igc: Refactor __igc_xdp_run_prog()

Refactor __igc_xdp_run_prog() helper from igc_xdp_run_prog(),
preparing the code for AF_XDP zero-copy support which is added
by upcoming patches.

The existing igc_xdp_run_prog() caters to regular XDP rx path
which has to verify if bpf_prog is not NULL. Zero-copy
path assumes that bpf_prog is not NULL and hence this check is
not required. Therefore it makes sense to refactor the common
code into a helper function, to avoid code duplication.

Signed-off-by: Andre Guedes <andre.guedes@intel.com>
Signed-off-by: Vedang Patel <vedang.patel@intel.com>
Signed-off-by: Jithu Joseph <jithu.joseph@intel.com>
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: Dvora Fuxbrumer <dvorax.fuxbrumer@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index edfe9d4..1961cc6 100644 (file)
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -2020,38 +2020,22 @@ static int igc_xdp_xmit_back(struct igc_adapter *adapter, struct xdp_buff *xdp)
        return res;
 }
 
-static struct sk_buff *igc_xdp_run_prog(struct igc_adapter *adapter,
-                                       struct xdp_buff *xdp)
+/* This function assumes rcu_read_lock() is held by the caller. */
+static int __igc_xdp_run_prog(struct igc_adapter *adapter,
+                             struct bpf_prog *prog,
+                             struct xdp_buff *xdp)
 {
-       struct bpf_prog *prog;
-       int res;
-       u32 act;
-
-       rcu_read_lock();
-
-       prog = READ_ONCE(adapter->xdp_prog);
-       if (!prog) {
-               res = IGC_XDP_PASS;
-               goto unlock;
-       }
+       u32 act = bpf_prog_run_xdp(prog, xdp);
 
-       act = bpf_prog_run_xdp(prog, xdp);
        switch (act) {
        case XDP_PASS:
-               res = IGC_XDP_PASS;
-               break;
+               return IGC_XDP_PASS;
        case XDP_TX:
-               if (igc_xdp_xmit_back(adapter, xdp) < 0)
-                       res = IGC_XDP_CONSUMED;
-               else
-                       res = IGC_XDP_TX;
-               break;
+               return igc_xdp_xmit_back(adapter, xdp) < 0 ?
+                       IGC_XDP_CONSUMED : IGC_XDP_TX;
        case XDP_REDIRECT:
-               if (xdp_do_redirect(adapter->netdev, xdp, prog) < 0)
-                       res = IGC_XDP_CONSUMED;
-               else
-                       res = IGC_XDP_REDIRECT;
-               break;
+               return xdp_do_redirect(adapter->netdev, xdp, prog) < 0 ?
+                       IGC_XDP_CONSUMED : IGC_XDP_REDIRECT;
        default:
                bpf_warn_invalid_xdp_action(act);
                fallthrough;
@@ -2059,9 +2043,25 @@ static struct sk_buff *igc_xdp_run_prog(struct igc_adapter *adapter,
                trace_xdp_exception(adapter->netdev, prog, act);
                fallthrough;
        case XDP_DROP:
-               res = IGC_XDP_CONSUMED;
-               break;
+               return IGC_XDP_CONSUMED;
        }
+}
+
+static struct sk_buff *igc_xdp_run_prog(struct igc_adapter *adapter,
+                                       struct xdp_buff *xdp)
+{
+       struct bpf_prog *prog;
+       int res;
+
+       rcu_read_lock();
+
+       prog = READ_ONCE(adapter->xdp_prog);
+       if (!prog) {
+               res = IGC_XDP_PASS;
+               goto unlock;
+       }
+
+       res = __igc_xdp_run_prog(adapter, prog, xdp);
 
 unlock:
        rcu_read_unlock();