base/SOURCES/0014-ethtool-Support-for-FEC-encoding-control.patch

From 6477a1f47b15c2a81a9995397942a0fc17f0b06f Mon Sep 17 00:00:00 2001
From: Dustin Byford <dustin@cumulusnetworks.com>
Date: Mon, 18 Dec 2017 14:57:41 -0800
Subject: [PATCH 14/14] ethtool: Support for FEC encoding control

As FEC settings and different FEC modes are mandatory
and configurable across various interfaces of 25G/50G/100G/40G,
the lack of FEC encoding control and reporting today is a source
for interoperability issues for many vendors

set-fec/show-fec option(s) are designed to provide control and report
the FEC encoding on the link.

$ethtool --set-fec swp1 encoding [off | RS | BaseR | auto]

Encoding: Types of encoding
Off    :  Turning off FEC
RS     :  Force RS-FEC encoding
BaseR  :  Force BaseR encoding
Auto   :  Default FEC settings for drivers, and would represent
          asking the hardware to essentially go into a best effort mode.

Here are a few examples of what we would expect if encoding=auto:
- if autoneg is on, we are  expecting FEC to be negotiated as on or off
  as long as protocol supports it
- if the hardware is capable of detecting the FEC encoding on it's
  receiver it will reconfigure its encoder to match
- in absence of the above, the configuration would be set to IEEE
  defaults.

>From our understanding, this is essentially what most hardware/driver
combinations are doing today in the absence of a way for users to
control the behavior.

$ethtool --show-fec  swp1
FEC parameters for swp1:
FEC encodings:  RS

ethtool devname output:
$ethtool swp1
Settings for swp1:
root@hpe-7712-03:~# ethtool swp18
Settings for swp18:
    Supported ports: [ FIBRE ]
    Supported link modes:   40000baseCR4/Full
                            40000baseSR4/Full
                            40000baseLR4/Full
                            100000baseSR4/Full
                            100000baseCR4/Full
                            100000baseLR4_ER4/Full
    Supported pause frame use: No
    Supports auto-negotiation: Yes
    Supported FEC modes: [RS | BaseR | None | Not reported]
    Advertised link modes:  Not reported
    Advertised pause frame use: No
    Advertised auto-negotiation: No
    Advertised FEC modes: [RS | BaseR | None | Not reported]
    Speed: 100000Mb/s
    Duplex: Full
    Port: FIBRE
    PHYAD: 106
    Transceiver: internal
    Auto-negotiation: off
    Link detected: yes

Signed-off-by: Vidya Sagar Ravipati <vidya.chowdary@gmail.com>
Signed-off-by: Dustin Byford <dustin@cumulusnetworks.com>
[code style + man page edits + commit message update]
Signed-off-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

(cherry picked from commit 8db75d1e4001ac4cdfc73d5bedd0ec6d58a3d617)

Conflicts:
	ethtool.8.in
	ethtool.c
---
 ethtool.8.in |  31 ++++++++++++++++
 ethtool.c    | 119 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 150 insertions(+)

diff --git a/ethtool.8.in b/ethtool.8.in
index c176cac..6816020 100644
--- a/ethtool.8.in
+++ b/ethtool.8.in
@@ -342,6 +342,13 @@ ethtool \- query or control network driver and hardware settings
 .B2 tx-lpi on off
 .BN tx-timer
 .BN advertise
+.HP
+.B ethtool \-\-show\-fec
+.I devname
+.HP
+.B ethtool \-\-set\-fec
+.I devname
+.B4 encoding auto off rs baser
 .
 .\" Adjust lines (i.e. full justification) and hyphenate.
 .ad
@@ -959,6 +966,30 @@ Values are as for
 Sets the amount of time the device should stay in idle mode prior to asserting
 its Tx LPI (in microseconds). This has meaning only when Tx LPI is enabled.
 .RE
+.TP
+.B \-\-show\-fec
+Queries the specified network device for its support of Forward Error Correction.
+.TP
+.B \-\-set\-fec
+Configures Forward Error Correction for the specified network device.
+
+Forward Error Correction modes selected by a user are expected to be persisted
+after any hotplug events. If a module is swapped that does not support the
+current FEC mode, the driver or firmware must take the link down
+administratively and report the problem in the system logs for users to correct.
+.RS 4
+.TP
+.A4 encoding auto off rs baser
+Sets the FEC encoding for the device.
+.TS
+nokeep;
+lB	l.
+auto	Use the driver's default encoding
+off	Turn off FEC
+RS	Force RS-FEC encoding
+BaseR	Force BaseR encoding
+.TE
+.RE
 .SH BUGS
 Not supported (in part or whole) on all network drivers.
 .SH AUTHOR
diff --git a/ethtool.c b/ethtool.c
index 1411d62..2e9ee2c 100644
--- a/ethtool.c
+++ b/ethtool.c
@@ -543,6 +543,9 @@ static void init_global_link_mode_masks(void)
 		ETHTOOL_LINK_MODE_Pause_BIT,
 		ETHTOOL_LINK_MODE_Asym_Pause_BIT,
 		ETHTOOL_LINK_MODE_Backplane_BIT,
+		ETHTOOL_LINK_MODE_FEC_NONE_BIT,
+		ETHTOOL_LINK_MODE_FEC_RS_BIT,
+		ETHTOOL_LINK_MODE_FEC_BASER_BIT,
 	};
 	unsigned int i;
 
@@ -690,6 +693,7 @@ static void dump_link_caps(const char *prefix, const char *an_prefix,
 	};
 	int indent;
 	int did1, new_line_pend, i;
+	int fecreported = 0;
 
 	/* Indent just like the separate functions used to */
 	indent = strlen(prefix) + 14;
@@ -741,6 +745,26 @@ static void dump_link_caps(const char *prefix, const char *an_prefix,
 			fprintf(stdout, "Yes\n");
 		else
 			fprintf(stdout, "No\n");
+
+		fprintf(stdout, "	%s FEC modes:", prefix);
+		if (ethtool_link_mode_test_bit(ETHTOOL_LINK_MODE_FEC_NONE_BIT,
+					       mask)) {
+			fprintf(stdout, " None");
+			fecreported = 1;
+		}
+		if (ethtool_link_mode_test_bit(ETHTOOL_LINK_MODE_FEC_BASER_BIT,
+					       mask)) {
+			fprintf(stdout, " BaseR");
+			fecreported = 1;
+		}
+		if (ethtool_link_mode_test_bit(ETHTOOL_LINK_MODE_FEC_RS_BIT,
+					       mask)) {
+			fprintf(stdout, " RS");
+			fecreported = 1;
+		}
+		if (!fecreported)
+			fprintf(stdout, " Not reported");
+		fprintf(stdout, "\n");
 	}
 }
 
@@ -1569,6 +1593,20 @@ static void dump_eeecmd(struct ethtool_eee *ep)
 	dump_link_caps("Link partner advertised EEE", "", link_mode, 1);
 }
 
+static void dump_fec(u32 fec)
+{
+	if (fec & ETHTOOL_FEC_NONE)
+		fprintf(stdout, " None");
+	if (fec & ETHTOOL_FEC_AUTO)
+		fprintf(stdout, " Auto");
+	if (fec & ETHTOOL_FEC_OFF)
+		fprintf(stdout, " Off");
+	if (fec & ETHTOOL_FEC_BASER)
+		fprintf(stdout, " BaseR");
+	if (fec & ETHTOOL_FEC_RS)
+		fprintf(stdout, " RS");
+}
+
 #define N_SOTS 7
 
 static char *so_timestamping_labels[N_SOTS] = {
@@ -4592,6 +4630,84 @@ static int do_seee(struct cmd_context *ctx)
 	return 0;
 }
 
+static int fecmode_str_to_type(const char *str)
+{
+	int fecmode = 0;
+
+	if (!str)
+		return fecmode;
+
+	if (!strcasecmp(str, "auto"))
+		fecmode |= ETHTOOL_FEC_AUTO;
+	else if (!strcasecmp(str, "off"))
+		fecmode |= ETHTOOL_FEC_OFF;
+	else if (!strcasecmp(str, "rs"))
+		fecmode |= ETHTOOL_FEC_RS;
+	else if (!strcasecmp(str, "baser"))
+		fecmode |= ETHTOOL_FEC_BASER;
+
+	return fecmode;
+}
+
+static int do_gfec(struct cmd_context *ctx)
+{
+	struct ethtool_fecparam feccmd = { 0 };
+	int rv;
+
+	if (ctx->argc != 0)
+		exit_bad_args();
+
+	feccmd.cmd = ETHTOOL_GFECPARAM;
+	rv = send_ioctl(ctx, &feccmd);
+	if (rv != 0) {
+		perror("Cannot get FEC settings");
+		return rv;
+	}
+
+	fprintf(stdout, "FEC parameters for %s:\n", ctx->devname);
+	fprintf(stdout, "Configured FEC encodings:");
+	dump_fec(feccmd.fec);
+	fprintf(stdout, "\n");
+
+	fprintf(stdout, "Active FEC encoding:");
+	dump_fec(feccmd.active_fec);
+	fprintf(stdout, "\n");
+
+	return 0;
+}
+
+static int do_sfec(struct cmd_context *ctx)
+{
+	char *fecmode_str = NULL;
+	struct ethtool_fecparam feccmd;
+	struct cmdline_info cmdline_fec[] = {
+		{ "encoding", CMDL_STR,  &fecmode_str,  &feccmd.fec},
+	};
+	int changed;
+	int fecmode;
+	int rv;
+
+	parse_generic_cmdline(ctx, &changed, cmdline_fec,
+			      ARRAY_SIZE(cmdline_fec));
+
+	if (!fecmode_str)
+		exit_bad_args();
+
+	fecmode = fecmode_str_to_type(fecmode_str);
+	if (!fecmode)
+		exit_bad_args();
+
+	feccmd.cmd = ETHTOOL_SFECPARAM;
+	feccmd.fec = fecmode;
+	rv = send_ioctl(ctx, &feccmd);
+	if (rv != 0) {
+		perror("Cannot set FEC settings");
+		return rv;
+	}
+
+	return 0;
+}
+
 #ifndef TEST_ETHTOOL
 int send_ioctl(struct cmd_context *ctx, void *cmd)
 {
@@ -4754,6 +4870,9 @@ static const struct option {
 	  "		[ advertise %x ]\n"
 	  "		[ tx-lpi on|off ]\n"
 	  "		[ tx-timer %d ]\n"},
+	{ "--show-fec", 1, do_gfec, "Show FEC settings"},
+	{ "--set-fec", 1, do_sfec, "Set FEC settings",
+	  "		[ encoding auto|off|rs|baser ]\n"},
 	{ "-h|--help", 0, show_usage, "Show this help" },
 	{ "--version", 0, do_version, "Show version number" },
 	{}
-- 
1.8.3.1