1 /*******************************************************************************
2 
3   Intel 10 Gigabit PCI Express Linux driver
4   Copyright(c) 1999 - 2013 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 	s32 ret_val = 0;
91 	/* Initialization values default for Tx settings */
92 	u32 credit_refill       = 0;
93 	u32 credit_max          = 0;
94 	u16 link_percentage     = 0;
95 	u8  bw_percent          = 0;
96 	u8  i;
97 
98 	if (dcb_config == NULL) {
99 		ret_val = DCB_ERR_CONFIG;
100 		goto out;
101 	}
102 
103 	min_credit = ((max_frame / 2) + DCB_CREDIT_QUANTUM - 1) /
104 			DCB_CREDIT_QUANTUM;
105 
106 	/* Find smallest link percentage */
107 	for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
108 		p = &dcb_config->tc_config[i].path[direction];
109 		bw_percent = dcb_config->bw_percentage[direction][p->bwg_id];
110 		link_percentage = p->bwg_percent;
111 
112 		link_percentage = (link_percentage * bw_percent) / 100;
113 
114 		if (link_percentage && link_percentage < min_percent)
115 			min_percent = link_percentage;
116 	}
117 
118 	/*
119 	 * The ratio between traffic classes will control the bandwidth
120 	 * percentages seen on the wire. To calculate this ratio we use
121 	 * a multiplier. It is required that the refill credits must be
122 	 * larger than the max frame size so here we find the smallest
123 	 * multiplier that will allow all bandwidth percentages to be
124 	 * greater than the max frame size.
125 	 */
126 	min_multiplier = (min_credit / min_percent) + 1;
127 
128 	/* Find out the link percentage for each TC first */
129 	for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
130 		p = &dcb_config->tc_config[i].path[direction];
131 		bw_percent = dcb_config->bw_percentage[direction][p->bwg_id];
132 
133 		link_percentage = p->bwg_percent;
134 		/* Must be careful of integer division for very small nums */
135 		link_percentage = (link_percentage * bw_percent) / 100;
136 		if (p->bwg_percent > 0 && link_percentage == 0)
137 			link_percentage = 1;
138 
139 		/* Save link_percentage for reference */
140 		p->link_percent = (u8)link_percentage;
141 
142 		/* Calculate credit refill ratio using multiplier */
143 		credit_refill = min(link_percentage * min_multiplier,
144 				    MAX_CREDIT_REFILL);
145 		p->data_credits_refill = (u16)credit_refill;
146 
147 		/* Calculate maximum credit for the TC */
148 		credit_max = (link_percentage * MAX_CREDIT) / 100;
149 
150 		/*
151 		 * Adjustment based on rule checking, if the percentage
152 		 * of a TC is too small, the maximum credit may not be
153 		 * enough to send out a jumbo frame in data plane arbitration.
154 		 */
155 		if (credit_max && (credit_max < min_credit))
156 			credit_max = min_credit;
157 
158 		if (direction == DCB_TX_CONFIG) {
159 			/*
160 			 * Adjustment based on rule checking, if the
161 			 * percentage of a TC is too small, the maximum
162 			 * credit may not be enough to send out a TSO
163 			 * packet in descriptor plane arbitration.
164 			 */
165 			if ((hw->mac.type == ixgbe_mac_82598EB) &&
166 			    credit_max &&
167 			    (credit_max < MINIMUM_CREDIT_FOR_TSO))
168 				credit_max = MINIMUM_CREDIT_FOR_TSO;
169 
170 			dcb_config->tc_config[i].desc_credits_max =
171 				(u16)credit_max;
172 		}
173 
174 		p->data_credits_max = (u16)credit_max;
175 	}
176 
177 out:
178 	return ret_val;
179 }
180 
181 void ixgbe_dcb_unpack_pfc(struct ixgbe_dcb_config *cfg, u8 *pfc_en)
182 {
183 	struct tc_configuration *tc_config = &cfg->tc_config[0];
184 	int tc;
185 
186 	for (*pfc_en = 0, tc = 0; tc < MAX_TRAFFIC_CLASS; tc++) {
187 		if (tc_config[tc].dcb_pfc != pfc_disabled)
188 			*pfc_en |= 1 << tc;
189 	}
190 }
191 
192 void ixgbe_dcb_unpack_refill(struct ixgbe_dcb_config *cfg, int direction,
193 			     u16 *refill)
194 {
195 	struct tc_configuration *tc_config = &cfg->tc_config[0];
196 	int tc;
197 
198 	for (tc = 0; tc < MAX_TRAFFIC_CLASS; tc++)
199 		refill[tc] = tc_config[tc].path[direction].data_credits_refill;
200 }
201 
202 void ixgbe_dcb_unpack_max(struct ixgbe_dcb_config *cfg, u16 *max)
203 {
204 	struct tc_configuration *tc_config = &cfg->tc_config[0];
205 	int tc;
206 
207 	for (tc = 0; tc < MAX_TRAFFIC_CLASS; tc++)
208 		max[tc] = tc_config[tc].desc_credits_max;
209 }
210 
211 void ixgbe_dcb_unpack_bwgid(struct ixgbe_dcb_config *cfg, int direction,
212 			    u8 *bwgid)
213 {
214 	struct tc_configuration *tc_config = &cfg->tc_config[0];
215 	int tc;
216 
217 	for (tc = 0; tc < MAX_TRAFFIC_CLASS; tc++)
218 		bwgid[tc] = tc_config[tc].path[direction].bwg_id;
219 }
220 
221 void ixgbe_dcb_unpack_prio(struct ixgbe_dcb_config *cfg, int direction,
222 			    u8 *ptype)
223 {
224 	struct tc_configuration *tc_config = &cfg->tc_config[0];
225 	int tc;
226 
227 	for (tc = 0; tc < MAX_TRAFFIC_CLASS; tc++)
228 		ptype[tc] = tc_config[tc].path[direction].prio_type;
229 }
230 
231 u8 ixgbe_dcb_get_tc_from_up(struct ixgbe_dcb_config *cfg, int direction, u8 up)
232 {
233 	struct tc_configuration *tc_config = &cfg->tc_config[0];
234 	u8 prio_mask = 1 << up;
235 	u8 tc = cfg->num_tcs.pg_tcs;
236 
237 	/* If tc is 0 then DCB is likely not enabled or supported */
238 	if (!tc)
239 		goto out;
240 
241 	/*
242 	 * Test from maximum TC to 1 and report the first match we find.  If
243 	 * we find no match we can assume that the TC is 0 since the TC must
244 	 * be set for all user priorities
245 	 */
246 	for (tc--; tc; tc--) {
247 		if (prio_mask & tc_config[tc].path[direction].up_to_tc_bitmap)
248 			break;
249 	}
250 out:
251 	return tc;
252 }
253 
254 void ixgbe_dcb_unpack_map(struct ixgbe_dcb_config *cfg, int direction, u8 *map)
255 {
256 	u8 up;
257 
258 	for (up = 0; up < MAX_USER_PRIORITY; up++)
259 		map[up] = ixgbe_dcb_get_tc_from_up(cfg, direction, up);
260 }
261 
262 /**
263  * ixgbe_dcb_hw_config - Config and enable DCB
264  * @hw: pointer to hardware structure
265  * @dcb_config: pointer to ixgbe_dcb_config structure
266  *
267  * Configure dcb settings and enable dcb mode.
268  */
269 s32 ixgbe_dcb_hw_config(struct ixgbe_hw *hw,
270                         struct ixgbe_dcb_config *dcb_config)
271 {
272 	s32 ret = 0;
273 	u8 pfc_en;
274 	u8 ptype[MAX_TRAFFIC_CLASS];
275 	u8 bwgid[MAX_TRAFFIC_CLASS];
276 	u8 prio_tc[MAX_TRAFFIC_CLASS];
277 	u16 refill[MAX_TRAFFIC_CLASS];
278 	u16 max[MAX_TRAFFIC_CLASS];
279 
280 	/* Unpack CEE standard containers */
281 	ixgbe_dcb_unpack_pfc(dcb_config, &pfc_en);
282 	ixgbe_dcb_unpack_refill(dcb_config, DCB_TX_CONFIG, refill);
283 	ixgbe_dcb_unpack_max(dcb_config, max);
284 	ixgbe_dcb_unpack_bwgid(dcb_config, DCB_TX_CONFIG, bwgid);
285 	ixgbe_dcb_unpack_prio(dcb_config, DCB_TX_CONFIG, ptype);
286 	ixgbe_dcb_unpack_map(dcb_config, DCB_TX_CONFIG, prio_tc);
287 
288 	switch (hw->mac.type) {
289 	case ixgbe_mac_82598EB:
290 		ret = ixgbe_dcb_hw_config_82598(hw, pfc_en, refill, max,
291 						bwgid, ptype);
292 		break;
293 	case ixgbe_mac_82599EB:
294 	case ixgbe_mac_X540:
295 		ret = ixgbe_dcb_hw_config_82599(hw, pfc_en, refill, max,
296 						bwgid, ptype, prio_tc);
297 		break;
298 	default:
299 		break;
300 	}
301 	return ret;
302 }
303 
304 /* Helper routines to abstract HW specifics from DCB netlink ops */
305 s32 ixgbe_dcb_hw_pfc_config(struct ixgbe_hw *hw, u8 pfc_en, u8 *prio_tc)
306 {
307 	int ret = -EINVAL;
308 
309 	switch (hw->mac.type) {
310 	case ixgbe_mac_82598EB:
311 		ret = ixgbe_dcb_config_pfc_82598(hw, pfc_en);
312 		break;
313 	case ixgbe_mac_82599EB:
314 	case ixgbe_mac_X540:
315 		ret = ixgbe_dcb_config_pfc_82599(hw, pfc_en, prio_tc);
316 		break;
317 	default:
318 		break;
319 	}
320 	return ret;
321 }
322 
323 s32 ixgbe_dcb_hw_ets(struct ixgbe_hw *hw, struct ieee_ets *ets, int max_frame)
324 {
325 	__u16 refill[IEEE_8021QAZ_MAX_TCS], max[IEEE_8021QAZ_MAX_TCS];
326 	__u8 prio_type[IEEE_8021QAZ_MAX_TCS];
327 	int i;
328 
329 	/* naively give each TC a bwg to map onto CEE hardware */
330 	__u8 bwg_id[IEEE_8021QAZ_MAX_TCS] = {0, 1, 2, 3, 4, 5, 6, 7};
331 
332 	/* Map TSA onto CEE prio type */
333 	for (i = 0; i < IEEE_8021QAZ_MAX_TCS; i++) {
334 		switch (ets->tc_tsa[i]) {
335 		case IEEE_8021QAZ_TSA_STRICT:
336 			prio_type[i] = 2;
337 			break;
338 		case IEEE_8021QAZ_TSA_ETS:
339 			prio_type[i] = 0;
340 			break;
341 		default:
342 			/* Hardware only supports priority strict or
343 			 * ETS transmission selection algorithms if
344 			 * we receive some other value from dcbnl
345 			 * throw an error
346 			 */
347 			return -EINVAL;
348 		}
349 	}
350 
351 	ixgbe_ieee_credits(ets->tc_tx_bw, refill, max, max_frame);
352 	return ixgbe_dcb_hw_ets_config(hw, refill, max,
353 				       bwg_id, prio_type, ets->prio_tc);
354 }
355 
356 s32 ixgbe_dcb_hw_ets_config(struct ixgbe_hw *hw,
357 			    u16 *refill, u16 *max, u8 *bwg_id,
358 			    u8 *prio_type, u8 *prio_tc)
359 {
360 	switch (hw->mac.type) {
361 	case ixgbe_mac_82598EB:
362 		ixgbe_dcb_config_rx_arbiter_82598(hw, refill, max,
363 							prio_type);
364 		ixgbe_dcb_config_tx_desc_arbiter_82598(hw, refill, max,
365 							     bwg_id, prio_type);
366 		ixgbe_dcb_config_tx_data_arbiter_82598(hw, refill, max,
367 							     bwg_id, prio_type);
368 		break;
369 	case ixgbe_mac_82599EB:
370 	case ixgbe_mac_X540:
371 		ixgbe_dcb_config_rx_arbiter_82599(hw, refill, max,
372 						  bwg_id, prio_type, prio_tc);
373 		ixgbe_dcb_config_tx_desc_arbiter_82599(hw, refill, max,
374 						       bwg_id, prio_type);
375 		ixgbe_dcb_config_tx_data_arbiter_82599(hw, refill, max, bwg_id,
376 						       prio_type, prio_tc);
377 		break;
378 	default:
379 		break;
380 	}
381 	return 0;
382 }
383 
384 static void ixgbe_dcb_read_rtrup2tc_82599(struct ixgbe_hw *hw, u8 *map)
385 {
386 	u32 reg, i;
387 
388 	reg = IXGBE_READ_REG(hw, IXGBE_RTRUP2TC);
389 	for (i = 0; i < MAX_USER_PRIORITY; i++)
390 		map[i] = IXGBE_RTRUP2TC_UP_MASK &
391 			(reg >> (i * IXGBE_RTRUP2TC_UP_SHIFT));
392 	return;
393 }
394 
395 void ixgbe_dcb_read_rtrup2tc(struct ixgbe_hw *hw, u8 *map)
396 {
397 	switch (hw->mac.type) {
398 	case ixgbe_mac_82599EB:
399 	case ixgbe_mac_X540:
400 		ixgbe_dcb_read_rtrup2tc_82599(hw, map);
401 		break;
402 	default:
403 		break;
404 	}
405 }
406