From: Dave Ertman <david.m.ertman@intel.com>
Date: Thu, 7 May 2020 17:41:01 -0700
Subject: ice: Fix check for contiguous TCs
Patch-mainline: v5.8-rc1
Git-commit: 891540024bb959c3ce8b71b851ba24cd3ad9423f
References: jsc#SLE-12878

The current implementation for contiguous TC check
is assuming that the UPs will be mapped to TCs in
a linear progressing fashion.  This is obviously
not always true.

Change the check to allow for various UP2TC mapping
configurations.

Signed-off-by: Dave Ertman <david.m.ertman@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 drivers/net/ethernet/intel/ice/ice_dcb_lib.c |   19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

--- a/drivers/net/ethernet/intel/ice/ice_dcb_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_dcb_lib.c
@@ -584,16 +584,21 @@ static int ice_dcb_sw_dflt_cfg(struct ic
  */
 static bool ice_dcb_tc_contig(u8 *prio_table)
 {
-	u8 max_tc = 0;
+	bool found_empty = false;
+	u8 used_tc = 0;
 	int i;
 
-	for (i = 0; i < CEE_DCBX_MAX_PRIO; i++) {
-		u8 cur_tc = prio_table[i];
+	/* Create a bitmap of used TCs */
+	for (i = 0; i < CEE_DCBX_MAX_PRIO; i++)
+		used_tc |= BIT(prio_table[i]);
 
-		if (cur_tc > max_tc)
-			return false;
-		else if (cur_tc == max_tc)
-			max_tc++;
+	for (i = 0; i < CEE_DCBX_MAX_PRIO; i++) {
+		if (used_tc & BIT(i)) {
+			if (found_empty)
+				return false;
+		} else {
+			found_empty = true;
+		}
 	}
 
 	return true;