nfp: split out common control message handling code

BPF's control message handler seems like a good base to built
on for request-reply control messages.  Split it out to allow
for reuse.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 81 insertions, 0 deletions

diff --git a/drivers/net/ethernet/netronome/nfp/ccm.h b/drivers/net/ethernet/netronome/nfp/ccm.h
new file mode 100644
index 000000000000..e2fe4b867958
--- /dev/null
+++ b/drivers/net/ethernet/netronome/nfp/ccm.h
@@ -0,0 +1,81 @@
+/* SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause) */
+/* Copyright (C) 2016-2019 Netronome Systems, Inc. */
+
+#ifndef NFP_CCM_H
+#define NFP_CCM_H 1
+
+#include <linux/bitmap.h>
+#include <linux/skbuff.h>
+#include <linux/wait.h>
+
+struct nfp_app;
+
+/* Firmware ABI */
+
+enum nfp_ccm_type {
+	NFP_CCM_TYPE_BPF_MAP_ALLOC	= 1,
+	NFP_CCM_TYPE_BPF_MAP_FREE	= 2,
+	NFP_CCM_TYPE_BPF_MAP_LOOKUP	= 3,
+	NFP_CCM_TYPE_BPF_MAP_UPDATE	= 4,
+	NFP_CCM_TYPE_BPF_MAP_DELETE	= 5,
+	NFP_CCM_TYPE_BPF_MAP_GETNEXT	= 6,
+	NFP_CCM_TYPE_BPF_MAP_GETFIRST	= 7,
+	NFP_CCM_TYPE_BPF_BPF_EVENT	= 8,
+	__NFP_CCM_TYPE_MAX,
+};
+
+#define NFP_CCM_ABI_VERSION		1
+
+struct nfp_ccm_hdr {
+	u8 type;
+	u8 ver;
+	__be16 tag;
+};
+
+static inline u8 nfp_ccm_get_type(struct sk_buff *skb)
+{
+	struct nfp_ccm_hdr *hdr;
+
+	hdr = (struct nfp_ccm_hdr *)skb->data;
+
+	return hdr->type;
+}
+
+static inline unsigned int nfp_ccm_get_tag(struct sk_buff *skb)
+{
+	struct nfp_ccm_hdr *hdr;
+
+	hdr = (struct nfp_ccm_hdr *)skb->data;
+
+	return be16_to_cpu(hdr->tag);
+}
+
+/* Implementation */
+
+/**
+ * struct nfp_ccm - common control message handling
+ * @tag_allocator:	bitmap of control message tags in use
+ * @tag_alloc_next:	next tag bit to allocate
+ * @tag_alloc_last:	next tag bit to be freed
+ *
+ * @replies:		received cmsg replies waiting to be consumed
+ * @wq:			work queue for waiting for cmsg replies
+ */
+struct nfp_ccm {
+	struct nfp_app *app;
+
+	DECLARE_BITMAP(tag_allocator, U16_MAX + 1);
+	u16 tag_alloc_next;
+	u16 tag_alloc_last;
+
+	struct sk_buff_head replies;
+	struct wait_queue_head wq;
+};
+
+int nfp_ccm_init(struct nfp_ccm *ccm, struct nfp_app *app);
+void nfp_ccm_clean(struct nfp_ccm *ccm);
+void nfp_ccm_rx(struct nfp_ccm *ccm, struct sk_buff *skb);
+struct sk_buff *
+nfp_ccm_communicate(struct nfp_ccm *ccm, struct sk_buff *skb,
+		    enum nfp_ccm_type type, unsigned int reply_size);
+#endif