git: eea2e089f8da - main - ixgbe: sysctl for TCP flag handling during TSO

The branch main has been updated by kbowling:

URL: https://cgit.FreeBSD.org/src/commit/?id=eea2e089f8dadf850a30ed837edd7a386427a9ed

commit eea2e089f8dadf850a30ed837edd7a386427a9ed
Author:     Michael Tuexen <tuexen@FreeBSD.org>
AuthorDate: 2024-11-21 01:18:17 +0000
Commit:     Kevin Bowling <kbowling@FreeBSD.org>
CommitDate: 2024-11-21 01:25:06 +0000

    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
  ************************************************************************/