1 files changed, 455 insertions, 0 deletions
diff --git a/drivers/net/wwan/iosm/iosm_ipc_mux.c b/drivers/net/wwan/iosm/iosm_ipc_mux.c
new file mode 100644
index 000000000000..c1c77ce699da
--- /dev/null
+++ b/drivers/net/wwan/iosm/iosm_ipc_mux.c
@@ -0,0 +1,455 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020-21 Intel Corporation.
+ */
+
+#include "iosm_ipc_mux_codec.h"
+
+/* At the begin of the runtime phase the IP MUX channel shall created. */
+static int ipc_mux_channel_create(struct iosm_mux *ipc_mux)
+{
+	int channel_id;
+
+	channel_id = ipc_imem_channel_alloc(ipc_mux->imem, ipc_mux->instance_id,
+					    IPC_CTYPE_WWAN);
+
+	if (channel_id < 0) {
+		dev_err(ipc_mux->dev,
+			"allocation of the MUX channel id failed");
+		ipc_mux->state = MUX_S_ERROR;
+		ipc_mux->event = MUX_E_NOT_APPLICABLE;
+		goto no_channel;
+	}
+
+	/* Establish the MUX channel in blocking mode. */
+	ipc_mux->channel = ipc_imem_channel_open(ipc_mux->imem, channel_id,
+						 IPC_HP_NET_CHANNEL_INIT);
+
+	if (!ipc_mux->channel) {
+		dev_err(ipc_mux->dev, "ipc_imem_channel_open failed");
+		ipc_mux->state = MUX_S_ERROR;
+		ipc_mux->event = MUX_E_NOT_APPLICABLE;
+		return -ENODEV; /* MUX channel is not available. */
+	}
+
+	/* Define the MUX active state properties. */
+	ipc_mux->state = MUX_S_ACTIVE;
+	ipc_mux->event = MUX_E_NO_ORDERS;
+
+no_channel:
+	return channel_id;
+}
+
+/* Reset the session/if id state. */
+static void ipc_mux_session_free(struct iosm_mux *ipc_mux, int if_id)
+{
+	struct mux_session *if_entry;
+
+	if_entry = &ipc_mux->session[if_id];
+	/* Reset the session state. */
+	if_entry->wwan = NULL;
+}
+
+/* Create and send the session open command. */
+static struct mux_cmd_open_session_resp *
+ipc_mux_session_open_send(struct iosm_mux *ipc_mux, int if_id)
+{
+	struct mux_cmd_open_session_resp *open_session_resp;
+	struct mux_acb *acb = &ipc_mux->acb;
+	union mux_cmd_param param;
+
+	/* open_session commands to one ACB and start transmission. */
+	param.open_session.flow_ctrl = 0;
+	param.open_session.ipv4v6_hints = 0;
+	param.open_session.reserved2 = 0;
+	param.open_session.dl_head_pad_len = cpu_to_le32(IPC_MEM_DL_ETH_OFFSET);
+
+	/* Finish and transfer ACB. The user thread is suspended.
+	 * It is a blocking function call, until CP responds or timeout.
+	 */
+	acb->wanted_response = MUX_CMD_OPEN_SESSION_RESP;
+	if (ipc_mux_dl_acb_send_cmds(ipc_mux, MUX_CMD_OPEN_SESSION, if_id, 0,
+				     &param, sizeof(param.open_session), true,
+				 false) ||
+	    acb->got_response != MUX_CMD_OPEN_SESSION_RESP) {
+		dev_err(ipc_mux->dev, "if_id %d: OPEN_SESSION send failed",
+			if_id);
+		return NULL;
+	}
+
+	open_session_resp = &ipc_mux->acb.got_param.open_session_resp;
+	if (open_session_resp->response != cpu_to_le32(MUX_CMD_RESP_SUCCESS)) {
+		dev_err(ipc_mux->dev,
+			"if_id %d,session open failed,response=%d", if_id,
+			open_session_resp->response);
+		return NULL;
+	}
+
+	return open_session_resp;
+}
+
+/* Open the first IP session. */
+static bool ipc_mux_session_open(struct iosm_mux *ipc_mux,
+				 struct mux_session_open *session_open)
+{
+	struct mux_cmd_open_session_resp *open_session_resp;
+	int if_id;
+
+	/* Search for a free session interface id. */
+	if_id = le32_to_cpu(session_open->if_id);
+	if (if_id < 0 || if_id >= ipc_mux->nr_sessions) {
+		dev_err(ipc_mux->dev, "invalid interface id=%d", if_id);
+		return false;
+	}
+
+	/* Create and send the session open command.
+	 * It is a blocking function call, until CP responds or timeout.
+	 */
+	open_session_resp = ipc_mux_session_open_send(ipc_mux, if_id);
+	if (!open_session_resp) {
+		ipc_mux_session_free(ipc_mux, if_id);
+		session_open->if_id = cpu_to_le32(-1);
+		return false;
+	}
+
+	/* Initialize the uplink skb accumulator. */
+	skb_queue_head_init(&ipc_mux->session[if_id].ul_list);
+
+	ipc_mux->session[if_id].dl_head_pad_len = IPC_MEM_DL_ETH_OFFSET;
+	ipc_mux->session[if_id].ul_head_pad_len =
+		le32_to_cpu(open_session_resp->ul_head_pad_len);
+	ipc_mux->session[if_id].wwan = ipc_mux->wwan;
+
+	/* Reset the flow ctrl stats of the session */
+	ipc_mux->session[if_id].flow_ctl_en_cnt = 0;
+	ipc_mux->session[if_id].flow_ctl_dis_cnt = 0;
+	ipc_mux->session[if_id].ul_flow_credits = 0;
+	ipc_mux->session[if_id].net_tx_stop = false;
+	ipc_mux->session[if_id].flow_ctl_mask = 0;
+
+	/* Save and return the assigned if id. */
+	session_open->if_id = cpu_to_le32(if_id);
+
+	return true;
+}
+
+/* Free pending session UL packet. */
+static void ipc_mux_session_reset(struct iosm_mux *ipc_mux, int if_id)
+{
+	/* Reset the session/if id state. */
+	ipc_mux_session_free(ipc_mux, if_id);
+
+	/* Empty the uplink skb accumulator. */
+	skb_queue_purge(&ipc_mux->session[if_id].ul_list);
+}
+
+static void ipc_mux_session_close(struct iosm_mux *ipc_mux,
+				  struct mux_session_close *msg)
+{
+	int if_id;
+
+	/* Copy the session interface id. */
+	if_id = le32_to_cpu(msg->if_id);
+
+	if (if_id < 0 || if_id >= ipc_mux->nr_sessions) {
+		dev_err(ipc_mux->dev, "invalid session id %d", if_id);
+		return;
+	}
+
+	/* Create and send the session close command.
+	 * It is a blocking function call, until CP responds or timeout.
+	 */
+	if (ipc_mux_dl_acb_send_cmds(ipc_mux, MUX_CMD_CLOSE_SESSION, if_id, 0,
+				     NULL, 0, true, false))
+		dev_err(ipc_mux->dev, "if_id %d: CLOSE_SESSION send failed",
+			if_id);
+
+	/* Reset the flow ctrl stats of the session */
+	ipc_mux->session[if_id].flow_ctl_en_cnt = 0;
+	ipc_mux->session[if_id].flow_ctl_dis_cnt = 0;
+	ipc_mux->session[if_id].flow_ctl_mask = 0;
+
+	ipc_mux_session_reset(ipc_mux, if_id);
+}
+
+static void ipc_mux_channel_close(struct iosm_mux *ipc_mux,
+				  struct mux_channel_close *channel_close_p)
+{
+	int i;
+
+	/* Free pending session UL packet. */
+	for (i = 0; i < ipc_mux->nr_sessions; i++)
+		if (ipc_mux->session[i].wwan)
+			ipc_mux_session_reset(ipc_mux, i);
+
+	ipc_imem_channel_close(ipc_mux->imem, ipc_mux->channel_id);
+
+	/* Reset the MUX object. */
+	ipc_mux->state = MUX_S_INACTIVE;
+	ipc_mux->event = MUX_E_INACTIVE;
+}
+
+/* CP has interrupted AP. If AP is in IP MUX mode, execute the pending ops. */
+static int ipc_mux_schedule(struct iosm_mux *ipc_mux, union mux_msg *msg)
+{
+	enum mux_event order;
+	bool success;
+	int ret = -EIO;
+
+	if (!ipc_mux->initialized) {
+		ret = -EAGAIN;
+		goto out;
+	}
+
+	order = msg->common.event;
+
+	switch (ipc_mux->state) {
+	case MUX_S_INACTIVE:
+		if (order != MUX_E_MUX_SESSION_OPEN)
+			goto out; /* Wait for the request to open a session */
+
+		if (ipc_mux->event == MUX_E_INACTIVE)
+			/* Establish the MUX channel and the new state. */
+			ipc_mux->channel_id = ipc_mux_channel_create(ipc_mux);
+
+		if (ipc_mux->state != MUX_S_ACTIVE) {
+			ret = ipc_mux->channel_id; /* Missing the MUX channel */
+			goto out;
+		}
+
+		/* Disable the TD update timer and open the first IP session. */
+		ipc_imem_td_update_timer_suspend(ipc_mux->imem, true);
+		ipc_mux->event = MUX_E_MUX_SESSION_OPEN;
+		success = ipc_mux_session_open(ipc_mux, &msg->session_open);
+
+		ipc_imem_td_update_timer_suspend(ipc_mux->imem, false);
+		if (success)
+			ret = ipc_mux->channel_id;
+		goto out;
+
+	case MUX_S_ACTIVE:
+		switch (order) {
+		case MUX_E_MUX_SESSION_OPEN:
+			/* Disable the TD update timer and open a session */
+			ipc_imem_td_update_timer_suspend(ipc_mux->imem, true);
+			ipc_mux->event = MUX_E_MUX_SESSION_OPEN;
+			success = ipc_mux_session_open(ipc_mux,
+						       &msg->session_open);
+			ipc_imem_td_update_timer_suspend(ipc_mux->imem, false);
+			if (success)
+				ret = ipc_mux->channel_id;
+			goto out;
+
+		case MUX_E_MUX_SESSION_CLOSE:
+			/* Release an IP session. */
+			ipc_mux->event = MUX_E_MUX_SESSION_CLOSE;
+			ipc_mux_session_close(ipc_mux, &msg->session_close);
+			ret = ipc_mux->channel_id;
+			goto out;
+
+		case MUX_E_MUX_CHANNEL_CLOSE:
+			/* Close the MUX channel pipes. */
+			ipc_mux->event = MUX_E_MUX_CHANNEL_CLOSE;
+			ipc_mux_channel_close(ipc_mux, &msg->channel_close);
+			ret = ipc_mux->channel_id;
+			goto out;
+
+		default:
+			/* Invalid order. */
+			goto out;
+		}
+
+	default:
+		dev_err(ipc_mux->dev,
+			"unexpected MUX transition: state=%d, event=%d",
+			ipc_mux->state, ipc_mux->event);
+	}
+out:
+	return ret;
+}
+
+struct iosm_mux *ipc_mux_init(struct ipc_mux_config *mux_cfg,
+			      struct iosm_imem *imem)
+{
+	struct iosm_mux *ipc_mux = kzalloc(sizeof(*ipc_mux), GFP_KERNEL);
+	int i, ul_tds, ul_td_size;
+	struct sk_buff_head *free_list;
+	struct sk_buff *skb;
+
+	if (!ipc_mux)
+		return NULL;
+
+	ipc_mux->protocol = mux_cfg->protocol;
+	ipc_mux->ul_flow = mux_cfg->ul_flow;
+	ipc_mux->nr_sessions = mux_cfg->nr_sessions;
+	ipc_mux->instance_id = mux_cfg->instance_id;
+	ipc_mux->wwan_q_offset = 0;
+
+	ipc_mux->pcie = imem->pcie;
+	ipc_mux->imem = imem;
+	ipc_mux->ipc_protocol = imem->ipc_protocol;
+	ipc_mux->dev = imem->dev;
+	ipc_mux->wwan = imem->wwan;
+
+	/* Get the reference to the UL ADB list. */
+	free_list = &ipc_mux->ul_adb.free_list;
+
+	/* Initialize the list with free ADB. */
+	skb_queue_head_init(free_list);
+
+	ul_td_size = IPC_MEM_MAX_DL_MUX_LITE_BUF_SIZE;
+
+	ul_tds = IPC_MEM_MAX_TDS_MUX_LITE_UL;
+
+	ipc_mux->ul_adb.dest_skb = NULL;
+
+	ipc_mux->initialized = true;
+	ipc_mux->adb_prep_ongoing = false;
+	ipc_mux->size_needed = 0;
+	ipc_mux->ul_data_pend_bytes = 0;
+	ipc_mux->state = MUX_S_INACTIVE;
+	ipc_mux->ev_mux_net_transmit_pending = false;
+	ipc_mux->tx_transaction_id = 0;
+	ipc_mux->rr_next_session = 0;
+	ipc_mux->event = MUX_E_INACTIVE;
+	ipc_mux->channel_id = -1;
+	ipc_mux->channel = NULL;
+
+	/* Allocate the list of UL ADB. */
+	for (i = 0; i < ul_tds; i++) {
+		dma_addr_t mapping;
+
+		skb = ipc_pcie_alloc_skb(ipc_mux->pcie, ul_td_size, GFP_ATOMIC,
+					 &mapping, DMA_TO_DEVICE, 0);
+		if (!skb) {
+			ipc_mux_deinit(ipc_mux);
+			return NULL;
+		}
+		/* Extend the UL ADB list. */
+		skb_queue_tail(free_list, skb);
+	}
+
+	return ipc_mux;
+}
+
+/* Informs the network stack to restart transmission for all opened session if
+ * Flow Control is not ON for that session.
+ */
+static void ipc_mux_restart_tx_for_all_sessions(struct iosm_mux *ipc_mux)
+{
+	struct mux_session *session;
+	int idx;
+
+	for (idx = 0; idx < ipc_mux->nr_sessions; idx++) {
+		session = &ipc_mux->session[idx];
+
+		if (!session->wwan)
+			continue;
+
+		/* If flow control of the session is OFF and if there was tx
+		 * stop then restart. Inform the network interface to restart
+		 * sending data.
+		 */
+		if (session->flow_ctl_mask == 0) {
+			session->net_tx_stop = false;
+			ipc_mux_netif_tx_flowctrl(session, idx, false);
+		}
+	}
+}
+
+/* Informs the network stack to stop sending further pkt for all opened
+ * sessions
+ */
+static void ipc_mux_stop_netif_for_all_sessions(struct iosm_mux *ipc_mux)
+{
+	struct mux_session *session;
+	int idx;
+
+	for (idx = 0; idx < ipc_mux->nr_sessions; idx++) {
+		session = &ipc_mux->session[idx];
+
+		if (!session->wwan)
+			continue;
+
+		ipc_mux_netif_tx_flowctrl(session, session->if_id, true);
+	}
+}
+
+void ipc_mux_check_n_restart_tx(struct iosm_mux *ipc_mux)
+{
+	if (ipc_mux->ul_flow == MUX_UL) {
+		int low_thresh = IPC_MEM_MUX_UL_FLOWCTRL_LOW_B;
+
+		if (ipc_mux->ul_data_pend_bytes < low_thresh)
+			ipc_mux_restart_tx_for_all_sessions(ipc_mux);
+	}
+}
+
+int ipc_mux_get_max_sessions(struct iosm_mux *ipc_mux)
+{
+	return ipc_mux ? ipc_mux->nr_sessions : -EFAULT;
+}
+
+enum ipc_mux_protocol ipc_mux_get_active_protocol(struct iosm_mux *ipc_mux)
+{
+	return ipc_mux ? ipc_mux->protocol : MUX_UNKNOWN;
+}
+
+int ipc_mux_open_session(struct iosm_mux *ipc_mux, int session_nr)
+{
+	struct mux_session_open *session_open;
+	union mux_msg mux_msg;
+
+	session_open = &mux_msg.session_open;
+	session_open->event = MUX_E_MUX_SESSION_OPEN;
+
+	session_open->if_id = cpu_to_le32(session_nr);
+	ipc_mux->session[session_nr].flags |= IPC_MEM_WWAN_MUX;
+	return ipc_mux_schedule(ipc_mux, &mux_msg);
+}
+
+int ipc_mux_close_session(struct iosm_mux *ipc_mux, int session_nr)
+{
+	struct mux_session_close *session_close;
+	union mux_msg mux_msg;
+	int ret_val;
+
+	session_close = &mux_msg.session_close;
+	session_close->event = MUX_E_MUX_SESSION_CLOSE;
+
+	session_close->if_id = cpu_to_le32(session_nr);
+	ret_val = ipc_mux_schedule(ipc_mux, &mux_msg);
+	ipc_mux->session[session_nr].flags &= ~IPC_MEM_WWAN_MUX;
+
+	return ret_val;
+}
+
+void ipc_mux_deinit(struct iosm_mux *ipc_mux)
+{
+	struct mux_channel_close *channel_close;
+	struct sk_buff_head *free_list;
+	union mux_msg mux_msg;
+	struct sk_buff *skb;
+
+	if (!ipc_mux->initialized)
+		return;
+	ipc_mux_stop_netif_for_all_sessions(ipc_mux);
+
+	channel_close = &mux_msg.channel_close;
+	channel_close->event = MUX_E_MUX_CHANNEL_CLOSE;
+	ipc_mux_schedule(ipc_mux, &mux_msg);
+
+	/* Empty the ADB free list. */
+	free_list = &ipc_mux->ul_adb.free_list;
+
+	/* Remove from the head of the downlink queue. */
+	while ((skb = skb_dequeue(free_list)))
+		ipc_pcie_kfree_skb(ipc_mux->pcie, skb);
+
+	if (ipc_mux->channel) {
+		ipc_mux->channel->ul_pipe.is_open = false;
+		ipc_mux->channel->dl_pipe.is_open = false;
+	}
+
+	kfree(ipc_mux);
+}