[Intel-wired-lan] [PATCH S39 v2 01/15] ice: Validate config for SW DCB map

[Tony Nguyen <anthony.l.nguyen@intel.com>]

From: Avinash Dayanand <avinash.dayanand@intel.com>

Validate the inputs for SW DCB config received either via lldptool or pcap
file. And don't apply DCB for bad bandwidth inputs. Without this patch, any
config having bad inputs will cause the loss of link making PF unusable
even after driver reload. Recoverable only via system reboot.

Signed-off-by: Avinash Dayanand <avinash.dayanand@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
v2:
- Allocate all bandwidth to TC0 if no TCs requested any bandwidth
- Remove zero bandwidth check on non-TC0
- Add message about reason for error and return from error immediately in
  ice_dcb_bwchk()
- Change a comment
---
 drivers/net/ethernet/intel/ice/ice_dcb_lib.c | 40 ++++++++++++++++++++
 drivers/net/ethernet/intel/ice/ice_dcb_lib.h |  1 +
 drivers/net/ethernet/intel/ice/ice_dcb_nl.c  |  6 +++
 3 files changed, 47 insertions(+)

diff --git a/drivers/net/ethernet/intel/ice/ice_dcb_lib.c b/drivers/net/ethernet/intel/ice/ice_dcb_lib.c
index 017b71d8e894..175b08219f7a 100644
--- a/drivers/net/ethernet/intel/ice/ice_dcb_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_dcb_lib.c
@@ -169,6 +169,43 @@ ice_peer_prep_tc_change(struct ice_peer_dev_int *peer_dev_int,
 	return 0;
 }
 
+/**
+ * ice_dcb_bwchk - check if ETS bandwidth input parameters are correct
+ * @pf: pointer to the PF struct
+ * @dcbcfg: pointer to DCB config structure
+ */
+int ice_dcb_bwchk(struct ice_pf *pf, struct ice_dcbx_cfg *dcbcfg)
+{
+	struct ice_dcb_ets_cfg *etscfg = &dcbcfg->etscfg;
+	u8 num_tc, total_bw = 0;
+	int i;
+
+	/* returns number of contigous TCs and 1 TC for non-contigous TCs,
+	 * since at least 1 TC has to be configured
+	 */
+	num_tc = ice_dcb_get_num_tc(dcbcfg);
+
+	/* no bandwidth checks required if there's only one TC, so assign
+	 * all bandwidth to TC0 and return
+	 */
+	if (num_tc == 1) {
+		etscfg->tcbwtable[0] = ICE_TC_MAX_BW;
+		return 0;
+	}
+
+	for (i = 0; i < num_tc; i++)
+		total_bw += etscfg->tcbwtable[i];
+
+	if (!total_bw) {
+		etscfg->tcbwtable[0] = ICE_TC_MAX_BW;
+	} else if (total_bw != ICE_TC_MAX_BW) {
+		dev_err(ice_pf_to_dev(pf), "Invalid config, total bandwidth must equal 100\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 /**
  * ice_pf_dcb_cfg - Apply new DCB configuration
  * @pf: pointer to the PF struct
@@ -206,6 +243,9 @@ int ice_pf_dcb_cfg(struct ice_pf *pf, struct ice_dcbx_cfg *new_cfg, bool locked)
 	/* Notify capable peers about impending change to TCs */
 	ice_for_each_peer(pf, NULL, ice_peer_prep_tc_change);
 
+	if (ice_dcb_bwchk(pf, new_cfg))
+		return -EINVAL;
+
 	/* Store old config in case FW config fails */
 	old_cfg = kmemdup(curr_cfg, sizeof(*old_cfg), GFP_KERNEL);
 	if (!old_cfg)
diff --git a/drivers/net/ethernet/intel/ice/ice_dcb_lib.h b/drivers/net/ethernet/intel/ice/ice_dcb_lib.h
index bb53edf462ba..11457b6ba145 100644
--- a/drivers/net/ethernet/intel/ice/ice_dcb_lib.h
+++ b/drivers/net/ethernet/intel/ice/ice_dcb_lib.h
@@ -20,6 +20,7 @@ u8 ice_dcb_get_num_tc(struct ice_dcbx_cfg *dcbcfg);
 u8 ice_dcb_get_tc(struct ice_vsi *vsi, int queue_index);
 int
 ice_pf_dcb_cfg(struct ice_pf *pf, struct ice_dcbx_cfg *new_cfg, bool locked);
+int ice_dcb_bwchk(struct ice_pf *pf, struct ice_dcbx_cfg *dcbcfg);
 void ice_pf_dcb_recfg(struct ice_pf *pf);
 void ice_vsi_cfg_dcb_rings(struct ice_vsi *vsi);
 int ice_init_pf_dcb(struct ice_pf *pf, bool locked);
diff --git a/drivers/net/ethernet/intel/ice/ice_dcb_nl.c b/drivers/net/ethernet/intel/ice/ice_dcb_nl.c
index b61aba428adb..c572aa5c28e0 100644
--- a/drivers/net/ethernet/intel/ice/ice_dcb_nl.c
+++ b/drivers/net/ethernet/intel/ice/ice_dcb_nl.c
@@ -95,6 +95,11 @@ static int ice_dcbnl_setets(struct net_device *netdev, struct ieee_ets *ets)
 		new_cfg->etsrec.prio_table[i] = ets->reco_prio_tc[i];
 	}
 
+	if (ice_dcb_bwchk(pf, new_cfg)) {
+		err = -EINVAL;
+		goto ets_out;
+	}
+
 	/* max_tc is a 1-8 value count of number of TC's, not a 0-7 value
 	 * for the TC's index number.  Add one to value if not zero, and
 	 * for zero set it to the FW's default value
@@ -119,6 +124,7 @@ static int ice_dcbnl_setets(struct net_device *netdev, struct ieee_ets *ets)
 	if (err == ICE_DCB_NO_HW_CHG)
 		err = ICE_DCB_HW_CHG_RST;
 
+ets_out:
 	mutex_unlock(&pf->tc_mutex);
 	return err;
 }
-- 
2.20.1