From 8ec3ede559956f8ad58db7b57d25ac724bab69e9 Mon Sep 17 00:00:00 2001 From: Maxime Chevallier Date: Thu, 20 Jun 2019 11:42:45 +0200 Subject: net: mvpp2: prs: Don't override the sign bit in SRAM parser shift 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 Signed-off-by: Maxime Chevallier Signed-off-by: David S. Miller --- drivers/net/ethernet/marvell/mvpp2/mvpp2_prs.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/net/ethernet/marvell/mvpp2') diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_prs.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_prs.c index ae2240074d8e..5692c6087bbb 100644 --- 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(struct mvpp2_prs_entry *pe, int shift, } /* 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, -- cgit v1.2.3-59-g8ed1b