1 /*
2  * Copyright (c) 2015, Mellanox Technologies. All rights reserved.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the
8  * OpenIB.org BSD license below:
9  *
10  *     Redistribution and use in source and binary forms, with or
11  *     without modification, are permitted provided that the following
12  *     conditions are met:
13  *
14  *      - Redistributions of source code must retain the above
15  *        copyright notice, this list of conditions and the following
16  *        disclaimer.
17  *
18  *      - Redistributions in binary form must reproduce the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer in the documentation and/or other materials
21  *        provided with the distribution.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30  * SOFTWARE.
31  */
32 
33 #include <linux/irq.h>
34 #include "en.h"
35 #include "en/txrx.h"
36 #include "en/xdp.h"
37 #include "en/xsk/rx.h"
38 #include "en/xsk/tx.h"
39 
40 static inline bool mlx5e_channel_no_affinity_change(struct mlx5e_channel *c)
41 {
42 	int current_cpu = smp_processor_id();
43 
44 	return cpumask_test_cpu(current_cpu, c->aff_mask);
45 }
46 
47 static void mlx5e_handle_tx_dim(struct mlx5e_txqsq *sq)
48 {
49 	struct mlx5e_sq_stats *stats = sq->stats;
50 	struct dim_sample dim_sample = {};
51 
52 	if (unlikely(!test_bit(MLX5E_SQ_STATE_AM, &sq->state)))
53 		return;
54 
55 	dim_update_sample(sq->cq.event_ctr, stats->packets, stats->bytes, &dim_sample);
56 	net_dim(&sq->dim, dim_sample);
57 }
58 
59 static void mlx5e_handle_rx_dim(struct mlx5e_rq *rq)
60 {
61 	struct mlx5e_rq_stats *stats = rq->stats;
62 	struct dim_sample dim_sample = {};
63 
64 	if (unlikely(!test_bit(MLX5E_RQ_STATE_AM, &rq->state)))
65 		return;
66 
67 	dim_update_sample(rq->cq.event_ctr, stats->packets, stats->bytes, &dim_sample);
68 	net_dim(&rq->dim, dim_sample);
69 }
70 
71 void mlx5e_trigger_irq(struct mlx5e_icosq *sq)
72 {
73 	struct mlx5_wq_cyc *wq = &sq->wq;
74 	struct mlx5e_tx_wqe *nopwqe;
75 	u16 pi = mlx5_wq_cyc_ctr2ix(wq, sq->pc);
76 
77 	sq->db.wqe_info[pi] = (struct mlx5e_icosq_wqe_info) {
78 		.wqe_type   = MLX5E_ICOSQ_WQE_NOP,
79 		.num_wqebbs = 1,
80 	};
81 
82 	nopwqe = mlx5e_post_nop(wq, sq->sqn, &sq->pc);
83 	mlx5e_notify_hw(wq, sq->pc, sq->uar_map, &nopwqe->ctrl);
84 }
85 
86 static bool mlx5e_napi_xsk_post(struct mlx5e_xdpsq *xsksq, struct mlx5e_rq *xskrq)
87 {
88 	bool busy_xsk = false, xsk_rx_alloc_err;
89 
90 	/* Handle the race between the application querying need_wakeup and the
91 	 * driver setting it:
92 	 * 1. Update need_wakeup both before and after the TX. If it goes to
93 	 * "yes", it can only happen with the first update.
94 	 * 2. If the application queried need_wakeup before we set it, the
95 	 * packets will be transmitted anyway, even w/o a wakeup.
96 	 * 3. Give a chance to clear need_wakeup after new packets were queued
97 	 * for TX.
98 	 */
99 	mlx5e_xsk_update_tx_wakeup(xsksq);
100 	busy_xsk |= mlx5e_xsk_tx(xsksq, MLX5E_TX_XSK_POLL_BUDGET);
101 	mlx5e_xsk_update_tx_wakeup(xsksq);
102 
103 	xsk_rx_alloc_err = INDIRECT_CALL_2(xskrq->post_wqes,
104 					   mlx5e_post_rx_mpwqes,
105 					   mlx5e_post_rx_wqes,
106 					   xskrq);
107 	busy_xsk |= mlx5e_xsk_update_rx_wakeup(xskrq, xsk_rx_alloc_err);
108 
109 	return busy_xsk;
110 }
111 
112 int mlx5e_napi_poll(struct napi_struct *napi, int budget)
113 {
114 	struct mlx5e_channel *c = container_of(napi, struct mlx5e_channel,
115 					       napi);
116 	struct mlx5e_ch_stats *ch_stats = c->stats;
117 	struct mlx5e_xdpsq *xsksq = &c->xsksq;
118 	struct mlx5e_txqsq __rcu **qos_sqs;
119 	struct mlx5e_rq *xskrq = &c->xskrq;
120 	struct mlx5e_rq *rq = &c->rq;
121 	bool aff_change = false;
122 	bool busy_xsk = false;
123 	bool busy = false;
124 	int work_done = 0;
125 	u16 qos_sqs_size;
126 	bool xsk_open;
127 	int i;
128 
129 	rcu_read_lock();
130 
131 	qos_sqs = rcu_dereference(c->qos_sqs);
132 
133 	xsk_open = test_bit(MLX5E_CHANNEL_STATE_XSK, c->state);
134 
135 	ch_stats->poll++;
136 
137 	for (i = 0; i < c->num_tc; i++)
138 		busy |= mlx5e_poll_tx_cq(&c->sq[i].cq, budget);
139 
140 	if (unlikely(qos_sqs)) {
141 		smp_rmb(); /* Pairs with mlx5e_qos_alloc_queues. */
142 		qos_sqs_size = READ_ONCE(c->qos_sqs_size);
143 
144 		for (i = 0; i < qos_sqs_size; i++) {
145 			struct mlx5e_txqsq *sq = rcu_dereference(qos_sqs[i]);
146 
147 			if (sq)
148 				busy |= mlx5e_poll_tx_cq(&sq->cq, budget);
149 		}
150 	}
151 
152 	busy |= mlx5e_poll_xdpsq_cq(&c->xdpsq.cq);
153 
154 	if (c->xdp)
155 		busy |= mlx5e_poll_xdpsq_cq(&c->rq_xdpsq.cq);
156 
157 	if (likely(budget)) { /* budget=0 means: don't poll rx rings */
158 		if (xsk_open)
159 			work_done = mlx5e_poll_rx_cq(&xskrq->cq, budget);
160 
161 		if (likely(budget - work_done))
162 			work_done += mlx5e_poll_rx_cq(&rq->cq, budget - work_done);
163 
164 		busy |= work_done == budget;
165 	}
166 
167 	mlx5e_poll_ico_cq(&c->icosq.cq);
168 	if (mlx5e_poll_ico_cq(&c->async_icosq.cq))
169 		/* Don't clear the flag if nothing was polled to prevent
170 		 * queueing more WQEs and overflowing the async ICOSQ.
171 		 */
172 		clear_bit(MLX5E_SQ_STATE_PENDING_XSK_TX, &c->async_icosq.state);
173 
174 	busy |= INDIRECT_CALL_2(rq->post_wqes,
175 				mlx5e_post_rx_mpwqes,
176 				mlx5e_post_rx_wqes,
177 				rq);
178 	if (xsk_open) {
179 		busy |= mlx5e_poll_xdpsq_cq(&xsksq->cq);
180 		busy_xsk |= mlx5e_napi_xsk_post(xsksq, xskrq);
181 	}
182 
183 	busy |= busy_xsk;
184 
185 	if (busy) {
186 		if (likely(mlx5e_channel_no_affinity_change(c))) {
187 			work_done = budget;
188 			goto out;
189 		}
190 		ch_stats->aff_change++;
191 		aff_change = true;
192 		if (budget && work_done == budget)
193 			work_done--;
194 	}
195 
196 	if (unlikely(!napi_complete_done(napi, work_done)))
197 		goto out;
198 
199 	ch_stats->arm++;
200 
201 	for (i = 0; i < c->num_tc; i++) {
202 		mlx5e_handle_tx_dim(&c->sq[i]);
203 		mlx5e_cq_arm(&c->sq[i].cq);
204 	}
205 	if (unlikely(qos_sqs)) {
206 		for (i = 0; i < qos_sqs_size; i++) {
207 			struct mlx5e_txqsq *sq = rcu_dereference(qos_sqs[i]);
208 
209 			if (sq) {
210 				mlx5e_handle_tx_dim(sq);
211 				mlx5e_cq_arm(&sq->cq);
212 			}
213 		}
214 	}
215 
216 	mlx5e_handle_rx_dim(rq);
217 
218 	mlx5e_cq_arm(&rq->cq);
219 	mlx5e_cq_arm(&c->icosq.cq);
220 	mlx5e_cq_arm(&c->async_icosq.cq);
221 	mlx5e_cq_arm(&c->xdpsq.cq);
222 
223 	if (xsk_open) {
224 		mlx5e_handle_rx_dim(xskrq);
225 		mlx5e_cq_arm(&xsksq->cq);
226 		mlx5e_cq_arm(&xskrq->cq);
227 	}
228 
229 	if (unlikely(aff_change && busy_xsk)) {
230 		mlx5e_trigger_irq(&c->icosq);
231 		ch_stats->force_irq++;
232 	}
233 
234 out:
235 	rcu_read_unlock();
236 
237 	return work_done;
238 }
239 
240 void mlx5e_completion_event(struct mlx5_core_cq *mcq, struct mlx5_eqe *eqe)
241 {
242 	struct mlx5e_cq *cq = container_of(mcq, struct mlx5e_cq, mcq);
243 
244 	napi_schedule(cq->napi);
245 	cq->event_ctr++;
246 	cq->ch_stats->events++;
247 }
248 
249 void mlx5e_cq_error_event(struct mlx5_core_cq *mcq, enum mlx5_event event)
250 {
251 	struct mlx5e_cq *cq = container_of(mcq, struct mlx5e_cq, mcq);
252 	struct net_device *netdev = cq->netdev;
253 
254 	netdev_err(netdev, "%s: cqn=0x%.6x event=0x%.2x\n",
255 		   __func__, mcq->cqn, event);
256 }
257