From e89f3c656ff17741aa3ea33c57bc177afedc999b Mon Sep 17 00:00:00 2001

From: Gal Pressman <galp@mellanox.com>

Date: Wed, 8 Mar 2017 16:03:51 +0200

Subject: [PATCH 5/7] ethtool: Support for configurable RSS hash function

This ethtool patch adds support to set and get the current RSS hash

function for the device through the new hfunc mask field in the

ethtool_rxfh struct. Kernel supported hash function names are queried

with ETHTOOL_GSTRINGS - each string is corresponding with a bit in hfunc

mask according to its index in the string-set.

(This corrects the mistaken revert from commit 126464e4da182064. -- JWL)

Signed-off-by: Eyal Perry <eyalpe@mellanox.com>

Signed-off-by: Gal Pressman <galp@mellanox.com>

Reviewed-by: Saeed Mahameed <saeedm@mellanox.com>

Signed-off-by: John W. Linville <linville@tuxdriver.com>

(cherry picked from commit b888f358763a20625a381e071ea50524a520c7c1)

---

 ethtool.8.in |  6 ++++++

 ethtool.c    | 66 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++---

 2 files changed, 69 insertions(+), 3 deletions(-)

diff --git a/ethtool.8.in b/ethtool.8.in

index 9631847..b69c5c6 100644

--- a/ethtool.8.in

+++ b/ethtool.8.in

@@ -301,6 +301,8 @@ ethtool \- query or control network driver and hardware settings

 .BI weight\  W0

 .IR W1

 .RB ...\ | \ default \ ]

+.RB [ hfunc

+.IR FUNC ]

 .HP

 .B ethtool \-f|\-\-flash

 .I devname file

@@ -853,6 +855,10 @@ Sets RSS hash key of the specified network device. RSS hash key should be of dev

 Hash key format must be in xx:yy:zz:aa:bb:cc format meaning both the nibbles of a byte should be mentioned

 even if a nibble is zero.

 .TP

+.BI hfunc

+Sets RSS hash function of the specified network device.

+List of RSS hash functions which kernel supports is shown as a part of the --show-rxfh command output.

+.TP

 .BI equal\  N

 Sets the receive flow hash indirection table to spread flows evenly

 between the first \fIN\fR receive queues.

diff --git a/ethtool.c b/ethtool.c

index ce48639..8eba6e6 100644

--- a/ethtool.c

+++ b/ethtool.c

@@ -3640,6 +3640,7 @@ static int do_grxfhindir(struct cmd_context *ctx,

 static int do_grxfh(struct cmd_context *ctx)

 {

+	struct ethtool_gstrings *hfuncs = NULL;

 	struct ethtool_rxfh rss_head = {0};

 	struct ethtool_rxnfc ring_count;

 	struct ethtool_rxfh *rss;

@@ -3697,6 +3698,26 @@ static int do_grxfh(struct cmd_context *ctx)

 			printf("%02x:", (u8) hkey[i]);

 	}

+	printf("RSS hash function:\n");

+	if (!rss->hfunc) {

+		printf("    Operation not supported\n");

+		goto out;

+	}

+

+	hfuncs = get_stringset(ctx, ETH_SS_RSS_HASH_FUNCS, 0, 1);

+	if (!hfuncs) {

+		perror("Cannot get hash functions names");

+		free(rss);

+		return 1;

+	}

+

+	for (i = 0; i < hfuncs->len; i++)

+		printf("    %s: %s\n",

+		       (const char *)hfuncs->data + i * ETH_GSTRING_LEN,

+		       (rss->hfunc & (1 << i)) ? "on" : "off");

+

+out:

+	free(hfuncs);

 	free(rss);

 	return 0;

 }

@@ -3800,11 +3821,16 @@ static int do_srxfh(struct cmd_context *ctx)

 	struct ethtool_rxfh *rss;

 	struct ethtool_rxnfc ring_count;

 	int rxfhindir_equal = 0, rxfhindir_default = 0;

+	struct ethtool_gstrings *hfuncs = NULL;

 	char **rxfhindir_weight = NULL;

 	char *rxfhindir_key = NULL;

+	char *req_hfunc_name = NULL;

+	char *hfunc_name = NULL;

 	char *hkey = NULL;

 	int err = 0;

+	int i;

 	u32 arg_num = 0, indir_bytes = 0;

+	u32 req_hfunc = 0;

 	u32 entry_size = sizeof(rss_head.rss_config[0]);

 	u32 num_weights = 0;

@@ -3836,6 +3862,12 @@ static int do_srxfh(struct cmd_context *ctx)

 		} else if (!strcmp(ctx->argp[arg_num], "default")) {

 			++arg_num;

 			rxfhindir_default = 1;

+		} else if (!strcmp(ctx->argp[arg_num], "hfunc")) {

+			++arg_num;

+			req_hfunc_name = ctx->argp[arg_num];

+			if (!req_hfunc_name)

+				exit_bad_args();

+			++arg_num;

 		} else {

 			exit_bad_args();

 		}

@@ -3868,7 +3900,8 @@ static int do_srxfh(struct cmd_context *ctx)

 	rss_head.cmd = ETHTOOL_GRSSH;

 	err = send_ioctl(ctx, &rss_head);

-	if (err < 0 && errno == EOPNOTSUPP && !rxfhindir_key) {

+	if (err < 0 && errno == EOPNOTSUPP && !rxfhindir_key &&

+	    !req_hfunc_name) {

 		return do_srxfhindir(ctx, rxfhindir_default, rxfhindir_equal,

 				     rxfhindir_weight, num_weights);

 	} else if (err < 0) {

@@ -3886,14 +3919,39 @@ static int do_srxfh(struct cmd_context *ctx)

 	if (rxfhindir_equal || rxfhindir_weight)

 		indir_bytes = rss_head.indir_size * entry_size;

+	if (rss_head.hfunc && req_hfunc_name) {

+		hfuncs = get_stringset(ctx, ETH_SS_RSS_HASH_FUNCS, 0, 1);

+		if (!hfuncs) {

+			perror("Cannot get hash functions names");

+			return 1;

+		}

+

+		for (i = 0; i < hfuncs->len && !req_hfunc ; i++) {

+			hfunc_name = (char *)(hfuncs->data +

+					      i * ETH_GSTRING_LEN);

+			if (!strncmp(hfunc_name, req_hfunc_name,

+				     ETH_GSTRING_LEN))

+				req_hfunc = (u32)1 << i;

+		}

+

+		if (!req_hfunc) {

+			fprintf(stderr,

+				"Unknown hash function: %s\n", req_hfunc_name);

+			free(hfuncs);

+			return 1;

+		}

+	}

+

 	rss = calloc(1, sizeof(*rss) + indir_bytes + rss_head.key_size);

 	if (!rss) {

 		perror("Cannot allocate memory for RX flow hash config");

-		return 1;

+		err = 1;

+		goto free;

 	}

 	rss->cmd = ETHTOOL_SRSSH;

 	rss->indir_size = rss_head.indir_size;

 	rss->key_size = rss_head.key_size;

+	rss->hfunc = req_hfunc;

 	if (fill_indir_table(&rss->indir_size, rss->rss_config, rxfhindir_default,

 			     rxfhindir_equal, rxfhindir_weight, num_weights)) {

@@ -3918,6 +3976,7 @@ free:

 		free(hkey);

 	free(rss);

+	free(hfuncs);

 	return err;

 }

@@ -4650,7 +4709,8 @@ static const struct option {

 	{ "-X|--set-rxfh-indir|--rxfh", 1, do_srxfh,

 	  "Set Rx flow hash indirection table and/or RSS hash key",

 	  "		[ equal N | weight W0 W1 ... | default ]\n"

-	  "		[ hkey %x:%x:%x:%x:%x:.... ]\n" },

+	  "		[ hkey %x:%x:%x:%x:%x:.... ]\n"

+	  "		[ hfunc FUNC ]\n" },

 	{ "-f|--flash", 1, do_flash,

 	  "Flash firmware image from the specified file to a region on the device",

 	  "               FILENAME [ REGION-NUMBER-TO-FLASH ]\n" },

-- 

1.8.3.1