From eea2e089f8dadf850a30ed837edd7a386427a9ed Mon Sep 17 00:00:00 2001
From: Michael Tuexen <tuexen@FreeBSD.org>
Date: Wed, 20 Nov 2024 18:18:17 -0700
Subject: ixgbe: sysctl for TCP flag handling during TSO
Add tso_tcp_flags_mask_first_segment, tso_tcp_flags_mask_middle_segment,
and tso_tcp_flags_mask_last_segment sysctl-variables to control the
handling of TCP flags during TSO.
This allows to fix the masks appropriate for classical ECN and to
configure appropriate masks for accurate ECN.
Michael notes emperically 82599 has an unexpected middle mask:
Chip First Middle Last
82599 0xFF6 0xFF6 0xF7F
which should be fixed up to 0xF76 (RFC 3168) in a future commit.
Reviewed by: rrs, rscheff
MFC after: 3 days
Sponsored by: Netflix
Differential Revision: https://reviews.freebsd.org/D44258
---
sys/dev/ixgbe/if_ix.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 56 insertions(+)
diff --git a/sys/dev/ixgbe/if_ix.c b/sys/dev/ixgbe/if_ix.c
index f8a620295aa4..ad690fdccef4 100644
--- a/sys/dev/ixgbe/if_ix.c
+++ b/sys/dev/ixgbe/if_ix.c
@@ -204,6 +204,7 @@ static int ixgbe_sysctl_tdh_handler(SYSCTL_HANDLER_ARGS);
static int ixgbe_sysctl_eee_state(SYSCTL_HANDLER_ARGS);
static int ixgbe_sysctl_wol_enable(SYSCTL_HANDLER_ARGS);
static int ixgbe_sysctl_wufc(SYSCTL_HANDLER_ARGS);
+static int ixgbe_sysctl_tso_tcp_flags_mask(SYSCTL_HANDLER_ARGS);
/* Deferred interrupt tasklets */
static void ixgbe_handle_msf(void *);
@@ -2756,6 +2757,24 @@ ixgbe_add_device_sysctls(if_ctx_t ctx)
CTLTYPE_STRING | CTLFLAG_RD, sc, 0,
ixgbe_sysctl_print_fw_version, "A", "Prints FW/NVM Versions");
+ SYSCTL_ADD_PROC(ctx_list, child, OID_AUTO,
+ "tso_tcp_flags_mask_first_segment",
+ CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
+ sc, 0, ixgbe_sysctl_tso_tcp_flags_mask, "IU",
+ "TSO TCP flags mask for first segment");
+
+ SYSCTL_ADD_PROC(ctx_list, child, OID_AUTO,
+ "tso_tcp_flags_mask_middle_segment",
+ CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
+ sc, 1, ixgbe_sysctl_tso_tcp_flags_mask, "IU",
+ "TSO TCP flags mask for middle segment");
+
+ SYSCTL_ADD_PROC(ctx_list, child, OID_AUTO,
+ "tso_tcp_flags_mask_last_segment",
+ CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
+ sc, 2, ixgbe_sysctl_tso_tcp_flags_mask, "IU",
+ "TSO TCP flags mask for last segment");
+
#ifdef IXGBE_DEBUG
/* testing sysctls (for all devices) */
SYSCTL_ADD_PROC(ctx_list, child, OID_AUTO, "power_state",
@@ -4742,6 +4761,43 @@ ixgbe_sysctl_eee_state(SYSCTL_HANDLER_ARGS)
return (error);
} /* ixgbe_sysctl_eee_state */
+static int
+ixgbe_sysctl_tso_tcp_flags_mask(SYSCTL_HANDLER_ARGS)
+{
+ struct ixgbe_softc *sc;
+ u32 reg, val, shift;
+ int error, mask;
+
+ sc = oidp->oid_arg1;
+ switch (oidp->oid_arg2) {
+ case 0:
+ reg = IXGBE_DTXTCPFLGL;
+ shift = 0;
+ break;
+ case 1:
+ reg = IXGBE_DTXTCPFLGL;
+ shift = 16;
+ break;
+ case 2:
+ reg = IXGBE_DTXTCPFLGH;
+ shift = 0;
+ break;
+ default:
+ return (EINVAL);
+ break;
+ }
+ val = IXGBE_READ_REG(&sc->hw, reg);
+ mask = (val >> shift) & 0xfff;
+ error = sysctl_handle_int(oidp, &mask, 0, req);
+ if (error != 0 || req->newptr == NULL)
+ return (error);
+ if (mask < 0 || mask > 0xfff)
+ return (EINVAL);
+ val = (val & ~(0xfff << shift)) | (mask << shift);
+ IXGBE_WRITE_REG(&sc->hw, reg, val);
+ return (0);
+}
+
/************************************************************************
* ixgbe_init_device_features
************************************************************************/
--
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