1 /*******************************************************************************
2 
3   Intel 10 Gigabit PCI Express Linux driver
4   Copyright(c) 1999 - 2014 Intel Corporation.
5 
6   This program is free software; you can redistribute it and/or modify it
7   under the terms and conditions of the GNU General Public License,
8   version 2, as published by the Free Software Foundation.
9 
10   This program is distributed in the hope it will be useful, but WITHOUT
11   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13   more details.
14 
15   You should have received a copy of the GNU General Public License along with
16   this program; if not, write to the Free Software Foundation, Inc.,
17   51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
18 
19   The full GNU General Public License is included in this distribution in
20   the file called "COPYING".
21 
22   Contact Information:
23   Linux NICS <linux.nics@intel.com>
24   e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
25   Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
26 
27 *******************************************************************************/
28 
29 
30 #include "ixgbe.h"
31 #include "ixgbe_type.h"
32 #include "ixgbe_dcb.h"
33 #include "ixgbe_dcb_82598.h"
34 #include "ixgbe_dcb_82599.h"
35 
36 /**
37  * ixgbe_ieee_credits - This calculates the ieee traffic class
38  * credits from the configured bandwidth percentages. Credits
39  * are the smallest unit programmable into the underlying
40  * hardware. The IEEE 802.1Qaz specification do not use bandwidth
41  * groups so this is much simplified from the CEE case.
42  */
43 static s32 ixgbe_ieee_credits(__u8 *bw, __u16 *refill,
44 			      __u16 *max, int max_frame)
45 {
46 	int min_percent = 100;
47 	int min_credit, multiplier;
48 	int i;
49 
50 	min_credit = ((max_frame / 2) + DCB_CREDIT_QUANTUM - 1) /
51 			DCB_CREDIT_QUANTUM;
52 
53 	for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
54 		if (bw[i] < min_percent && bw[i])
55 			min_percent = bw[i];
56 	}
57 
58 	multiplier = (min_credit / min_percent) + 1;
59 
60 	/* Find out the hw credits for each TC */
61 	for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
62 		int val = min(bw[i] * multiplier, MAX_CREDIT_REFILL);
63 
64 		if (val < min_credit)
65 			val = min_credit;
66 		refill[i] = val;
67 
68 		max[i] = bw[i] ? (bw[i] * MAX_CREDIT)/100 : min_credit;
69 	}
70 	return 0;
71 }
72 
73 /**
74  * ixgbe_dcb_calculate_tc_credits - Calculates traffic class credits
75  * @ixgbe_dcb_config: Struct containing DCB settings.
76  * @direction: Configuring either Tx or Rx.
77  *
78  * This function calculates the credits allocated to each traffic class.
79  * It should be called only after the rules are checked by
80  * ixgbe_dcb_check_config().
81  */
82 s32 ixgbe_dcb_calculate_tc_credits(struct ixgbe_hw *hw,
83 				   struct ixgbe_dcb_config *dcb_config,
84 				   int max_frame, u8 direction)
85 {
86 	struct tc_bw_alloc *p;
87 	int min_credit;
88 	int min_multiplier;
89 	int min_percent = 100;
90 	/* Initialization values default for Tx settings */
91 	u32 credit_refill       = 0;
92 	u32 credit_max          = 0;
93 	u16 link_percentage     = 0;
94 	u8  bw_percent          = 0;
95 	u8  i;
96 
97 	if (!dcb_config)
98 		return DCB_ERR_CONFIG;
99 
100 	min_credit = ((max_frame / 2) + DCB_CREDIT_QUANTUM - 1) /
101 			DCB_CREDIT_QUANTUM;
102 
103 	/* Find smallest link percentage */
104 	for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
105 		p = &dcb_config->tc_config[i].path[direction];
106 		bw_percent = dcb_config->bw_percentage[direction][p->bwg_id];
107 		link_percentage = p->bwg_percent;
108 
109 		link_percentage = (link_percentage * bw_percent) / 100;
110 
111 		if (link_percentage && link_percentage < min_percent)
112 			min_percent = link_percentage;
113 	}
114 
115 	/*
116 	 * The ratio between traffic classes will control the bandwidth
117 	 * percentages seen on the wire. To calculate this ratio we use
118 	 * a multiplier. It is required that the refill credits must be
119 	 * larger than the max frame size so here we find the smallest
120 	 * multiplier that will allow all bandwidth percentages to be
121 	 * greater than the max frame size.
122 	 */
123 	min_multiplier = (min_credit / min_percent) + 1;
124 
125 	/* Find out the link percentage for each TC first */
126 	for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
127 		p = &dcb_config->tc_config[i].path[direction];
128 		bw_percent = dcb_config->bw_percentage[direction][p->bwg_id];
129 
130 		link_percentage = p->bwg_percent;
131 		/* Must be careful of integer division for very small nums */
132 		link_percentage = (link_percentage * bw_percent) / 100;
133 		if (p->bwg_percent > 0 && link_percentage == 0)
134 			link_percentage = 1;
135 
136 		/* Save link_percentage for reference */
137 		p->link_percent = (u8)link_percentage;
138 
139 		/* Calculate credit refill ratio using multiplier */
140 		credit_refill = min(link_percentage * min_multiplier,
141 				    MAX_CREDIT_REFILL);
142 		p->data_credits_refill = (u16)credit_refill;
143 
144 		/* Calculate maximum credit for the TC */
145 		credit_max = (link_percentage * MAX_CREDIT) / 100;
146 
147 		/*
148 		 * Adjustment based on rule checking, if the percentage
149 		 * of a TC is too small, the maximum credit may not be
150 		 * enough to send out a jumbo frame in data plane arbitration.
151 		 */
152 		if (credit_max && (credit_max < min_credit))
153 			credit_max = min_credit;
154 
155 		if (direction == DCB_TX_CONFIG) {
156 			/*
157 			 * Adjustment based on rule checking, if the
158 			 * percentage of a TC is too small, the maximum
159 			 * credit may not be enough to send out a TSO
160 			 * packet in descriptor plane arbitration.
161 			 */
162 			if ((hw->mac.type == ixgbe_mac_82598EB) &&
163 			    credit_max &&
164 			    (credit_max < MINIMUM_CREDIT_FOR_TSO))
165 				credit_max = MINIMUM_CREDIT_FOR_TSO;
166 
167 			dcb_config->tc_config[i].desc_credits_max =
168 				(u16)credit_max;
169 		}
170 
171 		p->data_credits_max = (u16)credit_max;
172 	}
173 
174 	return 0;
175 }
176 
177 void ixgbe_dcb_unpack_pfc(struct ixgbe_dcb_config *cfg, u8 *pfc_en)
178 {
179 	struct tc_configuration *tc_config = &cfg->tc_config[0];
180 	int tc;
181 
182 	for (*pfc_en = 0, tc = 0; tc < MAX_TRAFFIC_CLASS; tc++) {
183 		if (tc_config[tc].dcb_pfc != pfc_disabled)
184 			*pfc_en |= 1 << tc;
185 	}
186 }
187 
188 void ixgbe_dcb_unpack_refill(struct ixgbe_dcb_config *cfg, int direction,
189 			     u16 *refill)
190 {
191 	struct tc_configuration *tc_config = &cfg->tc_config[0];
192 	int tc;
193 
194 	for (tc = 0; tc < MAX_TRAFFIC_CLASS; tc++)
195 		refill[tc] = tc_config[tc].path[direction].data_credits_refill;
196 }
197 
198 void ixgbe_dcb_unpack_max(struct ixgbe_dcb_config *cfg, u16 *max)
199 {
200 	struct tc_configuration *tc_config = &cfg->tc_config[0];
201 	int tc;
202 
203 	for (tc = 0; tc < MAX_TRAFFIC_CLASS; tc++)
204 		max[tc] = tc_config[tc].desc_credits_max;
205 }
206 
207 void ixgbe_dcb_unpack_bwgid(struct ixgbe_dcb_config *cfg, int direction,
208 			    u8 *bwgid)
209 {
210 	struct tc_configuration *tc_config = &cfg->tc_config[0];
211 	int tc;
212 
213 	for (tc = 0; tc < MAX_TRAFFIC_CLASS; tc++)
214 		bwgid[tc] = tc_config[tc].path[direction].bwg_id;
215 }
216 
217 void ixgbe_dcb_unpack_prio(struct ixgbe_dcb_config *cfg, int direction,
218 			    u8 *ptype)
219 {
220 	struct tc_configuration *tc_config = &cfg->tc_config[0];
221 	int tc;
222 
223 	for (tc = 0; tc < MAX_TRAFFIC_CLASS; tc++)
224 		ptype[tc] = tc_config[tc].path[direction].prio_type;
225 }
226 
227 u8 ixgbe_dcb_get_tc_from_up(struct ixgbe_dcb_config *cfg, int direction, u8 up)
228 {
229 	struct tc_configuration *tc_config = &cfg->tc_config[0];
230 	u8 prio_mask = 1 << up;
231 	u8 tc = cfg->num_tcs.pg_tcs;
232 
233 	/* If tc is 0 then DCB is likely not enabled or supported */
234 	if (!tc)
235 		return 0;
236 
237 	/*
238 	 * Test from maximum TC to 1 and report the first match we find.  If
239 	 * we find no match we can assume that the TC is 0 since the TC must
240 	 * be set for all user priorities
241 	 */
242 	for (tc--; tc; tc--) {
243 		if (prio_mask & tc_config[tc].path[direction].up_to_tc_bitmap)
244 			break;
245 	}
246 
247 	return tc;
248 }
249 
250 void ixgbe_dcb_unpack_map(struct ixgbe_dcb_config *cfg, int direction, u8 *map)
251 {
252 	u8 up;
253 
254 	for (up = 0; up < MAX_USER_PRIORITY; up++)
255 		map[up] = ixgbe_dcb_get_tc_from_up(cfg, direction, up);
256 }
257 
258 /**
259  * ixgbe_dcb_hw_config - Config and enable DCB
260  * @hw: pointer to hardware structure
261  * @dcb_config: pointer to ixgbe_dcb_config structure
262  *
263  * Configure dcb settings and enable dcb mode.
264  */
265 s32 ixgbe_dcb_hw_config(struct ixgbe_hw *hw,
266 			struct ixgbe_dcb_config *dcb_config)
267 {
268 	u8 pfc_en;
269 	u8 ptype[MAX_TRAFFIC_CLASS];
270 	u8 bwgid[MAX_TRAFFIC_CLASS];
271 	u8 prio_tc[MAX_TRAFFIC_CLASS];
272 	u16 refill[MAX_TRAFFIC_CLASS];
273 	u16 max[MAX_TRAFFIC_CLASS];
274 
275 	/* Unpack CEE standard containers */
276 	ixgbe_dcb_unpack_pfc(dcb_config, &pfc_en);
277 	ixgbe_dcb_unpack_refill(dcb_config, DCB_TX_CONFIG, refill);
278 	ixgbe_dcb_unpack_max(dcb_config, max);
279 	ixgbe_dcb_unpack_bwgid(dcb_config, DCB_TX_CONFIG, bwgid);
280 	ixgbe_dcb_unpack_prio(dcb_config, DCB_TX_CONFIG, ptype);
281 	ixgbe_dcb_unpack_map(dcb_config, DCB_TX_CONFIG, prio_tc);
282 
283 	switch (hw->mac.type) {
284 	case ixgbe_mac_82598EB:
285 		return ixgbe_dcb_hw_config_82598(hw, pfc_en, refill, max,
286 						 bwgid, ptype);
287 	case ixgbe_mac_82599EB:
288 	case ixgbe_mac_X540:
289 	case ixgbe_mac_X550:
290 	case ixgbe_mac_X550EM_x:
291 		return ixgbe_dcb_hw_config_82599(hw, pfc_en, refill, max,
292 						 bwgid, ptype, prio_tc);
293 	default:
294 		break;
295 	}
296 	return 0;
297 }
298 
299 /* Helper routines to abstract HW specifics from DCB netlink ops */
300 s32 ixgbe_dcb_hw_pfc_config(struct ixgbe_hw *hw, u8 pfc_en, u8 *prio_tc)
301 {
302 	switch (hw->mac.type) {
303 	case ixgbe_mac_82598EB:
304 		return ixgbe_dcb_config_pfc_82598(hw, pfc_en);
305 	case ixgbe_mac_82599EB:
306 	case ixgbe_mac_X540:
307 	case ixgbe_mac_X550:
308 	case ixgbe_mac_X550EM_x:
309 		return ixgbe_dcb_config_pfc_82599(hw, pfc_en, prio_tc);
310 	default:
311 		break;
312 	}
313 	return -EINVAL;
314 }
315 
316 s32 ixgbe_dcb_hw_ets(struct ixgbe_hw *hw, struct ieee_ets *ets, int max_frame)
317 {
318 	__u16 refill[IEEE_8021QAZ_MAX_TCS], max[IEEE_8021QAZ_MAX_TCS];
319 	__u8 prio_type[IEEE_8021QAZ_MAX_TCS];
320 	int i;
321 
322 	/* naively give each TC a bwg to map onto CEE hardware */
323 	__u8 bwg_id[IEEE_8021QAZ_MAX_TCS] = {0, 1, 2, 3, 4, 5, 6, 7};
324 
325 	/* Map TSA onto CEE prio type */
326 	for (i = 0; i < IEEE_8021QAZ_MAX_TCS; i++) {
327 		switch (ets->tc_tsa[i]) {
328 		case IEEE_8021QAZ_TSA_STRICT:
329 			prio_type[i] = 2;
330 			break;
331 		case IEEE_8021QAZ_TSA_ETS:
332 			prio_type[i] = 0;
333 			break;
334 		default:
335 			/* Hardware only supports priority strict or
336 			 * ETS transmission selection algorithms if
337 			 * we receive some other value from dcbnl
338 			 * throw an error
339 			 */
340 			return -EINVAL;
341 		}
342 	}
343 
344 	ixgbe_ieee_credits(ets->tc_tx_bw, refill, max, max_frame);
345 	return ixgbe_dcb_hw_ets_config(hw, refill, max,
346 				       bwg_id, prio_type, ets->prio_tc);
347 }
348 
349 s32 ixgbe_dcb_hw_ets_config(struct ixgbe_hw *hw,
350 			    u16 *refill, u16 *max, u8 *bwg_id,
351 			    u8 *prio_type, u8 *prio_tc)
352 {
353 	switch (hw->mac.type) {
354 	case ixgbe_mac_82598EB:
355 		ixgbe_dcb_config_rx_arbiter_82598(hw, refill, max,
356 							prio_type);
357 		ixgbe_dcb_config_tx_desc_arbiter_82598(hw, refill, max,
358 							     bwg_id, prio_type);
359 		ixgbe_dcb_config_tx_data_arbiter_82598(hw, refill, max,
360 							     bwg_id, prio_type);
361 		break;
362 	case ixgbe_mac_82599EB:
363 	case ixgbe_mac_X540:
364 	case ixgbe_mac_X550:
365 	case ixgbe_mac_X550EM_x:
366 		ixgbe_dcb_config_rx_arbiter_82599(hw, refill, max,
367 						  bwg_id, prio_type, prio_tc);
368 		ixgbe_dcb_config_tx_desc_arbiter_82599(hw, refill, max,
369 						       bwg_id, prio_type);
370 		ixgbe_dcb_config_tx_data_arbiter_82599(hw, refill, max, bwg_id,
371 						       prio_type, prio_tc);
372 		break;
373 	default:
374 		break;
375 	}
376 	return 0;
377 }
378 
379 static void ixgbe_dcb_read_rtrup2tc_82599(struct ixgbe_hw *hw, u8 *map)
380 {
381 	u32 reg, i;
382 
383 	reg = IXGBE_READ_REG(hw, IXGBE_RTRUP2TC);
384 	for (i = 0; i < MAX_USER_PRIORITY; i++)
385 		map[i] = IXGBE_RTRUP2TC_UP_MASK &
386 			(reg >> (i * IXGBE_RTRUP2TC_UP_SHIFT));
387 }
388 
389 void ixgbe_dcb_read_rtrup2tc(struct ixgbe_hw *hw, u8 *map)
390 {
391 	switch (hw->mac.type) {
392 	case ixgbe_mac_82599EB:
393 	case ixgbe_mac_X540:
394 	case ixgbe_mac_X550:
395 	case ixgbe_mac_X550EM_x:
396 		ixgbe_dcb_read_rtrup2tc_82599(hw, map);
397 		break;
398 	default:
399 		break;
400 	}
401 }
402