[PATCH net 1/2] bnge: fix RSS table sizing for large RX ring counts

[Vikas Gupta]

From: Dharmender Garg <dharmender.garg@xxxxxxxxxxxx>

bnge_adjust_pow_two() adds one block before rounding up to a power of
two only when the quotient is 0 or 1. A larger quotient that is already
a power of two is returned unchanged, so 129-192 RX rings get a
128-entry RSS indirection table and 257-320 rings a 256-entry one. The
rings above the table size never receive default RSS traffic.
bnxt_calc_nr_ring_pages() always adds one, which is correct.

Always add one block before rounding up. The same helper sizes the ring
pages; their count only changes when the number of entries divided by
the entries per page is a power of two of 2 or more, which does not
happen with the default ring sizes.

Fixes: 627c67f038d2 ("bng_en: Add resource management support")
Signed-off-by: Dharmender Garg <dharmender.garg@xxxxxxxxxxxx>
Reviewed-by: Vikas Gupta <vikas.gupta@xxxxxxxxxxxx>
---
 drivers/net/ethernet/broadcom/bnge/bnge_resc.h | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnge/bnge_resc.h b/drivers/net/ethernet/broadcom/bnge/bnge_resc.h
index b62a634669f6..c0b6992d7f82 100644
--- a/drivers/net/ethernet/broadcom/bnge/bnge_resc.h
+++ b/drivers/net/ethernet/broadcom/bnge/bnge_resc.h
@@ -81,13 +81,10 @@ bnge_adjust_pow_two(u32 total_ent, u16 ent_per_blk)
 {
 	u32 blks = total_ent / ent_per_blk;
 
-	if (blks == 0 || blks == 1)
-		return ++blks;
+	if (!blks)
+		return 1;
 
-	if (!is_power_of_2(blks))
-		blks = roundup_pow_of_two(blks);
-
-	return blks;
+	return roundup_pow_of_two(blks + 1);
 }
 
 #define BNGE_MAX_ROCE_MSIX		64
-- 
2.52.0