From: Maxime Chevallier <maxime.chevallier@bootlin.com>
Date: Thu, 20 Jun 2019 11:42:45 +0200
Subject: net: mvpp2: prs: Don't override the sign bit in SRAM parser shift
Patch-mainline: v5.3-rc1
Git-commit: 8ec3ede559956f8ad58db7b57d25ac724bab69e9
References: git-fixes
The Header Parser allows identifying various fields in the packet
headers, used for various kind of filtering and classification
steps.
This is a re-entrant process, where the offset in the packet header
depends on the previous lookup results. This offset is represented in
the SRAM results of the TCAM, as a shift to be operated.
This shift can be negative in some cases, such as in IPv6 parsing.
This commit prevents overriding the sign bit when setting the shift
value, which could cause instabilities when parsing IPv6 flows.
Fixes: 3f518509dedc ("ethernet: Add new driver for Marvell Armada 375 network unit")
Suggested-by: Alan Winkowski <walan@marvell.com>
Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
drivers/net/ethernet/marvell/mvpp2/mvpp2_prs.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_prs.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_prs.c
@@ -312,7 +312,8 @@ static void mvpp2_prs_sram_shift_set(str
}
/* Set value */
- pe->sram[MVPP2_BIT_TO_WORD(MVPP2_PRS_SRAM_SHIFT_OFFS)] = shift & MVPP2_PRS_SRAM_SHIFT_MASK;
+ pe->sram[MVPP2_BIT_TO_WORD(MVPP2_PRS_SRAM_SHIFT_OFFS)] |=
+ shift & MVPP2_PRS_SRAM_SHIFT_MASK;
/* Reset and set operation */
mvpp2_prs_sram_bits_clear(pe, MVPP2_PRS_SRAM_OP_SEL_SHIFT_OFFS,