1 /*-
2  * Copyright (c) 2018-2019 Mellanox Technologies. All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions
6  * are met:
7  * 1. Redistributions of source code must retain the above copyright
8  *    notice, this list of conditions and the following disclaimer.
9  * 2. Redistributions in binary form must reproduce the above copyright
10  *    notice, this list of conditions and the following disclaimer in the
11  *    documentation and/or other materials provided with the distribution.
12  *
13  * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS `AS IS' AND
14  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16  * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23  * SUCH DAMAGE.
24  *
25  * $FreeBSD$
26  */
27 
28 #include "opt_rss.h"
29 #include "opt_ratelimit.h"
30 
31 #include <dev/mlx5/mlx5_en/port_buffer.h>
32 
33 #define MLX5E_MAX_PORT_MTU  9216
34 
35 int mlx5e_port_query_buffer(struct mlx5e_priv *priv,
36 			    struct mlx5e_port_buffer *port_buffer)
37 {
38 	struct mlx5_core_dev *mdev = priv->mdev;
39 	int sz = MLX5_ST_SZ_BYTES(pbmc_reg);
40 	u32 total_used = 0;
41 	void *buffer;
42 	void *out;
43 	int err;
44 	int i;
45 
46 	out = kzalloc(sz, GFP_KERNEL);
47 	if (!out)
48 		return -ENOMEM;
49 
50 	err = mlx5e_port_query_pbmc(mdev, out);
51 	if (err)
52 		goto out;
53 
54 	for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
55 		buffer = MLX5_ADDR_OF(pbmc_reg, out, buffer[i]);
56 		port_buffer->buffer[i].lossy =
57 			MLX5_GET(bufferx_reg, buffer, lossy);
58 		port_buffer->buffer[i].epsb =
59 			MLX5_GET(bufferx_reg, buffer, epsb);
60 		port_buffer->buffer[i].size =
61 			MLX5_GET(bufferx_reg, buffer, size) << MLX5E_BUFFER_CELL_SHIFT;
62 		port_buffer->buffer[i].xon =
63 			MLX5_GET(bufferx_reg, buffer, xon_threshold) << MLX5E_BUFFER_CELL_SHIFT;
64 		port_buffer->buffer[i].xoff =
65 			MLX5_GET(bufferx_reg, buffer, xoff_threshold) << MLX5E_BUFFER_CELL_SHIFT;
66 		total_used += port_buffer->buffer[i].size;
67 
68 		mlx5e_dbg(HW, priv, "buffer %d: size=%d, xon=%d, xoff=%d, epsb=%d, lossy=%d\n", i,
69 			  port_buffer->buffer[i].size,
70 			  port_buffer->buffer[i].xon,
71 			  port_buffer->buffer[i].xoff,
72 			  port_buffer->buffer[i].epsb,
73 			  port_buffer->buffer[i].lossy);
74 	}
75 
76 	port_buffer->port_buffer_size =
77 		MLX5_GET(pbmc_reg, out, port_buffer_size) << MLX5E_BUFFER_CELL_SHIFT;
78 	port_buffer->spare_buffer_size =
79 		port_buffer->port_buffer_size - total_used;
80 
81 	mlx5e_dbg(HW, priv, "total buffer size=%d, spare buffer size=%d\n",
82 		  port_buffer->port_buffer_size,
83 		  port_buffer->spare_buffer_size);
84 out:
85 	kfree(out);
86 	return err;
87 }
88 
89 static int port_set_buffer(struct mlx5e_priv *priv,
90 			   struct mlx5e_port_buffer *port_buffer)
91 {
92 	struct mlx5_core_dev *mdev = priv->mdev;
93 	int sz = MLX5_ST_SZ_BYTES(pbmc_reg);
94 	void *buffer;
95 	void *in;
96 	int err;
97 	int i;
98 
99 	in = kzalloc(sz, GFP_KERNEL);
100 	if (!in)
101 		return -ENOMEM;
102 
103 	err = mlx5e_port_query_pbmc(mdev, in);
104 	if (err)
105 		goto out;
106 
107 	for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
108 		buffer = MLX5_ADDR_OF(pbmc_reg, in, buffer[i]);
109 
110 		MLX5_SET(bufferx_reg, buffer, size,
111 			 port_buffer->buffer[i].size >> MLX5E_BUFFER_CELL_SHIFT);
112 		MLX5_SET(bufferx_reg, buffer, lossy,
113 			 port_buffer->buffer[i].lossy);
114 		MLX5_SET(bufferx_reg, buffer, xoff_threshold,
115 			 port_buffer->buffer[i].xoff >> MLX5E_BUFFER_CELL_SHIFT);
116 		MLX5_SET(bufferx_reg, buffer, xon_threshold,
117 			 port_buffer->buffer[i].xon >> MLX5E_BUFFER_CELL_SHIFT);
118 	}
119 
120 	err = mlx5e_port_set_pbmc(mdev, in);
121 out:
122 	kfree(in);
123 	return err;
124 }
125 
126 /* xoff = ((301+2.16 * len [m]) * speed [Gbps] + 2.72 MTU [B]) */
127 static u32 calculate_xoff(struct mlx5e_priv *priv, unsigned int mtu)
128 {
129 	u32 speed;
130 	u32 xoff;
131 	int err;
132 
133 	err = mlx5e_port_linkspeed(priv->mdev, &speed);
134 	if (err) {
135 		mlx5_core_warn(priv->mdev, "cannot get port speed\n");
136 		speed = SPEED_40000;
137 	}
138 	speed = max_t(u32, speed, SPEED_40000);
139 	xoff = (301 + 216 * priv->dcbx.cable_len / 100) * speed / 1000 + 272 * mtu / 100;
140 
141 	mlx5e_dbg(HW, priv, "%s: xoff=%d\n", __func__, xoff);
142 	return xoff;
143 }
144 
145 static int update_xoff_threshold(struct mlx5e_priv *priv,
146     struct mlx5e_port_buffer *port_buffer, u32 xoff)
147 {
148 	int i;
149 
150 	for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
151 		if (port_buffer->buffer[i].lossy) {
152 			port_buffer->buffer[i].xoff = 0;
153 			port_buffer->buffer[i].xon  = 0;
154 			continue;
155 		}
156 
157 		if (port_buffer->buffer[i].size <
158 		    (xoff + MLX5E_MAX_PORT_MTU + (1 << MLX5E_BUFFER_CELL_SHIFT))) {
159 			mlx5_en_info(priv->ifp,
160 	"non-lossy buffer %d size %d less than xoff threshold %d\n",
161 			    i, port_buffer->buffer[i].size,
162 			    xoff + MLX5E_MAX_PORT_MTU +
163 			    (1 << MLX5E_BUFFER_CELL_SHIFT));
164 			return -ENOMEM;
165 		}
166 
167 		port_buffer->buffer[i].xoff = port_buffer->buffer[i].size - xoff;
168 		port_buffer->buffer[i].xon  =
169 			port_buffer->buffer[i].xoff - MLX5E_MAX_PORT_MTU;
170 	}
171 
172 	return 0;
173 }
174 
175 /**
176  * update_buffer_lossy()
177  *   mtu: device's MTU
178  *   pfc_en: <input> current pfc configuration
179  *   buffer: <input> current prio to buffer mapping
180  *   xoff:   <input> xoff value
181  *   port_buffer: <output> port receive buffer configuration
182  *   change: <output>
183  *
184  *   Update buffer configuration based on pfc configuration and priority
185  *   to buffer mapping.
186  *   Buffer's lossy bit is changed to:
187  *     lossless if there is at least one PFC enabled priority mapped to this buffer
188  *     lossy if all priorities mapped to this buffer are PFC disabled
189  *
190  *   Return:
191  *     Return 0 if no error.
192  *     Set change to true if buffer configuration is modified.
193  */
194 static int update_buffer_lossy(struct mlx5e_priv *priv, unsigned int mtu,
195 			       u8 pfc_en, u8 *buffer, u32 xoff,
196 			       struct mlx5e_port_buffer *port_buffer,
197 			       bool *change)
198 {
199 	bool changed = false;
200 	u8 lossy_count;
201 	u8 prio_count;
202 	u8 lossy;
203 	int prio;
204 	int err;
205 	int i;
206 
207 	for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
208 		prio_count = 0;
209 		lossy_count = 0;
210 
211 		for (prio = 0; prio < MLX5E_MAX_PRIORITY; prio++) {
212 			if (buffer[prio] != i)
213 				continue;
214 
215 			prio_count++;
216 			lossy_count += !(pfc_en & (1 << prio));
217 		}
218 
219 		if (lossy_count == prio_count)
220 			lossy = 1;
221 		else /* lossy_count < prio_count */
222 			lossy = 0;
223 
224 		if (lossy != port_buffer->buffer[i].lossy) {
225 			port_buffer->buffer[i].lossy = lossy;
226 			changed = true;
227 		}
228 	}
229 
230 	if (changed) {
231 		err = update_xoff_threshold(priv, port_buffer, xoff);
232 		if (err)
233 			return err;
234 
235 		*change = true;
236 	}
237 
238 	return 0;
239 }
240 
241 int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
242 				    u32 change, unsigned int mtu,
243 				    struct ieee_pfc *pfc,
244 				    u32 *buffer_size,
245 				    u8 *prio2buffer)
246 {
247 	struct mlx5e_port_buffer port_buffer;
248 	u32 xoff = calculate_xoff(priv, mtu);
249 	bool update_prio2buffer = false;
250 	u8 buffer[MLX5E_MAX_PRIORITY];
251 	bool update_buffer = false;
252 	u32 total_used = 0;
253 	u8 curr_pfc_en;
254 	int err;
255 	int i;
256 
257 	mlx5e_dbg(HW, priv, "%s: change=%x\n", __func__, change);
258 
259 	err = mlx5e_port_query_buffer(priv, &port_buffer);
260 	if (err)
261 		return err;
262 
263 	if (change & MLX5E_PORT_BUFFER_CABLE_LEN) {
264 		update_buffer = true;
265 		err = update_xoff_threshold(priv, &port_buffer, xoff);
266 		if (err)
267 			return err;
268 	}
269 
270 	if (change & MLX5E_PORT_BUFFER_PFC) {
271 		err = mlx5e_port_query_priority2buffer(priv->mdev, buffer);
272 		if (err)
273 			return err;
274 
275 		priv->sw_is_port_buf_owner = true;
276 		err = update_buffer_lossy(priv, mtu, pfc->pfc_en, buffer, xoff,
277 					  &port_buffer, &update_buffer);
278 		if (err)
279 			return err;
280 	}
281 
282 	if (change & MLX5E_PORT_BUFFER_PRIO2BUFFER) {
283 		update_prio2buffer = true;
284 		err = mlx5_query_port_pfc(priv->mdev, &curr_pfc_en, NULL);
285 		if (err)
286 			return err;
287 
288 		err = update_buffer_lossy(priv, mtu, curr_pfc_en, prio2buffer, xoff,
289 					  &port_buffer, &update_buffer);
290 		if (err)
291 			return err;
292 	}
293 
294 	if (change & MLX5E_PORT_BUFFER_SIZE) {
295 		for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
296 			mlx5e_dbg(HW, priv, "%s: buffer[%d]=%d\n", __func__, i, buffer_size[i]);
297 			if (!port_buffer.buffer[i].lossy && !buffer_size[i]) {
298 				mlx5e_dbg(HW, priv, "%s: lossless buffer[%d] size cannot be zero\n",
299 					  __func__, i);
300 				return -EINVAL;
301 			}
302 
303 			port_buffer.buffer[i].size = buffer_size[i];
304 			total_used += buffer_size[i];
305 		}
306 
307 		mlx5e_dbg(HW, priv, "%s: total buffer requested=%d\n", __func__, total_used);
308 
309 		if (total_used > port_buffer.port_buffer_size)
310 			return -EINVAL;
311 
312 		update_buffer = true;
313 		err = update_xoff_threshold(priv, &port_buffer, xoff);
314 		if (err)
315 			return err;
316 	}
317 
318 	/* Need to update buffer configuration if xoff value is changed */
319 	if (!update_buffer && xoff != priv->dcbx.xoff) {
320 		update_buffer = true;
321 		err = update_xoff_threshold(priv, &port_buffer, xoff);
322 		if (err)
323 			return err;
324 	}
325 	priv->dcbx.xoff = xoff;
326 
327 	/* Apply the settings */
328 	if (update_buffer) {
329 		priv->sw_is_port_buf_owner = true;
330 		err = port_set_buffer(priv, &port_buffer);
331 		if (err)
332 			return err;
333 	}
334 
335 	if (update_prio2buffer) {
336 		priv->sw_is_port_buf_owner = true;
337 		err = mlx5e_port_set_priority2buffer(priv->mdev, prio2buffer);
338 	}
339 
340 	return err;
341 }
342