xref: /dpdk/drivers/net/mlx4/mlx4_intr.c (revision 68a03efeed657e6e05f281479b33b51102797e15)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright 2017 6WIND S.A.
3  * Copyright 2017 Mellanox Technologies, Ltd
4  */
5 
6 /**
7  * @file
8  * Interrupts handling for mlx4 driver.
9  */
10 
11 #include <errno.h>
12 #include <stdint.h>
13 #include <stdlib.h>
14 
15 /* Verbs headers do not support -pedantic. */
16 #ifdef PEDANTIC
17 #pragma GCC diagnostic ignored "-Wpedantic"
18 #endif
19 #include <infiniband/verbs.h>
20 #ifdef PEDANTIC
21 #pragma GCC diagnostic error "-Wpedantic"
22 #endif
23 
24 #include <rte_alarm.h>
25 #include <rte_errno.h>
26 #include <ethdev_driver.h>
27 #include <rte_io.h>
28 #include <rte_interrupts.h>
29 
30 #include "mlx4.h"
31 #include "mlx4_glue.h"
32 #include "mlx4_rxtx.h"
33 #include "mlx4_utils.h"
34 
35 static int mlx4_link_status_check(struct mlx4_priv *priv);
36 
37 /**
38  * Clean up Rx interrupts handler.
39  *
40  * @param priv
41  *   Pointer to private structure.
42  */
43 static void
44 mlx4_rx_intr_vec_disable(struct mlx4_priv *priv)
45 {
46 	struct rte_intr_handle *intr_handle = &priv->intr_handle;
47 
48 	rte_intr_free_epoll_fd(intr_handle);
49 	free(intr_handle->intr_vec);
50 	intr_handle->nb_efd = 0;
51 	intr_handle->intr_vec = NULL;
52 }
53 
54 /**
55  * Allocate queue vector and fill epoll fd list for Rx interrupts.
56  *
57  * @param priv
58  *   Pointer to private structure.
59  *
60  * @return
61  *   0 on success, negative errno value otherwise and rte_errno is set.
62  */
63 static int
64 mlx4_rx_intr_vec_enable(struct mlx4_priv *priv)
65 {
66 	unsigned int i;
67 	unsigned int rxqs_n = ETH_DEV(priv)->data->nb_rx_queues;
68 	unsigned int n = RTE_MIN(rxqs_n, (uint32_t)RTE_MAX_RXTX_INTR_VEC_ID);
69 	unsigned int count = 0;
70 	struct rte_intr_handle *intr_handle = &priv->intr_handle;
71 
72 	mlx4_rx_intr_vec_disable(priv);
73 	intr_handle->intr_vec = malloc(n * sizeof(intr_handle->intr_vec[0]));
74 	if (intr_handle->intr_vec == NULL) {
75 		rte_errno = ENOMEM;
76 		ERROR("failed to allocate memory for interrupt vector,"
77 		      " Rx interrupts will not be supported");
78 		return -rte_errno;
79 	}
80 	for (i = 0; i != n; ++i) {
81 		struct rxq *rxq = ETH_DEV(priv)->data->rx_queues[i];
82 
83 		/* Skip queues that cannot request interrupts. */
84 		if (!rxq || !rxq->channel) {
85 			/* Use invalid intr_vec[] index to disable entry. */
86 			intr_handle->intr_vec[i] =
87 				RTE_INTR_VEC_RXTX_OFFSET +
88 				RTE_MAX_RXTX_INTR_VEC_ID;
89 			continue;
90 		}
91 		if (count >= RTE_MAX_RXTX_INTR_VEC_ID) {
92 			rte_errno = E2BIG;
93 			ERROR("too many Rx queues for interrupt vector size"
94 			      " (%d), Rx interrupts cannot be enabled",
95 			      RTE_MAX_RXTX_INTR_VEC_ID);
96 			mlx4_rx_intr_vec_disable(priv);
97 			return -rte_errno;
98 		}
99 		intr_handle->intr_vec[i] = RTE_INTR_VEC_RXTX_OFFSET + count;
100 		intr_handle->efds[count] = rxq->channel->fd;
101 		count++;
102 	}
103 	if (!count)
104 		mlx4_rx_intr_vec_disable(priv);
105 	else
106 		intr_handle->nb_efd = count;
107 	return 0;
108 }
109 
110 /**
111  * Process scheduled link status check.
112  *
113  * If LSC interrupts are requested, process related callback.
114  *
115  * @param priv
116  *   Pointer to private structure.
117  */
118 static void
119 mlx4_link_status_alarm(struct mlx4_priv *priv)
120 {
121 	const struct rte_intr_conf *const intr_conf =
122 		&ETH_DEV(priv)->data->dev_conf.intr_conf;
123 
124 	MLX4_ASSERT(priv->intr_alarm == 1);
125 	priv->intr_alarm = 0;
126 	if (intr_conf->lsc && !mlx4_link_status_check(priv))
127 		rte_eth_dev_callback_process(ETH_DEV(priv),
128 					     RTE_ETH_EVENT_INTR_LSC,
129 					     NULL);
130 }
131 
132 /**
133  * Check link status.
134  *
135  * In case of inconsistency, another check is scheduled.
136  *
137  * @param priv
138  *   Pointer to private structure.
139  *
140  * @return
141  *   0 on success (link status is consistent), negative errno value
142  *   otherwise and rte_errno is set.
143  */
144 static int
145 mlx4_link_status_check(struct mlx4_priv *priv)
146 {
147 	struct rte_eth_link *link = &ETH_DEV(priv)->data->dev_link;
148 	int ret = mlx4_link_update(ETH_DEV(priv), 0);
149 
150 	if (ret)
151 		return ret;
152 	if ((!link->link_speed && link->link_status) ||
153 	    (link->link_speed && !link->link_status)) {
154 		if (!priv->intr_alarm) {
155 			/* Inconsistent status, check again later. */
156 			ret = rte_eal_alarm_set(MLX4_INTR_ALARM_TIMEOUT,
157 						(void (*)(void *))
158 						mlx4_link_status_alarm,
159 						priv);
160 			if (ret)
161 				return ret;
162 			priv->intr_alarm = 1;
163 		}
164 		rte_errno = EINPROGRESS;
165 		return -rte_errno;
166 	}
167 	return 0;
168 }
169 
170 /**
171  * Handle interrupts from the NIC.
172  *
173  * @param priv
174  *   Pointer to private structure.
175  */
176 static void
177 mlx4_interrupt_handler(struct mlx4_priv *priv)
178 {
179 	enum { LSC, RMV, };
180 	static const enum rte_eth_event_type type[] = {
181 		[LSC] = RTE_ETH_EVENT_INTR_LSC,
182 		[RMV] = RTE_ETH_EVENT_INTR_RMV,
183 	};
184 	uint32_t caught[RTE_DIM(type)] = { 0 };
185 	struct ibv_async_event event;
186 	const struct rte_intr_conf *const intr_conf =
187 		&ETH_DEV(priv)->data->dev_conf.intr_conf;
188 	unsigned int i;
189 
190 	/* Read all message and acknowledge them. */
191 	while (!mlx4_glue->get_async_event(priv->ctx, &event)) {
192 		switch (event.event_type) {
193 		case IBV_EVENT_PORT_ACTIVE:
194 		case IBV_EVENT_PORT_ERR:
195 			if (intr_conf->lsc && !mlx4_link_status_check(priv))
196 				++caught[LSC];
197 			break;
198 		case IBV_EVENT_DEVICE_FATAL:
199 			if (intr_conf->rmv)
200 				++caught[RMV];
201 			break;
202 		default:
203 			DEBUG("event type %d on physical port %d not handled",
204 			      event.event_type, event.element.port_num);
205 		}
206 		mlx4_glue->ack_async_event(&event);
207 	}
208 	for (i = 0; i != RTE_DIM(caught); ++i)
209 		if (caught[i])
210 			rte_eth_dev_callback_process(ETH_DEV(priv), type[i],
211 						     NULL);
212 }
213 
214 /**
215  * MLX4 CQ notification .
216  *
217  * @param rxq
218  *   Pointer to receive queue structure.
219  * @param solicited
220  *   Is request solicited or not.
221  */
222 static void
223 mlx4_arm_cq(struct rxq *rxq, int solicited)
224 {
225 	struct mlx4_cq *cq = &rxq->mcq;
226 	uint64_t doorbell;
227 	uint32_t sn = cq->arm_sn & MLX4_CQ_DB_GEQ_N_MASK;
228 	uint32_t ci = cq->cons_index & MLX4_CQ_DB_CI_MASK;
229 	uint32_t cmd = solicited ? MLX4_CQ_DB_REQ_NOT_SOL : MLX4_CQ_DB_REQ_NOT;
230 
231 	*cq->arm_db = rte_cpu_to_be_32(sn << 28 | cmd | ci);
232 	/*
233 	 * Make sure that the doorbell record in host memory is
234 	 * written before ringing the doorbell via PCI MMIO.
235 	 */
236 	rte_wmb();
237 	doorbell = sn << 28 | cmd | cq->cqn;
238 	doorbell <<= 32;
239 	doorbell |= ci;
240 	rte_write64(rte_cpu_to_be_64(doorbell), cq->cq_db_reg);
241 }
242 
243 /**
244  * Uninstall interrupt handler.
245  *
246  * @param priv
247  *   Pointer to private structure.
248  *
249  * @return
250  *   0 on success, negative errno value otherwise and rte_errno is set.
251  */
252 int
253 mlx4_intr_uninstall(struct mlx4_priv *priv)
254 {
255 	int err = rte_errno; /* Make sure rte_errno remains unchanged. */
256 
257 	if (priv->intr_handle.fd != -1) {
258 		rte_intr_callback_unregister(&priv->intr_handle,
259 					     (void (*)(void *))
260 					     mlx4_interrupt_handler,
261 					     priv);
262 		priv->intr_handle.fd = -1;
263 	}
264 	rte_eal_alarm_cancel((void (*)(void *))mlx4_link_status_alarm, priv);
265 	priv->intr_alarm = 0;
266 	mlx4_rxq_intr_disable(priv);
267 	rte_errno = err;
268 	return 0;
269 }
270 
271 /**
272  * Install interrupt handler.
273  *
274  * @param priv
275  *   Pointer to private structure.
276  *
277  * @return
278  *   0 on success, negative errno value otherwise and rte_errno is set.
279  */
280 int
281 mlx4_intr_install(struct mlx4_priv *priv)
282 {
283 	const struct rte_intr_conf *const intr_conf =
284 		&ETH_DEV(priv)->data->dev_conf.intr_conf;
285 	int rc;
286 
287 	mlx4_intr_uninstall(priv);
288 	if (intr_conf->lsc | intr_conf->rmv) {
289 		priv->intr_handle.fd = priv->ctx->async_fd;
290 		rc = rte_intr_callback_register(&priv->intr_handle,
291 						(void (*)(void *))
292 						mlx4_interrupt_handler,
293 						priv);
294 		if (rc < 0) {
295 			rte_errno = -rc;
296 			goto error;
297 		}
298 	}
299 	return 0;
300 error:
301 	mlx4_intr_uninstall(priv);
302 	return -rte_errno;
303 }
304 
305 /**
306  * DPDK callback for Rx queue interrupt disable.
307  *
308  * @param dev
309  *   Pointer to Ethernet device structure.
310  * @param idx
311  *   Rx queue index.
312  *
313  * @return
314  *   0 on success, negative errno value otherwise and rte_errno is set.
315  */
316 int
317 mlx4_rx_intr_disable(struct rte_eth_dev *dev, uint16_t idx)
318 {
319 	struct rxq *rxq = dev->data->rx_queues[idx];
320 	struct ibv_cq *ev_cq;
321 	void *ev_ctx;
322 	int ret;
323 
324 	if (!rxq || !rxq->channel) {
325 		ret = EINVAL;
326 	} else {
327 		ret = mlx4_glue->get_cq_event(rxq->cq->channel, &ev_cq,
328 					      &ev_ctx);
329 		/** For non-zero ret save the errno (may be EAGAIN
330 		 * which means the get_cq_event function was called before
331 		 * receiving one).
332 		 */
333 		if (ret)
334 			ret = errno;
335 		else if (ev_cq != rxq->cq)
336 			ret = EINVAL;
337 	}
338 	if (ret) {
339 		rte_errno = ret;
340 		if (ret != EAGAIN)
341 			WARN("unable to disable interrupt on rx queue %d",
342 			     idx);
343 	} else {
344 		rxq->mcq.arm_sn++;
345 		mlx4_glue->ack_cq_events(rxq->cq, 1);
346 	}
347 	return -ret;
348 }
349 
350 /**
351  * DPDK callback for Rx queue interrupt enable.
352  *
353  * @param dev
354  *   Pointer to Ethernet device structure.
355  * @param idx
356  *   Rx queue index.
357  *
358  * @return
359  *   0 on success, negative errno value otherwise and rte_errno is set.
360  */
361 int
362 mlx4_rx_intr_enable(struct rte_eth_dev *dev, uint16_t idx)
363 {
364 	struct rxq *rxq = dev->data->rx_queues[idx];
365 	int ret = 0;
366 
367 	if (!rxq || !rxq->channel) {
368 		ret = EINVAL;
369 		rte_errno = ret;
370 		WARN("unable to arm interrupt on rx queue %d", idx);
371 	} else {
372 		mlx4_arm_cq(rxq, 0);
373 	}
374 	return -ret;
375 }
376 
377 /**
378  * Enable datapath interrupts.
379  *
380  * @param priv
381  *   Pointer to private structure.
382  *
383  * @return
384  *   0 on success, negative errno value otherwise and rte_errno is set.
385  */
386 int
387 mlx4_rxq_intr_enable(struct mlx4_priv *priv)
388 {
389 	const struct rte_intr_conf *const intr_conf =
390 		&ETH_DEV(priv)->data->dev_conf.intr_conf;
391 
392 	if (intr_conf->rxq && mlx4_rx_intr_vec_enable(priv) < 0)
393 		goto error;
394 	return 0;
395 error:
396 	return -rte_errno;
397 }
398 
399 /**
400  * Disable datapath interrupts, keeping other interrupts intact.
401  *
402  * @param priv
403  *   Pointer to private structure.
404  */
405 void
406 mlx4_rxq_intr_disable(struct mlx4_priv *priv)
407 {
408 	int err = rte_errno; /* Make sure rte_errno remains unchanged. */
409 
410 	mlx4_rx_intr_vec_disable(priv);
411 	rte_errno = err;
412 }
413