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 
30 #include <drm/drm_device.h>
31 #include <drm/drm_file.h>
32 
33 #include "radeon.h"
34 
35 /*
36  * Rings
37  * Most engines on the GPU are fed via ring buffers.  Ring
38  * buffers are areas of GPU accessible memory that the host
39  * writes commands into and the GPU reads commands out of.
40  * There is a rptr (read pointer) that determines where the
41  * GPU is currently reading, and a wptr (write pointer)
42  * which determines where the host has written.  When the
43  * pointers are equal, the ring is idle.  When the host
44  * writes commands to the ring buffer, it increments the
45  * wptr.  The GPU then starts fetching commands and executes
46  * them until the pointers are equal again.
47  */
48 static void radeon_debugfs_ring_init(struct radeon_device *rdev, struct radeon_ring *ring);
49 
50 /**
51  * radeon_ring_supports_scratch_reg - check if the ring supports
52  * writing to scratch registers
53  *
54  * @rdev: radeon_device pointer
55  * @ring: radeon_ring structure holding ring information
56  *
57  * Check if a specific ring supports writing to scratch registers (all asics).
58  * Returns true if the ring supports writing to scratch regs, false if not.
59  */
60 bool radeon_ring_supports_scratch_reg(struct radeon_device *rdev,
61 				      struct radeon_ring *ring)
62 {
63 	switch (ring->idx) {
64 	case RADEON_RING_TYPE_GFX_INDEX:
65 	case CAYMAN_RING_TYPE_CP1_INDEX:
66 	case CAYMAN_RING_TYPE_CP2_INDEX:
67 		return true;
68 	default:
69 		return false;
70 	}
71 }
72 
73 /**
74  * radeon_ring_free_size - update the free size
75  *
76  * @rdev: radeon_device pointer
77  * @ring: radeon_ring structure holding ring information
78  *
79  * Update the free dw slots in the ring buffer (all asics).
80  */
81 void radeon_ring_free_size(struct radeon_device *rdev, struct radeon_ring *ring)
82 {
83 	uint32_t rptr = radeon_ring_get_rptr(rdev, ring);
84 
85 	/* This works because ring_size is a power of 2 */
86 	ring->ring_free_dw = rptr + (ring->ring_size / 4);
87 	ring->ring_free_dw -= ring->wptr;
88 	ring->ring_free_dw &= ring->ptr_mask;
89 	if (!ring->ring_free_dw) {
90 		/* this is an empty ring */
91 		ring->ring_free_dw = ring->ring_size / 4;
92 		/*  update lockup info to avoid false positive */
93 		radeon_ring_lockup_update(rdev, ring);
94 	}
95 }
96 
97 /**
98  * radeon_ring_alloc - allocate space on the ring buffer
99  *
100  * @rdev: radeon_device pointer
101  * @ring: radeon_ring structure holding ring information
102  * @ndw: number of dwords to allocate in the ring buffer
103  *
104  * Allocate @ndw dwords in the ring buffer (all asics).
105  * Returns 0 on success, error on failure.
106  */
107 int radeon_ring_alloc(struct radeon_device *rdev, struct radeon_ring *ring, unsigned ndw)
108 {
109 	int r;
110 
111 	/* make sure we aren't trying to allocate more space than there is on the ring */
112 	if (ndw > (ring->ring_size / 4))
113 		return -ENOMEM;
114 	/* Align requested size with padding so unlock_commit can
115 	 * pad safely */
116 	radeon_ring_free_size(rdev, ring);
117 	ndw = (ndw + ring->align_mask) & ~ring->align_mask;
118 	while (ndw > (ring->ring_free_dw - 1)) {
119 		radeon_ring_free_size(rdev, ring);
120 		if (ndw < ring->ring_free_dw) {
121 			break;
122 		}
123 		r = radeon_fence_wait_next(rdev, ring->idx);
124 		if (r)
125 			return r;
126 	}
127 	ring->count_dw = ndw;
128 	ring->wptr_old = ring->wptr;
129 	return 0;
130 }
131 
132 /**
133  * radeon_ring_lock - lock the ring and allocate space on it
134  *
135  * @rdev: radeon_device pointer
136  * @ring: radeon_ring structure holding ring information
137  * @ndw: number of dwords to allocate in the ring buffer
138  *
139  * Lock the ring and allocate @ndw dwords in the ring buffer
140  * (all asics).
141  * Returns 0 on success, error on failure.
142  */
143 int radeon_ring_lock(struct radeon_device *rdev, struct radeon_ring *ring, unsigned ndw)
144 {
145 	int r;
146 
147 	mutex_lock(&rdev->ring_lock);
148 	r = radeon_ring_alloc(rdev, ring, ndw);
149 	if (r) {
150 		mutex_unlock(&rdev->ring_lock);
151 		return r;
152 	}
153 	return 0;
154 }
155 
156 /**
157  * radeon_ring_commit - tell the GPU to execute the new
158  * commands on the ring buffer
159  *
160  * @rdev: radeon_device pointer
161  * @ring: radeon_ring structure holding ring information
162  * @hdp_flush: Whether or not to perform an HDP cache flush
163  *
164  * Update the wptr (write pointer) to tell the GPU to
165  * execute new commands on the ring buffer (all asics).
166  */
167 void radeon_ring_commit(struct radeon_device *rdev, struct radeon_ring *ring,
168 			bool hdp_flush)
169 {
170 	/* If we are emitting the HDP flush via the ring buffer, we need to
171 	 * do it before padding.
172 	 */
173 	if (hdp_flush && rdev->asic->ring[ring->idx]->hdp_flush)
174 		rdev->asic->ring[ring->idx]->hdp_flush(rdev, ring);
175 	/* We pad to match fetch size */
176 	while (ring->wptr & ring->align_mask) {
177 		radeon_ring_write(ring, ring->nop);
178 	}
179 	mb();
180 	/* If we are emitting the HDP flush via MMIO, we need to do it after
181 	 * all CPU writes to VRAM finished.
182 	 */
183 	if (hdp_flush && rdev->asic->mmio_hdp_flush)
184 		rdev->asic->mmio_hdp_flush(rdev);
185 	radeon_ring_set_wptr(rdev, ring);
186 }
187 
188 /**
189  * radeon_ring_unlock_commit - tell the GPU to execute the new
190  * commands on the ring buffer and unlock it
191  *
192  * @rdev: radeon_device pointer
193  * @ring: radeon_ring structure holding ring information
194  * @hdp_flush: Whether or not to perform an HDP cache flush
195  *
196  * Call radeon_ring_commit() then unlock the ring (all asics).
197  */
198 void radeon_ring_unlock_commit(struct radeon_device *rdev, struct radeon_ring *ring,
199 			       bool hdp_flush)
200 {
201 	radeon_ring_commit(rdev, ring, hdp_flush);
202 	mutex_unlock(&rdev->ring_lock);
203 }
204 
205 /**
206  * radeon_ring_undo - reset the wptr
207  *
208  * @ring: radeon_ring structure holding ring information
209  *
210  * Reset the driver's copy of the wptr (all asics).
211  */
212 void radeon_ring_undo(struct radeon_ring *ring)
213 {
214 	ring->wptr = ring->wptr_old;
215 }
216 
217 /**
218  * radeon_ring_unlock_undo - reset the wptr and unlock the ring
219  *
220  * @rdev:       radeon device structure
221  * @ring: radeon_ring structure holding ring information
222  *
223  * Call radeon_ring_undo() then unlock the ring (all asics).
224  */
225 void radeon_ring_unlock_undo(struct radeon_device *rdev, struct radeon_ring *ring)
226 {
227 	radeon_ring_undo(ring);
228 	mutex_unlock(&rdev->ring_lock);
229 }
230 
231 /**
232  * radeon_ring_lockup_update - update lockup variables
233  *
234  * @rdev:       radeon device structure
235  * @ring: radeon_ring structure holding ring information
236  *
237  * Update the last rptr value and timestamp (all asics).
238  */
239 void radeon_ring_lockup_update(struct radeon_device *rdev,
240 			       struct radeon_ring *ring)
241 {
242 	atomic_set(&ring->last_rptr, radeon_ring_get_rptr(rdev, ring));
243 	atomic64_set(&ring->last_activity, jiffies_64);
244 }
245 
246 /**
247  * radeon_ring_test_lockup() - check if ring is lockedup by recording information
248  * @rdev:       radeon device structure
249  * @ring:       radeon_ring structure holding ring information
250  *
251  */
252 bool radeon_ring_test_lockup(struct radeon_device *rdev, struct radeon_ring *ring)
253 {
254 	uint32_t rptr = radeon_ring_get_rptr(rdev, ring);
255 	uint64_t last = atomic64_read(&ring->last_activity);
256 	uint64_t elapsed;
257 
258 	if (rptr != atomic_read(&ring->last_rptr)) {
259 		/* ring is still working, no lockup */
260 		radeon_ring_lockup_update(rdev, ring);
261 		return false;
262 	}
263 
264 	elapsed = jiffies_to_msecs(jiffies_64 - last);
265 	if (radeon_lockup_timeout && elapsed >= radeon_lockup_timeout) {
266 		dev_err(rdev->dev, "ring %d stalled for more than %llumsec\n",
267 			ring->idx, elapsed);
268 		return true;
269 	}
270 	/* give a chance to the GPU ... */
271 	return false;
272 }
273 
274 /**
275  * radeon_ring_backup - Back up the content of a ring
276  *
277  * @rdev: radeon_device pointer
278  * @ring: the ring we want to back up
279  * @data: placeholder for returned commit data
280  *
281  * Saves all unprocessed commits from a ring, returns the number of dwords saved.
282  */
283 unsigned radeon_ring_backup(struct radeon_device *rdev, struct radeon_ring *ring,
284 			    uint32_t **data)
285 {
286 	unsigned size, ptr, i;
287 
288 	/* just in case lock the ring */
289 	mutex_lock(&rdev->ring_lock);
290 	*data = NULL;
291 
292 	if (ring->ring_obj == NULL) {
293 		mutex_unlock(&rdev->ring_lock);
294 		return 0;
295 	}
296 
297 	/* it doesn't make sense to save anything if all fences are signaled */
298 	if (!radeon_fence_count_emitted(rdev, ring->idx)) {
299 		mutex_unlock(&rdev->ring_lock);
300 		return 0;
301 	}
302 
303 	/* calculate the number of dw on the ring */
304 	if (ring->rptr_save_reg)
305 		ptr = RREG32(ring->rptr_save_reg);
306 	else if (rdev->wb.enabled)
307 		ptr = le32_to_cpu(*ring->next_rptr_cpu_addr);
308 	else {
309 		/* no way to read back the next rptr */
310 		mutex_unlock(&rdev->ring_lock);
311 		return 0;
312 	}
313 
314 	size = ring->wptr + (ring->ring_size / 4);
315 	size -= ptr;
316 	size &= ring->ptr_mask;
317 	if (size == 0) {
318 		mutex_unlock(&rdev->ring_lock);
319 		return 0;
320 	}
321 
322 	/* and then save the content of the ring */
323 	*data = kvmalloc_array(size, sizeof(uint32_t), GFP_KERNEL);
324 	if (!*data) {
325 		mutex_unlock(&rdev->ring_lock);
326 		return 0;
327 	}
328 	for (i = 0; i < size; ++i) {
329 		(*data)[i] = ring->ring[ptr++];
330 		ptr &= ring->ptr_mask;
331 	}
332 
333 	mutex_unlock(&rdev->ring_lock);
334 	return size;
335 }
336 
337 /**
338  * radeon_ring_restore - append saved commands to the ring again
339  *
340  * @rdev: radeon_device pointer
341  * @ring: ring to append commands to
342  * @size: number of dwords we want to write
343  * @data: saved commands
344  *
345  * Allocates space on the ring and restore the previously saved commands.
346  */
347 int radeon_ring_restore(struct radeon_device *rdev, struct radeon_ring *ring,
348 			unsigned size, uint32_t *data)
349 {
350 	int i, r;
351 
352 	if (!size || !data)
353 		return 0;
354 
355 	/* restore the saved ring content */
356 	r = radeon_ring_lock(rdev, ring, size);
357 	if (r)
358 		return r;
359 
360 	for (i = 0; i < size; ++i) {
361 		radeon_ring_write(ring, data[i]);
362 	}
363 
364 	radeon_ring_unlock_commit(rdev, ring, false);
365 	kvfree(data);
366 	return 0;
367 }
368 
369 /**
370  * radeon_ring_init - init driver ring struct.
371  *
372  * @rdev: radeon_device pointer
373  * @ring: radeon_ring structure holding ring information
374  * @ring_size: size of the ring
375  * @rptr_offs: offset of the rptr writeback location in the WB buffer
376  * @nop: nop packet for this ring
377  *
378  * Initialize the driver information for the selected ring (all asics).
379  * Returns 0 on success, error on failure.
380  */
381 int radeon_ring_init(struct radeon_device *rdev, struct radeon_ring *ring, unsigned ring_size,
382 		     unsigned rptr_offs, u32 nop)
383 {
384 	int r;
385 
386 	ring->ring_size = ring_size;
387 	ring->rptr_offs = rptr_offs;
388 	ring->nop = nop;
389 	ring->rdev = rdev;
390 	/* Allocate ring buffer */
391 	if (ring->ring_obj == NULL) {
392 		r = radeon_bo_create(rdev, ring->ring_size, PAGE_SIZE, true,
393 				     RADEON_GEM_DOMAIN_GTT, 0, NULL,
394 				     NULL, &ring->ring_obj);
395 		if (r) {
396 			dev_err(rdev->dev, "(%d) ring create failed\n", r);
397 			return r;
398 		}
399 		r = radeon_bo_reserve(ring->ring_obj, false);
400 		if (unlikely(r != 0))
401 			return r;
402 		r = radeon_bo_pin(ring->ring_obj, RADEON_GEM_DOMAIN_GTT,
403 					&ring->gpu_addr);
404 		if (r) {
405 			radeon_bo_unreserve(ring->ring_obj);
406 			dev_err(rdev->dev, "(%d) ring pin failed\n", r);
407 			return r;
408 		}
409 		r = radeon_bo_kmap(ring->ring_obj,
410 				       (void **)&ring->ring);
411 		radeon_bo_unreserve(ring->ring_obj);
412 		if (r) {
413 			dev_err(rdev->dev, "(%d) ring map failed\n", r);
414 			return r;
415 		}
416 	}
417 	ring->ptr_mask = (ring->ring_size / 4) - 1;
418 	ring->ring_free_dw = ring->ring_size / 4;
419 	if (rdev->wb.enabled) {
420 		u32 index = RADEON_WB_RING0_NEXT_RPTR + (ring->idx * 4);
421 		ring->next_rptr_gpu_addr = rdev->wb.gpu_addr + index;
422 		ring->next_rptr_cpu_addr = &rdev->wb.wb[index/4];
423 	}
424 	radeon_debugfs_ring_init(rdev, ring);
425 	radeon_ring_lockup_update(rdev, ring);
426 	return 0;
427 }
428 
429 /**
430  * radeon_ring_fini - tear down the driver ring struct.
431  *
432  * @rdev: radeon_device pointer
433  * @ring: radeon_ring structure holding ring information
434  *
435  * Tear down the driver information for the selected ring (all asics).
436  */
437 void radeon_ring_fini(struct radeon_device *rdev, struct radeon_ring *ring)
438 {
439 	int r;
440 	struct radeon_bo *ring_obj;
441 
442 	mutex_lock(&rdev->ring_lock);
443 	ring_obj = ring->ring_obj;
444 	ring->ready = false;
445 	ring->ring = NULL;
446 	ring->ring_obj = NULL;
447 	mutex_unlock(&rdev->ring_lock);
448 
449 	if (ring_obj) {
450 		r = radeon_bo_reserve(ring_obj, false);
451 		if (likely(r == 0)) {
452 			radeon_bo_kunmap(ring_obj);
453 			radeon_bo_unpin(ring_obj);
454 			radeon_bo_unreserve(ring_obj);
455 		}
456 		radeon_bo_unref(&ring_obj);
457 	}
458 }
459 
460 /*
461  * Debugfs info
462  */
463 #if defined(CONFIG_DEBUG_FS)
464 
465 static int radeon_debugfs_ring_info_show(struct seq_file *m, void *unused)
466 {
467 	struct radeon_ring *ring = (struct radeon_ring *) m->private;
468 	struct radeon_device *rdev = ring->rdev;
469 
470 	uint32_t rptr, wptr, rptr_next;
471 	unsigned count, i, j;
472 
473 	radeon_ring_free_size(rdev, ring);
474 	count = (ring->ring_size / 4) - ring->ring_free_dw;
475 
476 	wptr = radeon_ring_get_wptr(rdev, ring);
477 	seq_printf(m, "wptr: 0x%08x [%5d]\n",
478 		   wptr, wptr);
479 
480 	rptr = radeon_ring_get_rptr(rdev, ring);
481 	seq_printf(m, "rptr: 0x%08x [%5d]\n",
482 		   rptr, rptr);
483 
484 	if (ring->rptr_save_reg) {
485 		rptr_next = RREG32(ring->rptr_save_reg);
486 		seq_printf(m, "rptr next(0x%04x): 0x%08x [%5d]\n",
487 			   ring->rptr_save_reg, rptr_next, rptr_next);
488 	} else
489 		rptr_next = ~0;
490 
491 	seq_printf(m, "driver's copy of the wptr: 0x%08x [%5d]\n",
492 		   ring->wptr, ring->wptr);
493 	seq_printf(m, "last semaphore signal addr : 0x%016llx\n",
494 		   ring->last_semaphore_signal_addr);
495 	seq_printf(m, "last semaphore wait addr   : 0x%016llx\n",
496 		   ring->last_semaphore_wait_addr);
497 	seq_printf(m, "%u free dwords in ring\n", ring->ring_free_dw);
498 	seq_printf(m, "%u dwords in ring\n", count);
499 
500 	if (!ring->ring)
501 		return 0;
502 
503 	/* print 8 dw before current rptr as often it's the last executed
504 	 * packet that is the root issue
505 	 */
506 	i = (rptr + ring->ptr_mask + 1 - 32) & ring->ptr_mask;
507 	for (j = 0; j <= (count + 32); j++) {
508 		seq_printf(m, "r[%5d]=0x%08x", i, ring->ring[i]);
509 		if (rptr == i)
510 			seq_puts(m, " *");
511 		if (rptr_next == i)
512 			seq_puts(m, " #");
513 		seq_puts(m, "\n");
514 		i = (i + 1) & ring->ptr_mask;
515 	}
516 	return 0;
517 }
518 
519 DEFINE_SHOW_ATTRIBUTE(radeon_debugfs_ring_info);
520 
521 static const char *radeon_debugfs_ring_idx_to_name(uint32_t ridx)
522 {
523 	switch (ridx) {
524 	case RADEON_RING_TYPE_GFX_INDEX:
525 		return "radeon_ring_gfx";
526 	case CAYMAN_RING_TYPE_CP1_INDEX:
527 		return "radeon_ring_cp1";
528 	case CAYMAN_RING_TYPE_CP2_INDEX:
529 		return "radeon_ring_cp2";
530 	case R600_RING_TYPE_DMA_INDEX:
531 		return "radeon_ring_dma1";
532 	case CAYMAN_RING_TYPE_DMA1_INDEX:
533 		return "radeon_ring_dma2";
534 	case R600_RING_TYPE_UVD_INDEX:
535 		return "radeon_ring_uvd";
536 	case TN_RING_TYPE_VCE1_INDEX:
537 		return "radeon_ring_vce1";
538 	case TN_RING_TYPE_VCE2_INDEX:
539 		return "radeon_ring_vce2";
540 	default:
541 		return NULL;
542 
543 	}
544 }
545 #endif
546 
547 static void radeon_debugfs_ring_init(struct radeon_device *rdev, struct radeon_ring *ring)
548 {
549 #if defined(CONFIG_DEBUG_FS)
550 	const char *ring_name = radeon_debugfs_ring_idx_to_name(ring->idx);
551 	struct dentry *root = rdev->ddev->primary->debugfs_root;
552 
553 	if (ring_name)
554 		debugfs_create_file(ring_name, 0444, root, ring,
555 				    &radeon_debugfs_ring_info_fops);
556 
557 #endif
558 }
559