From 81fa3e72ea1cd2761bc813d536bd3ccb190c5c6c Mon Sep 17 00:00:00 2001
From: cheloha <cheloha@openbsd.org>
Date: Sat, 24 Feb 2024 15:21:39 +0000
Subject: [PATCH] qwx(4): qwx_dp_rx_tid_del_func: fix dp_reo_cache_flush_elem
 expiration logic

Tweak a few things in qwx_dp_rx_tid_del_func() to make it behave
correctly on OpenBSD:

- struct dp_reo_cache_flush_elem: make ts a 64-bit count of nanoseconds

  Linux uses jiffies to timestamp dp_reo_cache_flush_elem.  Although
  OpenBSD has a global jiffies variable, we shouldn't use it outside
  of drm(4).  I would rather not use our global ticks variable, either.
  We can use getnsecuptime(9), a low-res 64-bit nanosecond timestamp,
  as a substitute.

- qwx_dp_rx_tid_del_func: replace gettime(9) with getnsecuptime(9)

- qwx_dp_rx_tid_del_func: convert DP_REO_DESC_FREE_TIMEOUT_MS to nanoseconds

- qwx_dp_rx_tid_del_func: reverse timestamp comparison operator

  This comparison is backwards.  Linux uses the time_after() macro to
  test whether a given entry has expired, so our ported code needs to
  test whether the current uptime is greater than or equal to a given
  entry's expiration time.

Joint effort with stsp@.  Tested by stsp@.

ok stsp@
---
 sys/dev/ic/qwx.c    | 8 ++++----
 sys/dev/ic/qwxvar.h | 4 ++--
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/sys/dev/ic/qwx.c b/sys/dev/ic/qwx.c
index 36b56ae559a..193fdae1420 100644
--- a/sys/dev/ic/qwx.c
+++ b/sys/dev/ic/qwx.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: qwx.c,v 1.51 2024/02/22 21:21:35 stsp Exp $	*/
+/*	$OpenBSD: qwx.c,v 1.52 2024/02/24 15:21:39 cheloha Exp $	*/
 
 /*
  * Copyright 2023 Stefan Sperling <stsp@openbsd.org>
@@ -23155,7 +23155,7 @@ qwx_dp_rx_tid_del_func(struct qwx_dp *dp, void *ctx,
 	struct qwx_softc *sc = dp->sc;
 	struct dp_rx_tid *rx_tid = ctx;
 	struct dp_reo_cache_flush_elem *elem, *tmp;
-	time_t now;
+	uint64_t now;
 
 	if (status == HAL_REO_CMD_DRAIN) {
 		goto free_desc;
@@ -23170,7 +23170,7 @@ qwx_dp_rx_tid_del_func(struct qwx_dp *dp, void *ctx,
 	if (!elem)
 		goto free_desc;
 
-	now = gettime();
+	now = getnsecuptime();
 	elem->ts = now;
 	memcpy(&elem->data, rx_tid, sizeof(*rx_tid));
 
@@ -23188,7 +23188,7 @@ qwx_dp_rx_tid_del_func(struct qwx_dp *dp, void *ctx,
 	/* Flush and invalidate aged REO desc from HW cache */
 	TAILQ_FOREACH_SAFE(elem, &dp->reo_cmd_cache_flush_list, entry, tmp) {
 		if (dp->reo_cmd_cache_flush_count > DP_REO_DESC_FREE_THRESHOLD ||
-		    now < elem->ts + DP_REO_DESC_FREE_TIMEOUT_MS) {
+		    now >= elem->ts + MSEC_TO_NSEC(DP_REO_DESC_FREE_TIMEOUT_MS)) {
 			TAILQ_REMOVE(&dp->reo_cmd_cache_flush_list, elem, entry);
 			dp->reo_cmd_cache_flush_count--;
 #ifdef notyet
diff --git a/sys/dev/ic/qwxvar.h b/sys/dev/ic/qwxvar.h
index 0399a4328aa..a84553d5bcb 100644
--- a/sys/dev/ic/qwxvar.h
+++ b/sys/dev/ic/qwxvar.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: qwxvar.h,v 1.22 2024/02/22 09:08:08 stsp Exp $	*/
+/*	$OpenBSD: qwxvar.h,v 1.23 2024/02/24 15:21:39 cheloha Exp $	*/
 
 /*
  * Copyright (c) 2018-2019 The Linux Foundation.
@@ -1041,7 +1041,7 @@ struct dp_rx_tid {
 struct dp_reo_cache_flush_elem {
 	TAILQ_ENTRY(dp_reo_cache_flush_elem) entry;
 	struct dp_rx_tid data;
-	unsigned long ts;
+	uint64_t ts;
 };
 
 TAILQ_HEAD(dp_reo_cmd_cache_flush_head, dp_reo_cache_flush_elem);
-- 
2.20.1