1) Encode UL packet into datagram.
2) Decode DL datagram and route it to network layer.
3) Supports credit based flow control.
Signed-off-by: M Chetan Kumar <m.chetan.kumar@xxxxxxxxx>
---
drivers/net/wwan/iosm/iosm_ipc_mux_codec.c | 901 +++++++++++++++++++++++++++++
drivers/net/wwan/iosm/iosm_ipc_mux_codec.h | 194 +++++++
2 files changed, 1095 insertions(+)
create mode 100644 drivers/net/wwan/iosm/iosm_ipc_mux_codec.c
create mode 100644 drivers/net/wwan/iosm/iosm_ipc_mux_codec.h
diff --git a/drivers/net/wwan/iosm/iosm_ipc_mux_codec.c b/drivers/net/wwan/iosm/iosm_ipc_mux_codec.c
new file mode 100644
index 000000000000..e18af8d9043b
--- /dev/null
+++ b/drivers/net/wwan/iosm/iosm_ipc_mux_codec.c
@@ -0,0 +1,901 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020 Intel Corporation.
+ */
+
+#include <linux/if_vlan.h>
+#include <linux/nospec.h>
+
+#include "iosm_ipc_imem_ops.h"
+#include "iosm_ipc_mux_codec.h"
+#include "iosm_ipc_task_queue.h"
+
+/* Test the link power state and send a MUX command in blocking mode. */
+static int mux_tq_cmd_send(struct iosm_imem *ipc_imem, int arg, void *msg,
+ size_t size)
+{
+ struct iosm_mux *ipc_mux = ipc_imem->mux;
+ const struct mux_acb *acb = msg;
+
+ skb_queue_tail(&ipc_mux->channel->ul_list, acb->skb);
+ imem_ul_send(ipc_mux->imem);
+
+ return 0;
+}
+
+static int mux_acb_send(struct iosm_mux *ipc_mux, bool blocking)
+{
+ struct completion *completion = &ipc_mux->channel->ul_sem;
+
+ if (ipc_task_queue_send_task(ipc_mux->imem, mux_tq_cmd_send, 0,
+ &ipc_mux->acb, sizeof(ipc_mux->acb),
+ false)) {
+ dev_err(ipc_mux->dev, "unable to send mux command");
+ return -1;
+ }
+
+ /* if blocking, suspend the app and wait for irq in the flash or
+ * crash phase. return false on timeout to indicate failure.
+ */
+ if (blocking) {
+ u32 wait_time_milliseconds = IPC_MUX_CMD_RUN_DEFAULT_TIMEOUT;
+
+ reinit_completion(completion);
+
+ if (wait_for_completion_interruptible_timeout
+ (completion, msecs_to_jiffies(wait_time_milliseconds)) ==
+ 0) {
+ dev_err(ipc_mux->dev, "ch[%d] timeout",
+ ipc_mux->channel_id);
+ ipc_uevent_send(ipc_mux->imem->dev, UEVENT_MDM_TIMEOUT);
+ return -ETIMEDOUT;
+ }
+ }
+
+ return 0;
+}
+
+/* Prepare mux Command */
+static struct mux_lite_cmdh *mux_lite_add_cmd(struct iosm_mux *ipc_mux, u32 cmd,
+ struct mux_acb *acb, void *param,
+ u32 param_size)
+{
+ struct mux_lite_cmdh *cmdh = (struct mux_lite_cmdh *)acb->skb->data;
+
+ cmdh->signature = MUX_SIG_CMDH;
+ cmdh->command_type = cmd;
+ cmdh->if_id = acb->if_id;
+
+ acb->cmd = cmd;
+
+ cmdh->cmd_len = offsetof(struct mux_lite_cmdh, param) + param_size;
+ cmdh->transaction_id = ipc_mux->tx_transaction_id++;
+
+ if (param)
+ memcpy(&cmdh->param, param, param_size);
+
+ skb_put(acb->skb, cmdh->cmd_len);
+
+ return cmdh;
+}
+
+static int mux_acb_alloc(struct iosm_mux *ipc_mux)
+{
+ struct mux_acb *acb = &ipc_mux->acb;
+ struct sk_buff *skb;
+ dma_addr_t mapping;
+
+ /* Allocate skb memory for the uplink buffer. */
+ skb = ipc_pcie_alloc_skb(ipc_mux->pcie, MUX_MAX_UL_ACB_BUF_SIZE,
+ GFP_ATOMIC, &mapping, DMA_TO_DEVICE, 0);
+ if (!skb)
+ return -ENOMEM;
+
+ /* Save the skb address. */
+ acb->skb = skb;
+
+ memset(skb->data, 0, MUX_MAX_UL_ACB_BUF_SIZE);
+
+ return 0;
+}
+
+int mux_dl_acb_send_cmds(struct iosm_mux *ipc_mux, u32 cmd_type, u8 if_id,
+ u32 transaction_id, union mux_cmd_param *param,
+ size_t res_size, bool blocking, bool respond)
+{
+ struct mux_acb *acb = &ipc_mux->acb;
+ struct mux_lite_cmdh *ack_lite;
+ int ret = 0;
+
+ acb->if_id = if_id;
+ ret = mux_acb_alloc(ipc_mux);
+ if (ret)
+ return ret;
+
+ ack_lite = mux_lite_add_cmd(ipc_mux, cmd_type, acb, param, res_size);
+ if (respond)
+ ack_lite->transaction_id = (u32)transaction_id;
+
+ ret = mux_acb_send(ipc_mux, blocking);
+
+ return ret;
+}
+
+void mux_netif_tx_flowctrl(struct mux_session *session, int idx, bool on)
+{
+ /* Inform the network interface to start/stop flow ctrl */
+ if (ipc_wwan_is_tx_stopped(session->wwan, idx) != on)
+ ipc_wwan_tx_flowctrl(session->wwan, idx, on);
+}
+
+static int mux_dl_cmdresps_decode_process(struct iosm_mux *ipc_mux,
+ struct mux_lite_cmdh *cmdh)
+{
+ struct mux_acb *acb = &ipc_mux->acb;
+
+ switch (cmdh->command_type) {
+ case MUX_CMD_OPEN_SESSION_RESP:
+ case MUX_CMD_CLOSE_SESSION_RESP:
+ /* Resume the control application. */
+ acb->got_param = cmdh->param;
+ break;
+
+ case MUX_LITE_CMD_FLOW_CTL_ACK:
+ /* This command type is not expected as response for
+ * Aggregation version of the protocol. So return non-zero.
+ */
+ if (ipc_mux->protocol != MUX_LITE)
+ return -EINVAL;
+
+ dev_dbg(ipc_mux->dev, "if %u FLOW_CTL_ACK %u received",
+ cmdh->if_id, cmdh->transaction_id);
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ acb->wanted_response = MUX_CMD_INVALID;
+ acb->got_response = cmdh->command_type;
+ complete(&ipc_mux->channel->ul_sem);
+
+ return 0;
+}
+
+static int mux_dl_dlcmds_decode_process(struct iosm_mux *ipc_mux,
+ struct mux_lite_cmdh *cmdh)
+{
+ union mux_cmd_param *param = &cmdh->param;
+ struct mux_session *session;
+ int new_size;
+
+ dev_dbg(ipc_mux->dev, "if_id[%d]: dlcmds decode process %d",
+ cmdh->if_id, cmdh->command_type);
+
+ switch (cmdh->command_type) {
+ case MUX_LITE_CMD_FLOW_CTL:
+
+ if (cmdh->if_id >= ipc_mux->nr_sessions) {
+ dev_err(ipc_mux->dev, "if_id [%d] not valid",
+ cmdh->if_id);
+ return -EINVAL; /* No session interface id. */
+ }
+
+ session = &ipc_mux->session[cmdh->if_id];
+
+ new_size = offsetof(struct mux_lite_cmdh, param) +
+ sizeof(param->flow_ctl);
+ if (param->flow_ctl.mask == 0xFFFFFFFF) {
+ /* Backward Compatibility */
+ if (cmdh->cmd_len == new_size)
+ session->flow_ctl_mask = param->flow_ctl.mask;
+ else
+ session->flow_ctl_mask = ~0;
+ /* if CP asks for FLOW CTRL Enable
+ * then set our internal flow control Tx flag
+ * to limit uplink session queueing
+ */
+ session->net_tx_stop = true;
+ /* Update the stats */
+ session->flow_ctl_en_cnt++;
+ } else if (param->flow_ctl.mask == 0) {
+ /* Just reset the Flow control mask and let
+ * mux_flow_ctrl_low_thre_b take control on
+ * our internal Tx flag and enabling kernel
+ * flow control
+ */
+ /* Backward Compatibility */
+ if (cmdh->cmd_len == new_size)
+ session->flow_ctl_mask = param->flow_ctl.mask;
+ else
+ session->flow_ctl_mask = 0;
+ /* Update the stats */
+ session->flow_ctl_dis_cnt++;
+ } else {
+ break;
+ }
+
+ dev_dbg(ipc_mux->dev, "if[%u] FLOW CTRL 0x%08X", cmdh->if_id,
+ param->flow_ctl.mask);
+ break;
+
+ case MUX_LITE_CMD_LINK_STATUS_REPORT:
+ break;
+
+ default:
+ return -EINVAL;
+ }
+ return 0;
+}
+
+/* Decode and Send appropriate response to a command block. */
+static void mux_dl_cmd_decode(struct iosm_mux *ipc_mux, struct sk_buff *skb)
+{
+ struct mux_lite_cmdh *cmdh = (struct mux_lite_cmdh *)skb->data;
+
+ if (mux_dl_cmdresps_decode_process(ipc_mux, cmdh)) {
+ /* Unable to decode command response indicates the cmd_type
+ * may be a command instead of response. So try to decoding it.
+ */
+ if (!mux_dl_dlcmds_decode_process(ipc_mux, cmdh)) {
+ /* Decoded command may need a response. Give the
+ * response according to the command type.
+ */
+ union mux_cmd_param *mux_cmd = NULL;
+ size_t size = 0;
+ u32 cmd = MUX_LITE_CMD_LINK_STATUS_REPORT_RESP;
+
+ if (cmdh->command_type ==
+ MUX_LITE_CMD_LINK_STATUS_REPORT) {
+ mux_cmd = &cmdh->param;
+ mux_cmd->link_status_resp.response =
+ MUX_CMD_RESP_SUCCESS;
+ /* response field is u32 */
+ size = sizeof(u32);
+ } else if (cmdh->command_type ==
+ MUX_LITE_CMD_FLOW_CTL) {
+ cmd = MUX_LITE_CMD_FLOW_CTL_ACK;
+ } else {
+ return;
+ }
+
+ if (mux_dl_acb_send_cmds(ipc_mux, cmd, cmdh->if_id,
+ cmdh->transaction_id, mux_cmd,
+ size, false, true))
+ dev_err(ipc_mux->dev,
+ "if_id %d: cmd send failed",
+ cmdh->if_id);
+ }
+ }
+}
+
+/* Pass the DL packet to the netif layer. */
+static int mux_net_receive(struct iosm_mux *ipc_mux, int if_id,
+ struct iosm_wwan *wwan, u32 offset, u8 service_class,
+ struct sk_buff *skb)
+{
+ /* for "zero copy" use clone */
+ struct sk_buff *dest_skb = skb_clone(skb, GFP_ATOMIC);
+
+ if (!dest_skb)
+ return -1;
+
+ skb_pull(dest_skb, offset);
+
+ skb_set_tail_pointer(dest_skb, dest_skb->len);
+
+ /* Goto the start of the Ethernet header. */
+ skb_push(dest_skb, ETH_HLEN);
+
+ /* map session to vlan */
+ __vlan_hwaccel_put_tag(dest_skb, htons(ETH_P_8021Q), if_id + 1);
+
+ /* Pass the packet to the netif layer. */
+ dest_skb->priority = service_class;
+
+ return ipc_wwan_receive(wwan, dest_skb, false);
+}
+
+/* Decode Flow Credit Table in the block */
+static void mux_dl_fcth_decode(struct iosm_mux *ipc_mux, void *block)
+{
+ struct ipc_mem_lite_gen_tbl *fct = (struct ipc_mem_lite_gen_tbl *)block;
+ struct iosm_wwan *wwan;
+ int ul_credits;
+ int if_id;
+
+ if (fct->vfl_length != sizeof(fct->vfl.nr_of_bytes)) {
+ dev_err(ipc_mux->dev, "unexpected FCT length: %d",
+ fct->vfl_length);
+ return;
+ }
+
+ if_id = fct->if_id;
+ if (if_id >= ipc_mux->nr_sessions) {
+ dev_err(ipc_mux->dev, "not supported if_id: %d", if_id);
+ return;
+ }
+
+ /* Is the session active ? */
+ if_id = array_index_nospec(if_id, ipc_mux->nr_sessions);
+ wwan = ipc_mux->session[if_id].wwan;
+ if (!wwan) {
+ dev_err(ipc_mux->dev, "session Net ID is NULL");
+ return;
+ }
+
+ ul_credits = fct->vfl.nr_of_bytes;
+
+ dev_dbg(ipc_mux->dev, "Flow_Credit:: if_id[%d] Old: %d Grants: %d",
+ if_id, ipc_mux->session[if_id].ul_flow_credits, ul_credits);
+
+ /* Update the Flow Credit information from ADB */
+ ipc_mux->session[if_id].ul_flow_credits += ul_credits;
+
+ /* Check whether the TX can be started */
+ if (ipc_mux->session[if_id].ul_flow_credits > 0) {
+ ipc_mux->session[if_id].net_tx_stop = false;
+ mux_netif_tx_flowctrl(&ipc_mux->session[if_id],
+ ipc_mux->session[if_id].if_id, false);
+ }
+}
+
+/* Decode non-aggregated datagram */
+static void mux_dl_adgh_decode(struct iosm_mux *ipc_mux, struct sk_buff *skb)
+{
+ u32 pad_len, packet_offset;
+ struct iosm_wwan *wwan;
+ struct mux_adgh *adgh;
+ u8 *block = skb->data;
+ int rc = 0;
+ u8 if_id;
+
+ adgh = (struct mux_adgh *)block;
+
+ if (adgh->signature != MUX_SIG_ADGH) {
+ dev_err(ipc_mux->dev, "invalid ADGH signature received");
+ return;
+ }
+
+ if_id = adgh->if_id;
+ if (if_id >= ipc_mux->nr_sessions) {
+ dev_err(ipc_mux->dev, "invalid if_id while decoding %d", if_id);
+ return;
+ }
+
+ /* Is the session active ? */
+ if_id = array_index_nospec(if_id, ipc_mux->nr_sessions);
+ wwan = ipc_mux->session[if_id].wwan;
+ if (!wwan) {
+ dev_err(ipc_mux->dev, "session Net ID is NULL");
+ return;
+ }
+
+ /* Store the pad len for the corresponding session
+ * Pad bytes as negotiated in the open session less the header size
+ * (see session management chapter for details).
+ * If resulting padding is zero or less, the additional head padding is
+ * omitted. For e.g., if HEAD_PAD_LEN = 16 or less, this field is
+ * omitted if HEAD_PAD_LEN = 20, then this field will have 4 bytes
+ * set to zero
+ */
+ pad_len =
+ ipc_mux->session[if_id].dl_head_pad_len - IPC_MEM_DL_ETH_OFFSET;
+ packet_offset = sizeof(*adgh) + pad_len;
+
+ if_id += ipc_mux->wwan_q_offset;
+
+ /* Pass the packet to the netif layer */
+ rc = mux_net_receive(ipc_mux, if_id, wwan, packet_offset,
+ adgh->service_class, skb);
+ if (rc) {
+ dev_err(ipc_mux->dev, "mux adgh decoding error");
+ return;
+ }
+ ipc_mux->session[if_id].flush = 1;
+}
+
+void ipc_mux_dl_decode(struct iosm_mux *ipc_mux, struct sk_buff *skb)
+{
+ u32 signature;
+
+ if (!skb->data)
+ return;
+
+ /* Decode the MUX header type. */
+ signature = le32_to_cpup((__le32 *)skb->data);
+
+ switch (signature) {
+ case MUX_SIG_ADGH:
+ mux_dl_adgh_decode(ipc_mux, skb);
+ break;
+
+ case MUX_SIG_FCTH:
+ mux_dl_fcth_decode(ipc_mux, skb->data);
+ break;
+
+ case MUX_SIG_CMDH:
+ mux_dl_cmd_decode(ipc_mux, skb);
+ break;
+
+ default:
+ dev_err(ipc_mux->dev, "invalid ABH signature");
+ }
+
+ ipc_pcie_kfree_skb(ipc_mux->pcie, skb);
+}
+
+static int mux_ul_skb_alloc(struct iosm_mux *ipc_mux, struct mux_adb *ul_adb,
+ u32 type)
+{
+ /* Take the first element of the free list. */
+ struct sk_buff *skb = skb_dequeue(&ul_adb->free_list);
+ int qlt_size;
+
+ if (!skb)
+ return -EBUSY; /* Wait for a free ADB skb. */
+
+ /* Mark it as UL ADB to select the right free operation. */
+ IPC_CB(skb)->op_type = (u8)UL_MUX_OP_ADB;
+
+ switch (type) {
+ case MUX_SIG_ADGH:
+ /* Save the ADB memory settings. */
+ ul_adb->dest_skb = skb;
+ ul_adb->buf = skb->data;
+ ul_adb->size = IPC_MEM_MAX_DL_MUX_LITE_BUF_SIZE;
+ /* reset statistic counter */
+ ul_adb->if_cnt = 0;
+ ul_adb->payload_size = 0;
+ ul_adb->dg_cnt_total = 0;
+
+ ul_adb->adgh = (struct mux_adgh *)skb->data;
+ memset(ul_adb->adgh, 0, sizeof(struct mux_adgh));
+ break;
+
+ case MUX_SIG_QLTH:
+ qlt_size = offsetof(struct ipc_mem_lite_gen_tbl, vfl) +
+ (MUX_QUEUE_LEVEL * sizeof(struct mux_lite_vfl));
+
+ if (qlt_size > IPC_MEM_MAX_DL_MUX_LITE_BUF_SIZE) {
+ dev_err(ipc_mux->dev,
+ "can't support. QLT size:%d SKB size: %d",
+ qlt_size, IPC_MEM_MAX_DL_MUX_LITE_BUF_SIZE);
+ return -1;
+ }
+
+ ul_adb->qlth_skb = skb;
+ memset((ul_adb->qlth_skb)->data, 0, qlt_size);
+ skb_put(skb, qlt_size);
+ break;
+ }
+
+ return 0;
+}
+
+static void mux_ul_adgh_finish(struct iosm_mux *ipc_mux)
+{
+ struct mux_adb *ul_adb = &ipc_mux->ul_adb;
+ long long bytes;
+ char *str;
+
+ if (!ul_adb || !ul_adb->dest_skb) {
+ dev_err(ipc_mux->dev, "no dest skb");
+ return;
+ }
+ skb_put(ul_adb->dest_skb, ul_adb->adgh->length);
+ skb_queue_tail(&ipc_mux->channel->ul_list, ul_adb->dest_skb);
+ ul_adb->dest_skb = NULL;
+
+ if (ipc_mux->ul_flow == MUX_UL_ON_CREDITS) {
+ struct mux_session *session;
+
+ session = &ipc_mux->session[ul_adb->adgh->if_id];
+ str = "available_credits";
+ bytes = (long long)session->ul_flow_credits;
+
+ } else {
+ str = "pend_bytes";
+ bytes = ipc_mux->ul_data_pend_bytes;
+ ipc_mux->ul_data_pend_bytes += ul_adb->adgh->length;
+ }
+
+ dev_dbg(ipc_mux->dev, "UL ADGH: size=%d, if_id=%d, payload=%d, %s=%lld",
+ ul_adb->adgh->length, ul_adb->adgh->if_id, ul_adb->payload_size,
+ str, bytes);
+}
+
+/* Allocates an ADB from the free list and initializes it with ADBH */
+static bool mux_ul_adb_allocate(struct iosm_mux *ipc_mux, struct mux_adb *adb,
+ int *size_needed, u32 type)
+{
+ bool ret_val = false;
+ int status;
+
+ if (!adb->dest_skb) {
+ /* Allocate memory for the ADB including of the
+ * datagram table header.
+ */
+ status = mux_ul_skb_alloc(ipc_mux, adb, type);
+ if (status != 0)
+ /* Is a pending ADB available ? */
+ ret_val = true; /* None. */
+
+ /* Update size need to zero only for new ADB memory */
+ *size_needed = 0;
+ }
+
+ return ret_val;
+}
+
+/* Informs the network stack to stop sending further packets for all opened
+ * sessions
+ */
+static void mux_stop_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;
+
+ session->net_tx_stop = true;
+ }
+}
+
+/* Sends Queue Level Table of all opened sessions */
+static bool mux_lite_send_qlt(struct iosm_mux *ipc_mux)
+{
+ struct ipc_mem_lite_gen_tbl *qlt;
+ struct mux_session *session;
+ bool qlt_updated = false;
+ int i;
+ int qlt_size;
+
+ if (!ipc_mux->initialized || ipc_mux->state != MUX_S_ACTIVE)
+ return qlt_updated;
+
+ qlt_size = offsetof(struct ipc_mem_lite_gen_tbl, vfl) +
+ MUX_QUEUE_LEVEL * sizeof(struct mux_lite_vfl);
+
+ for (i = 0; i < ipc_mux->nr_sessions; i++) {
+ session = &ipc_mux->session[i];
+
+ if (!session->wwan || session->flow_ctl_mask != 0)
+ continue;
+
+ if (mux_ul_skb_alloc(ipc_mux, &ipc_mux->ul_adb, MUX_SIG_QLTH)) {
+ dev_err(ipc_mux->dev,
+ "no reserved mem to send QLT of if_id: %d", i);
+ break;
+ }
+
+ /* Prepare QLT */
+ qlt = (struct ipc_mem_lite_gen_tbl *)(ipc_mux->ul_adb.qlth_skb)
+ ->data;
+ qlt->signature = MUX_SIG_QLTH;
+ qlt->length = qlt_size;
+ qlt->if_id = i;
+ qlt->vfl_length = MUX_QUEUE_LEVEL * sizeof(struct mux_lite_vfl);
+ qlt->reserved[0] = 0;
+ qlt->reserved[1] = 0;
+
+ qlt->vfl.nr_of_bytes = session->ul_list.qlen;
+
+ /* Add QLT to the transfer list. */
+ skb_queue_tail(&ipc_mux->channel->ul_list,
+ ipc_mux->ul_adb.qlth_skb);
+
+ qlt_updated = true;
+ ipc_mux->ul_adb.qlth_skb = NULL;
+ }
+
+ if (qlt_updated)
+ /* Updates the TDs with ul_list */
+ (void)imem_ul_write_td(ipc_mux->imem);
+
+ return qlt_updated;
+}
+
+/* Checks the available credits for the specified session and returns
+ * number of packets for which credits are available.
+ */
+static int mux_ul_bytes_credits_check(struct iosm_mux *ipc_mux,
+ struct mux_session *session,
+ struct sk_buff_head *ul_list,
+ int max_nr_of_pkts)
+{
+ int pkts_to_send = 0;
+ struct sk_buff *skb;
+ int credits = 0;
+
+ if (ipc_mux->ul_flow == MUX_UL_ON_CREDITS) {
+ credits = session->ul_flow_credits;
+ if (credits <= 0) {
+ dev_dbg(ipc_mux->dev,
+ "FC::if_id[%d] Insuff.Credits/Qlen:%d/%u",
+ session->if_id, session->ul_flow_credits,
+ session->ul_list.qlen); /* nr_of_bytes */
+ return 0;
+ }
+ } else {
+ credits = IPC_MEM_MUX_UL_FLOWCTRL_HIGH_B -
+ ipc_mux->ul_data_pend_bytes;
+ if (credits <= 0) {
+ mux_stop_tx_for_all_sessions(ipc_mux);
+
+ dev_dbg(ipc_mux->dev,
+ "if_id[%d] Stopped encoding.PendBytes: %llu, high_thresh: %d",
+ session->if_id, ipc_mux->ul_data_pend_bytes,
+ IPC_MEM_MUX_UL_FLOWCTRL_HIGH_B);
+ return 0;
+ }
+ }
+
+ /* Check if there are enough credits/bytes available to send the
+ * requested max_nr_of_pkts. Otherwise restrict the nr_of_pkts
+ * depending on available credits.
+ */
+ skb_queue_walk(ul_list, skb)
+ {
+ if (!(credits >= skb->len && pkts_to_send < max_nr_of_pkts))
+ break;
+ credits -= skb->len;
+ pkts_to_send++;
+ }
+
+ return pkts_to_send;
+}
+
+/* Encode the UL IP packet according to Lite spec. */
+static int mux_ul_adgh_encode(struct iosm_mux *ipc_mux, int session_id,
+ struct mux_session *session,
+ struct sk_buff_head *ul_list, struct mux_adb *adb,
+ int nr_of_pkts)
+{
+ int offset = sizeof(struct mux_adgh);
+ int adb_updated = -EINVAL;
+ struct sk_buff *src_skb;
+ int aligned_size = 0;
+ int nr_of_skb = 0;
+ u32 pad_len = 0;
+ int vlan_id;
+
+ /* Re-calculate the number of packets depending on number of bytes to be
+ * processed/available credits.
+ */
+ nr_of_pkts = mux_ul_bytes_credits_check(ipc_mux, session, ul_list,
+ nr_of_pkts);
+
+ /* If calculated nr_of_pkts from available credits is <= 0
+ * then nothing to do.
+ */
+ if (nr_of_pkts <= 0)
+ return 0;
+
+ /* Read configured UL head_pad_length for session.*/
+ if (session->ul_head_pad_len > IPC_MEM_DL_ETH_OFFSET)
+ pad_len = session->ul_head_pad_len - IPC_MEM_DL_ETH_OFFSET;
+
+ /* Process all pending UL packets for this session
+ * depending on the allocated datagram table size.
+ */
+ while (nr_of_pkts > 0) {
+ /* get destination skb allocated */
+ if (mux_ul_adb_allocate(ipc_mux, adb, &ipc_mux->size_needed,
+ MUX_SIG_ADGH)) {
+ dev_err(ipc_mux->dev, "no reserved memory for ADGH");
+ return -ENOMEM;
+ }
+
+ /* Peek at the head of the list. */
+ src_skb = skb_peek(ul_list);
+ if (!src_skb) {
+ dev_err(ipc_mux->dev,
+ "skb peek return NULL with count : %d",
+ nr_of_pkts);
+ break;
+ }
+
+ /* Calculate the memory value. */
+ aligned_size = ALIGN((pad_len + src_skb->len), 4);
+
+ ipc_mux->size_needed = sizeof(struct mux_adgh) + aligned_size;
+
+ if (ipc_mux->size_needed > adb->size) {
+ dev_dbg(ipc_mux->dev, "size needed %d, adgh size %d",
+ ipc_mux->size_needed, adb->size);
+ /* Return 1 if any IP packet is added to the transfer
+ * list.
+ */
+ return nr_of_skb ? 1 : 0;
+ }
+
+ vlan_id = session_id + ipc_mux->wwan_q_offset;
+ ipc_wwan_update_stats(session->wwan, vlan_id, src_skb->len,
+ true);
+
+ /* Add buffer (without head padding to next pending transfer) */
+ memcpy(adb->buf + offset + pad_len, src_skb->data,
+ src_skb->len);
+
+ adb->adgh->signature = MUX_SIG_ADGH;
+ adb->adgh->if_id = session_id;
+ adb->adgh->length =
+ sizeof(struct mux_adgh) + pad_len + src_skb->len;
+ adb->adgh->service_class = src_skb->priority;
+ adb->adgh->next_count = --nr_of_pkts;
+ adb->dg_cnt_total++;
+ adb->payload_size += src_skb->len;
+
+ if (ipc_mux->ul_flow == MUX_UL_ON_CREDITS)
+ /* Decrement the credit value as we are processing the
+ * datagram from the UL list.
+ */
+ session->ul_flow_credits -= src_skb->len;
+
+ /* Remove the processed elements and free it. */
+ src_skb = skb_dequeue(ul_list);
+ dev_kfree_skb(src_skb);
+ nr_of_skb++;
+
+ mux_ul_adgh_finish(ipc_mux);
+ }
+
+ if (nr_of_skb) {
+ /* Send QLT info to modem if pending bytes > high watermark
+ * in case of mux lite
+ */
+ if (ipc_mux->ul_flow == MUX_UL_ON_CREDITS ||
+ ipc_mux->ul_data_pend_bytes >=
+ IPC_MEM_MUX_UL_FLOWCTRL_LOW_B)
+ adb_updated = mux_lite_send_qlt(ipc_mux);
+ else
+ adb_updated = 1;
+
+ /* Updates the TDs with ul_list */
+ (void)imem_ul_write_td(ipc_mux->imem);
+ }
+
+ return adb_updated;
+}
+
+bool ipc_mux_ul_data_encode(struct iosm_mux *ipc_mux)
+{
+ struct sk_buff_head *ul_list;
+ struct mux_session *session;
+ int updated = 0;
+ int session_id;
+ int dg_n;
+ int i;
+
+ if (!ipc_mux || ipc_mux->state != MUX_S_ACTIVE ||
+ ipc_mux->adb_prep_ongoing)
+ return false;
+
+ ipc_mux->adb_prep_ongoing = true;
+
+ for (i = 0; i < ipc_mux->nr_sessions; i++) {
+ session_id = ipc_mux->rr_next_session;
+ session = &ipc_mux->session[session_id];
+
+ /* Go to next handle rr_next_session overflow */
+ ipc_mux->rr_next_session++;
+ if (ipc_mux->rr_next_session >= ipc_mux->nr_sessions)
+ ipc_mux->rr_next_session = 0;
+
+ if (!session->wwan || session->flow_ctl_mask ||
+ session->net_tx_stop)
+ continue;
+
+ ul_list = &session->ul_list;
+
+ /* Is something pending in UL and flow ctrl off */
+ dg_n = skb_queue_len(ul_list);
+ if (dg_n > MUX_MAX_UL_DG_ENTRIES)
+ dg_n = MUX_MAX_UL_DG_ENTRIES;
+
+ if (dg_n == 0)
+ /* Nothing to do for ipc_mux session
+ * -> try next session id.
+ */
+ continue;
+
+ updated = mux_ul_adgh_encode(ipc_mux, session_id, session,
+ ul_list, &ipc_mux->ul_adb, dg_n);
+ }
+
+ ipc_mux->adb_prep_ongoing = false;
+ return updated == 1;
+}
+
+void ipc_mux_ul_encoded_process(struct iosm_mux *ipc_mux, struct sk_buff *skb)
+{
+ struct mux_adgh *adgh;
+
+ adgh = (struct mux_adgh *)skb->data;
+
+ if (adgh->signature == MUX_SIG_ADGH && ipc_mux->ul_flow == MUX_UL)
+ ipc_mux->ul_data_pend_bytes -= adgh->length;
+
+ if (ipc_mux->ul_flow == MUX_UL)
+ dev_dbg(ipc_mux->dev, "ul_data_pend_bytes: %lld",
+ ipc_mux->ul_data_pend_bytes);
+
+ /* Reset the skb settings. */
+ skb->tail = 0;
+ skb->len = 0;
+
+ /* Add the consumed ADB to the free list. */
+ skb_queue_tail((&ipc_mux->ul_adb.free_list), skb);
+}
+
+/* Start the NETIF uplink send transfer in MUX mode. */
+static int mux_tq_ul_trigger_encode(struct iosm_imem *ipc_imem, int arg,
+ void *msg, size_t size)
+{
+ struct iosm_mux *ipc_mux = ipc_imem->mux;
+ bool ul_data_pend = false;
+
+ /* Add session UL data to a ADB and ADGH */
+ ul_data_pend = ipc_mux_ul_data_encode(ipc_mux);
+ if (ul_data_pend)
+ /* Delay the doorbell irq */
+ imem_td_update_timer_start(ipc_mux->imem);
+
+ /* reset the debounce flag */
+ ipc_mux->ev_mux_net_transmit_pending = false;
+
+ return 0;
+}
+
+int ipc_mux_ul_trigger_encode(struct iosm_mux *ipc_mux, int if_id,
+ struct sk_buff *skb)
+{
+ struct mux_session *session = &ipc_mux->session[if_id];
+
+ if (ipc_mux->channel &&
+ ipc_mux->channel->state != IMEM_CHANNEL_ACTIVE) {
+ dev_err(ipc_mux->dev,
+ "channel state is not IMEM_CHANNEL_ACTIVE");
+ return -1;
+ }
+
+ if (!session->wwan) {
+ dev_err(ipc_mux->dev, "session net ID is NULL");
+ return -1;
+ }
+
+ /* Session is under flow control.
+ * Check if packet can be queued in session list, if not
+ * suspend net tx
+ */
+ if (skb_queue_len(&session->ul_list) >=
+ (session->net_tx_stop ?
+ IPC_MEM_MUX_UL_SESS_FCON_THRESHOLD :
+ (IPC_MEM_MUX_UL_SESS_FCON_THRESHOLD *
+ IPC_MEM_MUX_UL_SESS_FCOFF_THRESHOLD_FACTOR))) {
+ mux_netif_tx_flowctrl(session, session->if_id, true);
+ return -EBUSY;
+ }
+
+ /* Add skb to the uplink skb accumulator. */
+ skb_queue_tail(&session->ul_list, skb);
+
+ /* Inform the IPC kthread to pass uplink IP packets to CP. */
+ if (!ipc_mux->ev_mux_net_transmit_pending) {
+ ipc_mux->ev_mux_net_transmit_pending = true;
+ if (ipc_task_queue_send_task(ipc_mux->imem,
+ mux_tq_ul_trigger_encode, 0, NULL,
+ 0, false))
+ return -EAGAIN;
+ }
+ dev_dbg(ipc_mux->dev, "mux ul if[%d] qlen=%d/%u, len=%d/%d, prio=%d",
+ if_id, skb_queue_len(&session->ul_list), session->ul_list.qlen,
+ skb->len, skb->truesize, skb->priority);
+
+ return 0;
+}
diff --git a/drivers/net/wwan/iosm/iosm_ipc_mux_codec.h b/drivers/net/wwan/iosm/iosm_ipc_mux_codec.h
new file mode 100644
index 000000000000..51171969d77c
--- /dev/null
+++ b/drivers/net/wwan/iosm/iosm_ipc_mux_codec.h
@@ -0,0 +1,194 @@
+/* SPDX-License-Identifier: GPL-2.0-only
+ *
+ * Copyright (C) 2020 Intel Corporation.
+ */
+
+#ifndef IOSM_IPC_MUX_CODEC_H
+#define IOSM_IPC_MUX_CODEC_H
+
+#include "iosm_ipc_mux.h"
+
+/* Queue level size and reporting
+ * >1 is enable, 0 is disable
+ */
+#define MUX_QUEUE_LEVEL 1
+
+/* Size of the buffer for the IP MUX commands. */
+#define MUX_MAX_UL_ACB_BUF_SIZE 256
+
+/* Maximum number of packets in a go per session */
+#define MUX_MAX_UL_DG_ENTRIES 100
+
+/* ADGH: Signature of the Datagram Header. */
+#define MUX_SIG_ADGH 0x48474441
+
+/* CMDH: Signature of the Command Header. */
+#define MUX_SIG_CMDH 0x48444D43
+
+/* QLTH: Signature of the Queue Level Table */
+#define MUX_SIG_QLTH 0x48544C51
+
+/* FCTH: Signature of the Flow Credit Table */
+#define MUX_SIG_FCTH 0x48544346
+
+/* MUX UL session threshold factor */
+#define IPC_MEM_MUX_UL_SESS_FCOFF_THRESHOLD_FACTOR (4)
+
+/* Size of the buffer for the IP MUX Lite data buffer. */
+#define IPC_MEM_MAX_DL_MUX_LITE_BUF_SIZE (2 * 1024)
+
+/* MUX UL session threshold in number of packets */
+#define IPC_MEM_MUX_UL_SESS_FCON_THRESHOLD (64)
+
+/* Default time out for sending IPC session commands like
+ * open session, close session etc
+ * unit : milliseconds
+ */
+#define IPC_MUX_CMD_RUN_DEFAULT_TIMEOUT 1000 /* 1 second */
+
+/* MUX UL flow control lower threshold in bytes */
+#define IPC_MEM_MUX_UL_FLOWCTRL_LOW_B 10240 /* 10KB */
+
+/* MUX UL flow control higher threshold in bytes (5ms worth of data)*/
+#define IPC_MEM_MUX_UL_FLOWCTRL_HIGH_B (110 * 1024)
+
+/**
+ * struct mux_adgh - Aggregated Datagram Header.
+ * @signature: Signature of the Aggregated Datagram Header(0x48474441)
+ * @length: Length (in bytes) of the datagram header. This length
+ * shall include the header size. Min value: 0x10
+ * @if_id: ID of the interface the datagrams belong to
+ * @opt_ipv4v6: Indicates IPv4(=0)/IPv6(=1), It is optional if not
+ * used set it to zero.
+ * @reserved: Reserved bits. Set to zero.
+ * @service_class: Service class identifier for the datagram.
+ * @next_count: Count of the datagrams that shall be following this
+ * datagrams for this interface. A count of zero means
+ * the next datagram may not belong to this interface.
+ * @reserved1: Reserved bytes, Set to zero
+ */
+struct mux_adgh {
+ u32 signature;
+ u16 length;
+ u8 if_id;
+ u8 opt_ipv4v6 : 1;
+ u8 reserved : 7;
+ u8 service_class;
+ u8 next_count;
+ u8 reserved1[6];
+};
+
+/**
+ * struct mux_lite_cmdh - MUX Lite Command Header
+ * @signature: Signature of the Command Header(0x48444D43)
+ * @cmd_len: Length (in bytes) of the command. This length shall
+ * include the header size. Minimum value: 0x10
+ * @if_id: ID of the interface the commands in the table belong to.
+ * @reserved: Reserved Set to zero.
+ * @command_type: Command Enum.
+ * @transaction_id: 4 byte value shall be generated and sent along with a
+ * command Responses and ACKs shall have the same
+ * Transaction ID as their commands. It shall be unique to
+ * the command transaction on the given interface.
+ * @param: Optional parameters used with the command.
+ */
+struct mux_lite_cmdh {
+ u32 signature;
+ u16 cmd_len;
+ u8 if_id;
+ u8 reserved;
+ u32 command_type;
+ u32 transaction_id;
+ union mux_cmd_param param;
+};
+
+/**
+ * struct mux_lite_vfl - value field in generic table
+ * @nr_of_bytes: Number of bytes available to transmit in the queue.
+ */
+struct mux_lite_vfl {
+ u32 nr_of_bytes;
+};
+
+/**
+ * struct ipc_mem_lite_gen_tbl - Generic table format for Queue Level
+ * and Flow Credit
+ * @signature: Signature of the table
+ * @length: Length of the table
+ * @if_id: ID of the interface the table belongs to
+ * @vfl_length: Value field length
+ * @reserved: Reserved
+ * @vfl: Value field of variable length
+ */
+struct ipc_mem_lite_gen_tbl {
+ u32 signature;
+ u16 length;
+ u8 if_id;
+ u8 vfl_length;
+ u32 reserved[2];
+ struct mux_lite_vfl vfl;
+};
+
+/**
+ * ipc_mux_dl_decode -Route the DL packet through the IP MUX layer
+ * depending on Header.
+ * @ipc_mux: Pointer to MUX data-struct
+ * @skb: Pointer to ipc_skb.
+ */
+void ipc_mux_dl_decode(struct iosm_mux *ipc_mux, struct sk_buff *skb);
+
+/**
+ * mux_dl_acb_send_cmds - Respond to the Command blocks.
+ * @ipc_mux: Pointer to MUX data-struct
+ * @cmd_type: Command
+ * @if_id: Session interface id.
+ * @transaction_id: Command transaction id.
+ * @param: Pointer to command params.
+ * @res_size: Response size
+ * @blocking: True for blocking send
+ * @respond: If true return transaction ID
+ *
+ * Returns: 0 in success and -ve for failure
+ */
+int mux_dl_acb_send_cmds(struct iosm_mux *ipc_mux, u32 cmd_type, u8 if_id,
+ u32 transaction_id, union mux_cmd_param *param,
+ size_t res_size, bool blocking, bool respond);
+
+/**
+ * mux_netif_tx_flowctrl - Enable/Disable TX flow control on MUX sessions.
+ * @session: Pointer to mux_session struct
+ * @idx: Session ID
+ * @on: true for Enable and false for disable flow control
+ */
+void mux_netif_tx_flowctrl(struct mux_session *session, int idx, bool on);
+
+/**
+ * ipc_mux_ul_trigger_encode - Route the UL packet through the IP MUX layer
+ * for encoding.
+ * @ipc_mux: Pointer to MUX data-struct
+ * @if_id: Session ID.
+ * @skb: Pointer to ipc_skb.
+ *
+ * Returns: 0 if successfully encoded
+ * -EAGAIN or -1 on failure
+ * -EBUSY or -2 if packet has to be retransmitted.
+ */
+int ipc_mux_ul_trigger_encode(struct iosm_mux *ipc_mux, int if_id,
+ struct sk_buff *skb);
+/**
+ * ipc_mux_ul_data_encode - UL encode function for calling from Tasklet context.
+ * @ipc_mux: Pointer to MUX data-struct
+ *
+ * Returns: TRUE if any packet of any session is encoded FALSE otherwise.
+ */
+bool ipc_mux_ul_data_encode(struct iosm_mux *ipc_mux);
+
+/**
+ * ipc_mux_ul_encoded_process - Handles the Modem processed UL data by adding
+ * the SKB to the UL free list.
+ * @ipc_mux: Pointer to MUX data-struct
+ * @skb: Pointer to ipc_skb.
+ */
+void ipc_mux_ul_encoded_process(struct iosm_mux *ipc_mux, struct sk_buff *skb);
+
+#endif
--
2.12.3
