[PATCH net-next 05/14] nfp: abm: add simple RED offload

[Jakub Kicinski]

Offload simple RED configurations.  For now support only DCTCP
like scenarios where min and max are the same.

Signed-off-by: Jakub Kicinski <jakub.kicin...@netronome.com>
---
 drivers/net/ethernet/netronome/nfp/abm/main.c | 82 +++++++++++++++++++
 drivers/net/ethernet/netronome/nfp/abm/main.h | 10 +++
 2 files changed, 92 insertions(+)

diff --git a/drivers/net/ethernet/netronome/nfp/abm/main.c 
b/drivers/net/ethernet/netronome/nfp/abm/main.c
index 28a18ac62040..22251d88c958 100644
--- a/drivers/net/ethernet/netronome/nfp/abm/main.c
+++ b/drivers/net/ethernet/netronome/nfp/abm/main.c
@@ -38,6 +38,8 @@
 #include <linux/netdevice.h>
 #include <linux/rcupdate.h>
 #include <linux/slab.h>
+#include <net/pkt_cls.h>
+#include <net/pkt_sched.h>
 
 #include "../nfpcore/nfp.h"
 #include "../nfpcore/nfp_cpp.h"
@@ -55,6 +57,84 @@ static u32 nfp_abm_portid(enum nfp_repr_type rtype, unsigned 
int id)
               FIELD_PREP(NFP_ABM_PORTID_ID, id);
 }
 
+static void
+nfp_abm_red_destroy(struct net_device *netdev, struct nfp_abm_link *alink,
+                   u32 handle)
+{
+       struct nfp_port *port = nfp_port_from_netdev(netdev);
+
+       if (handle != alink->qdiscs[0].handle)
+               return;
+
+       alink->qdiscs[0].handle = TC_H_UNSPEC;
+       port->tc_offload_cnt = 0;
+       nfp_abm_ctrl_set_all_q_lvls(alink, ~0);
+}
+
+static int
+nfp_abm_red_replace(struct net_device *netdev, struct nfp_abm_link *alink,
+                   struct tc_red_qopt_offload *opt)
+{
+       struct nfp_port *port = nfp_port_from_netdev(netdev);
+       int err;
+
+       if (opt->set.min != opt->set.max || !opt->set.is_ecn) {
+               nfp_warn(alink->abm->app->cpp,
+                        "RED offload failed - unsupported parameters\n");
+               err = -EINVAL;
+               goto err_destroy;
+       }
+       err = nfp_abm_ctrl_set_all_q_lvls(alink, opt->set.min);
+       if (err)
+               goto err_destroy;
+
+       alink->qdiscs[0].handle = opt->handle;
+       port->tc_offload_cnt = 1;
+
+       return 0;
+err_destroy:
+       if (alink->qdiscs[0].handle != TC_H_UNSPEC)
+               nfp_abm_red_destroy(netdev, alink, alink->qdiscs[0].handle);
+       return err;
+}
+
+static int
+nfp_abm_setup_tc_red(struct net_device *netdev, struct nfp_abm_link *alink,
+                    struct tc_red_qopt_offload *opt)
+{
+       if (opt->parent != TC_H_ROOT)
+               return -EOPNOTSUPP;
+
+       switch (opt->command) {
+       case TC_RED_REPLACE:
+               return nfp_abm_red_replace(netdev, alink, opt);
+       case TC_RED_DESTROY:
+               nfp_abm_red_destroy(netdev, alink, opt->handle);
+               return 0;
+       default:
+               return -EOPNOTSUPP;
+       }
+}
+
+static int
+nfp_abm_setup_tc(struct nfp_app *app, struct net_device *netdev,
+                enum tc_setup_type type, void *type_data)
+{
+       struct nfp_repr *repr = netdev_priv(netdev);
+       struct nfp_port *port;
+
+       port = nfp_port_from_netdev(netdev);
+       if (!port || port->type != NFP_PORT_PF_PORT)
+               return -EOPNOTSUPP;
+
+       switch (type) {
+       case TC_SETUP_QDISC_RED:
+               return nfp_abm_setup_tc_red(netdev, repr->app_priv, type_data);
+       default:
+               return -EOPNOTSUPP;
+       }
+}
+
 static struct net_device *nfp_abm_repr_get(struct nfp_app *app, u32 port_id)
 {
        enum nfp_repr_type rtype;
@@ -403,6 +483,8 @@ const struct nfp_app_type app_abm = {
        .vnic_alloc     = nfp_abm_vnic_alloc,
        .vnic_free      = nfp_abm_vnic_free,
 
+       .setup_tc       = nfp_abm_setup_tc,
+
        .eswitch_mode_get       = nfp_abm_eswitch_mode_get,
        .eswitch_mode_set       = nfp_abm_eswitch_mode_set,
 
diff --git a/drivers/net/ethernet/netronome/nfp/abm/main.h 
b/drivers/net/ethernet/netronome/nfp/abm/main.h
index 1ac651cdc140..979f98fb808b 100644
--- a/drivers/net/ethernet/netronome/nfp/abm/main.h
+++ b/drivers/net/ethernet/netronome/nfp/abm/main.h
@@ -58,18 +58,28 @@ struct nfp_abm {
        const struct nfp_rtsym *q_lvls;
 };
 
+/**
+ * struct nfp_red_qdisc - representation of single RED Qdisc
+ * @handle:    handle of currently offloaded RED Qdisc
+ */
+struct nfp_red_qdisc {
+       u32 handle;
+};
+
 /**
  * struct nfp_abm_link - port tuple of a ABM NIC
  * @abm:       back pointer to nfp_abm
  * @vnic:      data vNIC
  * @id:                id of the data vNIC
  * @queue_base:        id of base to host queue within PCIe (not QC idx)
+ * @qdiscs:    array of qdiscs
  */
 struct nfp_abm_link {
        struct nfp_abm *abm;
        struct nfp_net *vnic;
        unsigned int id;
        unsigned int queue_base;
+       struct nfp_red_qdisc qdiscs[1];
 };
 
 void nfp_abm_ctrl_read_params(struct nfp_abm_link *alink);
-- 
2.17.0