[net-next-2.6.git] / drivers / net / ixgbe / ixgbe_dcb.c

/*******************************************************************************

  Intel 10 Gigabit PCI Express Linux driver
  Copyright(c) 1999 - 2010 Intel Corporation.

  This program is free software; you can redistribute it and/or modify it
  under the terms and conditions of the GNU General Public License,
  version 2, as published by the Free Software Foundation.

  This program is distributed in the hope it will be useful, but WITHOUT
  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  more details.

  You should have received a copy of the GNU General Public License along with
  this program; if not, write to the Free Software Foundation, Inc.,
  51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.

  The full GNU General Public License is included in this distribution in
  the file called "COPYING".

  Contact Information:
  Linux NICS <linux.nics@intel.com>
  e1000-devel Mailing List <e1000-devel@lists.sourceforge.net>
  Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497

*******************************************************************************/


#include "ixgbe.h"
#include "ixgbe_type.h"
#include "ixgbe_dcb.h"
#include "ixgbe_dcb_82598.h"
#include "ixgbe_dcb_82599.h"

/**
 * ixgbe_dcb_calculate_tc_credits - Calculates traffic class credits
 * @ixgbe_dcb_config: Struct containing DCB settings.
 * @direction: Configuring either Tx or Rx.
 *
 * This function calculates the credits allocated to each traffic class.
 * It should be called only after the rules are checked by
 * ixgbe_dcb_check_config().
 */
s32 ixgbe_dcb_calculate_tc_credits(struct ixgbe_dcb_config *dcb_config,
				   int max_frame, u8 direction)
{
	struct tc_bw_alloc *p;
	int min_credit;
	int min_multiplier;
	int min_percent = 100;
	s32 ret_val = 0;
	/* Initialization values default for Tx settings */
	u32 credit_refill       = 0;
	u32 credit_max          = 0;
	u16 link_percentage     = 0;
	u8  bw_percent          = 0;
	u8  i;

	if (dcb_config == NULL) {
		ret_val = DCB_ERR_CONFIG;
		goto out;
	}

	min_credit = ((max_frame / 2) + DCB_CREDIT_QUANTUM - 1) /
			DCB_CREDIT_QUANTUM;

	/* Find smallest link percentage */
	for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
		p = &dcb_config->tc_config[i].path[direction];
		bw_percent = dcb_config->bw_percentage[direction][p->bwg_id];
		link_percentage = p->bwg_percent;

		link_percentage = (link_percentage * bw_percent) / 100;

		if (link_percentage && link_percentage < min_percent)
			min_percent = link_percentage;
	}

	/*
	 * The ratio between traffic classes will control the bandwidth
	 * percentages seen on the wire. To calculate this ratio we use
	 * a multiplier. It is required that the refill credits must be
	 * larger than the max frame size so here we find the smallest
	 * multiplier that will allow all bandwidth percentages to be
	 * greater than the max frame size.
	 */
	min_multiplier = (min_credit / min_percent) + 1;

	/* Find out the link percentage for each TC first */
	for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
		p = &dcb_config->tc_config[i].path[direction];
		bw_percent = dcb_config->bw_percentage[direction][p->bwg_id];

		link_percentage = p->bwg_percent;
		/* Must be careful of integer division for very small nums */
		link_percentage = (link_percentage * bw_percent) / 100;
		if (p->bwg_percent > 0 && link_percentage == 0)
			link_percentage = 1;

		/* Save link_percentage for reference */
		p->link_percent = (u8)link_percentage;

		/* Calculate credit refill ratio using multiplier */
		credit_refill = min(link_percentage * min_multiplier,
				    MAX_CREDIT_REFILL);
		p->data_credits_refill = (u16)credit_refill;

		/* Calculate maximum credit for the TC */
		credit_max = (link_percentage * MAX_CREDIT) / 100;

		/*
		 * Adjustment based on rule checking, if the percentage
		 * of a TC is too small, the maximum credit may not be
		 * enough to send out a jumbo frame in data plane arbitration.
		 */
		if (credit_max && (credit_max < min_credit))
			credit_max = min_credit;

		if (direction == DCB_TX_CONFIG) {
			/*
			 * Adjustment based on rule checking, if the
			 * percentage of a TC is too small, the maximum
			 * credit may not be enough to send out a TSO
			 * packet in descriptor plane arbitration.
			 */
			if (credit_max &&
			    (credit_max < MINIMUM_CREDIT_FOR_TSO))
				credit_max = MINIMUM_CREDIT_FOR_TSO;

			dcb_config->tc_config[i].desc_credits_max =
				(u16)credit_max;
		}

		p->data_credits_max = (u16)credit_max;
	}

out:
	return ret_val;
}

/**
 * ixgbe_dcb_hw_config - Config and enable DCB
 * @hw: pointer to hardware structure
 * @dcb_config: pointer to ixgbe_dcb_config structure
 *
 * Configure dcb settings and enable dcb mode.
 */
s32 ixgbe_dcb_hw_config(struct ixgbe_hw *hw,
                        struct ixgbe_dcb_config *dcb_config)
{
	s32 ret = 0;
	if (hw->mac.type == ixgbe_mac_82598EB)
		ret = ixgbe_dcb_hw_config_82598(hw, dcb_config);
	else if (hw->mac.type == ixgbe_mac_82599EB)
		ret = ixgbe_dcb_hw_config_82599(hw, dcb_config);
	return ret;
}
Commit	Line	Data
2f90b865 AD	1	/*******************************************************************************
	2
	3	Intel 10 Gigabit PCI Express Linux driver
8c47eaa7	4	Copyright(c) 1999 - 2010 Intel Corporation.
2f90b865 AD	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"
235ea828	34	#include "ixgbe_dcb_82599.h"
2f90b865	35
2f90b865 AD	36	/**
	37	* ixgbe_dcb_calculate_tc_credits - Calculates traffic class credits
	38	* @ixgbe_dcb_config: Struct containing DCB settings.
	39	* @direction: Configuring either Tx or Rx.
	40	*
	41	* This function calculates the credits allocated to each traffic class.
	42	* It should be called only after the rules are checked by
	43	* ixgbe_dcb_check_config().
	44	*/
	45	s32 ixgbe_dcb_calculate_tc_credits(struct ixgbe_dcb_config *dcb_config,
9806307a	46	int max_frame, u8 direction)
2f90b865 AD	47	{
2f90b865 AD	48	struct tc_bw_alloc *p;
9806307a JF	49	int min_credit;
	50	int min_multiplier;
	51	int min_percent = 100;
2f90b865 AD	52	s32 ret_val = 0;
	53	/* Initialization values default for Tx settings */
	54	u32 credit_refill = 0;
	55	u32 credit_max = 0;
	56	u16 link_percentage = 0;
	57	u8 bw_percent = 0;
	58	u8 i;
	59
	60	if (dcb_config == NULL) {
	61	ret_val = DCB_ERR_CONFIG;
	62	goto out;
	63	}
	64
9806307a JF	65	min_credit = ((max_frame / 2) + DCB_CREDIT_QUANTUM - 1) /
	66	DCB_CREDIT_QUANTUM;
	67
	68	/* Find smallest link percentage */
	69	for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
	70	p = &dcb_config->tc_config[i].path[direction];
	71	bw_percent = dcb_config->bw_percentage[direction][p->bwg_id];
	72	link_percentage = p->bwg_percent;
	73
	74	link_percentage = (link_percentage * bw_percent) / 100;
	75
	76	if (link_percentage && link_percentage < min_percent)
	77	min_percent = link_percentage;
	78	}
	79
	80	/*
	81	* The ratio between traffic classes will control the bandwidth
	82	* percentages seen on the wire. To calculate this ratio we use
	83	* a multiplier. It is required that the refill credits must be
	84	* larger than the max frame size so here we find the smallest
	85	* multiplier that will allow all bandwidth percentages to be
	86	* greater than the max frame size.
	87	*/
	88	min_multiplier = (min_credit / min_percent) + 1;
	89
2f90b865 AD	90	/* Find out the link percentage for each TC first */
	91	for (i = 0; i < MAX_TRAFFIC_CLASS; i++) {
	92	p = &dcb_config->tc_config[i].path[direction];
	93	bw_percent = dcb_config->bw_percentage[direction][p->bwg_id];
	94
	95	link_percentage = p->bwg_percent;
	96	/* Must be careful of integer division for very small nums */
	97	link_percentage = (link_percentage * bw_percent) / 100;
	98	if (p->bwg_percent > 0 && link_percentage == 0)
	99	link_percentage = 1;
	100
	101	/* Save link_percentage for reference */
	102	p->link_percent = (u8)link_percentage;
	103
9806307a JF	104	/* Calculate credit refill ratio using multiplier */
	105	credit_refill = min(link_percentage * min_multiplier,
	106	MAX_CREDIT_REFILL);
2f90b865 AD	107	p->data_credits_refill = (u16)credit_refill;
	108
	109	/* Calculate maximum credit for the TC */
	110	credit_max = (link_percentage * MAX_CREDIT) / 100;
	111
	112	/*
	113	* Adjustment based on rule checking, if the percentage
	114	* of a TC is too small, the maximum credit may not be
	115	* enough to send out a jumbo frame in data plane arbitration.
	116	*/
9806307a JF	117	if (credit_max && (credit_max < min_credit))
9806307a JF	118	credit_max = min_credit;
2f90b865 AD	119
	120	if (direction == DCB_TX_CONFIG) {
	121	/*
	122	* Adjustment based on rule checking, if the
	123	* percentage of a TC is too small, the maximum
	124	* credit may not be enough to send out a TSO
	125	* packet in descriptor plane arbitration.
	126	*/
	127	if (credit_max &&
	128	(credit_max < MINIMUM_CREDIT_FOR_TSO))
	129	credit_max = MINIMUM_CREDIT_FOR_TSO;
	130
	131	dcb_config->tc_config[i].desc_credits_max =
	132	(u16)credit_max;
	133	}
	134
	135	p->data_credits_max = (u16)credit_max;
	136	}
	137
	138	out:
	139	return ret_val;
	140	}
	141
2f90b865 AD	142	/**
	143	* ixgbe_dcb_hw_config - Config and enable DCB
	144	* @hw: pointer to hardware structure
	145	* @dcb_config: pointer to ixgbe_dcb_config structure
	146	*
	147	* Configure dcb settings and enable dcb mode.
	148	*/
	149	s32 ixgbe_dcb_hw_config(struct ixgbe_hw *hw,
	150	struct ixgbe_dcb_config *dcb_config)
	151	{
	152	s32 ret = 0;
	153	if (hw->mac.type == ixgbe_mac_82598EB)
	154	ret = ixgbe_dcb_hw_config_82598(hw, dcb_config);
235ea828 PW	155	else if (hw->mac.type == ixgbe_mac_82599EB)
235ea828 PW	156	ret = ixgbe_dcb_hw_config_82599(hw, dcb_config);
2f90b865 AD	157	return ret;
	158	}
	159