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]) */
calculate_xoff(struct mlx5e_priv * priv,unsigned int mtu)126 static u32 calculate_xoff(struct mlx5e_priv *priv, unsigned int mtu)
127 {
128 u32 speed;
129 u32 xoff;
130 int err;
131
132 err = mlx5e_port_linkspeed(priv->mdev, &speed);
133 if (err)
134 return 0;
135
136 xoff = (301 + 216 * priv->dcbx.cable_len / 100) * speed / 1000 + 272 * mtu / 100;
137
138 mlx5e_dbg(HW, priv, "%s: xoff=%d\n", __func__, xoff);
139 return xoff;
140 }
141
update_xoff_threshold(struct mlx5e_port_buffer * port_buffer,u32 xoff,unsigned int mtu)142 static int update_xoff_threshold(struct mlx5e_port_buffer *port_buffer,
143 u32 xoff, unsigned int mtu)
144 {
145 int i;
146
147 for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
148 if (port_buffer->buffer[i].lossy) {
149 port_buffer->buffer[i].xoff = 0;
150 port_buffer->buffer[i].xon = 0;
151 continue;
152 }
153
154 if (port_buffer->buffer[i].size <
155 (xoff + mtu + (1 << MLX5E_BUFFER_CELL_SHIFT)))
156 return -ENOMEM;
157
158 port_buffer->buffer[i].xoff = port_buffer->buffer[i].size - xoff;
159 port_buffer->buffer[i].xon = port_buffer->buffer[i].xoff - mtu;
160 }
161
162 return 0;
163 }
164
165 /**
166 * update_buffer_lossy()
167 * mtu: device's MTU
168 * pfc_en: <input> current pfc configuration
169 * buffer: <input> current prio to buffer mapping
170 * xoff: <input> xoff value
171 * port_buffer: <output> port receive buffer configuration
172 * change: <output>
173 *
174 * Update buffer configuration based on pfc configuraiton and priority
175 * to buffer mapping.
176 * Buffer's lossy bit is changed to:
177 * lossless if there is at least one PFC enabled priority mapped to this buffer
178 * lossy if all priorities mapped to this buffer are PFC disabled
179 *
180 * Return:
181 * Return 0 if no error.
182 * Set change to true if buffer configuration is modified.
183 */
update_buffer_lossy(unsigned int mtu,u8 pfc_en,u8 * buffer,u32 xoff,struct mlx5e_port_buffer * port_buffer,bool * change)184 static int update_buffer_lossy(unsigned int mtu,
185 u8 pfc_en, u8 *buffer, u32 xoff,
186 struct mlx5e_port_buffer *port_buffer,
187 bool *change)
188 {
189 bool changed = false;
190 u8 lossy_count;
191 u8 prio_count;
192 u8 lossy;
193 int prio;
194 int err;
195 int i;
196
197 for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
198 prio_count = 0;
199 lossy_count = 0;
200
201 for (prio = 0; prio < MLX5E_MAX_PRIORITY; prio++) {
202 if (buffer[prio] != i)
203 continue;
204
205 prio_count++;
206 lossy_count += !(pfc_en & (1 << prio));
207 }
208
209 if (lossy_count == prio_count)
210 lossy = 1;
211 else /* lossy_count < prio_count */
212 lossy = 0;
213
214 if (lossy != port_buffer->buffer[i].lossy) {
215 port_buffer->buffer[i].lossy = lossy;
216 changed = true;
217 }
218 }
219
220 if (changed) {
221 err = update_xoff_threshold(port_buffer, xoff, mtu);
222 if (err)
223 return err;
224
225 *change = true;
226 }
227
228 return 0;
229 }
230
mlx5e_port_manual_buffer_config(struct mlx5e_priv * priv,u32 change,unsigned int mtu,struct ieee_pfc * pfc,u32 * buffer_size,u8 * prio2buffer)231 int mlx5e_port_manual_buffer_config(struct mlx5e_priv *priv,
232 u32 change, unsigned int mtu,
233 struct ieee_pfc *pfc,
234 u32 *buffer_size,
235 u8 *prio2buffer)
236 {
237 struct mlx5e_port_buffer port_buffer;
238 u32 xoff = calculate_xoff(priv, mtu);
239 bool update_prio2buffer = false;
240 u8 buffer[MLX5E_MAX_PRIORITY];
241 bool update_buffer = false;
242 u32 total_used = 0;
243 u8 curr_pfc_en;
244 int err;
245 int i;
246
247 mlx5e_dbg(HW, priv, "%s: change=%x\n", __func__, change);
248
249 err = mlx5e_port_query_buffer(priv, &port_buffer);
250 if (err)
251 return err;
252
253 if (change & MLX5E_PORT_BUFFER_CABLE_LEN) {
254 update_buffer = true;
255 err = update_xoff_threshold(&port_buffer, xoff, mtu);
256 if (err)
257 return err;
258 }
259
260 if (change & MLX5E_PORT_BUFFER_PFC) {
261 err = mlx5e_port_query_priority2buffer(priv->mdev, buffer);
262 if (err)
263 return err;
264
265 err = update_buffer_lossy(mtu, pfc->pfc_en, buffer, xoff,
266 &port_buffer, &update_buffer);
267 if (err)
268 return err;
269 }
270
271 if (change & MLX5E_PORT_BUFFER_PRIO2BUFFER) {
272 update_prio2buffer = true;
273 err = mlx5_query_port_pfc(priv->mdev, &curr_pfc_en, NULL);
274 if (err)
275 return err;
276
277 err = update_buffer_lossy(mtu, curr_pfc_en, prio2buffer, xoff,
278 &port_buffer, &update_buffer);
279 if (err)
280 return err;
281 }
282
283 if (change & MLX5E_PORT_BUFFER_SIZE) {
284 for (i = 0; i < MLX5E_MAX_BUFFER; i++) {
285 mlx5e_dbg(HW, priv, "%s: buffer[%d]=%d\n", __func__, i, buffer_size[i]);
286 if (!port_buffer.buffer[i].lossy && !buffer_size[i]) {
287 mlx5e_dbg(HW, priv, "%s: lossless buffer[%d] size cannot be zero\n",
288 __func__, i);
289 return -EINVAL;
290 }
291
292 port_buffer.buffer[i].size = buffer_size[i];
293 total_used += buffer_size[i];
294 }
295
296 mlx5e_dbg(HW, priv, "%s: total buffer requested=%d\n", __func__, total_used);
297
298 if (total_used > port_buffer.port_buffer_size)
299 return -EINVAL;
300
301 update_buffer = true;
302 err = update_xoff_threshold(&port_buffer, xoff, mtu);
303 if (err)
304 return err;
305 }
306
307 /* Need to update buffer configuration if xoff value is changed */
308 if (!update_buffer && xoff != priv->dcbx.xoff) {
309 update_buffer = true;
310 err = update_xoff_threshold(&port_buffer, xoff, mtu);
311 if (err)
312 return err;
313 }
314 priv->dcbx.xoff = xoff;
315
316 /* Apply the settings */
317 if (update_buffer) {
318 err = port_set_buffer(priv, &port_buffer);
319 if (err)
320 return err;
321 }
322
323 if (update_prio2buffer)
324 err = mlx5e_port_set_priority2buffer(priv->mdev, prio2buffer);
325
326 return err;
327 }
328
