ifconfig: Improve CMIS parsing of breakout configs

This fixes a bug where we do not report all lanes when
a NIC configures a breakout.  Eg, we reported all 4
lanes when a NIC configured the optics as 1x400g, but
only printed the first lane's strength when configured as
4x100g.

Fix this by actually parsing the active lane count, rather
than pulling it from the default descriptor.

While here, optionally print page 10h when -vvvv is
specified. This aids in determining how a breakout is configured.
I put it under an extra level of verbosity, as I don't want
to let things get out of hand printing CMIS pages.

Sponsored by: Netflix
Reviewed by: kib, sumit.saxena_broadcom.com
Differential Revision: https://reviews.freebsd.org/D58263

lib/libifconfig/libifconfig_sfp.c

@@ -238,6 +238,27 @@ get_qsfp_info(struct i2c_info *ii, struct ifconfig_sfp_info *sfp)
 	return (ii->error);
 }
 
+/* Count active host lanes (nonzero AppSelCode) in the Active Control Set. */
+static uint8_t
+get_cmis_active_lanes(struct i2c_info *ii)
+{
+	uint8_t dpconfig[CMIS_MAX_LANES];
+	uint8_t lanes;
+	int i;
+
+	lanes = 0;
+	read_i2c_page(ii, CMIS_BASE, 0x11, 0, CMIS_P11_ACS_DPCONFIG1,
+	    sizeof(dpconfig), dpconfig);
+	if (ii->error != 0)
+		return (0);
+
+	for (i = 0; i < CMIS_MAX_LANES; i++) {
+		if ((dpconfig[i] & CMIS_ACS_APPSEL_MASK) != 0)
+			lanes++;
+	}
+	return (lanes);
+}
+
 static int
 get_cmis_info(struct i2c_info *ii, struct ifconfig_sfp_info *sfp)
 {
@@ -287,8 +308,10 @@ get_cmis_info(struct i2c_info *ii, struct ifconfig_sfp_info *sfp)
 		break;
 	}
 
-	/* Extract media lane count from app descriptor byte 2, bits 3:0 */
-	sfp->sfp_cmis_lanes = app_desc[CMIS_APP_LANE_COUNT] & 0x0F;
+	/* Count active lanes; fall back to the descriptor's media lane count. */
+	sfp->sfp_cmis_lanes = get_cmis_active_lanes(ii);
+	if (sfp->sfp_cmis_lanes == 0)
+		sfp->sfp_cmis_lanes = app_desc[CMIS_APP_LANE_COUNT] & 0x0F;
 
 	return (ii->error);
 }
@@ -657,15 +680,18 @@ ifconfig_sfp_get_sfp_status(ifconfig_handle_t *h, const char *name,
 
 	if (ifconfig_sfp_id_is_cmis(ii.id)) {
 		/*
-		 * For CMIS, we need the lane count from the module info.
-		 * Read the first Application Descriptor to get it.
+		 * Match the active-lane count reported by get_cmis_info();
+		 * fall back to the first descriptor's media lane count.
 		 */
 		uint8_t app_desc[CMIS_APP_DESC_SIZE];
 		size_t channels;
 
-		read_i2c(&ii, CMIS_BASE, CMIS_APP_DESC_START,
-		    CMIS_APP_DESC_SIZE, app_desc);
-		channels = app_desc[CMIS_APP_LANE_COUNT] & 0x0F;
+		channels = get_cmis_active_lanes(&ii);
+		if (channels == 0) {
+			read_i2c(&ii, CMIS_BASE, CMIS_APP_DESC_START,
+			    CMIS_APP_DESC_SIZE, app_desc);
+			channels = app_desc[CMIS_APP_LANE_COUNT] & 0x0F;
+		}
 		return (get_cmis_status(&ii, ss, channels));
 	}
 
@@ -779,12 +805,14 @@ ifconfig_sfp_get_sfp_dump(ifconfig_handle_t *h, const char *name,
 		return (-1);
 
 	if (ifconfig_sfp_id_is_cmis(ii.id)) {
-		/* Lower memory (0-127), Page 00h (128-255), Page 11h */
+		/* Lower memory (0-127), Page 00h, Page 11h, Page 10h */
 		read_i2c(&ii, CMIS_BASE, 0, 128, buf);
 		read_i2c_page(&ii, CMIS_BASE, 0x00, 0, 128, 128,
 		    buf + 128);
 		read_i2c_page(&ii, CMIS_BASE, 0x11, 0, 128, 128,
 		    buf + CMIS_DUMP_P11);
+		read_i2c_page(&ii, CMIS_BASE, 0x10, 0, 128, 128,
+		    buf + CMIS_DUMP_P10);
 	} else if (ifconfig_sfp_id_is_qsfp(ii.id)) {
 		read_i2c(&ii, SFF_8436_BASE, QSFP_DUMP0_START, QSFP_DUMP0_SIZE,
 		    buf + QSFP_DUMP0_START);
@@ -804,7 +832,7 @@ ifconfig_sfp_dump_region_count(const struct ifconfig_sfp_dump *dp)
 	uint8_t id_byte = dp->data[0];
 
 	if (ifconfig_sfp_id_is_cmis((enum sfp_id)id_byte))
-		return (3);
+		return (4);
 
 	switch ((enum sfp_id)id_byte) {
 	case SFP_ID_UNKNOWN:

lib/libifconfig/libifconfig_sfp.h

@@ -85,10 +85,11 @@ struct ifconfig_sfp_status {
 
 #define CMIS_DUMP_SIZE		512	/**< CMIS dump buffer size */
 #define CMIS_DUMP_P11		256	/**< offset of Page 11h in dump buffer */
+#define CMIS_DUMP_P10		384	/**< offset of Page 10h in dump buffer */
 
 /** SFP module I2C memory dump
  * SFP modules have one region, QSFP modules have two.
- * CMIS modules have three: lower memory, Page 00h, and Page 11h.
+ * CMIS modules have four: lower memory, Page 00h, Page 11h, and Page 10h.
  */
 struct ifconfig_sfp_dump {
 	uint8_t data[CMIS_DUMP_SIZE];	/**< memory dump data */

sbin/ifconfig/sfp.c

@@ -122,6 +122,11 @@ sfp_status(if_ctx *ctx)
 			printf("\n\tCMIS DUMP (Page 00h 128..255):\n");
 			hexdump(dump.data + 128, 128,
 			    "\t", HD_OMIT_COUNT | HD_OMIT_CHARS);
+			if (verbose > 3) {
+				printf("\n\tCMIS DUMP (Page 10h 128..255):\n");
+				hexdump(dump.data + CMIS_DUMP_P10, 128,
+				    "\t", HD_OMIT_COUNT | HD_OMIT_CHARS);
+			}
 			printf("\n\tCMIS DUMP (Page 11h 128..255):\n");
 			hexdump(dump.data + CMIS_DUMP_P11, 128,
 			    "\t", HD_OMIT_COUNT | HD_OMIT_CHARS);