Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 658 insertions, 0 deletions

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 000000000..109cf8930
--- /dev/null
+++ b/drivers/net/wwan/iosm/iosm_ipc_imem_ops.c
@@ -0,0 +1,658 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2020-21 Intel Corporation.
+ */
+
+#include <linux/delay.h>
+
+#include "iosm_ipc_chnl_cfg.h"
+#include "iosm_ipc_devlink.h"
+#include "iosm_ipc_imem.h"
+#include "iosm_ipc_imem_ops.h"
+#include "iosm_ipc_port.h"
+#include "iosm_ipc_task_queue.h"
+
+/* Open a packet data online channel between the network layer and CP. */
+int ipc_imem_sys_wwan_open(struct iosm_imem *ipc_imem, int if_id)
+{
+	dev_dbg(ipc_imem->dev, "%s if id: %d",
+		ipc_imem_phase_get_string(ipc_imem->phase), if_id);
+
+	/* The network interface is only supported in the runtime phase. */
+	if (ipc_imem_phase_update(ipc_imem) != IPC_P_RUN) {
+		dev_err(ipc_imem->dev, "net:%d : refused phase %s", if_id,
+			ipc_imem_phase_get_string(ipc_imem->phase));
+		return -EIO;
+	}
+
+	return ipc_mux_open_session(ipc_imem->mux, if_id);
+}
+
+/* Release a net link to CP. */
+void ipc_imem_sys_wwan_close(struct iosm_imem *ipc_imem, int if_id,
+			     int channel_id)
+{
+	if (ipc_imem->mux && if_id >= IP_MUX_SESSION_START &&
+	    if_id <= IP_MUX_SESSION_END)
+		ipc_mux_close_session(ipc_imem->mux, if_id);
+}
+
+/* Tasklet call to do uplink transfer. */
+static int ipc_imem_tq_cdev_write(struct iosm_imem *ipc_imem, int arg,
+				  void *msg, size_t size)
+{
+	ipc_imem_ul_send(ipc_imem);
+
+	return 0;
+}
+
+/* Through tasklet to do sio write. */
+static int ipc_imem_call_cdev_write(struct iosm_imem *ipc_imem)
+{
+	return ipc_task_queue_send_task(ipc_imem, ipc_imem_tq_cdev_write, 0,
+					NULL, 0, false);
+}
+
+/* Function for transfer UL data */
+int ipc_imem_sys_wwan_transmit(struct iosm_imem *ipc_imem,
+			       int if_id, int channel_id, struct sk_buff *skb)
+{
+	int ret = -EINVAL;
+
+	if (!ipc_imem || channel_id < 0)
+		goto out;
+
+	/* Is CP Running? */
+	if (ipc_imem->phase != IPC_P_RUN) {
+		dev_dbg(ipc_imem->dev, "phase %s transmit",
+			ipc_imem_phase_get_string(ipc_imem->phase));
+		ret = -EIO;
+		goto out;
+	}
+
+	/* Route the UL packet through IP MUX Layer */
+	ret = ipc_mux_ul_trigger_encode(ipc_imem->mux, if_id, skb);
+out:
+	return ret;
+}
+
+/* Initialize wwan channel */
+int ipc_imem_wwan_channel_init(struct iosm_imem *ipc_imem,
+			       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 -EIO;
+	}
+
+	ipc_chnl_cfg_get(&chnl_cfg, ipc_imem->nr_of_channels);
+
+	if (ipc_imem->mmio->mux_protocol == MUX_AGGREGATION &&
+	    ipc_imem->nr_of_channels == IPC_MEM_IP_CHL_ID_0) {
+		chnl_cfg.ul_nr_of_entries = IPC_MEM_MAX_TDS_MUX_AGGR_UL;
+		chnl_cfg.dl_nr_of_entries = IPC_MEM_MAX_TDS_MUX_AGGR_DL;
+		chnl_cfg.dl_buf_size = IPC_MEM_MAX_ADB_BUF_SIZE;
+	}
+
+	ipc_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);
+	if (!ipc_imem->wwan) {
+		dev_err(ipc_imem->dev,
+			"failed to register the ipc_wwan interfaces");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+/* Map SKB to DMA for transfer */
+static int ipc_imem_map_skb_to_dma(struct iosm_imem *ipc_imem,
+				   struct sk_buff *skb)
+{
+	struct iosm_pcie *ipc_pcie = ipc_imem->pcie;
+	char *buf = skb->data;
+	int len = skb->len;
+	dma_addr_t mapping;
+	int ret;
+
+	ret = ipc_pcie_addr_map(ipc_pcie, buf, len, &mapping, DMA_TO_DEVICE);
+
+	if (ret)
+		goto err;
+
+	BUILD_BUG_ON(sizeof(*IPC_CB(skb)) > sizeof(skb->cb));
+
+	IPC_CB(skb)->mapping = mapping;
+	IPC_CB(skb)->direction = DMA_TO_DEVICE;
+	IPC_CB(skb)->len = len;
+	IPC_CB(skb)->op_type = (u8)UL_DEFAULT;
+
+err:
+	return ret;
+}
+
+/* return true if channel is ready for use */
+static bool ipc_imem_is_channel_active(struct iosm_imem *ipc_imem,
+				       struct ipc_mem_channel *channel)
+{
+	enum ipc_phase phase;
+
+	/* 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);
+			goto channel_unavailable;
+		}
+		goto channel_available;
+
+	default:
+		/* Ignore uplink actions in all other phases. */
+		dev_err(ipc_imem->dev, "ch[%d]: confused phase %d",
+			channel->channel_id, phase);
+		goto channel_unavailable;
+	}
+	/* 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);
+		goto channel_unavailable;
+	}
+
+channel_available:
+	return true;
+
+channel_unavailable:
+	return false;
+}
+
+/**
+ * ipc_imem_sys_port_close - Release a sio link to CP.
+ * @ipc_imem:          Imem instance.
+ * @channel:           Channel instance.
+ */
+void ipc_imem_sys_port_close(struct iosm_imem *ipc_imem,
+			     struct ipc_mem_channel *channel)
+{
+	enum ipc_phase curr_phase;
+	int status = 0;
+	u32 tail = 0;
+
+	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) {
+		dev_err(ipc_imem->dev,
+			"nothing to do. Current Phase: %s",
+			ipc_imem_phase_get_string(curr_phase));
+		return;
+	}
+
+	if (channel->state == IMEM_CHANNEL_FREE) {
+		dev_err(ipc_imem->dev, "ch[%d]: invalid channel state %d",
+			channel->channel_id, channel->state);
+		return;
+	}
+
+	/* 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,
+				"Pend data Timeout 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,
+				"Pend data Timeout 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;
+
+	ipc_imem_pipe_close(ipc_imem, &channel->ul_pipe);
+	ipc_imem_pipe_close(ipc_imem, &channel->dl_pipe);
+
+	ipc_imem_channel_free(channel);
+}
+
+/* Open a PORT link to CP and return the channel */
+struct ipc_mem_channel *ipc_imem_sys_port_open(struct iosm_imem *ipc_imem,
+					       int chl_id, int hp_id)
+{
+	struct ipc_mem_channel *channel;
+	int ch_id;
+
+	/* The PORT interface is only supported in the runtime phase. */
+	if (ipc_imem_phase_update(ipc_imem) != IPC_P_RUN) {
+		dev_err(ipc_imem->dev, "PORT open refused, phase %s",
+			ipc_imem_phase_get_string(ipc_imem->phase));
+		return NULL;
+	}
+
+	ch_id = ipc_imem_channel_alloc(ipc_imem, chl_id, IPC_CTYPE_CTRL);
+
+	if (ch_id < 0) {
+		dev_err(ipc_imem->dev, "reservation of an PORT chnl id failed");
+		return NULL;
+	}
+
+	channel = ipc_imem_channel_open(ipc_imem, ch_id, hp_id);
+
+	if (!channel) {
+		dev_err(ipc_imem->dev, "PORT channel id open failed");
+		return NULL;
+	}
+
+	return channel;
+}
+
+/* transfer skb to modem */
+int ipc_imem_sys_cdev_write(struct iosm_cdev *ipc_cdev, struct sk_buff *skb)
+{
+	struct ipc_mem_channel *channel = ipc_cdev->channel;
+	struct iosm_imem *ipc_imem = ipc_cdev->ipc_imem;
+	int ret = -EIO;
+
+	if (!ipc_imem_is_channel_active(ipc_imem, channel) ||
+	    ipc_imem->phase == IPC_P_OFF_REQ)
+		goto out;
+
+	ret = ipc_imem_map_skb_to_dma(ipc_imem, skb);
+
+	if (ret)
+		goto out;
+
+	/* Add skb to the uplink skbuf accumulator. */
+	skb_queue_tail(&channel->ul_list, skb);
+
+	ret = ipc_imem_call_cdev_write(ipc_imem);
+
+	if (ret) {
+		skb_dequeue_tail(&channel->ul_list);
+		dev_err(ipc_cdev->dev, "channel id[%d] write failed\n",
+			ipc_cdev->channel->channel_id);
+	}
+out:
+	return ret;
+}
+
+/* Open a SIO link to CP and return the channel instance */
+struct ipc_mem_channel *ipc_imem_sys_devlink_open(struct iosm_imem *ipc_imem)
+{
+	struct ipc_mem_channel *channel;
+	enum ipc_phase phase;
+	int channel_id;
+
+	phase = ipc_imem_phase_update(ipc_imem);
+	switch (phase) {
+	case IPC_P_OFF:
+	case IPC_P_ROM:
+		/* Get a channel id as flash id and reserve it. */
+		channel_id = ipc_imem_channel_alloc(ipc_imem,
+						    IPC_MEM_CTRL_CHL_ID_7,
+						    IPC_CTYPE_CTRL);
+
+		if (channel_id < 0) {
+			dev_err(ipc_imem->dev,
+				"reservation of a flash channel id failed");
+			goto error;
+		}
+
+		ipc_imem->ipc_devlink->devlink_sio.channel_id = channel_id;
+		channel = &ipc_imem->channels[channel_id];
+
+		/* Enqueue chip info data to be read */
+		if (ipc_imem_devlink_trigger_chip_info(ipc_imem)) {
+			dev_err(ipc_imem->dev, "Enqueue of chip info failed");
+			channel->state = IMEM_CHANNEL_FREE;
+			goto error;
+		}
+
+		return channel;
+
+	case IPC_P_PSI:
+	case IPC_P_EBL:
+		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");
+			goto error;
+		}
+
+		channel_id = ipc_imem->ipc_devlink->devlink_sio.channel_id;
+		return ipc_imem_channel_open(ipc_imem, channel_id,
+					     IPC_HP_CDEV_OPEN);
+
+	default:
+		/* CP is in the wrong state (e.g. CRASH or CD_READY) */
+		dev_err(ipc_imem->dev, "SIO open refused, phase %d", phase);
+	}
+error:
+	return NULL;
+}
+
+/* Release a SIO channel link to CP. */
+void ipc_imem_sys_devlink_close(struct iosm_devlink *ipc_devlink)
+{
+	struct iosm_imem *ipc_imem = ipc_devlink->pcie->imem;
+	int boot_check_timeout = BOOT_CHECK_DEFAULT_TIMEOUT;
+	enum ipc_mem_exec_stage exec_stage;
+	struct ipc_mem_channel *channel;
+	int status = 0;
+	u32 tail = 0;
+
+	channel = ipc_imem->ipc_devlink->devlink_sio.channel;
+	/* Increase the total wait time to boot_check_timeout */
+	do {
+		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);
+		boot_check_timeout -= 20;
+	} while (boot_check_timeout > 0);
+
+	/* 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) {
+		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,
+				"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_protocol_get_head_tail_index(ipc_imem->ipc_protocol,
+					 &channel->dl_pipe, NULL, &tail);
+
+	if (tail != channel->dl_pipe.old_tail) {
+		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,
+				"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);
+		}
+	}
+
+	/* 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 */
+	ipc_imem_pipe_cleanup(ipc_imem, &channel->ul_pipe);
+	ipc_imem_pipe_cleanup(ipc_imem, &channel->dl_pipe);
+	ipc_imem->nr_of_channels--;
+}
+
+void ipc_imem_sys_devlink_notify_rx(struct iosm_devlink *ipc_devlink,
+				    struct sk_buff *skb)
+{
+	skb_queue_tail(&ipc_devlink->devlink_sio.rx_list, skb);
+	complete(&ipc_devlink->devlink_sio.read_sem);
+}
+
+/* PSI transfer */
+static int ipc_imem_sys_psi_transfer(struct iosm_imem *ipc_imem,
+				     struct ipc_mem_channel *channel,
+				     unsigned char *buf, int count)
+{
+	int psi_start_timeout = PSI_START_DEFAULT_TIMEOUT;
+	enum ipc_mem_exec_stage exec_stage;
+
+	dma_addr_t mapping = 0;
+	int ret;
+
+	ret = ipc_pcie_addr_map(ipc_imem->pcie, buf, count, &mapping,
+				DMA_TO_DEVICE);
+	if (ret)
+		goto pcie_addr_map_fail;
+
+	/* 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);
+	ipc_doorbell_fire(ipc_imem->pcie, 0, IPC_MEM_EXEC_STAGE_BOOT);
+
+	ret = wait_for_completion_interruptible_timeout
+		(&channel->ul_sem,
+		 msecs_to_jiffies(IPC_PSI_TRANSFER_TIMEOUT));
+
+	if (ret <= 0) {
+		dev_err(ipc_imem->dev, "Failed PSI transfer to CP, Error-%d",
+			ret);
+		goto psi_transfer_fail;
+	}
+	/* If the PSI download fails, return the CP boot ROM exit code */
+	if (ipc_imem->rom_exit_code != IMEM_ROM_EXIT_OPEN_EXT &&
+	    ipc_imem->rom_exit_code != IMEM_ROM_EXIT_CERT_EXT) {
+		ret = (-1) * ((int)ipc_imem->rom_exit_code);
+		goto psi_transfer_fail;
+	}
+
+	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)
+		goto psi_transfer_fail; /* Unknown status of CP PSI process. */
+
+	ipc_imem->phase = IPC_P_PSI;
+
+	/* Enter the PSI phase. */
+	dev_dbg(ipc_imem->dev, "execution_stage[%X] eq. PSI", exec_stage);
+
+	/* Request the RUNNING state from CP and wait until it was reached
+	 * or timeout.
+	 */
+	ipc_imem_ipc_init_check(ipc_imem);
+
+	ret = wait_for_completion_interruptible_timeout
+		(&channel->ul_sem, msecs_to_jiffies(IPC_PSI_TRANSFER_TIMEOUT));
+	if (ret <= 0) {
+		dev_err(ipc_imem->dev,
+			"Failed PSI RUNNING state on CP, Error-%d", ret);
+		goto psi_transfer_fail;
+	}
+
+	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_imem_phase_get_string(ipc_imem->phase),
+			ipc_mmio_get_ipc_state(ipc_imem->mmio));
+
+		goto psi_transfer_fail;
+	}
+
+	/* Create the flash channel for the transfer of the images. */
+	if (!ipc_imem_sys_devlink_open(ipc_imem)) {
+		dev_err(ipc_imem->dev, "can't open flash_channel");
+		goto psi_transfer_fail;
+	}
+
+	ret = 0;
+psi_transfer_fail:
+	ipc_pcie_addr_unmap(ipc_imem->pcie, count, mapping, DMA_TO_DEVICE);
+pcie_addr_map_fail:
+	return ret;
+}
+
+int ipc_imem_sys_devlink_write(struct iosm_devlink *ipc_devlink,
+			       unsigned char *buf, int count)
+{
+	struct iosm_imem *ipc_imem = ipc_devlink->pcie->imem;
+	struct ipc_mem_channel *channel;
+	struct sk_buff *skb;
+	dma_addr_t mapping;
+	int ret;
+
+	channel = ipc_imem->ipc_devlink->devlink_sio.channel;
+
+	/* 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 = ipc_imem_sys_psi_transfer(ipc_imem, channel, buf, count);
+		/* If the PSI transfer fails then send crash
+		 * Signature.
+		 */
+		if (ret > 0)
+			ipc_imem_msg_send_feature_set(ipc_imem,
+						      IPC_MEM_INBAND_CRASH_SIG,
+						      false);
+		goto out;
+	}
+
+	/* Allocate skb memory for the uplink buffer. */
+	skb = ipc_pcie_alloc_skb(ipc_devlink->pcie, count, GFP_KERNEL, &mapping,
+				 DMA_TO_DEVICE, 0);
+	if (!skb) {
+		ret = -ENOMEM;
+		goto out;
+	}
+
+	skb_put_data(skb, buf, count);
+
+	IPC_CB(skb)->op_type = UL_USR_OP_BLOCKED;
+
+	/* 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. */
+	if (!ipc_imem_call_cdev_write(ipc_imem)) {
+		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);
+			ipc_pcie_kfree_skb(ipc_devlink->pcie, skb);
+			goto out;
+		}
+	}
+	ret = 0;
+out:
+	return ret;
+}
+
+int ipc_imem_sys_devlink_read(struct iosm_devlink *devlink, u8 *data,
+			      u32 bytes_to_read, u32 *bytes_read)
+{
+	struct sk_buff *skb = NULL;
+	int rc = 0;
+
+	/* check skb is available in rx_list or wait for skb */
+	devlink->devlink_sio.devlink_read_pend = 1;
+	while (!skb && !(skb = skb_dequeue(&devlink->devlink_sio.rx_list))) {
+		if (!wait_for_completion_interruptible_timeout
+				(&devlink->devlink_sio.read_sem,
+				 msecs_to_jiffies(IPC_READ_TIMEOUT))) {
+			dev_err(devlink->dev, "Read timedout");
+			rc =  -ETIMEDOUT;
+			goto devlink_read_fail;
+		}
+	}
+	devlink->devlink_sio.devlink_read_pend = 0;
+	if (bytes_to_read < skb->len) {
+		dev_err(devlink->dev, "Invalid size,expected len %d", skb->len);
+		rc = -EINVAL;
+		goto devlink_read_fail;
+	}
+	*bytes_read = skb->len;
+	memcpy(data, skb->data, skb->len);
+
+devlink_read_fail:
+	dev_kfree_skb(skb);
+	return rc;
+}