1// SPDX-License-Identifier: GPL-2.0
2
3/*
4 * Copyright 2016-2019 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 */
20struct 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 */
34inline 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 */
50inline 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
58static 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 * hl_irq_handler_cq - irq handler for completion queue
71 *
72 * @irq: irq number
73 * @arg: pointer to completion queue structure
74 *
75 */
76irqreturn_t hl_irq_handler_cq(int irq, void *arg)
77{
78	struct hl_cq *cq = arg;
79	struct hl_device *hdev = cq->hdev;
80	struct hl_hw_queue *queue;
81	struct hl_cs_job *job;
82	bool shadow_index_valid;
83	u16 shadow_index;
84	struct hl_cq_entry *cq_entry, *cq_base;
85
86	if (hdev->disabled) {
87		dev_dbg(hdev->dev,
88			"Device disabled but received IRQ %d for CQ %d\n",
89			irq, cq->hw_queue_id);
90		return IRQ_HANDLED;
91	}
92
93	cq_base = cq->kernel_address;
94
95	while (1) {
96		bool entry_ready = ((le32_to_cpu(cq_base[cq->ci].data) &
97					CQ_ENTRY_READY_MASK)
98						>> CQ_ENTRY_READY_SHIFT);
99
100		if (!entry_ready)
101			break;
102
103		cq_entry = (struct hl_cq_entry *) &cq_base[cq->ci];
104
105		/* Make sure we read CQ entry contents after we've
106		 * checked the ownership bit.
107		 */
108		dma_rmb();
109
110		shadow_index_valid = ((le32_to_cpu(cq_entry->data) &
111					CQ_ENTRY_SHADOW_INDEX_VALID_MASK)
112					>> CQ_ENTRY_SHADOW_INDEX_VALID_SHIFT);
113
114		shadow_index = (u16) ((le32_to_cpu(cq_entry->data) &
115					CQ_ENTRY_SHADOW_INDEX_MASK)
116					>> CQ_ENTRY_SHADOW_INDEX_SHIFT);
117
118		queue = &hdev->kernel_queues[cq->hw_queue_id];
119
120		if ((shadow_index_valid) && (!hdev->disabled)) {
121			job = queue->shadow_queue[hl_pi_2_offset(shadow_index)];
122			queue_work(hdev->cq_wq[cq->cq_idx], &job->finish_work);
123		}
124
125		atomic_inc(&queue->ci);
126
127		/* Clear CQ entry ready bit */
128		cq_entry->data = cpu_to_le32(le32_to_cpu(cq_entry->data) &
129						~CQ_ENTRY_READY_MASK);
130
131		cq->ci = hl_cq_inc_ptr(cq->ci);
132
133		/* Increment free slots */
134		atomic_inc(&cq->free_slots_cnt);
135	}
136
137	return IRQ_HANDLED;
138}
139
140/**
141 * hl_irq_handler_eq - irq handler for event queue
142 *
143 * @irq: irq number
144 * @arg: pointer to event queue structure
145 *
146 */
147irqreturn_t hl_irq_handler_eq(int irq, void *arg)
148{
149	struct hl_eq *eq = arg;
150	struct hl_device *hdev = eq->hdev;
151	struct hl_eq_entry *eq_entry;
152	struct hl_eq_entry *eq_base;
153	struct hl_eqe_work *handle_eqe_work;
154
155	eq_base = eq->kernel_address;
156
157	while (1) {
158		bool entry_ready =
159			((le32_to_cpu(eq_base[eq->ci].hdr.ctl) &
160				EQ_CTL_READY_MASK) >> EQ_CTL_READY_SHIFT);
161
162		if (!entry_ready)
163			break;
164
165		eq_entry = &eq_base[eq->ci];
166
167		/*
168		 * Make sure we read EQ entry contents after we've
169		 * checked the ownership bit.
170		 */
171		dma_rmb();
172
173		if (hdev->disabled) {
174			dev_warn(hdev->dev,
175				"Device disabled but received IRQ %d for EQ\n",
176					irq);
177			goto skip_irq;
178		}
179
180		handle_eqe_work = kmalloc(sizeof(*handle_eqe_work), GFP_ATOMIC);
181		if (handle_eqe_work) {
182			INIT_WORK(&handle_eqe_work->eq_work, irq_handle_eqe);
183			handle_eqe_work->hdev = hdev;
184
185			memcpy(&handle_eqe_work->eq_entry, eq_entry,
186					sizeof(*eq_entry));
187
188			queue_work(hdev->eq_wq, &handle_eqe_work->eq_work);
189		}
190skip_irq:
191		/* Clear EQ entry ready bit */
192		eq_entry->hdr.ctl =
193			cpu_to_le32(le32_to_cpu(eq_entry->hdr.ctl) &
194							~EQ_CTL_READY_MASK);
195
196		eq->ci = hl_eq_inc_ptr(eq->ci);
197
198		hdev->asic_funcs->update_eq_ci(hdev, eq->ci);
199	}
200
201	return IRQ_HANDLED;
202}
203
204/**
205 * hl_cq_init - main initialization function for an cq object
206 *
207 * @hdev: pointer to device structure
208 * @q: pointer to cq structure
209 * @hw_queue_id: The H/W queue ID this completion queue belongs to
210 *
211 * Allocate dma-able memory for the completion queue and initialize fields
212 * Returns 0 on success
213 */
214int hl_cq_init(struct hl_device *hdev, struct hl_cq *q, u32 hw_queue_id)
215{
216	void *p;
217
218	p = hdev->asic_funcs->asic_dma_alloc_coherent(hdev, HL_CQ_SIZE_IN_BYTES,
219				&q->bus_address, GFP_KERNEL | __GFP_ZERO);
220	if (!p)
221		return -ENOMEM;
222
223	q->hdev = hdev;
224	q->kernel_address = p;
225	q->hw_queue_id = hw_queue_id;
226	q->ci = 0;
227	q->pi = 0;
228
229	atomic_set(&q->free_slots_cnt, HL_CQ_LENGTH);
230
231	return 0;
232}
233
234/**
235 * hl_cq_fini - destroy completion queue
236 *
237 * @hdev: pointer to device structure
238 * @q: pointer to cq structure
239 *
240 * Free the completion queue memory
241 */
242void hl_cq_fini(struct hl_device *hdev, struct hl_cq *q)
243{
244	hdev->asic_funcs->asic_dma_free_coherent(hdev, HL_CQ_SIZE_IN_BYTES,
245						 q->kernel_address,
246						 q->bus_address);
247}
248
249void hl_cq_reset(struct hl_device *hdev, struct hl_cq *q)
250{
251	q->ci = 0;
252	q->pi = 0;
253
254	atomic_set(&q->free_slots_cnt, HL_CQ_LENGTH);
255
256	/*
257	 * It's not enough to just reset the PI/CI because the H/W may have
258	 * written valid completion entries before it was halted and therefore
259	 * we need to clean the actual queues so we won't process old entries
260	 * when the device is operational again
261	 */
262
263	memset(q->kernel_address, 0, HL_CQ_SIZE_IN_BYTES);
264}
265
266/**
267 * hl_eq_init - main initialization function for an event queue object
268 *
269 * @hdev: pointer to device structure
270 * @q: pointer to eq structure
271 *
272 * Allocate dma-able memory for the event queue and initialize fields
273 * Returns 0 on success
274 */
275int hl_eq_init(struct hl_device *hdev, struct hl_eq *q)
276{
277	void *p;
278
279	p = hdev->asic_funcs->cpu_accessible_dma_pool_alloc(hdev,
280							HL_EQ_SIZE_IN_BYTES,
281							&q->bus_address);
282	if (!p)
283		return -ENOMEM;
284
285	q->hdev = hdev;
286	q->kernel_address = p;
287	q->ci = 0;
288
289	return 0;
290}
291
292/**
293 * hl_eq_fini - destroy event queue
294 *
295 * @hdev: pointer to device structure
296 * @q: pointer to eq structure
297 *
298 * Free the event queue memory
299 */
300void hl_eq_fini(struct hl_device *hdev, struct hl_eq *q)
301{
302	flush_workqueue(hdev->eq_wq);
303
304	hdev->asic_funcs->cpu_accessible_dma_pool_free(hdev,
305					HL_EQ_SIZE_IN_BYTES,
306					q->kernel_address);
307}
308
309void hl_eq_reset(struct hl_device *hdev, struct hl_eq *q)
310{
311	q->ci = 0;
312
313	/*
314	 * It's not enough to just reset the PI/CI because the H/W may have
315	 * written valid completion entries before it was halted and therefore
316	 * we need to clean the actual queues so we won't process old entries
317	 * when the device is operational again
318	 */
319
320	memset(q->kernel_address, 0, HL_EQ_SIZE_IN_BYTES);
321}
322