soc: qcom: ipa: IPA endpoints

This patch includes the code implementing an IPA endpoint.  This is
the primary abstraction implemented by the IPA.  An endpoint is one
end of a network connection between two entities physically
connected to the IPA.  Specifically, the AP and the modem implement
endpoints, and an (AP endpoint, modem endpoint) pair implements the
transfer of network data in one direction between the AP and modem.

Endpoints are built on top of GSI channels, but IPA endpoints
represent the higher-level functionality that the IPA provides.
Data can be sent through a GSI channel, but it is the IPA endpoint
that represents what is on the "other end" to receive that data.
Other functionality, including aggregation, checksum offload and
(at some future date) IP routing and filtering are all associated
with the IPA endpoint.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ipa/ipa_endpoint.h

+/* SPDX-License-Identifier: GPL-2.0 */
+
+/* Copyright (c) 2012-2018, The Linux Foundation. All rights reserved.
+ * Copyright (C) 2019-2020 Linaro Ltd.
+ */
+#ifndef _IPA_ENDPOINT_H_
+#define _IPA_ENDPOINT_H_
+
+#include <linux/types.h>
+#include <linux/workqueue.h>
+#include <linux/if_ether.h>
+
+#include "gsi.h"
+#include "ipa_reg.h"
+
+struct net_device;
+struct sk_buff;
+
+struct ipa;
+struct ipa_gsi_endpoint_data;
+
+/* Non-zero granularity of counter used to implement aggregation timeout */
+#define IPA_AGGR_GRANULARITY		500	/* microseconds */
+
+#define IPA_MTU			ETH_DATA_LEN
+
+enum ipa_endpoint_name {
+	IPA_ENDPOINT_AP_MODEM_TX	= 0,
+	IPA_ENDPOINT_MODEM_LAN_TX,
+	IPA_ENDPOINT_MODEM_COMMAND_TX,
+	IPA_ENDPOINT_AP_COMMAND_TX,
+	IPA_ENDPOINT_MODEM_AP_TX,
+	IPA_ENDPOINT_AP_LAN_RX,
+	IPA_ENDPOINT_AP_MODEM_RX,
+	IPA_ENDPOINT_MODEM_AP_RX,
+	IPA_ENDPOINT_MODEM_LAN_RX,
+	IPA_ENDPOINT_COUNT,	/* Number of names (not an index) */
+};
+
+#define IPA_ENDPOINT_MAX		32	/* Max supported by driver */
+
+/**
+ * struct ipa_endpoint - IPA endpoint information
+ * @client:	Client associated with the endpoint
+ * @channel_id:	EP's GSI channel
+ * @evt_ring_id: EP's GSI channel event ring
+ */
+struct ipa_endpoint {
+	struct ipa *ipa;
+	enum ipa_seq_type seq_type;
+	enum gsi_ee_id ee_id;
+	u32 channel_id;
+	u32 endpoint_id;
+	bool toward_ipa;
+	const struct ipa_endpoint_config_data *data;
+
+	u32 trans_tre_max;	/* maximum descriptors per transaction */
+	u32 evt_ring_id;
+
+	/* Net device this endpoint is associated with, if any */
+	struct net_device *netdev;
+
+	/* Receive buffer replenishing for RX endpoints */
+	bool replenish_enabled;
+	u32 replenish_ready;
+	atomic_t replenish_saved;
+	atomic_t replenish_backlog;
+	struct delayed_work replenish_work;		/* global wq */
+};
+
+void ipa_endpoint_modem_hol_block_clear_all(struct ipa *ipa);
+
+void ipa_endpoint_modem_pause_all(struct ipa *ipa, bool enable);
+
+int ipa_endpoint_modem_exception_reset_all(struct ipa *ipa);
+
+int ipa_endpoint_skb_tx(struct ipa_endpoint *endpoint, struct sk_buff *skb);
+
+int ipa_endpoint_stop(struct ipa_endpoint *endpoint);
+
+void ipa_endpoint_exit_one(struct ipa_endpoint *endpoint);
+
+int ipa_endpoint_enable_one(struct ipa_endpoint *endpoint);
+void ipa_endpoint_disable_one(struct ipa_endpoint *endpoint);
+
+void ipa_endpoint_suspend_one(struct ipa_endpoint *endpoint);
+void ipa_endpoint_resume_one(struct ipa_endpoint *endpoint);
+
+void ipa_endpoint_suspend(struct ipa *ipa);
+void ipa_endpoint_resume(struct ipa *ipa);
+
+void ipa_endpoint_setup(struct ipa *ipa);
+void ipa_endpoint_teardown(struct ipa *ipa);
+
+int ipa_endpoint_config(struct ipa *ipa);
+void ipa_endpoint_deconfig(struct ipa *ipa);
+
+void ipa_endpoint_default_route_set(struct ipa *ipa, u32 endpoint_id);
+void ipa_endpoint_default_route_clear(struct ipa *ipa);
+
+u32 ipa_endpoint_init(struct ipa *ipa, u32 count,
+		      const struct ipa_gsi_endpoint_data *data);
+void ipa_endpoint_exit(struct ipa *ipa);
+
+void ipa_endpoint_trans_complete(struct ipa_endpoint *ipa,
+				 struct gsi_trans *trans);
+void ipa_endpoint_trans_release(struct ipa_endpoint *ipa,
+				struct gsi_trans *trans);
+
+#endif /* _IPA_ENDPOINT_H_ */