[PATCH 4.19 12/77] net: mvpp2: Add TCAM entry to drop flow control pause frames

Greg Kroah-Hartman
2021-01-11T13:55:41Z

From: Stefan Chulski <stefanc@marvell.com>

[ Upstream commit 3f48fab62bb81a7f9d01e9d43c40395fad011dd5 ]

Issue:
Flow control frame used to pause GoP(MAC) was delivered to the CPU
and created a load on the CPU. Since XOFF/XON frames are used only
by MAC, these frames should be dropped inside MAC.

Fix:
According to 802.3-2012 - IEEE Standard for Ethernet pause frame
has unique destination MAC address 01-80-C2-00-00-01.
Add TCAM parser entry to track and drop pause frames by destination MAC.

Fixes: 3f518509dedc ("ethernet: Add new driver for Marvell Armada 375 network unit")
Signed-off-by: Stefan Chulski <stefanc@marvell.com>
Link: https://lore.kernel.org/r/1608229817-21951-1-git-send-email-stefanc@marvell.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/marvell/mvpp2/mvpp2_prs.c | 33 +++++++++++++++++++++++++
drivers/net/ethernet/marvell/mvpp2/mvpp2_prs.h | 2 -
2 files changed, 34 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_prs.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_prs.c
@@ -405,6 +405,38 @@ static int mvpp2_prs_tcam_first_free(str
return -EINVAL;
}

+/* Drop flow control pause frames */
+static void mvpp2_prs_drop_fc(struct mvpp2 *priv)
+{
+ unsigned char da[ETH_ALEN] = { 0x01, 0x80, 0xC2, 0x00, 0x00, 0x01 };
+ struct mvpp2_prs_entry pe;
+ unsigned int len;
+
+ memset(&pe, 0, sizeof(pe));
+
+ /* For all ports - drop flow control frames */
+ pe.index = MVPP2_PE_FC_DROP;
+ mvpp2_prs_tcam_lu_set(&pe, MVPP2_PRS_LU_MAC);
+
+ /* Set match on DA */
+ len = ETH_ALEN;
+ while (len--)
+ mvpp2_prs_tcam_data_byte_set(&pe, len, da[len], 0xff);
+
+ mvpp2_prs_sram_ri_update(&pe, MVPP2_PRS_RI_DROP_MASK,
+ MVPP2_PRS_RI_DROP_MASK);
+
+ mvpp2_prs_sram_bits_set(&pe, MVPP2_PRS_SRAM_LU_GEN_BIT, 1);
+ mvpp2_prs_sram_next_lu_set(&pe, MVPP2_PRS_LU_FLOWS);
+
+ /* Mask all ports */
+ mvpp2_prs_tcam_port_map_set(&pe, MVPP2_PRS_PORT_MASK);
+
+ /* Update shadow table and hw entry */
+ mvpp2_prs_shadow_set(priv, pe.index, MVPP2_PRS_LU_MAC);
+ mvpp2_prs_hw_write(priv, &pe);
+}
+
/* Enable/disable dropping all mac da's */
static void mvpp2_prs_mac_drop_all_set(struct mvpp2 *priv, int port, bool add)
{
@@ -1162,6 +1194,7 @@ static void mvpp2_prs_mac_init(struct mv
mvpp2_prs_hw_write(priv, &pe);

/* Create dummy entries for drop all and promiscuous modes */
+ mvpp2_prs_drop_fc(priv);
mvpp2_prs_mac_drop_all_set(priv, 0, false);
mvpp2_prs_mac_promisc_set(priv, 0, MVPP2_PRS_L2_UNI_CAST, false);
mvpp2_prs_mac_promisc_set(priv, 0, MVPP2_PRS_L2_MULTI_CAST, false);
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_prs.h
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_prs.h
@@ -129,7 +129,7 @@
#define MVPP2_PE_VID_EDSA_FLTR_DEFAULT (MVPP2_PRS_TCAM_SRAM_SIZE - 7)
#define MVPP2_PE_VLAN_DBL (MVPP2_PRS_TCAM_SRAM_SIZE - 6)
#define MVPP2_PE_VLAN_NONE (MVPP2_PRS_TCAM_SRAM_SIZE - 5)
-/* reserved */
+#define MVPP2_PE_FC_DROP (MVPP2_PRS_TCAM_SRAM_SIZE - 4)
#define MVPP2_PE_MAC_MC_PROMISCUOUS (MVPP2_PRS_TCAM_SRAM_SIZE - 3)
#define MVPP2_PE_MAC_UC_PROMISCUOUS (MVPP2_PRS_TCAM_SRAM_SIZE - 2)
#define MVPP2_PE_MAC_NON_PROMISCUOUS (MVPP2_PRS_TCAM_SRAM_SIZE - 1)