git: d93919dc9b6e - stable/15 - enetc: Use the common RSS key

The branch stable/15 has been updated by kbowling:

URL: https://cgit.FreeBSD.org/src/commit/?id=d93919dc9b6eb5ce3c5ec92b3dcb8d762da25beb

commit d93919dc9b6eb5ce3c5ec92b3dcb8d762da25beb
Author:     Kevin Bowling <kbowling@FreeBSD.org>
AuthorDate: 2026-09-18 08:56:00 +0000
Commit:     Kevin Bowling <kbowling@FreeBSD.org>
CommitDate: 2026-10-29 06:48:06 +0000

    enetc: Use the common RSS key
    
    Replace the random register words with rss_getkey() and decode each
    four-byte chunk with le32dec() before writing the port's key registers.
    
    Keep the RSS capability check and existing queue-count and indirection
    table programming unchanged.
    
    Reviewed by:    gallatin
    Sponsored by:   BBOX.io
    Differential Revision:  https://reviews.freebsd.org/D59805
    
    (cherry picked from commit 449fc84f370b079619eaa0d70008391ac07718f5)
---
 sys/dev/enetc/if_enetc.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/sys/dev/enetc/if_enetc.c b/sys/dev/enetc/if_enetc.c
index 81e59dc10559..228eb0e26b03 100644
--- a/sys/dev/enetc/if_enetc.c
+++ b/sys/dev/enetc/if_enetc.c
@@ -44,6 +44,7 @@
 #include <net/if_types.h>
 #include <net/if_media.h>
 #include <net/iflib.h>
+#include <net/rss_config.h>
 
 #include <dev/enetc/enetc_hw.h>
 #include <dev/enetc/enetc.h>
@@ -603,6 +604,7 @@ enetc_setup_rss(struct enetc_softc *sc)
 {
 	struct iflib_dma_info dma;
 	int error, i, buckets_num = 0;
+	uint8_t rss_key[RSS_KEYSIZE];
 	uint8_t *rss_table;
 	uint32_t reg;
 
@@ -614,8 +616,11 @@ enetc_setup_rss(struct enetc_softc *sc)
 	if (buckets_num == 0)
 		return (ENOTSUP);
 
+	_Static_assert(ENETC_RSSHASH_KEY_SIZE == RSS_KEYSIZE,
+	    "RSS key size mismatch");
+	rss_getkey(rss_key);
 	for (i = 0; i < ENETC_RSSHASH_KEY_SIZE / sizeof(uint32_t); i++) {
-		arc4rand((uint8_t *)&reg, sizeof(reg), 0);
+		reg = le32dec(rss_key + i * sizeof(reg));
 		ENETC_PORT_WR4(sc, ENETC_PRSSK(i), reg);
 	}