1 /*
2 * Copyright (c) 2018, 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 #include "port_buffer.h"
33
mlx5e_port_query_buffer(struct mlx5e_priv * priv,struct mlx5e_port_buffer * port_buffer)34 int mlx5e_port_query_buffer(struct mlx5e_priv *priv,
35 struct mlx5e_port_buffer *port_buffer)
36 {
37 struct mlx5_core_dev *mdev = priv->mdev;
38 int sz = MLX5_ST_SZ_BYTES(pbmc_reg);
39 u32 total_used = 0;
40 void *buffer;
41 void *out;
42 int err;
43 int i;
44
45 out = kzalloc(sz, GFP_KERNEL);
46 if (!out)
47 return -ENOMEM;
48
49 err = mlx5e_port_query_pbmc(mdev, out);
50 if (err)
51 goto out;
52
53 for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
54 buffer = MLX5_ADDR_OF(pbmc_reg, out, buffer[i]);
55 port_buffer->buffer[i].lossy =
56 MLX5_GET(bufferx_reg, buffer, lossy);
57 port_buffer->buffer[i].epsb =
58 MLX5_GET(bufferx_reg, buffer, epsb);
59 port_buffer->buffer[i].size =
60 MLX5_GET(bufferx_reg, buffer, size) << MLX5E_BUFFER_CELL_SHIFT;
61 port_buffer->buffer[i].xon =
62 MLX5_GET(bufferx_reg, buffer, xon_threshold) << MLX5E_BUFFER_CELL_SHIFT;
63 port_buffer->buffer[i].xoff =
64 MLX5_GET(bufferx_reg, buffer, xoff_threshold) << MLX5E_BUFFER_CELL_SHIFT;
65 total_used += port_buffer->buffer[i].size;
66
67 mlx5e_dbg(HW, priv, "buffer %d: size=%d, xon=%d, xoff=%d, epsb=%d, lossy=%d\n", i,
68 port_buffer->buffer[i].size,
69 port_buffer->buffer[i].xon,
70 port_buffer->buffer[i].xoff,
71 port_buffer->buffer[i].epsb,
72 port_buffer->buffer[i].lossy);
73 }
74
75 port_buffer->port_buffer_size =
76 MLX5_GET(pbmc_reg, out, port_buffer_size) << MLX5E_BUFFER_CELL_SHIFT;
77 port_buffer->spare_buffer_size =
78 port_buffer->port_buffer_size - total_used;
79
80 mlx5e_dbg(HW, priv, "total buffer size=%d, spare buffer size=%d\n",
81 port_buffer->port_buffer_size,
82 port_buffer->spare_buffer_size);
83 out:
84 kfree(out);
85 return err;
86 }
87
port_set_buffer(struct mlx5e_priv * priv,struct mlx5e_port_buffer * port_buffer)88 static int port_set_buffer(struct mlx5e_priv *priv,
89 struct mlx5e_port_buffer *port_buffer)
90 {
91 struct mlx5_core_dev *mdev = priv->mdev;
92 int sz = MLX5_ST_SZ_BYTES(pbmc_reg);
93 void *buffer;
94 void *in;
95 int err;
96 int i;
97
98 in = kzalloc(sz, GFP_KERNEL);
99 if (!in)
100 return -ENOMEM;
101
102 err = mlx5e_port_query_pbmc(mdev, in);
103 if (err)
104 goto out;
105
106 for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
107 buffer = MLX5_ADDR_OF(pbmc_reg, in, buffer[i]);
108
109 MLX5_SET(bufferx_reg, buffer, size,
110 port_buffer->buffer[i].size >> MLX5E_BUFFER_CELL_SHIFT);
111 MLX5_SET(bufferx_reg, buffer, lossy,
112 port_buffer->buffer[i].lossy);
113 MLX5_SET(bufferx_reg, buffer, xoff_threshold,
114 port_buffer->buffer[i].xoff >> MLX5E_BUFFER_CELL_SHIFT);
115 MLX5_SET(bufferx_reg, buffer, xon_threshold,
116 port_buffer->buffer[i].xon >> MLX5E_BUFFER_CELL_SHIFT);
117 }
118
119 err = mlx5e_port_set_pbmc(mdev, in);
120 out:
121 kfree(in);
122 return err;
123 }
124
125 /* xoff = ((301+2.16 * len [m]) * speed [Gbps] + 2.72 MTU [B])
126 * minimum speed value is 40Gbps
127 */
calculate_xoff(struct mlx5e_priv * priv,unsigned int mtu)128 static u32 calculate_xoff(struct mlx5e_priv *priv, unsigned int mtu)
129 {
130 u32 speed;
131 u32 xoff;
132 int err;
133
134 err = mlx5e_port_linkspeed(priv->mdev, &speed);
135 if (err)
136 speed = SPEED_40000;
137 speed = max_t(u32, speed, SPEED_40000);
138
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
update_xoff_threshold(struct mlx5e_port_buffer * port_buffer,u32 xoff,unsigned int max_mtu)145 static int update_xoff_threshold(struct mlx5e_port_buffer *port_buffer,
146 u32 xoff, unsigned int max_mtu)
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 + max_mtu + (1 << MLX5E_BUFFER_CELL_SHIFT)))
159 return -ENOMEM;
160
161 port_buffer->buffer[i].xoff = port_buffer->buffer[i].size - xoff;
162 port_buffer->buffer[i].xon =
163 port_buffer->buffer[i].xoff - max_mtu;
164 }
165
166 return 0;
167 }
168
169 /**
170 * update_buffer_lossy - Update buffer configuration based on pfc
171 * @max_mtu: netdev's max_mtu
172 * @pfc_en: <input> current pfc configuration
173 * @buffer: <input> current prio to buffer mapping
174 * @xoff: <input> xoff value
175 * @port_buffer: <output> port receive buffer configuration
176 * @change: <output>
177 *
178 * Update buffer configuration based on pfc configuraiton and
179 * priority to buffer mapping.
180 * Buffer's lossy bit is changed to:
181 * lossless if there is at least one PFC enabled priority
182 * mapped to this buffer lossy if all priorities mapped to
183 * this buffer are PFC disabled
184 *
185 * @return: 0 if no error,
186 * sets change to true if buffer configuration was modified.
187 */
update_buffer_lossy(unsigned int max_mtu,u8 pfc_en,u8 * buffer,u32 xoff,struct mlx5e_port_buffer * port_buffer,bool * change)188 static int update_buffer_lossy(unsigned int max_mtu,
189 u8 pfc_en, u8 *buffer, u32 xoff,
190 struct mlx5e_port_buffer *port_buffer,
191 bool *change)
192 {
193 bool changed = false;
194 u8 lossy_count;
195 u8 prio_count;
196 u8 lossy;
197 int prio;
198 int err;
199 int i;
200
201 for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
202 prio_count = 0;
203 lossy_count = 0;
204
205 for (prio = 0; prio < MLX5E_MAX_PRIORITY; prio++) {
206 if (buffer[prio] != i)
207 continue;
208
209 prio_count++;
210 lossy_count += !(pfc_en & (1 << prio));
211 }
212
213 if (lossy_count == prio_count)
214 lossy = 1;
215 else /* lossy_count < prio_count */
216 lossy = 0;
217
218 if (lossy != port_buffer->buffer[i].lossy) {
219 port_buffer->buffer[i].lossy = lossy;
220 changed = true;
221 }
222 }
223
224 if (changed) {
225 err = update_xoff_threshold(port_buffer, xoff, max_mtu);
226 if (err)
227 return err;
228
229 *change = true;
230 }
231
232 return 0;
233 }
234
235 #define MINIMUM_MAX_MTU 9216
mlx5e_port_manual_buffer_config(struct mlx5e_priv * priv,u32 change,unsigned int mtu,struct ieee_pfc * pfc,u32 * buffer_size,u8 * prio2buffer)236 int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
237 u32 change, unsigned int mtu,
238 struct ieee_pfc *pfc,
239 u32 *buffer_size,
240 u8 *prio2buffer)
241 {
242 struct mlx5e_port_buffer port_buffer;
243 u32 xoff = calculate_xoff(priv, mtu);
244 bool update_prio2buffer = false;
245 u8 buffer[MLX5E_MAX_PRIORITY];
246 bool update_buffer = false;
247 unsigned int max_mtu;
248 u32 total_used = 0;
249 u8 curr_pfc_en;
250 int err;
251 int i;
252
253 mlx5e_dbg(HW, priv, "%s: change=%x\n", __func__, change);
254 max_mtu = max_t(unsigned int, priv->netdev->max_mtu, MINIMUM_MAX_MTU);
255
256 err = mlx5e_port_query_buffer(priv, &port_buffer);
257 if (err)
258 return err;
259
260 if (change & MLX5E_PORT_BUFFER_CABLE_LEN) {
261 update_buffer = true;
262 err = update_xoff_threshold(&port_buffer, xoff, max_mtu);
263 if (err)
264 return err;
265 }
266
267 if (change & MLX5E_PORT_BUFFER_PFC) {
268 err = mlx5e_port_query_priority2buffer(priv->mdev, buffer);
269 if (err)
270 return err;
271
272 err = update_buffer_lossy(max_mtu, pfc->pfc_en, buffer, xoff,
273 &port_buffer, &update_buffer);
274 if (err)
275 return err;
276 }
277
278 if (change & MLX5E_PORT_BUFFER_PRIO2BUFFER) {
279 update_prio2buffer = true;
280 err = mlx5_query_port_pfc(priv->mdev, &curr_pfc_en, NULL);
281 if (err)
282 return err;
283
284 err = update_buffer_lossy(max_mtu, curr_pfc_en, prio2buffer,
285 xoff, &port_buffer, &update_buffer);
286 if (err)
287 return err;
288 }
289
290 if (change & MLX5E_PORT_BUFFER_SIZE) {
291 for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
292 mlx5e_dbg(HW, priv, "%s: buffer[%d]=%d\n", __func__, i, buffer_size[i]);
293 if (!port_buffer.buffer[i].lossy && !buffer_size[i]) {
294 mlx5e_dbg(HW, priv, "%s: lossless buffer[%d] size cannot be zero\n",
295 __func__, i);
296 return -EINVAL;
297 }
298
299 port_buffer.buffer[i].size = buffer_size[i];
300 total_used += buffer_size[i];
301 }
302
303 mlx5e_dbg(HW, priv, "%s: total buffer requested=%d\n", __func__, total_used);
304
305 if (total_used > port_buffer.port_buffer_size)
306 return -EINVAL;
307
308 update_buffer = true;
309 err = update_xoff_threshold(&port_buffer, xoff, max_mtu);
310 if (err)
311 return err;
312 }
313
314 /* Need to update buffer configuration if xoff value is changed */
315 if (!update_buffer && xoff != priv->dcbx.xoff) {
316 update_buffer = true;
317 err = update_xoff_threshold(&port_buffer, xoff, max_mtu);
318 if (err)
319 return err;
320 }
321 priv->dcbx.xoff = xoff;
322
323 /* Apply the settings */
324 if (update_buffer) {
325 err = port_set_buffer(priv, &port_buffer);
326 if (err)
327 return err;
328 }
329
330 if (update_prio2buffer)
331 err = mlx5e_port_set_priority2buffer(priv->mdev, prio2buffer);
332
333 return err;
334 }
335
