xref: /linux/drivers/net/ethernet/intel/ixgbe/ixgbe_dcb.c (revision 37744feebc086908fd89760650f458ab19071750)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright(c) 1999 - 2018 Intel Corporation. */
3 
4 #include "ixgbe.h"
5 #include "ixgbe_type.h"
6 #include "ixgbe_dcb.h"
7 #include "ixgbe_dcb_82598.h"
8 #include "ixgbe_dcb_82599.h"
9 
10 /**
11  * ixgbe_ieee_credits - This calculates the ieee traffic class
12  * credits from the configured bandwidth percentages. Credits
13  * are the smallest unit programmable into the underlying
14  * hardware. The IEEE 802.1Qaz specification do not use bandwidth
15  * groups so this is much simplified from the CEE case.
16  * @bw: bandwidth index by traffic class
17  * @refill: refill credits index by traffic class
18  * @max: max credits by traffic class
19  * @max_frame: maximum frame size
20  */
21 static s32 ixgbe_ieee_credits(__u8 *bw, __u16 *refill,
22 			      __u16 *max, int max_frame)
23 {
24 	int min_percent = 100;
25 	int min_credit, multiplier;
26 	int i;
27 
28 	min_credit = ((max_frame / 2) + DCB_CREDIT_QUANTUM - 1) /
29 			DCB_CREDIT_QUANTUM;
30 
31 	for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
32 		if (bw[i] < min_percent && bw[i])
33 			min_percent = bw[i];
34 	}
35 
36 	multiplier = (min_credit / min_percent) + 1;
37 
38 	/* Find out the hw credits for each TC */
39 	for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
40 		int val = min(bw[i] * multiplier, MAX_CREDIT_REFILL);
41 
42 		if (val < min_credit)
43 			val = min_credit;
44 		refill[i] = val;
45 
46 		max[i] = bw[i] ? (bw[i] * MAX_CREDIT)/100 : min_credit;
47 	}
48 	return 0;
49 }
50 
51 /**
52  * ixgbe_dcb_calculate_tc_credits - Calculates traffic class credits
53  * @hw: pointer to hardware structure
54  * @dcb_config: Struct containing DCB settings
55  * @max_frame: Maximum frame size
56  * @direction: Configuring either Tx or Rx
57  *
58  * This function calculates the credits allocated to each traffic class.
59  * It should be called only after the rules are checked by
60  * ixgbe_dcb_check_config().
61  */
62 s32 ixgbe_dcb_calculate_tc_credits(struct ixgbe_hw *hw,
63 				   struct ixgbe_dcb_config *dcb_config,
64 				   int max_frame, u8 direction)
65 {
66 	struct tc_bw_alloc *p;
67 	int min_credit;
68 	int min_multiplier;
69 	int min_percent = 100;
70 	/* Initialization values default for Tx settings */
71 	u32 credit_refill       = 0;
72 	u32 credit_max          = 0;
73 	u16 link_percentage     = 0;
74 	u8  bw_percent          = 0;
75 	u8  i;
76 
77 	if (!dcb_config)
78 		return DCB_ERR_CONFIG;
79 
80 	min_credit = ((max_frame / 2) + DCB_CREDIT_QUANTUM - 1) /
81 			DCB_CREDIT_QUANTUM;
82 
83 	/* Find smallest link percentage */
84 	for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
85 		p = &dcb_config->tc_config[i].path[direction];
86 		bw_percent = dcb_config->bw_percentage[direction][p->bwg_id];
87 		link_percentage = p->bwg_percent;
88 
89 		link_percentage = (link_percentage * bw_percent) / 100;
90 
91 		if (link_percentage && link_percentage < min_percent)
92 			min_percent = link_percentage;
93 	}
94 
95 	/*
96 	 * The ratio between traffic classes will control the bandwidth
97 	 * percentages seen on the wire. To calculate this ratio we use
98 	 * a multiplier. It is required that the refill credits must be
99 	 * larger than the max frame size so here we find the smallest
100 	 * multiplier that will allow all bandwidth percentages to be
101 	 * greater than the max frame size.
102 	 */
103 	min_multiplier = (min_credit / min_percent) + 1;
104 
105 	/* Find out the link percentage for each TC first */
106 	for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
107 		p = &dcb_config->tc_config[i].path[direction];
108 		bw_percent = dcb_config->bw_percentage[direction][p->bwg_id];
109 
110 		link_percentage = p->bwg_percent;
111 		/* Must be careful of integer division for very small nums */
112 		link_percentage = (link_percentage * bw_percent) / 100;
113 		if (p->bwg_percent > 0 && link_percentage == 0)
114 			link_percentage = 1;
115 
116 		/* Save link_percentage for reference */
117 		p->link_percent = (u8)link_percentage;
118 
119 		/* Calculate credit refill ratio using multiplier */
120 		credit_refill = min(link_percentage * min_multiplier,
121 				    MAX_CREDIT_REFILL);
122 
123 		/* Refill at least minimum credit */
124 		if (credit_refill < min_credit)
125 			credit_refill = min_credit;
126 
127 		p->data_credits_refill = (u16)credit_refill;
128 
129 		/* Calculate maximum credit for the TC */
130 		credit_max = (link_percentage * MAX_CREDIT) / 100;
131 
132 		/*
133 		 * Adjustment based on rule checking, if the percentage
134 		 * of a TC is too small, the maximum credit may not be
135 		 * enough to send out a jumbo frame in data plane arbitration.
136 		 */
137 		if (credit_max < min_credit)
138 			credit_max = min_credit;
139 
140 		if (direction == DCB_TX_CONFIG) {
141 			/*
142 			 * Adjustment based on rule checking, if the
143 			 * percentage of a TC is too small, the maximum
144 			 * credit may not be enough to send out a TSO
145 			 * packet in descriptor plane arbitration.
146 			 */
147 			if ((hw->mac.type == ixgbe_mac_82598EB) &&
148 			    credit_max &&
149 			    (credit_max < MINIMUM_CREDIT_FOR_TSO))
150 				credit_max = MINIMUM_CREDIT_FOR_TSO;
151 
152 			dcb_config->tc_config[i].desc_credits_max =
153 				(u16)credit_max;
154 		}
155 
156 		p->data_credits_max = (u16)credit_max;
157 	}
158 
159 	return 0;
160 }
161 
162 void ixgbe_dcb_unpack_pfc(struct ixgbe_dcb_config *cfg, u8 *pfc_en)
163 {
164 	struct tc_configuration *tc_config = &cfg->tc_config[0];
165 	int tc;
166 
167 	for (*pfc_en = 0, tc = 0; tc < MAX_TRAFFIC_CLASS; tc++) {
168 		if (tc_config[tc].dcb_pfc != pfc_disabled)
169 			*pfc_en |= BIT(tc);
170 	}
171 }
172 
173 void ixgbe_dcb_unpack_refill(struct ixgbe_dcb_config *cfg, int direction,
174 			     u16 *refill)
175 {
176 	struct tc_configuration *tc_config = &cfg->tc_config[0];
177 	int tc;
178 
179 	for (tc = 0; tc < MAX_TRAFFIC_CLASS; tc++)
180 		refill[tc] = tc_config[tc].path[direction].data_credits_refill;
181 }
182 
183 void ixgbe_dcb_unpack_max(struct ixgbe_dcb_config *cfg, u16 *max)
184 {
185 	struct tc_configuration *tc_config = &cfg->tc_config[0];
186 	int tc;
187 
188 	for (tc = 0; tc < MAX_TRAFFIC_CLASS; tc++)
189 		max[tc] = tc_config[tc].desc_credits_max;
190 }
191 
192 void ixgbe_dcb_unpack_bwgid(struct ixgbe_dcb_config *cfg, int direction,
193 			    u8 *bwgid)
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 		bwgid[tc] = tc_config[tc].path[direction].bwg_id;
200 }
201 
202 void ixgbe_dcb_unpack_prio(struct ixgbe_dcb_config *cfg, int direction,
203 			    u8 *ptype)
204 {
205 	struct tc_configuration *tc_config = &cfg->tc_config[0];
206 	int tc;
207 
208 	for (tc = 0; tc < MAX_TRAFFIC_CLASS; tc++)
209 		ptype[tc] = tc_config[tc].path[direction].prio_type;
210 }
211 
212 u8 ixgbe_dcb_get_tc_from_up(struct ixgbe_dcb_config *cfg, int direction, u8 up)
213 {
214 	struct tc_configuration *tc_config = &cfg->tc_config[0];
215 	u8 prio_mask = BIT(up);
216 	u8 tc = cfg->num_tcs.pg_tcs;
217 
218 	/* If tc is 0 then DCB is likely not enabled or supported */
219 	if (!tc)
220 		return 0;
221 
222 	/*
223 	 * Test from maximum TC to 1 and report the first match we find.  If
224 	 * we find no match we can assume that the TC is 0 since the TC must
225 	 * be set for all user priorities
226 	 */
227 	for (tc--; tc; tc--) {
228 		if (prio_mask & tc_config[tc].path[direction].up_to_tc_bitmap)
229 			break;
230 	}
231 
232 	return tc;
233 }
234 
235 void ixgbe_dcb_unpack_map(struct ixgbe_dcb_config *cfg, int direction, u8 *map)
236 {
237 	u8 up;
238 
239 	for (up = 0; up < MAX_USER_PRIORITY; up++)
240 		map[up] = ixgbe_dcb_get_tc_from_up(cfg, direction, up);
241 }
242 
243 /**
244  * ixgbe_dcb_hw_config - Config and enable DCB
245  * @hw: pointer to hardware structure
246  * @dcb_config: pointer to ixgbe_dcb_config structure
247  *
248  * Configure dcb settings and enable dcb mode.
249  */
250 s32 ixgbe_dcb_hw_config(struct ixgbe_hw *hw,
251 			struct ixgbe_dcb_config *dcb_config)
252 {
253 	u8 pfc_en;
254 	u8 ptype[MAX_TRAFFIC_CLASS];
255 	u8 bwgid[MAX_TRAFFIC_CLASS];
256 	u8 prio_tc[MAX_TRAFFIC_CLASS];
257 	u16 refill[MAX_TRAFFIC_CLASS];
258 	u16 max[MAX_TRAFFIC_CLASS];
259 
260 	/* Unpack CEE standard containers */
261 	ixgbe_dcb_unpack_pfc(dcb_config, &pfc_en);
262 	ixgbe_dcb_unpack_refill(dcb_config, DCB_TX_CONFIG, refill);
263 	ixgbe_dcb_unpack_max(dcb_config, max);
264 	ixgbe_dcb_unpack_bwgid(dcb_config, DCB_TX_CONFIG, bwgid);
265 	ixgbe_dcb_unpack_prio(dcb_config, DCB_TX_CONFIG, ptype);
266 	ixgbe_dcb_unpack_map(dcb_config, DCB_TX_CONFIG, prio_tc);
267 
268 	switch (hw->mac.type) {
269 	case ixgbe_mac_82598EB:
270 		return ixgbe_dcb_hw_config_82598(hw, pfc_en, refill, max,
271 						 bwgid, ptype);
272 	case ixgbe_mac_82599EB:
273 	case ixgbe_mac_X540:
274 	case ixgbe_mac_X550:
275 	case ixgbe_mac_X550EM_x:
276 	case ixgbe_mac_x550em_a:
277 		return ixgbe_dcb_hw_config_82599(hw, pfc_en, refill, max,
278 						 bwgid, ptype, prio_tc);
279 	default:
280 		break;
281 	}
282 	return 0;
283 }
284 
285 /* Helper routines to abstract HW specifics from DCB netlink ops */
286 s32 ixgbe_dcb_hw_pfc_config(struct ixgbe_hw *hw, u8 pfc_en, u8 *prio_tc)
287 {
288 	switch (hw->mac.type) {
289 	case ixgbe_mac_82598EB:
290 		return ixgbe_dcb_config_pfc_82598(hw, pfc_en);
291 	case ixgbe_mac_82599EB:
292 	case ixgbe_mac_X540:
293 	case ixgbe_mac_X550:
294 	case ixgbe_mac_X550EM_x:
295 	case ixgbe_mac_x550em_a:
296 		return ixgbe_dcb_config_pfc_82599(hw, pfc_en, prio_tc);
297 	default:
298 		break;
299 	}
300 	return -EINVAL;
301 }
302 
303 s32 ixgbe_dcb_hw_ets(struct ixgbe_hw *hw, struct ieee_ets *ets, int max_frame)
304 {
305 	__u16 refill[IEEE_8021QAZ_MAX_TCS], max[IEEE_8021QAZ_MAX_TCS];
306 	__u8 prio_type[IEEE_8021QAZ_MAX_TCS];
307 	int i;
308 
309 	/* naively give each TC a bwg to map onto CEE hardware */
310 	__u8 bwg_id[IEEE_8021QAZ_MAX_TCS] = {0, 1, 2, 3, 4, 5, 6, 7};
311 
312 	/* Map TSA onto CEE prio type */
313 	for (i = 0; i < IEEE_8021QAZ_MAX_TCS; i++) {
314 		switch (ets->tc_tsa[i]) {
315 		case IEEE_8021QAZ_TSA_STRICT:
316 			prio_type[i] = 2;
317 			break;
318 		case IEEE_8021QAZ_TSA_ETS:
319 			prio_type[i] = 0;
320 			break;
321 		default:
322 			/* Hardware only supports priority strict or
323 			 * ETS transmission selection algorithms if
324 			 * we receive some other value from dcbnl
325 			 * throw an error
326 			 */
327 			return -EINVAL;
328 		}
329 	}
330 
331 	ixgbe_ieee_credits(ets->tc_tx_bw, refill, max, max_frame);
332 	return ixgbe_dcb_hw_ets_config(hw, refill, max,
333 				       bwg_id, prio_type, ets->prio_tc);
334 }
335 
336 s32 ixgbe_dcb_hw_ets_config(struct ixgbe_hw *hw,
337 			    u16 *refill, u16 *max, u8 *bwg_id,
338 			    u8 *prio_type, u8 *prio_tc)
339 {
340 	switch (hw->mac.type) {
341 	case ixgbe_mac_82598EB:
342 		ixgbe_dcb_config_rx_arbiter_82598(hw, refill, max,
343 							prio_type);
344 		ixgbe_dcb_config_tx_desc_arbiter_82598(hw, refill, max,
345 							     bwg_id, prio_type);
346 		ixgbe_dcb_config_tx_data_arbiter_82598(hw, refill, max,
347 							     bwg_id, prio_type);
348 		break;
349 	case ixgbe_mac_82599EB:
350 	case ixgbe_mac_X540:
351 	case ixgbe_mac_X550:
352 	case ixgbe_mac_X550EM_x:
353 	case ixgbe_mac_x550em_a:
354 		ixgbe_dcb_config_rx_arbiter_82599(hw, refill, max,
355 						  bwg_id, prio_type, prio_tc);
356 		ixgbe_dcb_config_tx_desc_arbiter_82599(hw, refill, max,
357 						       bwg_id, prio_type);
358 		ixgbe_dcb_config_tx_data_arbiter_82599(hw, refill, max, bwg_id,
359 						       prio_type, prio_tc);
360 		break;
361 	default:
362 		break;
363 	}
364 	return 0;
365 }
366 
367 static void ixgbe_dcb_read_rtrup2tc_82599(struct ixgbe_hw *hw, u8 *map)
368 {
369 	u32 reg, i;
370 
371 	reg = IXGBE_READ_REG(hw, IXGBE_RTRUP2TC);
372 	for (i = 0; i < MAX_USER_PRIORITY; i++)
373 		map[i] = IXGBE_RTRUP2TC_UP_MASK &
374 			(reg >> (i * IXGBE_RTRUP2TC_UP_SHIFT));
375 }
376 
377 void ixgbe_dcb_read_rtrup2tc(struct ixgbe_hw *hw, u8 *map)
378 {
379 	switch (hw->mac.type) {
380 	case ixgbe_mac_82599EB:
381 	case ixgbe_mac_X540:
382 	case ixgbe_mac_X550:
383 	case ixgbe_mac_X550EM_x:
384 	case ixgbe_mac_x550em_a:
385 		ixgbe_dcb_read_rtrup2tc_82599(hw, map);
386 		break;
387 	default:
388 		break;
389 	}
390 }
391