1) Binds logical channel between host-device for communication.
2) Implements device specific(Char/Net) IO operations.
3) Inject primary BootLoader FW image to modem.

Signed-off-by: M Chetan Kumar <m.chetan.ku...@intel.com>
---
 drivers/net/wwan/iosm/iosm_ipc_imem_ops.c | 779 ++++++++++++++++++++++++++++++
 drivers/net/wwan/iosm/iosm_ipc_imem_ops.h | 102 ++++
 2 files changed, 881 insertions(+)
 create mode 100644 drivers/net/wwan/iosm/iosm_ipc_imem_ops.c
 create mode 100644 drivers/net/wwan/iosm/iosm_ipc_imem_ops.h

diff --git a/drivers/net/wwan/iosm/iosm_ipc_imem_ops.c 
b/drivers/net/wwan/iosm/iosm_ipc_imem_ops.c
new file mode 100644
index 000000000000..2e2f3f43e21c
--- /dev/null
+++ b/drivers/net/wwan/iosm/iosm_ipc_imem_ops.c
@@ -0,0 +1,779 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020 Intel Corporation.
+ */
+
+#include <linux/delay.h>
+
+#include "iosm_ipc_chnl_cfg.h"
+#include "iosm_ipc_imem.h"
+#include "iosm_ipc_imem_ops.h"
+#include "iosm_ipc_sio.h"
+#include "iosm_ipc_task_queue.h"
+
+/* Open a packet data online channel between the network layer and CP. */
+int imem_sys_wwan_open(void *instance, int vlan_id)
+{
+       struct iosm_imem *ipc_imem = instance;
+
+       dev_dbg(ipc_imem->dev, "%s[vlan id:%d]",
+               ipc_ap_phase_get_string(ipc_imem->phase), vlan_id);
+
+       /* The network interface is only supported in the runtime phase. */
+       if (imem_ap_phase_update(ipc_imem) != IPC_P_RUN) {
+               dev_err(ipc_imem->dev, "[net:%d]: refused phase %s", vlan_id,
+                       ipc_ap_phase_get_string(ipc_imem->phase));
+               return -1;
+       }
+
+       /* check for the vlan tag
+        * if tag 1 to 8 then create IP MUX channel sessions.
+        * if tag 257 to 512 then create dss channel.
+        * To start MUX session from 0 as vlan tag would start from 1
+        * so map it to if_id = vlan_id - 1
+        */
+       if (vlan_id > 0 && vlan_id <= ipc_mux_get_max_sessions(ipc_imem->mux)) {
+               return ipc_mux_open_session(ipc_imem->mux, vlan_id - 1);
+       } else if (vlan_id > 256 && vlan_id < 512) {
+               int ch_id =
+                       imem_channel_alloc(ipc_imem, vlan_id, IPC_CTYPE_WWAN);
+
+               if (imem_channel_open(ipc_imem, ch_id, IPC_HP_NET_CHANNEL_INIT))
+                       return ch_id;
+       }
+
+       return -1;
+}
+
+/* Release a net link to CP. */
+void imem_sys_wwan_close(void *instance, int vlan_id, int channel_id)
+{
+       struct iosm_imem *ipc_imem = instance;
+
+       if (ipc_imem->mux && vlan_id > 0 &&
+           vlan_id <= ipc_mux_get_max_sessions(ipc_imem->mux))
+               ipc_mux_close_session(ipc_imem->mux, vlan_id - 1);
+
+       else if ((vlan_id > 256 && vlan_id < 512))
+               imem_channel_close(ipc_imem, channel_id);
+}
+
+/* Tasklet call to do uplink transfer. */
+static int imem_tq_sio_write(void *instance, int arg, void *msg, size_t size)
+{
+       struct iosm_imem *ipc_imem = instance;
+
+       ipc_imem->ev_sio_write_pending = false;
+       imem_ul_send(ipc_imem);
+
+       return 0;
+}
+
+/* Through tasklet to do sio write. */
+static bool imem_call_sio_write(struct iosm_imem *ipc_imem)
+{
+       if (ipc_imem->ev_sio_write_pending)
+               return false;
+
+       ipc_imem->ev_sio_write_pending = true;
+
+       return (!ipc_task_queue_send_task(ipc_imem, imem_tq_sio_write, 0, NULL,
+                                         0, false));
+}
+
+/* Add to the ul list skb */
+static int imem_wwan_transmit(struct iosm_imem *ipc_imem, int vlan_id,
+                             int channel_id, struct sk_buff *skb)
+{
+       struct ipc_mem_channel *channel;
+
+       channel = &ipc_imem->channels[channel_id];
+
+       if (channel->state != IMEM_CHANNEL_ACTIVE) {
+               dev_err(ipc_imem->dev, "invalid state of channel %d",
+                       channel_id);
+               return -1;
+       }
+
+       if (ipc_pcie_addr_map(ipc_imem->pcie, skb->data, skb->len,
+                             &IPC_CB(skb)->mapping, DMA_TO_DEVICE)) {
+               dev_err(ipc_imem->dev, "failed to map skb");
+               IPC_CB(skb)->direction = DMA_TO_DEVICE;
+               IPC_CB(skb)->len = skb->len;
+               IPC_CB(skb)->op_type = UL_DEFAULT;
+               return -1;
+       }
+
+       /* Add skb to the uplink skbuf accumulator */
+       skb_queue_tail(&channel->ul_list, skb);
+       imem_call_sio_write(ipc_imem);
+
+       return 0;
+}
+
+/* Function for transfer UL data
+ * WWAN layer must free the packet in case if imem fails to transmit.
+ * In case of success, imem layer will free it.
+ */
+int imem_sys_wwan_transmit(void *instance, int vlan_id, int channel_id,
+                          struct sk_buff *skb)
+{
+       struct iosm_imem *ipc_imem = instance;
+       int ret = -1;
+
+       if (!ipc_imem || channel_id < 0)
+               return -EINVAL;
+
+       /* Is CP Running? */
+       if (ipc_imem->phase != IPC_P_RUN) {
+               dev_dbg(ipc_imem->dev, "%s[transmit, vlanid:%d]",
+                       ipc_ap_phase_get_string(ipc_imem->phase), vlan_id);
+               return -EBUSY;
+       }
+
+       if (ipc_imem->channels[channel_id].ctype == IPC_CTYPE_WWAN) {
+               if (vlan_id > 0 &&
+                   vlan_id <= ipc_mux_get_max_sessions(ipc_imem->mux))
+                       /* Route the UL packet through IP MUX Layer */
+                       ret = ipc_mux_ul_trigger_encode(ipc_imem->mux,
+                                                       vlan_id - 1, skb);
+               /* Control channels and Low latency data channel for VoLTE*/
+               else if (vlan_id > 256 && vlan_id < 512)
+                       ret = imem_wwan_transmit(ipc_imem, vlan_id, channel_id,
+                                                skb);
+       } else {
+               dev_err(ipc_imem->dev,
+                       "invalid channel type on channel %d: ctype: %d",
+                       channel_id, ipc_imem->channels[channel_id].ctype);
+       }
+
+       return ret;
+}
+
+void wwan_channel_init(struct iosm_imem *ipc_imem, int total_sessions,
+                      enum ipc_mux_protocol mux_type)
+{
+       struct ipc_chnl_cfg chnl_cfg = { 0 };
+
+       ipc_imem->cp_version = ipc_mmio_get_cp_version(ipc_imem->mmio);
+
+       /* If modem version is invalid (0xffffffff), do not initialize WWAN. */
+       if (ipc_imem->cp_version == -1) {
+               dev_err(ipc_imem->dev, "invalid CP version");
+               return;
+       }
+
+       while (ipc_imem->nr_of_channels < IPC_MEM_MAX_CHANNELS &&
+              !ipc_chnl_cfg_get(&chnl_cfg, ipc_imem->nr_of_channels,
+                                mux_type)) {
+               dev_dbg(ipc_imem->dev,
+                       "initializing entry :%d id:%d ul_pipe:%d dl_pipe:%d",
+                       ipc_imem->nr_of_channels, chnl_cfg.id, chnl_cfg.ul_pipe,
+                       chnl_cfg.dl_pipe);
+
+               imem_channel_init(ipc_imem, IPC_CTYPE_WWAN, chnl_cfg,
+                                 IRQ_MOD_OFF);
+       }
+       /* WWAN registration. */
+       ipc_imem->wwan = ipc_wwan_init(ipc_imem, ipc_imem->dev, total_sessions);
+       if (!ipc_imem->wwan)
+               dev_err(ipc_imem->dev,
+                       "failed to register the ipc_wwan interfaces");
+}
+
+/* Copies the data from user space */
+static struct sk_buff *
+imem_sio_copy_from_user_to_skb(struct iosm_imem *ipc_imem, int channel_id,
+                              const unsigned char __user *buf, int size,
+                              int is_blocking)
+{
+       struct sk_buff *skb;
+       dma_addr_t mapping;
+
+       /* Allocate skb memory for the uplink buffer. */
+       skb = ipc_pcie_alloc_skb(ipc_imem->pcie, size, GFP_KERNEL, &mapping,
+                                DMA_TO_DEVICE, 0);
+       if (!skb)
+               return skb;
+
+       if (copy_from_user(skb_put(skb, size), buf, size) != 0) {
+               dev_err(ipc_imem->dev, "ch[%d]: copy from user failed",
+                       channel_id);
+               ipc_pcie_kfree_skb(ipc_imem->pcie, skb);
+               return NULL;
+       }
+
+       IPC_CB(skb)->op_type =
+               (u8)(is_blocking ? UL_USR_OP_BLOCKED : UL_DEFAULT);
+
+       return skb;
+}
+
+/* Save the complete PSI image in a specific imem region, prepare the doorbell
+ * scratchpad and inform* the ROM driver. The flash app is suspended until the
+ * CP has processed the information. After the start of the PSI image, CP shall
+ * set the execution state to PSI and generate the irq, then the flash app
+ * is resumed or timeout.
+ */
+static int imem_psi_transfer(struct iosm_imem *ipc_imem,
+                            struct ipc_mem_channel *channel,
+                            const unsigned char __user *buf, int count)
+{
+       enum ipc_mem_exec_stage exec_stage = IPC_MEM_EXEC_STAGE_INVALID;
+       int psi_start_timeout = PSI_START_DEFAULT_TIMEOUT;
+       dma_addr_t mapping = 0;
+       int status, result;
+       void *dest_buf;
+
+       imem_hrtimer_stop(&ipc_imem->startup_timer);
+
+       /* Allocate the buffer for the PSI image. */
+       dest_buf = pci_alloc_consistent(ipc_imem->pcie->pci, count, &mapping);
+       if (!dest_buf) {
+               dev_err(ipc_imem->dev, "ch[%d] cannot allocate %d bytes",
+                       channel->channel_id, count);
+               return -1;
+       }
+
+       /* Copy the PSI image from user to kernel space. */
+       if (copy_from_user(dest_buf, buf, count) != 0) {
+               dev_err(ipc_imem->dev, "ch[%d] copy from user failed",
+                       channel->channel_id);
+               goto error;
+       }
+
+       /* Save the PSI information for the CP ROM driver on the doorbell
+        * scratchpad.
+        */
+       ipc_mmio_set_psi_addr_and_size(ipc_imem->mmio, mapping, count);
+
+       /* Trigger the CP interrupt to process the PSI information. */
+       ipc_doorbell_fire(ipc_imem->pcie, 0, IPC_MEM_EXEC_STAGE_BOOT);
+       /* Suspend the flash app and wait for irq. */
+       status = WAIT_FOR_TIMEOUT(&channel->ul_sem, IPC_PSI_TRANSFER_TIMEOUT);
+
+       if (status <= 0) {
+               dev_err(ipc_imem->dev,
+                       "ch[%d] timeout, failed PSI transfer to CP",
+                       channel->channel_id);
+               ipc_uevent_send(ipc_imem->dev, UEVENT_MDM_TIMEOUT);
+               goto error;
+       }
+
+       /* CP should have copied the PSI image. */
+       pci_free_consistent(ipc_imem->pcie->pci, count, dest_buf, mapping);
+
+       /* If the PSI download fails, return the CP boot ROM exit code to the
+        * flash app received about the doorbell scratchpad.
+        */
+       if (ipc_imem->rom_exit_code != IMEM_ROM_EXIT_OPEN_EXT &&
+           ipc_imem->rom_exit_code != IMEM_ROM_EXIT_CERT_EXT)
+               return (-1) * ((int)ipc_imem->rom_exit_code);
+
+       dev_dbg(ipc_imem->dev, "PSI image successfully downloaded");
+
+       /* Wait psi_start_timeout milliseconds until the CP PSI image is
+        * running and updates the execution_stage field with
+        * IPC_MEM_EXEC_STAGE_PSI. Verify the execution stage.
+        */
+       while (psi_start_timeout > 0) {
+               exec_stage = ipc_mmio_get_exec_stage(ipc_imem->mmio);
+
+               if (exec_stage == IPC_MEM_EXEC_STAGE_PSI)
+                       break;
+
+               msleep(20);
+               psi_start_timeout -= 20;
+       }
+
+       if (exec_stage != IPC_MEM_EXEC_STAGE_PSI)
+               return -1; /* Unknown status of the CP PSI process. */
+
+       /* Enter the PSI phase. */
+       dev_dbg(ipc_imem->dev, "execution_stage[%X] eq. PSI", exec_stage);
+
+       ipc_imem->phase = IPC_P_PSI;
+
+       /* Request the RUNNING state from CP and wait until it was reached
+        * or timeout.
+        */
+       imem_ipc_init_check(ipc_imem);
+
+       /* Suspend the flash app, wait for irq and evaluate the CP IPC state. */
+       status = WAIT_FOR_TIMEOUT(&channel->ul_sem, IPC_PSI_TRANSFER_TIMEOUT);
+       if (status <= 0) {
+               dev_err(ipc_imem->dev,
+                       "ch[%d] timeout, failed PSI RUNNING state on CP",
+                       channel->channel_id);
+               ipc_uevent_send(ipc_imem->dev, UEVENT_MDM_TIMEOUT);
+               return -1;
+       }
+
+       if (ipc_mmio_get_ipc_state(ipc_imem->mmio) !=
+           IPC_MEM_DEVICE_IPC_RUNNING) {
+               dev_err(ipc_imem->dev,
+                       "ch[%d] %s: unexpected CP IPC state %d, not RUNNING",
+                       channel->channel_id,
+                       ipc_ap_phase_get_string(ipc_imem->phase),
+                       ipc_mmio_get_ipc_state(ipc_imem->mmio));
+
+               return -1;
+       }
+
+       /* Create the flash channel for the transfer of the images. */
+       result = imem_sys_sio_open(ipc_imem);
+       if (result < 0) {
+               dev_err(ipc_imem->dev, "can't open flash_channel");
+               return result;
+       }
+
+       /* Inform the flash app that the PSI was sent and start on CP.
+        * The flash app shall wait for the CP status in blocking read
+        * entry point.
+        */
+       return count;
+error:
+       pci_free_consistent(ipc_imem->pcie->pci, count, dest_buf, mapping);
+
+       return -1;
+}
+
+/* Get the write active channel */
+static struct ipc_mem_channel *
+imem_sio_write_channel(struct iosm_imem *ipc_imem, int ch,
+                      const unsigned char __user *buf, int size)
+{
+       struct ipc_mem_channel *channel;
+       enum ipc_phase phase;
+
+       if (ch < 0 || ch >= ipc_imem->nr_of_channels || size <= 0) {
+               dev_err(ipc_imem->dev, "invalid channel No. or buff size");
+               return NULL;
+       }
+
+       channel = &ipc_imem->channels[ch];
+       /* Update the current operation phase. */
+       phase = ipc_imem->phase;
+
+       /* Select the operation depending on the execution stage. */
+       switch (phase) {
+       case IPC_P_RUN:
+       case IPC_P_PSI:
+       case IPC_P_EBL:
+               break;
+
+       case IPC_P_ROM:
+               /* Prepare the PSI image for the CP ROM driver and
+                * suspend the flash app.
+                */
+               if (channel->state != IMEM_CHANNEL_RESERVED) {
+                       dev_err(ipc_imem->dev,
+                               "ch[%d]:invalid channel state %d,expected %d",
+                               ch, channel->state, IMEM_CHANNEL_RESERVED);
+                       return NULL;
+               }
+               return channel;
+
+       default:
+               /* Ignore uplink actions in all other phases. */
+               dev_err(ipc_imem->dev, "ch[%d]: confused phase %d", ch, phase);
+               return NULL;
+       }
+
+       /* Check the full availability of the channel. */
+       if (channel->state != IMEM_CHANNEL_ACTIVE) {
+               dev_err(ipc_imem->dev, "ch[%d]: confused channel state %d", ch,
+                       channel->state);
+               return NULL;
+       }
+
+       return channel;
+}
+
+/* Release a sio link to CP. */
+void imem_sys_sio_close(struct iosm_sio *ipc_sio)
+{
+       struct iosm_imem *ipc_imem = ipc_sio->imem_instance;
+       int channel_id = ipc_sio->channel_id;
+       struct ipc_mem_channel *channel;
+       enum ipc_phase curr_phase;
+       int boot_check_timeout = 0;
+       int status = 0;
+       u32 tail = 0;
+
+       if (channel_id < 0 || channel_id >= ipc_imem->nr_of_channels) {
+               dev_err(ipc_imem->dev, "invalid channel id %d", channel_id);
+               return;
+       }
+       if (channel_id != IPC_MEM_MBIM_CTRL_CH_ID)
+               boot_check_timeout = BOOT_CHECK_DEFAULT_TIMEOUT;
+
+       channel = &ipc_imem->channels[channel_id];
+
+       curr_phase = ipc_imem->phase;
+
+       /* If current phase is IPC_P_OFF or SIO ID is -ve then
+        * channel is already freed. Nothing to do.
+        */
+       if (curr_phase == IPC_P_OFF || channel->sio_id < 0) {
+               dev_err(ipc_imem->dev,
+                       "nothing to do. Current Phase: %s SIO ID: %d",
+                       ipc_ap_phase_get_string(curr_phase), channel->sio_id);
+               return;
+       }
+
+       if (channel->state == IMEM_CHANNEL_FREE) {
+               dev_err(ipc_imem->dev, "ch[%d]: invalid channel state %d",
+                       channel_id, channel->state);
+               return;
+       }
+       /* Free only the channel id in the CP power off mode. */
+       if (channel->state == IMEM_CHANNEL_RESERVED) {
+               imem_channel_free(channel);
+               return;
+       }
+
+       if (channel_id != IPC_MEM_MBIM_CTRL_CH_ID &&
+           ipc_imem->flash_channel_id >= 0) {
+               int i;
+               enum ipc_mem_exec_stage exec_stage;
+
+               /* Increase the total wait time to boot_check_timeout */
+               for (i = 0; i < boot_check_timeout; i++) {
+                       /* user space can terminate either the modem is finished
+                        * with Downloading or finished transferring Coredump.
+                        */
+                       exec_stage = ipc_mmio_get_exec_stage(ipc_imem->mmio);
+                       if (exec_stage == IPC_MEM_EXEC_STAGE_RUN ||
+                           exec_stage == IPC_MEM_EXEC_STAGE_PSI)
+                               break;
+
+                       msleep(20);
+               }
+
+               msleep(100);
+       }
+       /* If there are any pending TDs then wait for Timeout/Completion before
+        * closing pipe.
+        */
+       if (channel->ul_pipe.old_tail != channel->ul_pipe.old_head) {
+               ipc_imem->app_notify_ul_pend = 1;
+
+               /* Suspend the user app and wait a certain time for processing
+                * UL Data.
+                */
+               status = WAIT_FOR_TIMEOUT(&ipc_imem->ul_pend_sem,
+                                         IPC_PEND_DATA_TIMEOUT);
+
+               if (status == 0) {
+                       dev_dbg(ipc_imem->dev,
+                               "Pending data Timeout on UL-Pipe:%d Head:%d 
Tail:%d",
+                               channel->ul_pipe.pipe_nr,
+                               channel->ul_pipe.old_head,
+                               channel->ul_pipe.old_tail);
+               }
+
+               ipc_imem->app_notify_ul_pend = 0;
+       }
+
+       /* If there are any pending TDs then wait for Timeout/Completion before
+        * closing pipe.
+        */
+       ipc_protocol_get_head_tail_index(ipc_imem->ipc_protocol,
+                                        &channel->dl_pipe, NULL, &tail);
+
+       if (tail != channel->dl_pipe.old_tail) {
+               ipc_imem->app_notify_dl_pend = 1;
+
+               /* Suspend the user app and wait a certain time for processing
+                * DL Data.
+                */
+               status = WAIT_FOR_TIMEOUT(&ipc_imem->dl_pend_sem,
+                                         IPC_PEND_DATA_TIMEOUT);
+
+               if (status == 0) {
+                       dev_dbg(ipc_imem->dev,
+                               "Pending data Timeout on DL-Pipe:%d Head:%d 
Tail:%d",
+                               channel->dl_pipe.pipe_nr,
+                               channel->dl_pipe.old_head,
+                               channel->dl_pipe.old_tail);
+               }
+
+               ipc_imem->app_notify_dl_pend = 0;
+       }
+
+       /* Due to wait for completion in messages, there is a small window
+        * between closing the pipe and updating the channel is closed. In this
+        * small window there could be HP update from Host Driver. Hence update
+        * the channel state as CLOSING to aviod unnecessary interrupt
+        * towards CP.
+        */
+       channel->state = IMEM_CHANNEL_CLOSING;
+
+       /* Release the pipe resources */
+       if (channel_id != IPC_MEM_MBIM_CTRL_CH_ID &&
+           ipc_imem->flash_channel_id != -1) {
+               /* don't send close for software download pipes, as
+                * the device is already rebooting
+                */
+               imem_pipe_cleanup(ipc_imem, &channel->ul_pipe);
+               imem_pipe_cleanup(ipc_imem, &channel->dl_pipe);
+       } else {
+               imem_pipe_close(ipc_imem, &channel->ul_pipe);
+               imem_pipe_close(ipc_imem, &channel->dl_pipe);
+       }
+
+       imem_channel_free(channel);
+
+       if (channel_id != IPC_MEM_MBIM_CTRL_CH_ID)
+               /* Reset the global flash channel id. */
+               ipc_imem->flash_channel_id = -1;
+}
+
+/* Open a MBIM link to CP and return the channel id. */
+int imem_sys_mbim_open(void *instance)
+{
+       struct iosm_imem *ipc_imem = instance;
+       int ch_id;
+
+       /* The MBIM interface is only supported in the runtime phase. */
+       if (imem_ap_phase_update(ipc_imem) != IPC_P_RUN) {
+               dev_err(ipc_imem->dev, "MBIM open refused, phase %s",
+                       ipc_ap_phase_get_string(ipc_imem->phase));
+               return -1;
+       }
+
+       ch_id = imem_channel_alloc(ipc_imem, IPC_MEM_MBIM_CTRL_CH_ID,
+                                  IPC_CTYPE_MBIM);
+
+       if (ch_id < 0) {
+               dev_err(ipc_imem->dev, "reservation of an MBIM chnl id failed");
+               return ch_id;
+       }
+
+       if (!imem_channel_open(ipc_imem, ch_id, IPC_HP_SIO_OPEN)) {
+               dev_err(ipc_imem->dev, "MBIM channel id open failed");
+               return -1;
+       }
+
+       return ch_id;
+}
+
+/* Open a SIO link to CP and return the channel id. */
+int imem_sys_sio_open(void *instance)
+{
+       struct iosm_imem *ipc_imem = instance;
+       struct ipc_chnl_cfg chnl_cfg = { 0 };
+       enum ipc_phase phase;
+       int channel_id;
+
+       phase = imem_ap_phase_update(ipc_imem);
+
+       /* The control link to CP is only supported in the power off, psi or
+        * run phase.
+        */
+       switch (phase) {
+       case IPC_P_OFF:
+       case IPC_P_ROM:
+               /* Get a channel id as flash id and reserve it. */
+               channel_id = imem_channel_alloc(ipc_imem, IPC_MEM_FLASH_CH_ID,
+                                               IPC_CTYPE_FLASH);
+               if (channel_id < 0) {
+                       dev_err(ipc_imem->dev,
+                               "reservation of a flash channel id failed");
+                       return channel_id;
+               }
+
+               /* Enqueue chip info data to be read */
+               if (imem_trigger_chip_info(ipc_imem)) {
+                       imem_channel_close(ipc_imem, channel_id);
+                       return -1;
+               }
+
+               /* Save the flash channel id to execute the ROM interworking. */
+               ipc_imem->flash_channel_id = channel_id;
+
+               return channel_id;
+
+       case IPC_P_PSI:
+       case IPC_P_EBL:
+               /* The channel id used as flash id shall be already
+                * present as reserved.
+                */
+               if (ipc_imem->flash_channel_id < 0) {
+                       dev_err(ipc_imem->dev,
+                               "missing a valid flash channel id");
+                       return -1;
+               }
+               channel_id = ipc_imem->flash_channel_id;
+
+               ipc_imem->cp_version = ipc_mmio_get_cp_version(ipc_imem->mmio);
+               if (ipc_imem->cp_version == -1) {
+                       dev_err(ipc_imem->dev, "invalid CP version");
+                       return -1;
+               }
+
+               /* PSI may have changed the CP version field, which may
+                * result in a different channel configuration.
+                * Fetch and update the flash channel config
+                */
+               if (ipc_chnl_cfg_get(&chnl_cfg, ipc_imem->flash_channel_id,
+                                    MUX_UNKNOWN)) {
+                       dev_err(ipc_imem->dev,
+                               "failed to get flash pipe configuration");
+                       return -1;
+               }
+
+               ipc_imem_channel_update(ipc_imem, channel_id, chnl_cfg,
+                                       IRQ_MOD_OFF);
+
+               if (!imem_channel_open(ipc_imem, channel_id, IPC_HP_SIO_OPEN))
+                       return -1;
+
+               return channel_id;
+
+       default:
+               /* CP is in the wrong state (e.g. CRASH or CD_READY) */
+               dev_err(ipc_imem->dev, "SIO open refused, phase %d", phase);
+               return -1;
+       }
+}
+
+ssize_t imem_sys_sio_read(struct iosm_sio *ipc_sio, unsigned char __user *buf,
+                         size_t size, struct sk_buff *skb)
+{
+       unsigned char __user *dest_buf, *dest_end;
+       size_t dest_len, src_len, copied_b = 0;
+       unsigned char *src_buf;
+
+       /* Prepare the destination space. */
+       dest_buf = buf;
+       dest_end = dest_buf + size;
+
+       /* Copy the accumulated rx packets. */
+       while (skb) {
+               /* Prepare the source elements. */
+               src_buf = skb->data;
+               src_len = skb->len;
+
+               /* Calculate the current size of the destination buffer. */
+               dest_len = dest_end - dest_buf;
+
+               /* Compute the number of bytes to copy. */
+               copied_b = (dest_len < src_len) ? dest_len : src_len;
+
+               /* Copy the chars into the user space buffer. */
+               if (copy_to_user((void __user *)dest_buf, src_buf, copied_b) !=
+                   0) {
+                       dev_err(ipc_sio->dev,
+                               "chid[%d] userspace copy failed n=%zu\n",
+                               ipc_sio->channel_id, copied_b);
+                       ipc_pcie_kfree_skb(ipc_sio->pcie, skb);
+                       return -EFAULT;
+               }
+
+               /* Update the source elements. */
+               skb->data = src_buf + copied_b;
+               skb->len = skb->len - copied_b;
+
+               /* Update the desctination pointer. */
+               dest_buf += copied_b;
+
+               /* Test the fill level of the user buffer. */
+               if (dest_buf >= dest_end) {
+                       /* Free the consumed skbuf or save the pending skbuf
+                        * to consume it in the read call.
+                        */
+                       if (skb->len == 0)
+                               ipc_pcie_kfree_skb(ipc_sio->pcie, skb);
+                       else
+                               ipc_sio->rx_pending_buf = skb;
+
+                       /* Return the number of saved chars. */
+                       break;
+               }
+
+               /* Free the consumed skbuf. */
+               ipc_pcie_kfree_skb(ipc_sio->pcie, skb);
+
+               /* Get the next skbuf element. */
+               skb = skb_dequeue(&ipc_sio->rx_list);
+       }
+
+       /* Return the number of saved chars. */
+       copied_b = dest_buf - buf;
+       return copied_b;
+}
+
+int imem_sys_sio_write(struct iosm_sio *ipc_sio,
+                      const unsigned char __user *buf, int count,
+                      bool blocking_write)
+{
+       struct iosm_imem *ipc_imem = ipc_sio->imem_instance;
+       int channel_id = ipc_sio->channel_id;
+       struct ipc_mem_channel *channel;
+       struct sk_buff *skb;
+       int ret = -1;
+
+       channel = imem_sio_write_channel(ipc_imem, channel_id, buf, count);
+
+       if (!channel || ipc_imem->phase == IPC_P_OFF_REQ)
+               return ret;
+
+       /* In the ROM phase the PSI image is passed to CP about a specific
+        * shared memory area and doorbell scratchpad directly.
+        */
+       if (ipc_imem->phase == IPC_P_ROM) {
+               ret = imem_psi_transfer(ipc_imem, channel, buf, count);
+
+               /* If the PSI transfer is successful then send Feature
+                * Set message.
+                */
+               if (ret > 0)
+                       imem_msg_send_feature_set(ipc_imem,
+                                                 IPC_MEM_INBAND_CRASH_SIG,
+                                                 false);
+               return ret;
+       }
+
+       /* Allocate skb memory for the uplink buffer.*/
+       skb = imem_sio_copy_from_user_to_skb(ipc_imem, channel_id, buf, count,
+                                            blocking_write);
+       if (!skb)
+               return ret;
+
+       /* Add skb to the uplink skbuf accumulator. */
+       skb_queue_tail(&channel->ul_list, skb);
+
+       /* Inform the IPC tasklet to pass uplink IP packets to CP.
+        * Blocking write waits for UL completion notification,
+        * non-blocking write simply returns the count.
+        */
+       if (imem_call_sio_write(ipc_imem) && blocking_write) {
+               /* Suspend the app and wait for UL data completion. */
+               int status =
+                       wait_for_completion_interruptible(&channel->ul_sem);
+
+               if (status < 0) {
+                       dev_err(ipc_imem->dev,
+                               "ch[%d] no CP confirmation, status=%d",
+                               channel->channel_id, status);
+                       return status;
+               }
+       }
+
+       return count;
+}
+
+int imem_sys_sio_receive(struct iosm_sio *ipc_sio, struct sk_buff *skb)
+{
+       dev_dbg(ipc_sio->dev, "sio receive[c-id:%d]: %d", ipc_sio->channel_id,
+               skb->len);
+
+       skb_queue_tail((&ipc_sio->rx_list), skb);
+
+       complete(&ipc_sio->read_sem);
+       wake_up_interruptible(&ipc_sio->poll_inq);
+
+       return 0;
+}
diff --git a/drivers/net/wwan/iosm/iosm_ipc_imem_ops.h 
b/drivers/net/wwan/iosm/iosm_ipc_imem_ops.h
new file mode 100644
index 000000000000..c60295056499
--- /dev/null
+++ b/drivers/net/wwan/iosm/iosm_ipc_imem_ops.h
@@ -0,0 +1,102 @@
+/* SPDX-License-Identifier: GPL-2.0-only
+ *
+ * Copyright (C) 2020 Intel Corporation.
+ */
+
+#ifndef IOSM_IPC_IMEM_OPS_H
+#define IOSM_IPC_IMEM_OPS_H
+
+#include "iosm_ipc_mux_codec.h"
+
+/* Maximum length of the SIO device names */
+#define IPC_SIO_DEVNAME_LEN 32
+#define IPC_READ_TIMEOUT 500
+
+/* The delay in ms for defering the unregister */
+#define SIO_UNREGISTER_DEFER_DELAY_MS 1
+
+/* Default delay till CP PSI image is running and modem updates the
+ * execution stage.
+ * unit : milliseconds
+ */
+#define PSI_START_DEFAULT_TIMEOUT 3000
+
+/* Default time out when closing SIO, till the modem is in
+ * running state.
+ * unit : milliseconds
+ */
+#define BOOT_CHECK_DEFAULT_TIMEOUT 400
+
+/**
+ * imem_sys_sio_open - Open a sio link to CP.
+ * @instance:  Imem instance.
+ *
+ * Return: chnl id on success, -EINVAL or -1 for failure
+ */
+int imem_sys_sio_open(void *instance);
+
+/**
+ * imem_sys_mbim_open - Open a mbim link to CP.
+ * @instance:  Imem instance.
+ *
+ * Return: chnl id on success, -EINVAL or -1 for failure
+ */
+int imem_sys_mbim_open(void *instance);
+
+/**
+ * imem_sys_sio_close - Release a sio link to CP.
+ * @ipc_sio:           iosm sio instance.
+ */
+void imem_sys_sio_close(struct iosm_sio *ipc_sio);
+
+/**
+ * imem_sys_sio_read - Copy the rx data to the user space buffer and free the
+ *                    skbuf.
+ * @ipc_sio:   Pointer to iosm_sio structi.
+ * @buf:       Pointer to destination buffer.
+ * @size:      Size of destination buffer.
+ * @skb:       Pointer to source buffer.
+ *
+ * Return: Number of bytes read, -EFAULT and -EINVAL for failure
+ */
+ssize_t imem_sys_sio_read(struct iosm_sio *ipc_sio, unsigned char __user *buf,
+                         size_t size, struct sk_buff *skb);
+
+/**
+ * imem_sys_sio_write - Route the uplink buffer to CP.
+ * @ipc_sio:           iosm_sio instance.
+ * @buf:               Pointer to source buffer.
+ * @count:             Number of data bytes to write.
+ * @blocking_write:    if true wait for UL data completion.
+ *
+ * Return: Number of bytes read, -EINVAL and -1  for failure
+ */
+int imem_sys_sio_write(struct iosm_sio *ipc_sio,
+                      const unsigned char __user *buf, int count,
+                      bool blocking_write);
+
+/**
+ * imem_sys_sio_receive - Receive downlink characters from CP, the downlink
+ *             skbuf is added at the end of the downlink or rx list.
+ * @ipc_sio:    Pointer to ipc char data-struct
+ * @skb:        Pointer to sk buffer
+ *
+ * Returns: 0 on success, -EINVAL on failure
+ */
+int imem_sys_sio_receive(struct iosm_sio *ipc_sio, struct sk_buff *skb);
+
+int imem_sys_wwan_open(void *instance, int vlan_id);
+
+void imem_sys_wwan_close(void *instance, int vlan_id, int channel_id);
+
+int imem_sys_wwan_transmit(void *instance, int vlan_id, int channel_id,
+                          struct sk_buff *skb);
+/**
+ * wwan_channel_init - Initializes WWAN channels and the channel for MUX.
+ * @ipc_imem:          Pointer to iosm_imem struct.
+ * @total_sessions:    Total sessions.
+ * @mux_type:          Type of mux protocol.
+ */
+void wwan_channel_init(struct iosm_imem *ipc_imem, int total_sessions,
+                      enum ipc_mux_protocol mux_type);
+#endif
-- 
2.12.3

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