1 files changed, 73 insertions, 0 deletions

diff --git a/net/core/xdp.c b/net/core/xdp.c
new file mode 100644
index 000000000000..097a0f74e004
--- /dev/null
+++ b/net/core/xdp.c
@@ -0,0 +1,73 @@
+/* net/core/xdp.c
+ *
+ * Copyright (c) 2017 Jesper Dangaard Brouer, Red Hat Inc.
+ * Released under terms in GPL version 2.  See COPYING.
+ */
+#include <linux/types.h>
+#include <linux/mm.h>
+
+#include <net/xdp.h>
+
+#define REG_STATE_NEW           0x0
+#define REG_STATE_REGISTERED    0x1
+#define REG_STATE_UNREGISTERED  0x2
+#define REG_STATE_UNUSED        0x3
+
+void xdp_rxq_info_unreg(struct xdp_rxq_info *xdp_rxq)
+{
+        /* Simplify driver cleanup code paths, allow unreg "unused" */
+        if (xdp_rxq->reg_state == REG_STATE_UNUSED)
+                return;
+
+        WARN(!(xdp_rxq->reg_state == REG_STATE_REGISTERED), "Driver BUG");
+
+        xdp_rxq->reg_state = REG_STATE_UNREGISTERED;
+        xdp_rxq->dev = NULL;
+}
+EXPORT_SYMBOL_GPL(xdp_rxq_info_unreg);
+
+static void xdp_rxq_info_init(struct xdp_rxq_info *xdp_rxq)
+{
+        memset(xdp_rxq, 0, sizeof(*xdp_rxq));
+}
+
+/* Returns 0 on success, negative on failure */
+int xdp_rxq_info_reg(struct xdp_rxq_info *xdp_rxq,
+                     struct net_device *dev, u32 queue_index)
+{
+        if (xdp_rxq->reg_state == REG_STATE_UNUSED) {
+                WARN(1, "Driver promised not to register this");
+                return -EINVAL;
+        }
+
+        if (xdp_rxq->reg_state == REG_STATE_REGISTERED) {
+                WARN(1, "Missing unregister, handled but fix driver");
+                xdp_rxq_info_unreg(xdp_rxq);
+        }
+
+        if (!dev) {
+                WARN(1, "Missing net_device from driver");
+                return -ENODEV;
+        }
+
+        /* State either UNREGISTERED or NEW */
+        xdp_rxq_info_init(xdp_rxq);
+        xdp_rxq->dev = dev;
+        xdp_rxq->queue_index = queue_index;
+
+        xdp_rxq->reg_state = REG_STATE_REGISTERED;
+        return 0;
+}
+EXPORT_SYMBOL_GPL(xdp_rxq_info_reg);
+
+void xdp_rxq_info_unused(struct xdp_rxq_info *xdp_rxq)
+{
+        xdp_rxq->reg_state = REG_STATE_UNUSED;
+}
+EXPORT_SYMBOL_GPL(xdp_rxq_info_unused);
+
+bool xdp_rxq_info_is_reg(struct xdp_rxq_info *xdp_rxq)
+{
+        return (xdp_rxq->reg_state == REG_STATE_REGISTERED);
+}
+EXPORT_SYMBOL_GPL(xdp_rxq_info_is_reg);