->asic->ring[ring->idx]->hdp_flush(rdev, ring);
191 	/* We pad to match fetch size */
192 	while (ring->wptr & ring->align_mask) {
193 		radeon_ring_write(ring, ring->nop);
194 	}
195 	mb();
196 	/* If we are emitting the HDP flush via MMIO, we need to do it after
197 	 * all CPU writes to VRAM finished.
198 	 */
199 	if (rdev->asic->mmio_hdp_flush)
200 		rdev->asic->mmio_hdp_flush(rdev);
201 	radeon_ring_set_wptr(rdev, ring);
202 }
203 
204 /**
205  * radeon_ring_unlock_commit - tell the GPU to execute the new
206  * commands on the ring buffer and unlock it
207  *
208  * @rdev: radeon_device pointer
209  * @ring: radeon_ring structure holding ring information
210  *
211  * Call radeon_ring_commit() then unlock the ring (all asics).
212  */
213 void radeon_ring_unlock_commit(struct radeon_device *rdev, struct radeon_ring *ring)
214 {
215 	radeon_ring_commit(rdev, ring);
216 	mutex_unlock(&rdev->ring_lock);
217 }
218 
219 /**
220  * radeon_ring_undo - reset the wptr
221  *
222  * @ring: radeon_ring structure holding ring information
223  *
224  * Reset the driver's copy of the wptr (all asics).
225  */
226 void radeon_ring_undo(struct radeon_ring *ring)
227 {
228 	ring->wptr = ring->wptr_old;
229 }
230 
231 /**
232  * radeon_ring_unlock_undo - reset the wptr and unlock the ring
233  *
234  * @ring: radeon_ring structure holding ring information
235  *
236  * Call radeon_ring_undo() then unlock the ring (all asics).
237  */
238 void radeon_ring_unlock_undo(struct radeon_device *rdev, struct radeon_ring *ring)
239 {
240 	radeon_ring_undo(ring);
241 	mutex_unlock(&rdev->ring_lock);
242 }
243 
244 /**
245  * radeon_ring_lockup_update - update lockup variables
246  *
247  * @ring: radeon_ring structure holding ring information
248  *
249  * Update the last rptr value and timestamp (all asics).
250  */
251 void radeon_ring_lockup_update(struct radeon_device *rdev,
252 			       struct radeon_ring *ring)
253 {
254 	atomic_set(&ring->last_rptr, radeon_ring_get_rptr(rdev, ring));
255 	atomic64_set(&ring->last_activity, jiffies_64);
256 }
257 
258 /**
259  * radeon_ring_test_lockup() - check if ring is lockedup by recording information
260  * @rdev:       radeon device structure
261  * @ring:       radeon_ring structure holding ring information
262  *
263  */
264 bool radeon_ring_test_lockup(struct radeon_device *rdev, struct radeon_ring *ring)
265 {
266 	uint32_t rptr = radeon_ring_get_rptr(rdev, ring);
267 	uint64_t last = atomic64_read(&ring->last_activity);
268 	uint64_t elapsed;
269 
270 	if (rptr != atomic_read(&ring->last_rptr)) {
271 		/* ring is still working, no lockup */
272 		radeon_ring_lockup_update(rdev, ring);
273 		return false;
274 	}
275 
276 	elapsed = jiffies_to_msecs(jiffies_64 - last);
277 	if (radeon_lockup_timeout && elapsed >= radeon_lockup_timeout) {
278 		dev_err(rdev->dev, "ring %d stalled for more than %llumsec\n",
279 			ring->idx, elapsed);
280 		return true;
281 	}
282 	/* give a chance to the GPU ... */
283 	return false;
284 }
285 
286 /**
287  * radeon_ring_backup - Back up the content of a ring
288  *
289  * @rdev: radeon_device pointer
290  * @ring: the ring we want to back up
291  *
292  * Saves all unprocessed commits from a ring, returns the number of dwords saved.
293  */
294 unsigned radeon_ring_backup(struct radeon_device *rdev, struct radeon_ring *ring,
295 			    uint32_t **data)
296 {
297 	unsigned size, ptr, i;
298 
299 	/* just in case lock the ring */
300 	mutex_lock(&rdev->ring_lock);
301 	*data = NULL;
302 
303 	if (ring->ring_obj == NULL) {
304 		mutex_unlock(&rdev->ring_lock);
305 		return 0;
306 	}
307 
308 	/* it doesn't make sense to save anything if all fences are signaled */
309 	if (!radeon_fence_count_emitted(rdev, ring->idx)) {
310 		mutex_unlock(&rdev->ring_lock);
311 		return 0;
312 	}
313 
314 	/* calculate the number of dw on the ring */
315 	if (ring->rptr_save_reg)
316 		ptr = RREG32(ring->rptr_save_reg);
317 	else if (rdev->wb.enabled)
318 		ptr = le32_to_cpu(*ring->next_rptr_cpu_addr);
319 	else {
320 		/* no way to read back the next rptr */
321 		mutex_unlock(&rdev->ring_lock);
322 		return 0;
323 	}
324 
325 	size = ring->wptr + (ring->ring_size / 4);
326 	size -= ptr;
327 	size &= ring->ptr_mask;
328 	if (size == 0) {
329 		mutex_unlock(&rdev->ring_lock);
330 		return 0;
331 	}
332 
333 	/* and then save the content of the ring */
334 	*data = kmalloc_array(size, sizeof(uint32_t), GFP_KERNEL);
335 	if (!*data) {
336 		mutex_unlock(&rdev->ring_lock);
337 		return 0;
338 	}
339 	for (i = 0; i < size; ++i) {
340 		(*data)[i] = ring->ring[ptr++];
341 		ptr &= ring->ptr_mask;
342 	}
343 
344 	mutex_unlock(&rdev->ring_lock);
345 	return size;
346 }
347 
348 /**
349  * radeon_ring_restore - append saved commands to the ring again
350  *
351  * @rdev: radeon_device pointer
352  * @ring: ring to append commands to
353  * @size: number of dwords we want to write
354  * @data: saved commands
355  *
356  * Allocates space on the ring and restore the previously saved commands.
357  */
358 int radeon_ring_restore(struct radeon_device *rdev, struct radeon_ring *ring,
359 			unsigned size, uint32_t *data)
360 {
361 	int i, r;
362 
363 	if (!size || !data)
364 		return 0;
365 
366 	/* restore the saved ring content */
367 	r = radeon_ring_lock(rdev, ring, size);
368 	if (r)
369 		return r;
370 
371 	for (i = 0; i < size; ++i) {
372 		radeon_ring_write(ring, data[i]);
373 	}
374 
375 	radeon_ring_unlock_commit(rdev, ring);
376 	kfree(data);
377 	return 0;
378 }
379 
380 /**
381  * radeon_ring_init - init driver ring struct.
382  *
383  * @rdev: radeon_device pointer
384  * @ring: radeon_ring structure holding ring information
385  * @ring_size: size of the ring
386  * @rptr_offs: offset of the rptr writeback location in the WB buffer
387  * @nop: nop packet for this ring
388  *
389  * Initialize the driver information for the selected ring (all asics).
390  * Returns 0 on success, error on failure.
391  */
392 int radeon_ring_init(struct radeon_device *rdev, struct radeon_ring *ring, unsigned ring_size,
393 		     unsigned rptr_offs, u32 nop)
394 {
395 	int r;
396 
397 	ring->ring_size = ring_size;
398 	ring->rptr_offs = rptr_offs;
399 	ring->nop = nop;
400 	/* Allocate ring buffer */
401 	if (ring->ring_obj == NULL) {
402 		r = radeon_bo_create(rdev, ring->ring_size, PAGE_SIZE, true,
403 				     RADEON_GEM_DOMAIN_GTT,
404 				     (rdev->flags & RADEON_IS_PCIE) ?
405 				     RADEON_GEM_GTT_WC : 0,
406 				     NULL, &ring->ring_obj);
407 		if (r) {
408 			dev_err(rdev->dev, "(%d) ring create failed\n", r);
409 			return r;
410 		}
411 		r = radeon_bo_reserve(ring->ring_obj, false);
412 		if (unlikely(r != 0))
413 			return r;
414 		r = radeon_bo_pin(ring->ring_obj, RADEON_GEM_DOMAIN_GTT,
415 					&ring->gpu_addr);
416 		if (r) {
417 			radeon_bo_unreserve(ring->ring_obj);
418 			dev_err(rdev->dev, "(%d) ring pin failed\n", r);
419 			return r;
420 		}
421 		r = radeon_bo_kmap(ring->ring_obj,
422 				       (void **)&ring->ring);
423 		radeon_bo_unreserve(ring->ring_obj);
424 		if (r) {
425 			dev_err(rdev->dev, "(%d) ring map failed\n", r);
426 			return r;
427 		}
428 	}
429 	ring->ptr_mask = (ring->ring_size / 4) - 1;
430 	ring->ring_free_dw = ring->ring_size / 4;
431 	if (rdev->wb.enabled) {
432 		u32 index = RADEON_WB_RING0_NEXT_RPTR + (ring->idx * 4);
433 		ring->next_rptr_gpu_addr = rdev->wb.gpu_addr + index;
434 		ring->next_rptr_cpu_addr = &rdev->wb.wb[index/4];
435 	}
436 	if (radeon_debugfs_ring_init(rdev, ring)) {
437 		DRM_ERROR("Failed to register debugfs file for rings !\n");
438 	}
439 	radeon_ring_lockup_update(rdev, ring);
440 	return 0;
441 }
442 
443 /**
444  * radeon_ring_fini - tear down the driver ring struct.
445  *
446  * @rdev: radeon_device pointer
447  * @ring: radeon_ring structure holding ring information
448  *
449  * Tear down the driver information for the selected ring (all asics).
450  */
451 void radeon_ring_fini(struct radeon_device *rdev, struct radeon_ring *ring)
452 {
453 	int r;
454 	struct radeon_bo *ring_obj;
455 
456 	mutex_lock(&rdev->ring_lock);
457 	ring_obj = ring->ring_obj;
458 	ring->ready = false;
459 	ring->ring = NULL;
460 	ring->ring_obj = NULL;
461 	mutex_unlock(&rdev->ring_lock);
462 
463 	if (ring_obj) {
464 		r = radeon_bo_reserve(ring_obj, false);
465 		if (likely(r == 0)) {
466 			radeon_bo_kunmap(ring_obj);
467 			radeon_bo_unpin(ring_obj);
468 			radeon_bo_unreserve(ring_obj);
469 		}
470 		radeon_bo_unref(&ring_obj);
471 	}
472 }
473 
474 /*
475  * Debugfs info
476  */
477 #if defined(CONFIG_DEBUG_FS)
478 
479 static int radeon_debugfs_ring_info(struct seq_file *m, void *data)
480 {
481 	struct drm_info_node *node = (struct drm_info_node *) m->private;
482 	struct drm_device *dev = node->minor->dev;
483 	struct radeon_device *rdev = dev->dev_private;
484 	int ridx = *(int*)node->info_ent->data;
485 	struct radeon_ring *ring = &rdev->ring[ridx];
486 
487 	uint32_t rptr, wptr, rptr_next;
488 	unsigned count, i, j;
489 
490 	radeon_ring_free_size(rdev, ring);
491 	count = (ring->ring_size / 4) - ring->ring_free_dw;
492 
493 	wptr = radeon_ring_get_wptr(rdev, ring);
494 	seq_printf(m, "wptr: 0x%08x [%5d]\n",
495 		   wptr, wptr);
496 
497 	rptr = radeon_ring_get_rptr(rdev, ring);
498 	seq_printf(m, "rptr: 0x%08x [%5d]\n",
499 		   rptr, rptr);
500 
501 	if (ring->rptr_save_reg) {
502 		rptr_next = RREG32(ring->rptr_save_reg);
503 		seq_printf(m, "rptr next(0x%04x): 0x%08x [%5d]\n",
504 			   ring->rptr_save_reg, rptr_next, rptr_next);
505 	} else
506 		rptr_next = ~0;
507 
508 	seq_printf(m, "driver's copy of the wptr: 0x%08x [%5d]\n",
509 		   ring->wptr, ring->wptr);
510 	seq_printf(m, "last semaphore signal addr : 0x%016llx\n",
511 		   ring->last_semaphore_signal_addr);
512 	seq_printf(m, "last semaphore wait addr   : 0x%016llx\n",
513 		   ring->last_semaphore_wait_addr);
514 	seq_printf(m, "%u free dwords in ring\n", ring->ring_free_dw);
515 	seq_printf(m, "%u dwords in ring\n", count);
516 
517 	if (!ring->ready)
518 		return 0;
519 
520 	/* print 8 dw before current rptr as often it's the last executed
521 	 * packet that is the root issue
522 	 */
523 	i = (rptr + ring->ptr_mask + 1 - 32) & ring->ptr_mask;
524 	for (j = 0; j <= (count + 32); j++) {
525 		seq_printf(m, "r[%5d]=0x%08x", i, ring->ring[i]);
526 		if (rptr == i)
527 			seq_puts(m, " *");
528 		if (rptr_next == i)
529 			seq_puts(m, " #");
530 		seq_puts(m, "\n");
531 		i = (i + 1) & ring->ptr_mask;
532 	}
533 	return 0;
534 }
535 
536 static int radeon_gfx_index = RADEON_RING_TYPE_GFX_INDEX;
537 static int cayman_cp1_index = CAYMAN_RING_TYPE_CP1_INDEX;
538 static int cayman_cp2_index = CAYMAN_RING_TYPE_CP2_INDEX;
539 static int radeon_dma1_index = R600_RING_TYPE_DMA_INDEX;
540 static int radeon_dma2_index = CAYMAN_RING_TYPE_DMA1_INDEX;
541 static int r600_uvd_index = R600_RING_TYPE_UVD_INDEX;
542 static int si_vce1_index = TN_RING_TYPE_VCE1_INDEX;
543 static int si_vce2_index = TN_RING_TYPE_VCE2_INDEX;
544 
545 static struct drm_info_list radeon_debugfs_ring_info_list[] = {
546 	{"radeon_ring_gfx", radeon_debugfs_ring_info, 0, &radeon_gfx_index},
547 	{"radeon_ring_cp1", radeon_debugfs_ring_info, 0, &cayman_cp1_index},
548 	{"radeon_ring_cp2", radeon_debugfs_ring_info, 0, &cayman_cp2_index},
549 	{"radeon_ring_dma1", radeon_debugfs_ring_info, 0, &radeon_dma1_index},
550 	{"radeon_ring_dma2", radeon_debugfs_ring_info, 0, &radeon_dma2_index},
551 	{"radeon_ring_uvd", radeon_debugfs_ring_info, 0, &r600_uvd_index},
552 	{"radeon_ring_vce1", radeon_debugfs_ring_info, 0, &si_vce1_index},
553 	{"radeon_ring_vce2", radeon_debugfs_ring_info, 0, &si_vce2_index},
554 };
555 
556 #endif
557 
558 static int radeon_debugfs_ring_init(struct radeon_device *rdev, struct radeon_ring *ring)
559 {
560 #if defined(CONFIG_DEBUG_FS)
561 	unsigned i;
562 	for (i = 0; i < ARRAY_SIZE(radeon_debugfs_ring_info_list); ++i) {
563 		struct drm_info_list *info = &radeon_debugfs_ring_info_list[i];
564 		int ridx = *(int*)radeon_debugfs_ring_info_list[i].data;
565 		unsigned r;
566 
567 		if (&rdev->ring[ridx] != ring)
568 			continue;
569 
570 		r = radeon_debugfs_add_files(rdev, info, 1);
571 		if (r)
572 			return r;
573 	}
574 #endif
575 	return 0;
576 }
577