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From:   Steen Hegelund <steen.hegelund@microchip.com>
To:     "David S . Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>
CC:     Steen Hegelund <steen.hegelund@microchip.com>,
        <UNGLinuxDriver@microchip.com>,
        Randy Dunlap <rdunlap@infradead.org>,
        "Casper Andersson" <casper.casan@gmail.com>,
        Russell King <rmk+kernel@armlinux.org.uk>,
        Wan Jiabing <wanjiabing@vivo.com>,
        "Nathan Huckleberry" <nhuck@google.com>,
        <linux-kernel@vger.kernel.org>, <netdev@vger.kernel.org>,
        <linux-arm-kernel@lists.infradead.org>,
        "Steen Hegelund" <Steen.Hegelund@microchip.com>,
        Daniel Machon <daniel.machon@microchip.com>,
        Horatiu Vultur <horatiu.vultur@microchip.com>,
        Lars Povlsen <lars.povlsen@microchip.com>
Subject: [PATCH net-next v2 7/8] net: microchip: sparx5: Add VCAP locking to protect rules
Date:   Thu, 17 Nov 2022 22:31:13 +0100
Message-ID: <20221117213114.699375-8-steen.hegelund@microchip.com>
In-Reply-To: <20221117213114.699375-1-steen.hegelund@microchip.com>
References: <20221117213114.699375-1-steen.hegelund@microchip.com>
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This ensures that the VCAP cache and the lists maintained in the VCAP
instance is protected when accessed by different clients.

Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
---
 .../net/ethernet/microchip/sparx5/sparx5_vcap_impl.c   |  2 ++
 drivers/net/ethernet/microchip/vcap/vcap_api.c         | 10 ++++++++++
 drivers/net/ethernet/microchip/vcap/vcap_api.h         |  1 +
 drivers/net/ethernet/microchip/vcap/vcap_api_debugfs.c |  2 ++
 4 files changed, 15 insertions(+)

diff --git a/drivers/net/ethernet/microchip/sparx5/sparx5_vcap_impl.c b/drivers/net/ethernet/microchip/sparx5/sparx5_vcap_impl.c
index e70ff1aa6d57..0c4d4e6d51e6 100644
--- a/drivers/net/ethernet/microchip/sparx5/sparx5_vcap_impl.c
+++ b/drivers/net/ethernet/microchip/sparx5/sparx5_vcap_impl.c
@@ -579,6 +579,7 @@ static void sparx5_vcap_admin_free(struct vcap_admin *admin)
 {
 	if (!admin)
 		return;
+	mutex_destroy(&admin->lock);
 	kfree(admin->cache.keystream);
 	kfree(admin->cache.maskstream);
 	kfree(admin->cache.actionstream);
@@ -598,6 +599,7 @@ sparx5_vcap_admin_alloc(struct sparx5 *sparx5, struct vcap_control *ctrl,
 	INIT_LIST_HEAD(&admin->list);
 	INIT_LIST_HEAD(&admin->rules);
 	INIT_LIST_HEAD(&admin->enabled);
+	mutex_init(&admin->lock);
 	admin->vtype = cfg->vtype;
 	admin->vinst = cfg->vinst;
 	admin->lookups = cfg->lookups;
diff --git a/drivers/net/ethernet/microchip/vcap/vcap_api.c b/drivers/net/ethernet/microchip/vcap/vcap_api.c
index 3415605350c9..ac7a32ff755e 100644
--- a/drivers/net/ethernet/microchip/vcap/vcap_api.c
+++ b/drivers/net/ethernet/microchip/vcap/vcap_api.c
@@ -1054,6 +1054,7 @@ int vcap_add_rule(struct vcap_rule *rule)
 	if (ret)
 		return ret;
 	/* Insert the new rule in the list of vcap rules */
+	mutex_lock(&ri->admin->lock);
 	ret = vcap_insert_rule(ri, &move);
 	if (ret < 0) {
 		pr_err("%s:%d: could not insert rule in vcap list: %d\n",
@@ -1072,6 +1073,7 @@ int vcap_add_rule(struct vcap_rule *rule)
 	if (ret)
 		pr_err("%s:%d: rule write error: %d\n", __func__, __LINE__, ret);
 out:
+	mutex_unlock(&ri->admin->lock);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(vcap_add_rule);
@@ -1221,9 +1223,11 @@ int vcap_del_rule(struct vcap_control *vctrl, struct net_device *ndev, u32 id)
 		gap = vcap_fill_rule_gap(ri);
 
 	/* Delete the rule from the list of rules and the cache */
+	mutex_lock(&admin->lock);
 	list_del(&ri->list);
 	vctrl->ops->init(ndev, admin, admin->last_used_addr, ri->size + gap);
 	kfree(ri);
+	mutex_unlock(&admin->lock);
 
 	/* Update the last used address, set to default when no rules */
 	if (list_empty(&admin->rules)) {
@@ -1246,6 +1250,8 @@ int vcap_del_rules(struct vcap_control *vctrl, struct vcap_admin *admin)
 
 	if (ret)
 		return ret;
+
+	mutex_lock(&admin->lock);
 	list_for_each_entry_safe(ri, next_ri, &admin->rules, list) {
 		vctrl->ops->init(ri->ndev, admin, ri->addr, ri->size);
 		list_del(&ri->list);
@@ -1258,6 +1264,7 @@ int vcap_del_rules(struct vcap_control *vctrl, struct vcap_admin *admin)
 		list_del(&eport->list);
 		kfree(eport);
 	}
+	mutex_unlock(&admin->lock);
 
 	return 0;
 }
@@ -1687,10 +1694,13 @@ int vcap_enable_lookups(struct vcap_control *vctrl, struct net_device *ndev,
 	if (chain_id) {
 		if (vcap_is_enabled(admin, ndev, cookie))
 			return -EADDRINUSE;
+		mutex_lock(&admin->lock);
 		vcap_enable(admin, ndev, cookie);
 	} else {
+		mutex_lock(&admin->lock);
 		vcap_disable(admin, ndev, cookie);
 	}
+	mutex_unlock(&admin->lock);
 
 	return 0;
 }
diff --git a/drivers/net/ethernet/microchip/vcap/vcap_api.h b/drivers/net/ethernet/microchip/vcap/vcap_api.h
index e71e7d3d79c2..f4a5ba5ffa87 100644
--- a/drivers/net/ethernet/microchip/vcap/vcap_api.h
+++ b/drivers/net/ethernet/microchip/vcap/vcap_api.h
@@ -167,6 +167,7 @@ struct vcap_admin {
 	struct list_head list; /* for insertion in vcap_control */
 	struct list_head rules; /* list of rules */
 	struct list_head enabled; /* list of enabled ports */
+	struct mutex lock; /* control access to rules */
 	enum vcap_type vtype;  /* type of vcap */
 	int vinst; /* instance number within the same type */
 	int first_cid; /* first chain id in this vcap */
diff --git a/drivers/net/ethernet/microchip/vcap/vcap_api_debugfs.c b/drivers/net/ethernet/microchip/vcap/vcap_api_debugfs.c
index 981c4ed6ad7d..891034e349de 100644
--- a/drivers/net/ethernet/microchip/vcap/vcap_api_debugfs.c
+++ b/drivers/net/ethernet/microchip/vcap/vcap_api_debugfs.c
@@ -625,6 +625,7 @@ static int vcap_show_admin(struct vcap_control *vctrl,
 	int ret = 0;
 
 	vcap_show_admin_info(vctrl, admin, out);
+	mutex_lock(&admin->lock);
 	list_for_each_entry(elem, &admin->rules, list) {
 		ri = vcap_dup_rule(elem);
 		if (IS_ERR(ri))
@@ -638,6 +639,7 @@ static int vcap_show_admin(struct vcap_control *vctrl,
 free_rule:
 		vcap_free_rule((struct vcap_rule *)ri);
 	}
+	mutex_unlock(&admin->lock);
 	return ret;
 }
 
-- 
2.38.1