1 // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
2 /* Copyright (c) 2019-2020, Mellanox Technologies inc. All rights reserved. */
3 
4 #include <net/xdp_sock_drv.h>
5 #include "pool.h"
6 #include "setup.h"
7 #include "en/params.h"
8 
9 static int mlx5e_xsk_map_pool(struct mlx5e_priv *priv,
10 			      struct xsk_buff_pool *pool)
11 {
12 	struct device *dev = mlx5_core_dma_dev(priv->mdev);
13 
14 	return xsk_pool_dma_map(pool, dev, DMA_ATTR_SKIP_CPU_SYNC);
15 }
16 
17 static void mlx5e_xsk_unmap_pool(struct mlx5e_priv *priv,
18 				 struct xsk_buff_pool *pool)
19 {
20 	return xsk_pool_dma_unmap(pool, DMA_ATTR_SKIP_CPU_SYNC);
21 }
22 
23 static int mlx5e_xsk_get_pools(struct mlx5e_xsk *xsk)
24 {
25 	if (!xsk->pools) {
26 		xsk->pools = kcalloc(MLX5E_MAX_NUM_CHANNELS,
27 				     sizeof(*xsk->pools), GFP_KERNEL);
28 		if (unlikely(!xsk->pools))
29 			return -ENOMEM;
30 	}
31 
32 	xsk->refcnt++;
33 	xsk->ever_used = true;
34 
35 	return 0;
36 }
37 
38 static void mlx5e_xsk_put_pools(struct mlx5e_xsk *xsk)
39 {
40 	if (!--xsk->refcnt) {
41 		kfree(xsk->pools);
42 		xsk->pools = NULL;
43 	}
44 }
45 
46 static int mlx5e_xsk_add_pool(struct mlx5e_xsk *xsk, struct xsk_buff_pool *pool, u16 ix)
47 {
48 	int err;
49 
50 	err = mlx5e_xsk_get_pools(xsk);
51 	if (unlikely(err))
52 		return err;
53 
54 	xsk->pools[ix] = pool;
55 	return 0;
56 }
57 
58 static void mlx5e_xsk_remove_pool(struct mlx5e_xsk *xsk, u16 ix)
59 {
60 	xsk->pools[ix] = NULL;
61 
62 	mlx5e_xsk_put_pools(xsk);
63 }
64 
65 static bool mlx5e_xsk_is_pool_sane(struct xsk_buff_pool *pool)
66 {
67 	return xsk_pool_get_headroom(pool) <= 0xffff &&
68 		xsk_pool_get_chunk_size(pool) <= 0xffff;
69 }
70 
71 void mlx5e_build_xsk_param(struct xsk_buff_pool *pool, struct mlx5e_xsk_param *xsk)
72 {
73 	xsk->headroom = xsk_pool_get_headroom(pool);
74 	xsk->chunk_size = xsk_pool_get_chunk_size(pool);
75 }
76 
77 static int mlx5e_xsk_enable_locked(struct mlx5e_priv *priv,
78 				   struct xsk_buff_pool *pool, u16 ix)
79 {
80 	struct mlx5e_params *params = &priv->channels.params;
81 	struct mlx5e_xsk_param xsk;
82 	struct mlx5e_channel *c;
83 	int err;
84 
85 	if (unlikely(mlx5e_xsk_get_pool(&priv->channels.params, &priv->xsk, ix)))
86 		return -EBUSY;
87 
88 	if (unlikely(!mlx5e_xsk_is_pool_sane(pool)))
89 		return -EINVAL;
90 
91 	err = mlx5e_xsk_map_pool(priv, pool);
92 	if (unlikely(err))
93 		return err;
94 
95 	err = mlx5e_xsk_add_pool(&priv->xsk, pool, ix);
96 	if (unlikely(err))
97 		goto err_unmap_pool;
98 
99 	mlx5e_build_xsk_param(pool, &xsk);
100 
101 	if (!test_bit(MLX5E_STATE_OPENED, &priv->state)) {
102 		/* XSK objects will be created on open. */
103 		goto validate_closed;
104 	}
105 
106 	if (!params->xdp_prog) {
107 		/* XSK objects will be created when an XDP program is set,
108 		 * and the channels are reopened.
109 		 */
110 		goto validate_closed;
111 	}
112 
113 	c = priv->channels.c[ix];
114 
115 	err = mlx5e_open_xsk(priv, params, &xsk, pool, c);
116 	if (unlikely(err))
117 		goto err_remove_pool;
118 
119 	mlx5e_activate_xsk(c);
120 	mlx5e_trigger_napi_icosq(c);
121 
122 	/* Don't wait for WQEs, because the newer xdpsock sample doesn't provide
123 	 * any Fill Ring entries at the setup stage.
124 	 */
125 
126 	err = mlx5e_rx_res_xsk_activate(priv->rx_res, &priv->channels, ix);
127 	if (unlikely(err))
128 		goto err_deactivate;
129 
130 	return 0;
131 
132 err_deactivate:
133 	mlx5e_deactivate_xsk(c);
134 	mlx5e_close_xsk(c);
135 
136 err_remove_pool:
137 	mlx5e_xsk_remove_pool(&priv->xsk, ix);
138 
139 err_unmap_pool:
140 	mlx5e_xsk_unmap_pool(priv, pool);
141 
142 	return err;
143 
144 validate_closed:
145 	/* Check the configuration in advance, rather than fail at a later stage
146 	 * (in mlx5e_xdp_set or on open) and end up with no channels.
147 	 */
148 	if (!mlx5e_validate_xsk_param(params, &xsk, priv->mdev)) {
149 		err = -EINVAL;
150 		goto err_remove_pool;
151 	}
152 
153 	return 0;
154 }
155 
156 static int mlx5e_xsk_disable_locked(struct mlx5e_priv *priv, u16 ix)
157 {
158 	struct xsk_buff_pool *pool = mlx5e_xsk_get_pool(&priv->channels.params,
159 						   &priv->xsk, ix);
160 	struct mlx5e_channel *c;
161 
162 	if (unlikely(!pool))
163 		return -EINVAL;
164 
165 	if (!test_bit(MLX5E_STATE_OPENED, &priv->state))
166 		goto remove_pool;
167 
168 	/* XSK RQ and SQ are only created if XDP program is set. */
169 	if (!priv->channels.params.xdp_prog)
170 		goto remove_pool;
171 
172 	c = priv->channels.c[ix];
173 	mlx5e_rx_res_xsk_deactivate(priv->rx_res, ix);
174 	mlx5e_deactivate_xsk(c);
175 	mlx5e_close_xsk(c);
176 
177 remove_pool:
178 	mlx5e_xsk_remove_pool(&priv->xsk, ix);
179 	mlx5e_xsk_unmap_pool(priv, pool);
180 
181 	return 0;
182 }
183 
184 static int mlx5e_xsk_enable_pool(struct mlx5e_priv *priv, struct xsk_buff_pool *pool,
185 				 u16 ix)
186 {
187 	int err;
188 
189 	mutex_lock(&priv->state_lock);
190 	err = mlx5e_xsk_enable_locked(priv, pool, ix);
191 	mutex_unlock(&priv->state_lock);
192 
193 	return err;
194 }
195 
196 static int mlx5e_xsk_disable_pool(struct mlx5e_priv *priv, u16 ix)
197 {
198 	int err;
199 
200 	mutex_lock(&priv->state_lock);
201 	err = mlx5e_xsk_disable_locked(priv, ix);
202 	mutex_unlock(&priv->state_lock);
203 
204 	return err;
205 }
206 
207 int mlx5e_xsk_setup_pool(struct net_device *dev, struct xsk_buff_pool *pool, u16 qid)
208 {
209 	struct mlx5e_priv *priv = netdev_priv(dev);
210 	struct mlx5e_params *params = &priv->channels.params;
211 	u16 ix;
212 
213 	if (unlikely(!mlx5e_qid_get_ch_if_in_group(params, qid, MLX5E_RQ_GROUP_XSK, &ix)))
214 		return -EINVAL;
215 
216 	return pool ? mlx5e_xsk_enable_pool(priv, pool, ix) :
217 		      mlx5e_xsk_disable_pool(priv, ix);
218 }
219