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From:   Horatiu Vultur <horatiu.vultur@microchip.com>
To:     <linux-arm-kernel@lists.infradead.org>, <netdev@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>
CC:     <davem@davemloft.net>, <edumazet@google.com>, <kuba@kernel.org>,
        <pabeni@redhat.com>, <lars.povlsen@microchip.com>,
        <Steen.Hegelund@microchip.com>, <daniel.machon@microchip.com>,
        <UNGLinuxDriver@microchip.com>, <casper.casan@gmail.com>,
        Horatiu Vultur <horatiu.vultur@microchip.com>
Subject: [PATCH net-next] net: microchip: vcap: Change how the rule id is generated
Date:   Mon, 28 Nov 2022 15:29:59 +0100
Message-ID: <20221128142959.8325-1-horatiu.vultur@microchip.com>
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Precedence: bulk

Currently whenever a new rule id is generated, it picks up the next
number bigger than previous id. So it would always be 1, 2, 3, etc.
When the rule with id 1 will be deleted and a new rule will be added,
it will have the id 4 and not id 1.
In theory this can be a problem if at some point a rule will be added
and removed ~0 times. Then no more rules can be added because there
are no more ids.

Change this such that when a new rule is added, search for an empty
rule id starting with value of 1 as value 0 is reserved.

Fixes: c9da1ac1c212 ("net: microchip: sparx5: Adding initial tc flower support for VCAP API")
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
---
 drivers/net/ethernet/microchip/vcap/vcap_api.c | 7 +------
 drivers/net/ethernet/microchip/vcap/vcap_api.h | 1 -
 2 files changed, 1 insertion(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/microchip/vcap/vcap_api.c b/drivers/net/ethernet/microchip/vcap/vcap_api.c
index b50d002b646dc..b65819f3a927f 100644
--- a/drivers/net/ethernet/microchip/vcap/vcap_api.c
+++ b/drivers/net/ethernet/microchip/vcap/vcap_api.c
@@ -974,17 +974,12 @@ static u32 vcap_next_rule_addr(u32 addr, struct vcap_rule_internal *ri)
 /* Assign a unique rule id and autogenerate one if id == 0 */
 static u32 vcap_set_rule_id(struct vcap_rule_internal *ri)
 {
-	u32 next_id;
-
 	if (ri->data.id != 0)
 		return ri->data.id;
 
-	next_id = ri->vctrl->rule_id + 1;
-
-	for (next_id = ri->vctrl->rule_id + 1; next_id < ~0; ++next_id) {
+	for (u32 next_id = 1; next_id < ~0; ++next_id) {
 		if (!vcap_lookup_rule(ri->vctrl, next_id)) {
 			ri->data.id = next_id;
-			ri->vctrl->rule_id = next_id;
 			break;
 		}
 	}
diff --git a/drivers/net/ethernet/microchip/vcap/vcap_api.h b/drivers/net/ethernet/microchip/vcap/vcap_api.h
index ca4499838306f..689c7270f2a89 100644
--- a/drivers/net/ethernet/microchip/vcap/vcap_api.h
+++ b/drivers/net/ethernet/microchip/vcap/vcap_api.h
@@ -268,7 +268,6 @@ struct vcap_operations {
 
 /* VCAP API Client control interface */
 struct vcap_control {
-	u32 rule_id; /* last used rule id (unique across VCAP instances) */
 	struct vcap_operations *ops;  /* client supplied operations */
 	const struct vcap_info *vcaps; /* client supplied vcap models */
 	const struct vcap_statistics *stats; /* client supplied vcap stats */
-- 
2.38.0