path: root/drivers/net/ethernet/intel/ice/ice_dcb_lib.c

// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2019, Intel Corporation. */

#include "ice_dcb_lib.h"
#include "ice_dcb_nl.h"
#include "ice_devlink.h"

/**
 * ice_dcb_get_ena_tc - return bitmap of enabled TCs
 * @dcbcfg: DCB config to evaluate for enabled TCs
 */
static u8 ice_dcb_get_ena_tc(struct ice_dcbx_cfg *dcbcfg)
{
	u8 i, num_tc, ena_tc = 1;

	num_tc = ice_dcb_get_num_tc(dcbcfg);

	for (i = 0; i < num_tc; i++)
		ena_tc |= BIT(i);

	return ena_tc;
}

/**
 * ice_is_pfc_causing_hung_q
 * @pf: pointer to PF structure
 * @txqueue: Tx queue which is supposedly hung queue
 *
 * find if PFC is causing the hung queue, if yes return true else false
 */
bool ice_is_pfc_causing_hung_q(struct ice_pf *pf, unsigned int txqueue)
{
	u8 num_tcs = 0, i, tc, up_mapped_tc, up_in_tc = 0;
	u64 ref_prio_xoff[ICE_MAX_UP];
	struct ice_vsi *vsi;
	u32 up2tc;

	vsi = ice_get_main_vsi(pf);
	if (!vsi)
		return false;

	ice_for_each_traffic_class(i)
		if (vsi->tc_cfg.ena_tc & BIT(i))
			num_tcs++;

	/* first find out the TC to which the hung queue belongs to */
	for (tc = 0; tc < num_tcs - 1; tc++)
		if (ice_find_q_in_range(vsi->tc_cfg.tc_info[tc].qoffset,
					vsi->tc_cfg.tc_info[tc + 1].qoffset,
					txqueue))
			break;

	/* Build a bit map of all UPs associated to the suspect hung queue TC,
	 * so that we check for its counter increment.
	 */
	up2tc = rd32(&pf->hw, PRTDCB_TUP2TC);
	for (i = 0; i < ICE_MAX_UP; i++) {
		up_mapped_tc = (up2tc >> (i * 3)) & 0x7;
		if (up_mapped_tc == tc)
			up_in_tc |= BIT(i);
	}

	/* Now that we figured out that hung queue is PFC enabled, still the
	 * Tx timeout can be legitimate. So to make sure Tx timeout is
	 * absolutely caused by PFC storm, check if the counters are
	 * incrementing.
	 */
	for (i = 0; i < ICE_MAX_UP; i++)
		if (up_in_tc & BIT(i))
			ref_prio_xoff[i] = pf->stats.priority_xoff_rx[i];

	ice_update_dcb_stats(pf);

	for (i = 0; i < ICE_MAX_UP; i++)
		if (up_in_tc & BIT(i))
			if (pf->stats.priority_xoff_rx[i] > ref_prio_xoff[i])
				return true;

	return false;
}

/**
 * ice_dcb_get_mode - gets the DCB mode
 * @port_info: pointer to port info structure
 * @host: if set it's HOST if not it's MANAGED
 */
static u8 ice_dcb_get_mode(struct ice_port_info *port_info, bool host)
{
	u8 mode;

	if (host)
		mode = DCB_CAP_DCBX_HOST;
	else
		mode = DCB_CAP_DCBX_LLD_MANAGED;

	if (port_info->qos_cfg.local_dcbx_cfg.dcbx_mode & ICE_DCBX_MODE_CEE)
		return mode | DCB_CAP_DCBX_VER_CEE;
	else
		return mode | DCB_CAP_DCBX_VER_IEEE;
}

/**
 * ice_dcb_get_num_tc - Get the number of TCs from DCBX config
 * @dcbcfg: config to retrieve number of TCs from
 */
u8 ice_dcb_get_num_tc(struct ice_dcbx_cfg *dcbcfg)
{
	bool tc_unused = false;
	u8 num_tc = 0;
	u8 ret = 0;
	int i;

	/* Scan the ETS Config Priority Table to find traffic classes
	 * enabled and create a bitmask of enabled TCs
	 */
	for (i = 0; i < CEE_DCBX_MAX_PRIO; i++)
		num_tc |= BIT(dcbcfg->etscfg.prio_table[i]);

	/* Scan bitmask for contiguous TCs starting with TC0 */
	for (i = 0; i < IEEE_8021QAZ_MAX_TCS; i++) {
		if (num_tc & BIT(i)) {
			if (!tc_unused) {
				ret++;
			} else {
				pr_err("Non-contiguous TCs - Disabling DCB\n");
				return 1;
			}
		} else {
			tc_unused = true;
		}
	}

	/* There is always at least 1 TC */
	if (!ret)
		ret = 1;

	return ret;
}

/**
 * ice_get_first_droptc - returns number of first droptc
 * @vsi: used to find the first droptc
 *
 * This function returns the value of first_droptc.
 * When DCB is enabled, first droptc information is derived from enabled_tc
 * and PFC enabled bits. otherwise this function returns 0 as there is one
 * TC without DCB (tc0)
 */
static u8 ice_get_first_droptc(struct ice_vsi *vsi)
{
	struct ice_dcbx_cfg *cfg = &vsi->port_info->qos_cfg.local_dcbx_cfg;
	struct device *dev = ice_pf_to_dev(vsi->back);
	u8 num_tc, ena_tc_map, pfc_ena_map;
	u8 i;

	num_tc = ice_dcb_get_num_tc(cfg);

	/* get bitmap of enabled TCs */
	ena_tc_map = ice_dcb_get_ena_tc(cfg);

	/* get bitmap of PFC enabled TCs */
	pfc_ena_map = cfg->pfc.pfcena;

	/* get first TC that is not PFC enabled */
	for (i = 0; i < num_tc; i++) {
		if ((ena_tc_map & BIT(i)) && (!(pfc_ena_map & BIT(i