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 <[email protected]>
---
drivers/net/wwan/iosm/iosm_ipc_imem_ops.c | 768 ++++++++++++++++++++++++++++++
drivers/net/wwan/iosm/iosm_ipc_imem_ops.h | 129 +++++
2 files changed, 897 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..b6da96ca1332
--- /dev/null
+++ b/drivers/net/wwan/iosm/iosm_ipc_imem_ops.c
@@ -0,0 +1,768 @@
+// 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(struct iosm_imem *ipc_imem, int vlan_id)
+{
+ 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(struct iosm_imem *ipc_imem, int vlan_id,
+ int channel_id)
+{
+ 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(struct iosm_imem *ipc_imem, int arg, void *msg,
+ size_t size)
+{
+ 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 skb to the ul list */
+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 */
+int imem_sys_wwan_transmit(struct iosm_imem *ipc_imem, int vlan_id,
+ int channel_id, struct sk_buff *skb)
+{
+ 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)) {
+ 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;
+}
+
+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;
+ 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_completion_interruptible_timeout
+ (&channel->ul_sem,
+ msecs_to_jiffies(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.
+ */
+ do {
+ 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;
+ } while (psi_start_timeout > 0);
+
+ 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_completion_interruptible_timeout
+ (&channel->ul_sem, msecs_to_jiffies(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. */
+ if (!imem_sys_sio_open(ipc_imem)) {
+ dev_err(ipc_imem->dev, "can't open flash_channel");
+ return -1;
+ }
+
+ /* 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,
+ struct ipc_mem_channel *channel,
+ const unsigned char __user *buf, int size)
+{
+ enum ipc_phase phase;
+
+ if (size <= 0) {
+ dev_err(ipc_imem->dev, "invalid buff size");
+ return NULL;
+ }
+
+ /* 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",
+ channel->channel_id, 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",
+ channel->channel_id, 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",
+ channel->channel_id, 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->ipc_imem;
+ struct ipc_mem_channel *channel = ipc_sio->channel;
+ enum ipc_phase curr_phase;
+ int boot_check_timeout = 0;
+ int status = 0;
+ u32 tail = 0;
+
+ if (channel->channel_id != IPC_MEM_MBIM_CTRL_CH_ID)
+ boot_check_timeout = BOOT_CHECK_DEFAULT_TIMEOUT;
+
+ 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->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->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_completion_interruptible_timeout
+ (&ipc_imem->ul_pend_sem,
+ msecs_to_jiffies(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_completion_interruptible_timeout
+ (&ipc_imem->dl_pend_sem,
+ msecs_to_jiffies(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->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->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 */
+struct ipc_mem_channel *imem_sys_mbim_open(struct iosm_imem *ipc_imem)
+{
+ int ch_id;
+ struct ipc_mem_channel *channel;
+
+ /* 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 NULL;
+ }
+
+ 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 NULL;
+ }
+
+ channel = imem_channel_open(ipc_imem, ch_id, IPC_HP_SIO_OPEN);
+
+ if (!channel) {
+ dev_err(ipc_imem->dev, "MBIM channel id open failed");
+ return NULL;
+ }
+
+ return channel;
+}
+
+/* Open a SIO link to CP and return the channel id. */
+struct ipc_mem_channel *imem_sys_sio_open(struct iosm_imem *ipc_imem)
+{
+ struct ipc_chnl_cfg chnl_cfg = { 0 };
+ enum ipc_phase phase;
+ int channel_id;
+ struct ipc_mem_channel *channel;
+
+ 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 NULL;
+ }
+
+ /* Enqueue chip info data to be read */
+ if (imem_trigger_chip_info(ipc_imem)) {
+ imem_channel_close(ipc_imem, channel_id);
+ return NULL;
+ }
+
+ /* Save the flash channel id to execute the ROM interworking. */
+ ipc_imem->flash_channel_id = channel_id;
+
+ channel = &ipc_imem->channels[channel_id];
+ return channel;
+
+ 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 NULL;
+ }
+ 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 NULL;
+ }
+
+ /* 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)) {
+ dev_err(ipc_imem->dev,
+ "failed to get flash pipe configuration");
+ return NULL;
+ }
+
+ ipc_imem_channel_update(ipc_imem, channel_id, chnl_cfg,
+ IRQ_MOD_OFF);
+
+ channel = imem_channel_open(ipc_imem, channel_id,
+ IPC_HP_SIO_OPEN);
+ if (!channel)
+ return NULL;
+
+ return channel;
+
+ 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 NULL;
+ }
+}
+
+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->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->ipc_imem;
+ struct ipc_mem_channel *channel = ipc_sio->channel;
+ struct sk_buff *skb;
+ int ret = -1;
+
+ set_bit(WRITE_IN_USE, &ipc_sio->flag);
+ /* Applying memory barrier so that ipc_sio->flag is updated
+ * before being read
+ */
+ smp_mb__after_atomic();
+
+ channel = imem_sio_write_channel(ipc_imem, channel, buf, count);
+
+ if (!channel || ipc_imem->phase == IPC_P_OFF_REQ)
+ goto err;
+
+ /* 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 fails then send crash
+ * Signature.
+ */
+ if (ret > 0)
+ imem_msg_send_feature_set(ipc_imem,
+ IPC_MEM_INBAND_CRASH_SIG,
+ false);
+ goto err;
+ }
+
+ /* Allocate skb memory for the uplink buffer.*/
+ skb = imem_sio_copy_from_user_to_skb(ipc_imem, channel->channel_id, buf,
+ count, blocking_write);
+ if (!skb)
+ goto err;
+
+ /* 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. */
+ ret = wait_for_completion_interruptible(&channel->ul_sem);
+
+ if (ret < 0) {
+ dev_err(ipc_imem->dev,
+ "ch[%d] no CP confirmation, status=%d",
+ channel->channel_id, ret);
+ goto err;
+ }
+ }
+ ret = count;
+err:
+ clear_bit(WRITE_IN_USE, &ipc_sio->flag);
+ /* Applying memory barrier so that ipc_sio->flag is updated
+ * before being read
+ */
+ smp_mb__after_atomic();
+ return ret;
+}
+
+int imem_sys_sio_receive(struct iosm_sio *ipc_sio, struct sk_buff *skb)
+{
+ skb_queue_tail((&ipc_sio->rx_list), skb);
+
+ if (test_bit(IS_BLOCKING, &ipc_sio->flag))
+ complete(&ipc_sio->read_sem);
+ else if (!test_bit(IS_BLOCKING, &ipc_sio->flag))
+ 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..75af9d838742
--- /dev/null
+++ b/drivers/net/wwan/iosm/iosm_ipc_imem_ops.h
@@ -0,0 +1,129 @@
+/* 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
+
+/* Maximum wait time for blocking read */
+#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.
+ * @ipc_imem: Imem instance.
+ *
+ * Return: channel instance on success, NULL for failure
+ */
+struct ipc_mem_channel *imem_sys_sio_open(struct iosm_imem *ipc_imem);
+
+/**
+ * imem_sys_mbim_open - Open a mbim link to CP.
+ * @ipc_imem: Imem instance.
+ *
+ * Return: channel instance on success, NULL for failure
+ */
+struct ipc_mem_channel *imem_sys_mbim_open(struct iosm_imem *ipc_imem);
+
+/**
+ * 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);
+
+/**
+ * imem_sys_wwan_open - Open packet data online channel between network layer
+ * and CP.
+ * @ipc_imem: Imem instance.
+ * @vlan_id: VLAN tag of the VLAN device.
+ *
+ * Return: Channel ID on success, -1 on failure
+ */
+int imem_sys_wwan_open(struct iosm_imem *ipc_imem, int vlan_id);
+
+/**
+ * imem_sys_wwan_close - Close packet data online channel between network layer
+ * and CP.
+ * @ipc_imem: Imem instance.
+ * @vlan_id: VLAN tag of the VLAN device.
+ * @channel_id: Channel ID to be closed.
+ */
+void imem_sys_wwan_close(struct iosm_imem *ipc_imem, int vlan_id,
+ int channel_id);
+
+/**
+ * imem_sys_wwan_transmit - Function for transfer UL data
+ * @ipc_imem: Imem instance.
+ * @vlan_id: VLAN tag of the VLAN device.
+ * @channel_id: Channel ID used
+ * @skb: Pointer to sk buffer
+ *
+ * Return: 0 on success, negative value on failure
+ */
+int imem_sys_wwan_transmit(struct iosm_imem *ipc_imem, 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