xref: /dpdk/drivers/net/txgbe/base/txgbe_dcb.c (revision f8aadb64)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2015-2020 Beijing WangXun Technology Co., Ltd.
3  * Copyright(c) 2010-2017 Intel Corporation
4  */
5 
6 #include "txgbe_type.h"
7 #include "txgbe_hw.h"
8 #include "txgbe_dcb.h"
9 #include "txgbe_dcb_hw.h"
10 
11 /**
12  *  txgbe_pfc_enable - Enable flow control
13  *  @hw: pointer to hardware structure
14  *  @tc_num: traffic class number
15  *  Enable flow control according to the current settings.
16  */
17 int
txgbe_dcb_pfc_enable(struct txgbe_hw * hw,uint8_t tc_num)18 txgbe_dcb_pfc_enable(struct txgbe_hw *hw, uint8_t tc_num)
19 {
20 	int ret_val = 0;
21 	uint32_t mflcn_reg, fccfg_reg;
22 	uint32_t pause_time;
23 	uint32_t fcrtl, fcrth;
24 	uint8_t i;
25 	uint8_t nb_rx_en;
26 
27 	/* Validate the water mark configuration */
28 	if (!hw->fc.pause_time) {
29 		ret_val = TXGBE_ERR_INVALID_LINK_SETTINGS;
30 		goto out;
31 	}
32 
33 	/* Low water mark of zero causes XOFF floods */
34 	if (hw->fc.current_mode & txgbe_fc_tx_pause) {
35 		 /* High/Low water can not be 0 */
36 		if (!hw->fc.high_water[tc_num] ||
37 		    !hw->fc.low_water[tc_num]) {
38 			PMD_INIT_LOG(ERR, "Invalid water mark configuration");
39 			ret_val = TXGBE_ERR_INVALID_LINK_SETTINGS;
40 			goto out;
41 		}
42 
43 		if (hw->fc.low_water[tc_num] >= hw->fc.high_water[tc_num]) {
44 			PMD_INIT_LOG(ERR, "Invalid water mark configuration");
45 			ret_val = TXGBE_ERR_INVALID_LINK_SETTINGS;
46 			goto out;
47 		}
48 	}
49 	/* Negotiate the fc mode to use */
50 	txgbe_fc_autoneg(hw);
51 
52 	/* Disable any previous flow control settings */
53 	mflcn_reg = rd32(hw, TXGBE_RXFCCFG);
54 	mflcn_reg &= ~(TXGBE_RXFCCFG_FC | TXGBE_RXFCCFG_PFC);
55 
56 	fccfg_reg = rd32(hw, TXGBE_TXFCCFG);
57 	fccfg_reg &= ~(TXGBE_TXFCCFG_FC | TXGBE_TXFCCFG_PFC);
58 
59 	switch (hw->fc.current_mode) {
60 	case txgbe_fc_none:
61 		/*
62 		 * If the count of enabled RX Priority Flow control > 1,
63 		 * and the TX pause can not be disabled
64 		 */
65 		nb_rx_en = 0;
66 		for (i = 0; i < TXGBE_DCB_TC_MAX; i++) {
67 			uint32_t reg = rd32(hw, TXGBE_FCWTRHI(i));
68 			if (reg & TXGBE_FCWTRHI_XOFF)
69 				nb_rx_en++;
70 		}
71 		if (nb_rx_en > 1)
72 			fccfg_reg |= TXGBE_TXFCCFG_PFC;
73 		break;
74 	case txgbe_fc_rx_pause:
75 		/*
76 		 * Rx Flow control is enabled and Tx Flow control is
77 		 * disabled by software override. Since there really
78 		 * isn't a way to advertise that we are capable of RX
79 		 * Pause ONLY, we will advertise that we support both
80 		 * symmetric and asymmetric Rx PAUSE.  Later, we will
81 		 * disable the adapter's ability to send PAUSE frames.
82 		 */
83 		mflcn_reg |= TXGBE_RXFCCFG_PFC;
84 		/*
85 		 * If the count of enabled RX Priority Flow control > 1,
86 		 * and the TX pause can not be disabled
87 		 */
88 		nb_rx_en = 0;
89 		for (i = 0; i < TXGBE_DCB_TC_MAX; i++) {
90 			uint32_t reg = rd32(hw, TXGBE_FCWTRHI(i));
91 			if (reg & TXGBE_FCWTRHI_XOFF)
92 				nb_rx_en++;
93 		}
94 		if (nb_rx_en > 1)
95 			fccfg_reg |= TXGBE_TXFCCFG_PFC;
96 		break;
97 	case txgbe_fc_tx_pause:
98 		/*
99 		 * Tx Flow control is enabled, and Rx Flow control is
100 		 * disabled by software override.
101 		 */
102 		fccfg_reg |= TXGBE_TXFCCFG_PFC;
103 		break;
104 	case txgbe_fc_full:
105 		/* Flow control (both Rx and Tx) is enabled by SW override. */
106 		mflcn_reg |= TXGBE_RXFCCFG_PFC;
107 		fccfg_reg |= TXGBE_TXFCCFG_PFC;
108 		break;
109 	default:
110 		PMD_DRV_LOG(DEBUG, "Flow control param set incorrectly");
111 		ret_val = TXGBE_ERR_CONFIG;
112 		goto out;
113 	}
114 
115 	/* Set 802.3x based flow control settings. */
116 	wr32(hw, TXGBE_RXFCCFG, mflcn_reg);
117 	wr32(hw, TXGBE_TXFCCFG, fccfg_reg);
118 
119 	/* Set up and enable Rx high/low water mark thresholds, enable XON. */
120 	if ((hw->fc.current_mode & txgbe_fc_tx_pause) &&
121 		hw->fc.high_water[tc_num]) {
122 		fcrtl = TXGBE_FCWTRLO_TH(hw->fc.low_water[tc_num]) |
123 			TXGBE_FCWTRLO_XON;
124 		fcrth = TXGBE_FCWTRHI_TH(hw->fc.high_water[tc_num]) |
125 			TXGBE_FCWTRHI_XOFF;
126 	} else {
127 		/*
128 		 * In order to prevent Tx hangs when the internal Tx
129 		 * switch is enabled we must set the high water mark
130 		 * to the maximum FCRTH value.  This allows the Tx
131 		 * switch to function even under heavy Rx workloads.
132 		 */
133 		fcrtl = 0;
134 		fcrth = rd32(hw, TXGBE_PBRXSIZE(tc_num)) - 32;
135 	}
136 	wr32(hw, TXGBE_FCWTRLO(tc_num), fcrtl);
137 	wr32(hw, TXGBE_FCWTRHI(tc_num), fcrth);
138 
139 	/* Configure pause time (2 TCs per register) */
140 	pause_time = TXGBE_RXFCFSH_TIME(hw->fc.pause_time);
141 	for (i = 0; i < (TXGBE_DCB_TC_MAX / 2); i++)
142 		wr32(hw, TXGBE_FCXOFFTM(i), pause_time * 0x00010001);
143 
144 	/* Configure flow control refresh threshold value */
145 	wr32(hw, TXGBE_RXFCRFSH, pause_time / 2);
146 
147 out:
148 	return ret_val;
149 }
150 
151 /**
152  * txgbe_dcb_calculate_tc_credits_cee - Calculates traffic class credits
153  * @hw: pointer to hardware structure
154  * @dcb_config: Struct containing DCB settings
155  * @max_frame_size: Maximum frame size
156  * @direction: Configuring either Tx or Rx
157  *
158  * This function calculates the credits allocated to each traffic class.
159  * It should be called only after the rules are checked by
160  * txgbe_dcb_check_config_cee().
161  */
txgbe_dcb_calculate_tc_credits_cee(struct txgbe_hw * hw,struct txgbe_dcb_config * dcb_config,u32 max_frame_size,u8 direction)162 s32 txgbe_dcb_calculate_tc_credits_cee(struct txgbe_hw *hw,
163 				   struct txgbe_dcb_config *dcb_config,
164 				   u32 max_frame_size, u8 direction)
165 {
166 	struct txgbe_dcb_tc_path *p;
167 	u32 min_multiplier	= 0;
168 	u16 min_percent		= 100;
169 	s32 ret_val =		0;
170 	/* Initialization values default for Tx settings */
171 	u32 min_credit		= 0;
172 	u32 credit_refill	= 0;
173 	u32 credit_max		= 0;
174 	u16 link_percentage	= 0;
175 	u8  bw_percent		= 0;
176 	u8  i;
177 
178 	UNREFERENCED_PARAMETER(hw);
179 
180 	if (dcb_config == NULL) {
181 		ret_val = TXGBE_ERR_CONFIG;
182 		goto out;
183 	}
184 
185 	min_credit = ((max_frame_size / 2) + TXGBE_DCB_CREDIT_QUANTUM - 1) /
186 		     TXGBE_DCB_CREDIT_QUANTUM;
187 
188 	/* Find smallest link percentage */
189 	for (i = 0; i < TXGBE_DCB_TC_MAX; i++) {
190 		p = &dcb_config->tc_config[i].path[direction];
191 		bw_percent = dcb_config->bw_percentage[p->bwg_id][direction];
192 		link_percentage = p->bwg_percent;
193 
194 		link_percentage = (link_percentage * bw_percent) / 100;
195 
196 		if (link_percentage && link_percentage < min_percent)
197 			min_percent = link_percentage;
198 	}
199 
200 	/*
201 	 * The ratio between traffic classes will control the bandwidth
202 	 * percentages seen on the wire. To calculate this ratio we use
203 	 * a multiplier. It is required that the refill credits must be
204 	 * larger than the max frame size so here we find the smallest
205 	 * multiplier that will allow all bandwidth percentages to be
206 	 * greater than the max frame size.
207 	 */
208 	min_multiplier = (min_credit / min_percent) + 1;
209 
210 	/* Find out the link percentage for each TC first */
211 	for (i = 0; i < TXGBE_DCB_TC_MAX; i++) {
212 		p = &dcb_config->tc_config[i].path[direction];
213 		bw_percent = dcb_config->bw_percentage[p->bwg_id][direction];
214 
215 		link_percentage = p->bwg_percent;
216 		/* Must be careful of integer division for very small nums */
217 		link_percentage = (link_percentage * bw_percent) / 100;
218 		if (p->bwg_percent > 0 && link_percentage == 0)
219 			link_percentage = 1;
220 
221 		/* Save link_percentage for reference */
222 		p->link_percent = (u8)link_percentage;
223 
224 		/* Calculate credit refill ratio using multiplier */
225 		credit_refill = min(link_percentage * min_multiplier,
226 				    (u32)TXGBE_DCB_MAX_CREDIT_REFILL);
227 
228 		/* Refill at least minimum credit */
229 		if (credit_refill < min_credit)
230 			credit_refill = min_credit;
231 
232 		p->data_credits_refill = (u16)credit_refill;
233 
234 		/* Calculate maximum credit for the TC */
235 		credit_max = (link_percentage * TXGBE_DCB_MAX_CREDIT) / 100;
236 
237 		/*
238 		 * Adjustment based on rule checking, if the percentage
239 		 * of a TC is too small, the maximum credit may not be
240 		 * enough to send out a jumbo frame in data plane arbitration.
241 		 */
242 		if (credit_max < min_credit)
243 			credit_max = min_credit;
244 
245 		if (direction == TXGBE_DCB_TX_CONFIG) {
246 			dcb_config->tc_config[i].desc_credits_max =
247 								(u16)credit_max;
248 		}
249 
250 		p->data_credits_max = (u16)credit_max;
251 	}
252 
253 out:
254 	return ret_val;
255 }
256 
257 /**
258  * txgbe_dcb_unpack_pfc_cee - Unpack dcb_config PFC info
259  * @cfg: dcb configuration to unpack into hardware consumable fields
260  * @map: user priority to traffic class map
261  * @pfc_up: u8 to store user priority PFC bitmask
262  *
263  * This unpacks the dcb configuration PFC info which is stored per
264  * traffic class into a 8bit user priority bitmask that can be
265  * consumed by hardware routines. The priority to tc map must be
266  * updated before calling this routine to use current up-to maps.
267  */
txgbe_dcb_unpack_pfc_cee(struct txgbe_dcb_config * cfg,u8 * map,u8 * pfc_up)268 void txgbe_dcb_unpack_pfc_cee(struct txgbe_dcb_config *cfg, u8 *map, u8 *pfc_up)
269 {
270 	struct txgbe_dcb_tc_config *tc_config = &cfg->tc_config[0];
271 	int up;
272 
273 	/*
274 	 * If the TC for this user priority has PFC enabled then set the
275 	 * matching bit in 'pfc_up' to reflect that PFC is enabled.
276 	 */
277 	for (*pfc_up = 0, up = 0; up < TXGBE_DCB_UP_MAX; up++) {
278 		if (tc_config[map[up]].pfc != txgbe_dcb_pfc_disabled)
279 			*pfc_up |= 1 << up;
280 	}
281 }
282 
txgbe_dcb_unpack_refill_cee(struct txgbe_dcb_config * cfg,int direction,u16 * refill)283 void txgbe_dcb_unpack_refill_cee(struct txgbe_dcb_config *cfg, int direction,
284 			     u16 *refill)
285 {
286 	struct txgbe_dcb_tc_config *tc_config = &cfg->tc_config[0];
287 	int tc;
288 
289 	for (tc = 0; tc < TXGBE_DCB_TC_MAX; tc++)
290 		refill[tc] = tc_config[tc].path[direction].data_credits_refill;
291 }
292 
txgbe_dcb_unpack_max_cee(struct txgbe_dcb_config * cfg,u16 * max)293 void txgbe_dcb_unpack_max_cee(struct txgbe_dcb_config *cfg, u16 *max)
294 {
295 	struct txgbe_dcb_tc_config *tc_config = &cfg->tc_config[0];
296 	int tc;
297 
298 	for (tc = 0; tc < TXGBE_DCB_TC_MAX; tc++)
299 		max[tc] = tc_config[tc].desc_credits_max;
300 }
301 
txgbe_dcb_unpack_bwgid_cee(struct txgbe_dcb_config * cfg,int direction,u8 * bwgid)302 void txgbe_dcb_unpack_bwgid_cee(struct txgbe_dcb_config *cfg, int direction,
303 			    u8 *bwgid)
304 {
305 	struct txgbe_dcb_tc_config *tc_config = &cfg->tc_config[0];
306 	int tc;
307 
308 	for (tc = 0; tc < TXGBE_DCB_TC_MAX; tc++)
309 		bwgid[tc] = tc_config[tc].path[direction].bwg_id;
310 }
311 
txgbe_dcb_unpack_tsa_cee(struct txgbe_dcb_config * cfg,int direction,u8 * tsa)312 void txgbe_dcb_unpack_tsa_cee(struct txgbe_dcb_config *cfg, int direction,
313 			   u8 *tsa)
314 {
315 	struct txgbe_dcb_tc_config *tc_config = &cfg->tc_config[0];
316 	int tc;
317 
318 	for (tc = 0; tc < TXGBE_DCB_TC_MAX; tc++)
319 		tsa[tc] = tc_config[tc].path[direction].tsa;
320 }
321 
txgbe_dcb_get_tc_from_up(struct txgbe_dcb_config * cfg,int direction,u8 up)322 u8 txgbe_dcb_get_tc_from_up(struct txgbe_dcb_config *cfg, int direction, u8 up)
323 {
324 	struct txgbe_dcb_tc_config *tc_config = &cfg->tc_config[0];
325 	u8 prio_mask = 1 << up;
326 	u8 tc = cfg->num_tcs.pg_tcs;
327 
328 	/* If tc is 0 then DCB is likely not enabled or supported */
329 	if (!tc)
330 		goto out;
331 
332 	/*
333 	 * Test from maximum TC to 1 and report the first match we find.  If
334 	 * we find no match we can assume that the TC is 0 since the TC must
335 	 * be set for all user priorities
336 	 */
337 	for (tc--; tc; tc--) {
338 		if (prio_mask & tc_config[tc].path[direction].up_to_tc_bitmap)
339 			break;
340 	}
341 out:
342 	return tc;
343 }
344 
txgbe_dcb_unpack_map_cee(struct txgbe_dcb_config * cfg,int direction,u8 * map)345 void txgbe_dcb_unpack_map_cee(struct txgbe_dcb_config *cfg, int direction,
346 			      u8 *map)
347 {
348 	u8 up;
349 
350 	for (up = 0; up < TXGBE_DCB_UP_MAX; up++)
351 		map[up] = txgbe_dcb_get_tc_from_up(cfg, direction, up);
352 }
353 
354 /* Helper routines to abstract HW specifics from DCB netlink ops */
txgbe_dcb_config_pfc(struct txgbe_hw * hw,u8 pfc_en,u8 * map)355 s32 txgbe_dcb_config_pfc(struct txgbe_hw *hw, u8 pfc_en, u8 *map)
356 {
357 	int ret = TXGBE_ERR_PARAM;
358 	ret = txgbe_dcb_config_pfc_raptor(hw, pfc_en, map);
359 	return ret;
360 }
361 
362