1 // SPDX-License-Identifier: GPL-2.0
2 
3 /*
4  * Copyright 2016-2022 HabanaLabs, Ltd.
5  * All Rights Reserved.
6  */
7 
8 #include "habanalabs.h"
9 
10 #include <linux/slab.h>
11 
12 /**
13  * struct hl_eqe_work - This structure is used to schedule work of EQ
14  *                      entry and cpucp_reset event
15  *
16  * @eq_work:          workqueue object to run when EQ entry is received
17  * @hdev:             pointer to device structure
18  * @eq_entry:         copy of the EQ entry
19  */
20 struct hl_eqe_work {
21 	struct work_struct	eq_work;
22 	struct hl_device	*hdev;
23 	struct hl_eq_entry	eq_entry;
24 };
25 
26 /**
27  * hl_cq_inc_ptr - increment ci or pi of cq
28  *
29  * @ptr: the current ci or pi value of the completion queue
30  *
31  * Increment ptr by 1. If it reaches the number of completion queue
32  * entries, set it to 0
33  */
34 inline u32 hl_cq_inc_ptr(u32 ptr)
35 {
36 	ptr++;
37 	if (unlikely(ptr == HL_CQ_LENGTH))
38 		ptr = 0;
39 	return ptr;
40 }
41 
42 /**
43  * hl_eq_inc_ptr - increment ci of eq
44  *
45  * @ptr: the current ci value of the event queue
46  *
47  * Increment ptr by 1. If it reaches the number of event queue
48  * entries, set it to 0
49  */
50 static inline u32 hl_eq_inc_ptr(u32 ptr)
51 {
52 	ptr++;
53 	if (unlikely(ptr == HL_EQ_LENGTH))
54 		ptr = 0;
55 	return ptr;
56 }
57 
58 static void irq_handle_eqe(struct work_struct *work)
59 {
60 	struct hl_eqe_work *eqe_work = container_of(work, struct hl_eqe_work,
61 							eq_work);
62 	struct hl_device *hdev = eqe_work->hdev;
63 
64 	hdev->asic_funcs->handle_eqe(hdev, &eqe_work->eq_entry);
65 
66 	kfree(eqe_work);
67 }
68 
69 /**
70  * job_finish - queue job finish work
71  *
72  * @hdev: pointer to device structure
73  * @cs_seq: command submission sequence
74  * @cq: completion queue
75  * @timestamp: interrupt timestamp
76  *
77  */
78 static void job_finish(struct hl_device *hdev, u32 cs_seq, struct hl_cq *cq, ktime_t timestamp)
79 {
80 	struct hl_hw_queue *queue;
81 	struct hl_cs_job *job;
82 
83 	queue = &hdev->kernel_queues[cq->hw_queue_id];
84 	job = queue->shadow_queue[hl_pi_2_offset(cs_seq)];
85 	job->timestamp = timestamp;
86 	queue_work(hdev->cq_wq[cq->cq_idx], &job->finish_work);
87 
88 	atomic_inc(&queue->ci);
89 }
90 
91 /**
92  * cs_finish - queue all cs jobs finish work
93  *
94  * @hdev: pointer to device structure
95  * @cs_seq: command submission sequence
96  * @timestamp: interrupt timestamp
97  *
98  */
99 static void cs_finish(struct hl_device *hdev, u16 cs_seq, ktime_t timestamp)
100 {
101 	struct asic_fixed_properties *prop = &hdev->asic_prop;
102 	struct hl_hw_queue *queue;
103 	struct hl_cs *cs;
104 	struct hl_cs_job *job;
105 
106 	cs = hdev->shadow_cs_queue[cs_seq & (prop->max_pending_cs - 1)];
107 	if (!cs) {
108 		dev_warn(hdev->dev,
109 			"No pointer to CS in shadow array at index %d\n",
110 			cs_seq);
111 		return;
112 	}
113 
114 	list_for_each_entry(job, &cs->job_list, cs_node) {
115 		queue = &hdev->kernel_queues[job->hw_queue_id];
116 		atomic_inc(&queue->ci);
117 	}
118 
119 	cs->completion_timestamp = timestamp;
120 	queue_work(hdev->cs_cmplt_wq, &cs->finish_work);
121 }
122 
123 /**
124  * hl_irq_handler_cq - irq handler for completion queue
125  *
126  * @irq: irq number
127  * @arg: pointer to completion queue structure
128  *
129  */
130 irqreturn_t hl_irq_handler_cq(int irq, void *arg)
131 {
132 	struct hl_cq *cq = arg;
133 	struct hl_device *hdev = cq->hdev;
134 	bool shadow_index_valid, entry_ready;
135 	u16 shadow_index;
136 	struct hl_cq_entry *cq_entry, *cq_base;
137 	ktime_t timestamp = ktime_get();
138 
139 	if (hdev->disabled) {
140 		dev_dbg(hdev->dev,
141 			"Device disabled but received IRQ %d for CQ %d\n",
142 			irq, cq->hw_queue_id);
143 		return IRQ_HANDLED;
144 	}
145 
146 	cq_base = cq->kernel_address;
147 
148 	while (1) {
149 		cq_entry = (struct hl_cq_entry *) &cq_base[cq->ci];
150 
151 		entry_ready = !!FIELD_GET(CQ_ENTRY_READY_MASK,
152 				le32_to_cpu(cq_entry->data));
153 		if (!entry_ready)
154 			break;
155 
156 		/* Make sure we read CQ entry contents after we've
157 		 * checked the ownership bit.
158 		 */
159 		dma_rmb();
160 
161 		shadow_index_valid =
162 			!!FIELD_GET(CQ_ENTRY_SHADOW_INDEX_VALID_MASK,
163 					le32_to_cpu(cq_entry->data));
164 
165 		shadow_index = FIELD_GET(CQ_ENTRY_SHADOW_INDEX_MASK,
166 				le32_to_cpu(cq_entry->data));
167 
168 		/*
169 		 * CQ interrupt handler has 2 modes of operation:
170 		 * 1. Interrupt per CS completion: (Single CQ for all queues)
171 		 *    CQ entry represents a completed CS
172 		 *
173 		 * 2. Interrupt per CS job completion in queue: (CQ per queue)
174 		 *    CQ entry represents a completed job in a certain queue
175 		 */
176 		if (shadow_index_valid && !hdev->disabled) {
177 			if (hdev->asic_prop.completion_mode ==
178 					HL_COMPLETION_MODE_CS)
179 				cs_finish(hdev, shadow_index, timestamp);
180 			else
181 				job_finish(hdev, shadow_index, cq, timestamp);
182 		}
183 
184 		/* Clear CQ entry ready bit */
185 		cq_entry->data = cpu_to_le32(le32_to_cpu(cq_entry->data) &
186 						~CQ_ENTRY_READY_MASK);
187 
188 		cq->ci = hl_cq_inc_ptr(cq->ci);
189 
190 		/* Increment free slots */
191 		atomic_inc(&cq->free_slots_cnt);
192 	}
193 
194 	return IRQ_HANDLED;
195 }
196 
197 /*
198  * hl_ts_free_objects - handler of the free objects workqueue.
199  * This function should put refcount to objects that the registration node
200  * took refcount to them.
201  * @work: workqueue object pointer
202  */
203 static void hl_ts_free_objects(struct work_struct *work)
204 {
205 	struct timestamp_reg_work_obj *job =
206 			container_of(work, struct timestamp_reg_work_obj, free_obj);
207 	struct timestamp_reg_free_node *free_obj, *temp_free_obj;
208 	struct list_head *free_list_head = job->free_obj_head;
209 	struct hl_device *hdev = job->hdev;
210 
211 	list_for_each_entry_safe(free_obj, temp_free_obj, free_list_head, free_objects_node) {
212 		dev_dbg(hdev->dev, "About to put refcount to buf (%p) cq_cb(%p)\n",
213 					free_obj->buf,
214 					free_obj->cq_cb);
215 
216 		hl_mmap_mem_buf_put(free_obj->buf);
217 		hl_cb_put(free_obj->cq_cb);
218 		kfree(free_obj);
219 	}
220 
221 	kfree(free_list_head);
222 	kfree(job);
223 }
224 
225 /*
226  * This function called with spin_lock of wait_list_lock taken
227  * This function will set timestamp and delete the registration node from the
228  * wait_list_lock.
229  * and since we're protected with spin_lock here, so we cannot just put the refcount
230  * for the objects here, since the release function may be called and it's also a long
231  * logic (which might sleep also) that cannot be handled in irq context.
232  * so here we'll be filling a list with nodes of "put" jobs and then will send this
233  * list to a dedicated workqueue to do the actual put.
234  */
235 static int handle_registration_node(struct hl_device *hdev, struct hl_user_pending_interrupt *pend,
236 						struct list_head **free_list, ktime_t now)
237 {
238 	struct timestamp_reg_free_node *free_node;
239 	u64 timestamp;
240 
241 	if (!(*free_list)) {
242 		/* Alloc/Init the timestamp registration free objects list */
243 		*free_list = kmalloc(sizeof(struct list_head), GFP_ATOMIC);
244 		if (!(*free_list))
245 			return -ENOMEM;
246 
247 		INIT_LIST_HEAD(*free_list);
248 	}
249 
250 	free_node = kmalloc(sizeof(*free_node), GFP_ATOMIC);
251 	if (!free_node)
252 		return -ENOMEM;
253 
254 	timestamp = ktime_to_ns(now);
255 
256 	*pend->ts_reg_info.timestamp_kernel_addr = timestamp;
257 
258 	dev_dbg(hdev->dev, "Timestamp is set to ts cb address (%p), ts: 0x%llx\n",
259 			pend->ts_reg_info.timestamp_kernel_addr,
260 			*(u64 *)pend->ts_reg_info.timestamp_kernel_addr);
261 
262 	list_del(&pend->wait_list_node);
263 
264 	/* Mark kernel CB node as free */
265 	pend->ts_reg_info.in_use = 0;
266 
267 	/* Putting the refcount for ts_buff and cq_cb objects will be handled
268 	 * in workqueue context, just add job to free_list.
269 	 */
270 	free_node->buf = pend->ts_reg_info.buf;
271 	free_node->cq_cb = pend->ts_reg_info.cq_cb;
272 	list_add(&free_node->free_objects_node, *free_list);
273 
274 	return 0;
275 }
276 
277 static void handle_user_interrupt(struct hl_device *hdev, struct hl_user_interrupt *intr)
278 {
279 	struct hl_user_pending_interrupt *pend, *temp_pend;
280 	struct list_head *ts_reg_free_list_head = NULL;
281 	struct timestamp_reg_work_obj *job;
282 	bool reg_node_handle_fail = false;
283 	ktime_t now = ktime_get();
284 	int rc;
285 
286 	/* For registration nodes:
287 	 * As part of handling the registration nodes, we should put refcount to
288 	 * some objects. the problem is that we cannot do that under spinlock
289 	 * or in irq handler context at all (since release functions are long and
290 	 * might sleep), so we will need to handle that part in workqueue context.
291 	 * To avoid handling kmalloc failure which compels us rolling back actions
292 	 * and move nodes hanged on the free list back to the interrupt wait list
293 	 * we always alloc the job of the WQ at the beginning.
294 	 */
295 	job = kmalloc(sizeof(*job), GFP_ATOMIC);
296 	if (!job)
297 		return;
298 
299 	spin_lock(&intr->wait_list_lock);
300 	list_for_each_entry_safe(pend, temp_pend, &intr->wait_list_head, wait_list_node) {
301 		if ((pend->cq_kernel_addr && *(pend->cq_kernel_addr) >= pend->cq_target_value) ||
302 				!pend->cq_kernel_addr) {
303 			if (pend->ts_reg_info.buf) {
304 				if (!reg_node_handle_fail) {
305 					rc = handle_registration_node(hdev, pend,
306 								&ts_reg_free_list_head, now);
307 					if (rc)
308 						reg_node_handle_fail = true;
309 				}
310 			} else {
311 				/* Handle wait target value node */
312 				pend->fence.timestamp = now;
313 				complete_all(&pend->fence.completion);
314 			}
315 		}
316 	}
317 	spin_unlock(&intr->wait_list_lock);
318 
319 	if (ts_reg_free_list_head) {
320 		INIT_WORK(&job->free_obj, hl_ts_free_objects);
321 		job->free_obj_head = ts_reg_free_list_head;
322 		job->hdev = hdev;
323 		queue_work(hdev->ts_free_obj_wq, &job->free_obj);
324 	} else {
325 		kfree(job);
326 	}
327 }
328 
329 /**
330  * hl_irq_handler_user_interrupt - irq handler for user interrupts
331  *
332  * @irq: irq number
333  * @arg: pointer to user interrupt structure
334  *
335  */
336 irqreturn_t hl_irq_handler_user_interrupt(int irq, void *arg)
337 {
338 	struct hl_user_interrupt *user_int = arg;
339 	struct hl_device *hdev = user_int->hdev;
340 
341 	switch (user_int->type) {
342 	case HL_USR_INTERRUPT_CQ:
343 		handle_user_interrupt(hdev, &hdev->common_user_cq_interrupt);
344 
345 		/* Handle user cq interrupt registered on this specific irq */
346 		handle_user_interrupt(hdev, user_int);
347 		break;
348 	case HL_USR_INTERRUPT_DECODER:
349 		handle_user_interrupt(hdev, &hdev->common_decoder_interrupt);
350 
351 		/* Handle decoder interrupt registered on this specific irq */
352 		handle_user_interrupt(hdev, user_int);
353 		break;
354 	default:
355 		break;
356 	}
357 
358 	return IRQ_HANDLED;
359 }
360 
361 /**
362  * hl_irq_handler_default - default irq handler
363  *
364  * @irq: irq number
365  * @arg: pointer to user interrupt structure
366  *
367  */
368 irqreturn_t hl_irq_handler_default(int irq, void *arg)
369 {
370 	struct hl_user_interrupt *user_interrupt = arg;
371 	struct hl_device *hdev = user_interrupt->hdev;
372 	u32 interrupt_id = user_interrupt->interrupt_id;
373 
374 	dev_err(hdev->dev, "got invalid user interrupt %u", interrupt_id);
375 
376 	return IRQ_HANDLED;
377 }
378 
379 /**
380  * hl_irq_handler_eq - irq handler for event queue
381  *
382  * @irq: irq number
383  * @arg: pointer to event queue structure
384  *
385  */
386 irqreturn_t hl_irq_handler_eq(int irq, void *arg)
387 {
388 	struct hl_eq *eq = arg;
389 	struct hl_device *hdev = eq->hdev;
390 	struct hl_eq_entry *eq_entry;
391 	struct hl_eq_entry *eq_base;
392 	struct hl_eqe_work *handle_eqe_work;
393 	bool entry_ready;
394 	u32 cur_eqe;
395 	u16 cur_eqe_index;
396 
397 	eq_base = eq->kernel_address;
398 
399 	while (1) {
400 		cur_eqe = le32_to_cpu(eq_base[eq->ci].hdr.ctl);
401 		entry_ready = !!FIELD_GET(EQ_CTL_READY_MASK, cur_eqe);
402 
403 		if (!entry_ready)
404 			break;
405 
406 		cur_eqe_index = FIELD_GET(EQ_CTL_INDEX_MASK, cur_eqe);
407 		if ((hdev->event_queue.check_eqe_index) &&
408 				(((eq->prev_eqe_index + 1) & EQ_CTL_INDEX_MASK)
409 							!= cur_eqe_index)) {
410 			dev_dbg(hdev->dev,
411 				"EQE 0x%x in queue is ready but index does not match %d!=%d",
412 				eq_base[eq->ci].hdr.ctl,
413 				((eq->prev_eqe_index + 1) & EQ_CTL_INDEX_MASK),
414 				cur_eqe_index);
415 			break;
416 		}
417 
418 		eq->prev_eqe_index++;
419 
420 		eq_entry = &eq_base[eq->ci];
421 
422 		/*
423 		 * Make sure we read EQ entry contents after we've
424 		 * checked the ownership bit.
425 		 */
426 		dma_rmb();
427 
428 		if (hdev->disabled && !hdev->reset_info.in_compute_reset) {
429 			dev_warn(hdev->dev, "Device disabled but received an EQ event\n");
430 			goto skip_irq;
431 		}
432 
433 		handle_eqe_work = kmalloc(sizeof(*handle_eqe_work), GFP_ATOMIC);
434 		if (handle_eqe_work) {
435 			INIT_WORK(&handle_eqe_work->eq_work, irq_handle_eqe);
436 			handle_eqe_work->hdev = hdev;
437 
438 			memcpy(&handle_eqe_work->eq_entry, eq_entry,
439 					sizeof(*eq_entry));
440 
441 			queue_work(hdev->eq_wq, &handle_eqe_work->eq_work);
442 		}
443 skip_irq:
444 		/* Clear EQ entry ready bit */
445 		eq_entry->hdr.ctl =
446 			cpu_to_le32(le32_to_cpu(eq_entry->hdr.ctl) &
447 							~EQ_CTL_READY_MASK);
448 
449 		eq->ci = hl_eq_inc_ptr(eq->ci);
450 
451 		hdev->asic_funcs->update_eq_ci(hdev, eq->ci);
452 	}
453 
454 	return IRQ_HANDLED;
455 }
456 
457 /**
458  * hl_irq_handler_dec_abnrm - Decoder error interrupt handler
459  * @irq: IRQ number
460  * @arg: pointer to decoder structure.
461  */
462 irqreturn_t hl_irq_handler_dec_abnrm(int irq, void *arg)
463 {
464 	struct hl_dec *dec = arg;
465 
466 	schedule_work(&dec->completion_abnrm_work);
467 
468 	return IRQ_HANDLED;
469 }
470 
471 /**
472  * hl_cq_init - main initialization function for an cq object
473  *
474  * @hdev: pointer to device structure
475  * @q: pointer to cq structure
476  * @hw_queue_id: The H/W queue ID this completion queue belongs to
477  *               HL_INVALID_QUEUE if cq is not attached to any specific queue
478  *
479  * Allocate dma-able memory for the completion queue and initialize fields
480  * Returns 0 on success
481  */
482 int hl_cq_init(struct hl_device *hdev, struct hl_cq *q, u32 hw_queue_id)
483 {
484 	void *p;
485 
486 	p = hl_asic_dma_alloc_coherent(hdev, HL_CQ_SIZE_IN_BYTES, &q->bus_address,
487 					GFP_KERNEL | __GFP_ZERO);
488 	if (!p)
489 		return -ENOMEM;
490 
491 	q->hdev = hdev;
492 	q->kernel_address = p;
493 	q->hw_queue_id = hw_queue_id;
494 	q->ci = 0;
495 	q->pi = 0;
496 
497 	atomic_set(&q->free_slots_cnt, HL_CQ_LENGTH);
498 
499 	return 0;
500 }
501 
502 /**
503  * hl_cq_fini - destroy completion queue
504  *
505  * @hdev: pointer to device structure
506  * @q: pointer to cq structure
507  *
508  * Free the completion queue memory
509  */
510 void hl_cq_fini(struct hl_device *hdev, struct hl_cq *q)
511 {
512 	hl_asic_dma_free_coherent(hdev, HL_CQ_SIZE_IN_BYTES, q->kernel_address, q->bus_address);
513 }
514 
515 void hl_cq_reset(struct hl_device *hdev, struct hl_cq *q)
516 {
517 	q->ci = 0;
518 	q->pi = 0;
519 
520 	atomic_set(&q->free_slots_cnt, HL_CQ_LENGTH);
521 
522 	/*
523 	 * It's not enough to just reset the PI/CI because the H/W may have
524 	 * written valid completion entries before it was halted and therefore
525 	 * we need to clean the actual queues so we won't process old entries
526 	 * when the device is operational again
527 	 */
528 
529 	memset(q->kernel_address, 0, HL_CQ_SIZE_IN_BYTES);
530 }
531 
532 /**
533  * hl_eq_init - main initialization function for an event queue object
534  *
535  * @hdev: pointer to device structure
536  * @q: pointer to eq structure
537  *
538  * Allocate dma-able memory for the event queue and initialize fields
539  * Returns 0 on success
540  */
541 int hl_eq_init(struct hl_device *hdev, struct hl_eq *q)
542 {
543 	void *p;
544 
545 	p = hl_cpu_accessible_dma_pool_alloc(hdev, HL_EQ_SIZE_IN_BYTES, &q->bus_address);
546 	if (!p)
547 		return -ENOMEM;
548 
549 	q->hdev = hdev;
550 	q->kernel_address = p;
551 	q->ci = 0;
552 	q->prev_eqe_index = 0;
553 
554 	return 0;
555 }
556 
557 /**
558  * hl_eq_fini - destroy event queue
559  *
560  * @hdev: pointer to device structure
561  * @q: pointer to eq structure
562  *
563  * Free the event queue memory
564  */
565 void hl_eq_fini(struct hl_device *hdev, struct hl_eq *q)
566 {
567 	flush_workqueue(hdev->eq_wq);
568 
569 	hl_cpu_accessible_dma_pool_free(hdev, HL_EQ_SIZE_IN_BYTES, q->kernel_address);
570 }
571 
572 void hl_eq_reset(struct hl_device *hdev, struct hl_eq *q)
573 {
574 	q->ci = 0;
575 	q->prev_eqe_index = 0;
576 
577 	/*
578 	 * It's not enough to just reset the PI/CI because the H/W may have
579 	 * written valid completion entries before it was halted and therefore
580 	 * we need to clean the actual queues so we won't process old entries
581 	 * when the device is operational again
582 	 */
583 
584 	memset(q->kernel_address, 0, HL_EQ_SIZE_IN_BYTES);
585 }
586