--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <linux/mrp_bridge.h>
+#include "br_private_mrp.h"
+
+static const u8 mrp_test_dmac[ETH_ALEN] = { 0x1, 0x15, 0x4e, 0x0, 0x0, 0x1 };
+
+static struct net_bridge_port *br_mrp_get_port(struct net_bridge *br,
+                                              u32 ifindex)
+{
+       struct net_bridge_port *res = NULL;
+       struct net_bridge_port *port;
+
+       list_for_each_entry(port, &br->port_list, list) {
+               if (port->dev->ifindex == ifindex) {
+                       res = port;
+                       break;
+               }
+       }
+
+       return res;
+}
+
+static struct br_mrp *br_mrp_find_id(struct net_bridge *br, u32 ring_id)
+{
+       struct br_mrp *res = NULL;
+       struct br_mrp *mrp;
+
+       list_for_each_entry_rcu(mrp, &br->mrp_list, list,
+                               lockdep_rtnl_is_held()) {
+               if (mrp->ring_id == ring_id) {
+                       res = mrp;
+                       break;
+               }
+       }
+
+       return res;
+}
+
+static struct br_mrp *br_mrp_find_port(struct net_bridge *br,
+                                      struct net_bridge_port *p)
+{
+       struct br_mrp *res = NULL;
+       struct br_mrp *mrp;
+
+       list_for_each_entry_rcu(mrp, &br->mrp_list, list,
+                               lockdep_rtnl_is_held()) {
+               if (rcu_access_pointer(mrp->p_port) == p ||
+                   rcu_access_pointer(mrp->s_port) == p) {
+                       res = mrp;
+                       break;
+               }
+       }
+
+       return res;
+}
+
+static int br_mrp_next_seq(struct br_mrp *mrp)
+{
+       mrp->seq_id++;
+       return mrp->seq_id;
+}
+
+static struct sk_buff *br_mrp_skb_alloc(struct net_bridge_port *p,
+                                       const u8 *src, const u8 *dst)
+{
+       struct ethhdr *eth_hdr;
+       struct sk_buff *skb;
+       u16 *version;
+
+       skb = dev_alloc_skb(MRP_MAX_FRAME_LENGTH);
+       if (!skb)
+               return NULL;
+
+       skb->dev = p->dev;
+       skb->protocol = htons(ETH_P_MRP);
+       skb->priority = MRP_FRAME_PRIO;
+       skb_reserve(skb, sizeof(*eth_hdr));
+
+       eth_hdr = skb_push(skb, sizeof(*eth_hdr));
+       ether_addr_copy(eth_hdr->h_dest, dst);
+       ether_addr_copy(eth_hdr->h_source, src);
+       eth_hdr->h_proto = htons(ETH_P_MRP);
+
+       version = skb_put(skb, sizeof(*version));
+       *version = cpu_to_be16(MRP_VERSION);
+
+       return skb;
+}
+
+static void br_mrp_skb_tlv(struct sk_buff *skb,
+                          enum br_mrp_tlv_header_type type,
+                          u8 length)
+{
+       struct br_mrp_tlv_hdr *hdr;
+
+       hdr = skb_put(skb, sizeof(*hdr));
+       hdr->type = type;
+       hdr->length = length;
+}
+
+static void br_mrp_skb_common(struct sk_buff *skb, struct br_mrp *mrp)
+{
+       struct br_mrp_common_hdr *hdr;
+
+       br_mrp_skb_tlv(skb, BR_MRP_TLV_HEADER_COMMON, sizeof(*hdr));
+
+       hdr = skb_put(skb, sizeof(*hdr));
+       hdr->seq_id = cpu_to_be16(br_mrp_next_seq(mrp));
+       memset(hdr->domain, 0xff, MRP_DOMAIN_UUID_LENGTH);
+}
+
+static struct sk_buff *br_mrp_alloc_test_skb(struct br_mrp *mrp,
+                                            struct net_bridge_port *p,
+                                            enum br_mrp_port_role_type port_role)
+{
+       struct br_mrp_ring_test_hdr *hdr = NULL;
+       struct sk_buff *skb = NULL;
+
+       if (!p)
+               return NULL;
+
+       skb = br_mrp_skb_alloc(p, p->dev->dev_addr, mrp_test_dmac);
+       if (!skb)
+               return NULL;
+
+       br_mrp_skb_tlv(skb, BR_MRP_TLV_HEADER_RING_TEST, sizeof(*hdr));
+       hdr = skb_put(skb, sizeof(*hdr));
+
+       hdr->prio = cpu_to_be16(MRP_DEFAULT_PRIO);
+       ether_addr_copy(hdr->sa, p->br->dev->dev_addr);
+       hdr->port_role = cpu_to_be16(port_role);
+       hdr->state = cpu_to_be16(mrp->ring_state);
+       hdr->transitions = cpu_to_be16(mrp->ring_transitions);
+       hdr->timestamp = cpu_to_be32(jiffies_to_msecs(jiffies));
+
+       br_mrp_skb_common(skb, mrp);
+       br_mrp_skb_tlv(skb, BR_MRP_TLV_HEADER_END, 0x0);
+
+       return skb;
+}
+
+static void br_mrp_test_work_expired(struct work_struct *work)
+{
+       struct delayed_work *del_work = to_delayed_work(work);
+       struct br_mrp *mrp = container_of(del_work, struct br_mrp, test_work);
+       struct net_bridge_port *p;
+       bool notify_open = false;
+       struct sk_buff *skb;
+
+       if (time_before_eq(mrp->test_end, jiffies))
+               return;
+
+       if (mrp->test_count_miss < mrp->test_max_miss) {
+               mrp->test_count_miss++;
+       } else {
+               /* Notify that the ring is open only if the ring state is
+                * closed, otherwise it would continue to notify at every
+                * interval.
+                */
+               if (mrp->ring_state == BR_MRP_RING_STATE_CLOSED)
+                       notify_open = true;
+       }
+
+       rcu_read_lock();
+
+       p = rcu_dereference(mrp->p_port);
+       if (p) {
+               skb = br_mrp_alloc_test_skb(mrp, p, BR_MRP_PORT_ROLE_PRIMARY);
+               if (!skb)
+                       goto out;
+
+               skb_reset_network_header(skb);
+               dev_queue_xmit(skb);
+
+               if (notify_open && !mrp->ring_role_offloaded)
+                       br_mrp_port_open(p->dev, true);
+       }
+
+       p = rcu_dereference(mrp->s_port);
+       if (p) {
+               skb = br_mrp_alloc_test_skb(mrp, p, BR_MRP_PORT_ROLE_SECONDARY);
+               if (!skb)
+                       goto out;
+
+               skb_reset_network_header(skb);
+               dev_queue_xmit(skb);
+
+               if (notify_open && !mrp->ring_role_offloaded)
+                       br_mrp_port_open(p->dev, true);
+       }
+
+out:
+       rcu_read_unlock();
+
+       queue_delayed_work(system_wq, &mrp->test_work,
+                          usecs_to_jiffies(mrp->test_interval));
+}
+
+/* Deletes the MRP instance.
+ * note: called under rtnl_lock
+ */
+static void br_mrp_del_impl(struct net_bridge *br, struct br_mrp *mrp)
+{
+       struct net_bridge_port *p;
+
+       /* Stop sending MRP_Test frames */
+       cancel_delayed_work_sync(&mrp->test_work);
+       br_mrp_switchdev_send_ring_test(br, mrp, 0, 0, 0);
+
+       br_mrp_switchdev_del(br, mrp);
+
+       /* Reset the ports */
+       p = rtnl_dereference(mrp->p_port);
+       if (p) {
+               spin_lock_bh(&br->lock);
+               p->state = BR_STATE_FORWARDING;
+               p->flags &= ~BR_MRP_AWARE;
+               spin_unlock_bh(&br->lock);
+               br_mrp_port_switchdev_set_state(p, BR_STATE_FORWARDING);
+               rcu_assign_pointer(mrp->p_port, NULL);
+       }
+
+       p = rtnl_dereference(mrp->s_port);
+       if (p) {
+               spin_lock_bh(&br->lock);
+               p->state = BR_STATE_FORWARDING;
+               p->flags &= ~BR_MRP_AWARE;
+               spin_unlock_bh(&br->lock);
+               br_mrp_port_switchdev_set_state(p, BR_STATE_FORWARDING);
+               rcu_assign_pointer(mrp->s_port, NULL);
+       }
+
+       list_del_rcu(&mrp->list);
+       kfree_rcu(mrp, rcu);
+}
+
+/* Adds a new MRP instance.
+ * note: called under rtnl_lock
+ */
+int br_mrp_add(struct net_bridge *br, struct br_mrp_instance *instance)
+{
+       struct net_bridge_port *p;
+       struct br_mrp *mrp;
+       int err;
+
+       /* If the ring exists, it is not possible to create another one with the
+        * same ring_id
+        */
+       mrp = br_mrp_find_id(br, instance->ring_id);
+       if (mrp)
+               return -EINVAL;
+
+       if (!br_mrp_get_port(br, instance->p_ifindex) ||
+           !br_mrp_get_port(br, instance->s_ifindex))
+               return -EINVAL;
+
+       mrp = kzalloc(sizeof(*mrp), GFP_KERNEL);
+       if (!mrp)
+               return -ENOMEM;
+
+       mrp->ring_id = instance->ring_id;
+
+       p = br_mrp_get_port(br, instance->p_ifindex);
+       spin_lock_bh(&br->lock);
+       p->state = BR_STATE_FORWARDING;
+       p->flags |= BR_MRP_AWARE;
+       spin_unlock_bh(&br->lock);
+       rcu_assign_pointer(mrp->p_port, p);
+
+       p = br_mrp_get_port(br, instance->s_ifindex);
+       spin_lock_bh(&br->lock);
+       p->state = BR_STATE_FORWARDING;
+       p->flags |= BR_MRP_AWARE;
+       spin_unlock_bh(&br->lock);
+       rcu_assign_pointer(mrp->s_port, p);
+
+       INIT_DELAYED_WORK(&mrp->test_work, br_mrp_test_work_expired);
+       list_add_tail_rcu(&mrp->list, &br->mrp_list);
+
+       err = br_mrp_switchdev_add(br, mrp);
+       if (err)
+               goto delete_mrp;
+
+       return 0;
+
+delete_mrp:
+       br_mrp_del_impl(br, mrp);
+
+       return err;
+}
+
+/* Deletes the MRP instance from which the port is part of
+ * note: called under rtnl_lock
+ */
+void br_mrp_port_del(struct net_bridge *br, struct net_bridge_port *p)
+{
+       struct br_mrp *mrp = br_mrp_find_port(br, p);
+
+       /* If the port is not part of a MRP instance just bail out */
+       if (!mrp)
+               return;
+
+       br_mrp_del_impl(br, mrp);
+}
+
+/* Deletes existing MRP instance based on ring_id
+ * note: called under rtnl_lock
+ */
+int br_mrp_del(struct net_bridge *br, struct br_mrp_instance *instance)
+{
+       struct br_mrp *mrp = br_mrp_find_id(br, instance->ring_id);
+
+       if (!mrp)
+               return -EINVAL;
+
+       br_mrp_del_impl(br, mrp);
+
+       return 0;
+}
+
+/* Set port state, port state can be forwarding, blocked or disabled
+ * note: already called with rtnl_lock
+ */
+int br_mrp_set_port_state(struct net_bridge_port *p,
+                         enum br_mrp_port_state_type state)
+{
+       if (!p || !(p->flags & BR_MRP_AWARE))
+               return -EINVAL;
+
+       spin_lock_bh(&p->br->lock);
+
+       if (state == BR_MRP_PORT_STATE_FORWARDING)
+               p->state = BR_STATE_FORWARDING;
+       else
+               p->state = BR_STATE_BLOCKING;
+
+       spin_unlock_bh(&p->br->lock);
+
+       br_mrp_port_switchdev_set_state(p, state);
+
+       return 0;
+}
+
+/* Set port role, port role can be primary or secondary
+ * note: already called with rtnl_lock
+ */
+int br_mrp_set_port_role(struct net_bridge_port *p,
+                        struct br_mrp_port_role *role)
+{
+       struct br_mrp *mrp;
+
+       if (!p || !(p->flags & BR_MRP_AWARE))
+               return -EINVAL;
+
+       mrp = br_mrp_find_id(p->br, role->ring_id);
+
+       if (!mrp)
+               return -EINVAL;
+
+       if (role->role == BR_MRP_PORT_ROLE_PRIMARY)
+               rcu_assign_pointer(mrp->p_port, p);
+       else
+               rcu_assign_pointer(mrp->s_port, p);
+
+       br_mrp_port_switchdev_set_role(p, role->role);
+
+       return 0;
+}
+
+/* Set ring state, ring state can be only Open or Closed
+ * note: already called with rtnl_lock
+ */
+int br_mrp_set_ring_state(struct net_bridge *br,
+                         struct br_mrp_ring_state *state)
+{
+       struct br_mrp *mrp = br_mrp_find_id(br, state->ring_id);
+
+       if (!mrp)
+               return -EINVAL;
+
+       if (mrp->ring_state == BR_MRP_RING_STATE_CLOSED &&
+           state->ring_state != BR_MRP_RING_STATE_CLOSED)
+               mrp->ring_transitions++;
+
+       mrp->ring_state = state->ring_state;
+
+       br_mrp_switchdev_set_ring_state(br, mrp, state->ring_state);
+
+       return 0;
+}
+
+/* Set ring role, ring role can be only MRM(Media Redundancy Manager) or
+ * MRC(Media Redundancy Client).
+ * note: already called with rtnl_lock
+ */
+int br_mrp_set_ring_role(struct net_bridge *br,
+                        struct br_mrp_ring_role *role)
+{
+       struct br_mrp *mrp = br_mrp_find_id(br, role->ring_id);
+       int err;
+
+       if (!mrp)
+               return -EINVAL;
+
+       mrp->ring_role = role->ring_role;
+
+       /* If there is an error just bailed out */
+       err = br_mrp_switchdev_set_ring_role(br, mrp, role->ring_role);
+       if (err && err != -EOPNOTSUPP)
+               return err;
+
+       /* Now detect if the HW actually applied the role or not. If the HW
+        * applied the role it means that the SW will not to do those operations
+        * anymore. For example if the role ir MRM then the HW will notify the
+        * SW when ring is open, but if the is not pushed to the HW the SW will
+        * need to detect when the ring is open
+        */
+       mrp->ring_role_offloaded = err == -EOPNOTSUPP ? 0 : 1;
+
+       return 0;
+}
+
+/* Start to generate MRP test frames, the frames are generated by HW and if it
+ * fails, they are generated by the SW.
+ * note: already called with rtnl_lock
+ */
+int br_mrp_start_test(struct net_bridge *br,
+                     struct br_mrp_start_test *test)
+{
+       struct br_mrp *mrp = br_mrp_find_id(br, test->ring_id);
+
+       if (!mrp)
+               return -EINVAL;
+
+       /* Try to push it to the HW and if it fails then continue to generate in
+        * SW and if that also fails then return error
+        */
+       if (!br_mrp_switchdev_send_ring_test(br, mrp, test->interval,
+                                            test->max_miss, test->period))
+               return 0;
+
+       mrp->test_interval = test->interval;
+       mrp->test_end = jiffies + usecs_to_jiffies(test->period);
+       mrp->test_max_miss = test->max_miss;
+       mrp->test_count_miss = 0;
+       queue_delayed_work(system_wq, &mrp->test_work,
+                          usecs_to_jiffies(test->interval));
+
+       return 0;
+}
+
+/* Process only MRP Test frame. All the other MRP frames are processed by
+ * userspace application
+ * note: already called with rcu_read_lock
+ */
+static void br_mrp_mrm_process(struct br_mrp *mrp, struct net_bridge_port *port,
+                              struct sk_buff *skb)
+{
+       const struct br_mrp_tlv_hdr *hdr;
+       struct br_mrp_tlv_hdr _hdr;
+
+       /* Each MRP header starts with a version field which is 16 bits.
+        * Therefore skip the version and get directly the TLV header.
+        */
+       hdr = skb_header_pointer(skb, sizeof(uint16_t), sizeof(_hdr), &_hdr);
+       if (!hdr)
+               return;
+
+       if (hdr->type != BR_MRP_TLV_HEADER_RING_TEST)
+               return;
+
+       mrp->test_count_miss = 0;
+
+       /* Notify the userspace that the ring is closed only when the ring is
+        * not closed
+        */
+       if (mrp->ring_state != BR_MRP_RING_STATE_CLOSED)
+               br_mrp_port_open(port->dev, false);
+}
+
+/* This will just forward the frame to the other mrp ring port(MRC role) or will
+ * not do anything.
+ * note: already called with rcu_read_lock
+ */
+static int br_mrp_rcv(struct net_bridge_port *p,
+                     struct sk_buff *skb, struct net_device *dev)
+{
+       struct net_device *s_dev, *p_dev, *d_dev;
+       struct net_bridge_port *p_port, *s_port;
+       struct net_bridge *br;
+       struct sk_buff *nskb;
+       struct br_mrp *mrp;
+
+       /* If port is disabled don't accept any frames */
+       if (p->state == BR_STATE_DISABLED)
+               return 0;
+
+       br = p->br;
+       mrp =  br_mrp_find_port(br, p);
+       if (unlikely(!mrp))
+               return 0;
+
+       p_port = rcu_dereference(mrp->p_port);
+       if (!p_port)
+               return 0;
+
+       s_port = rcu_dereference(mrp->s_port);
+       if (!s_port)
+               return 0;
+
+       /* If the role is MRM then don't forward the frames */
+       if (mrp->ring_role == BR_MRP_RING_ROLE_MRM) {
+               br_mrp_mrm_process(mrp, p, skb);
+               return 1;
+       }
+
+       /* Clone the frame and forward it on the other MRP port */
+       nskb = skb_clone(skb, GFP_ATOMIC);
+       if (!nskb)
+               return 0;
+
+       p_dev = p_port->dev;
+       s_dev = s_port->dev;
+
+       if (p_dev == dev)
+               d_dev = s_dev;
+       else
+               d_dev = p_dev;
+
+       nskb->dev = d_dev;
+       skb_push(nskb, ETH_HLEN);
+       dev_queue_xmit(nskb);
+
+       return 1;
+}
+
+/* Check if the frame was received on a port that is part of MRP ring
+ * and if the frame has MRP eth. In that case process the frame otherwise do
+ * normal forwarding.
+ * note: already called with rcu_read_lock
+ */
+int br_mrp_process(struct net_bridge_port *p, struct sk_buff *skb)
+{
+       /* If there is no MRP instance do normal forwarding */
+       if (likely(!(p->flags & BR_MRP_AWARE)))
+               goto out;
+
+       if (unlikely(skb->protocol == htons(ETH_P_MRP)))
+               return br_mrp_rcv(p, skb, p->dev);
+
+out:
+       return 0;
+}
+
+bool br_mrp_enabled(struct net_bridge *br)
+{
+       return !list_empty(&br->mrp_list);
+}