Adding upstream version 4.19.249.upstream/4.19.249upstream

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

1 files changed, 1024 insertions, 0 deletions

diff --git a/drivers/hid/intel-ish-hid/ishtp/hbm.c b/drivers/hid/intel-ish-hid/ishtp/hbm.c
new file mode 100644
index 000000000..8b5dd580c
--- /dev/null
+++ b/drivers/hid/intel-ish-hid/ishtp/hbm.c
@@ -0,0 +1,1024 @@
+/*
+ * ISHTP bus layer messages handling
+ *
+ * Copyright (c) 2003-2016, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ */
+
+#include <linux/export.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+#include <linux/spinlock.h>
+#include "ishtp-dev.h"
+#include "hbm.h"
+#include "client.h"
+
+/**
+ * ishtp_hbm_fw_cl_allocate() - Allocate FW clients
+ * @dev: ISHTP device instance
+ *
+ * Allocates storage for fw clients
+ */
+static void ishtp_hbm_fw_cl_allocate(struct ishtp_device *dev)
+{
+	struct ishtp_fw_client *clients;
+	int b;
+
+	/* count how many ISH clients we have */
+	for_each_set_bit(b, dev->fw_clients_map, ISHTP_CLIENTS_MAX)
+		dev->fw_clients_num++;
+
+	if (dev->fw_clients_num <= 0)
+		return;
+
+	/* allocate storage for fw clients representation */
+	clients = kcalloc(dev->fw_clients_num, sizeof(struct ishtp_fw_client),
+			  GFP_KERNEL);
+	if (!clients) {
+		dev->dev_state = ISHTP_DEV_RESETTING;
+		ish_hw_reset(dev);
+		return;
+	}
+	dev->fw_clients = clients;
+}
+
+/**
+ * ishtp_hbm_cl_hdr() - construct client hbm header
+ * @cl: client
+ * @hbm_cmd: host bus message command
+ * @buf: buffer for cl header
+ * @len: buffer length
+ *
+ * Initialize HBM buffer
+ */
+static inline void ishtp_hbm_cl_hdr(struct ishtp_cl *cl, uint8_t hbm_cmd,
+	void *buf, size_t len)
+{
+	struct ishtp_hbm_cl_cmd *cmd = buf;
+
+	memset(cmd, 0, len);
+
+	cmd->hbm_cmd = hbm_cmd;
+	cmd->host_addr = cl->host_client_id;
+	cmd->fw_addr = cl->fw_client_id;
+}
+
+/**
+ * ishtp_hbm_cl_addr_equal() - Compare client address
+ * @cl: client
+ * @buf: Client command buffer
+ *
+ * Compare client address with the address in command buffer
+ *
+ * Return: True if they have the same address
+ */
+static inline bool ishtp_hbm_cl_addr_equal(struct ishtp_cl *cl, void *buf)
+{
+	struct ishtp_hbm_cl_cmd *cmd = buf;
+
+	return cl->host_client_id == cmd->host_addr &&
+		cl->fw_client_id == cmd->fw_addr;
+}
+
+/**
+ * ishtp_hbm_start_wait() - Wait for HBM start message
+ * @dev: ISHTP device instance
+ *
+ * Wait for HBM start message from firmware
+ *
+ * Return: 0 if HBM start is/was received else timeout error
+ */
+int ishtp_hbm_start_wait(struct ishtp_device *dev)
+{
+	int ret;
+
+	if (dev->hbm_state > ISHTP_HBM_START)
+		return 0;
+
+	dev_dbg(dev->devc, "Going to wait for ishtp start. hbm_state=%08X\n",
+		dev->hbm_state);
+	ret = wait_event_interruptible_timeout(dev->wait_hbm_recvd_msg,
+					dev->hbm_state >= ISHTP_HBM_STARTED,
+					(ISHTP_INTEROP_TIMEOUT * HZ));
+
+	dev_dbg(dev->devc,
+		"Woke up from waiting for ishtp start. hbm_state=%08X\n",
+		dev->hbm_state);
+
+	if (ret <= 0 && (dev->hbm_state <= ISHTP_HBM_START)) {
+		dev->hbm_state = ISHTP_HBM_IDLE;
+		dev_err(dev->devc,
+		"waiting for ishtp start failed. ret=%d hbm_state=%08X\n",
+			ret, dev->hbm_state);
+		return -ETIMEDOUT;
+	}
+	return 0;
+}
+
+/**
+ * ishtp_hbm_start_req() - Send HBM start message
+ * @dev: ISHTP device instance
+ *
+ * Send HBM start message to firmware
+ *
+ * Return: 0 if success else error code
+ */
+int ishtp_hbm_start_req(struct ishtp_device *dev)
+{
+	struct ishtp_msg_hdr hdr;
+	unsigned char data[128];
+	struct ishtp_msg_hdr *ishtp_hdr = &hdr;
+	struct hbm_host_version_request *start_req;
+	const size_t len = sizeof(struct hbm_host_version_request);
+
+	ishtp_hbm_hdr(ishtp_hdr, len);
+
+	/* host start message */
+	start_req = (struct hbm_host_version_request *)data;
+	memset(start_req, 0, len);
+	start_req->hbm_cmd = HOST_START_REQ_CMD;
+	start_req->host_version.major_version = HBM_MAJOR_VERSION;
+	start_req->host_version.minor_version = HBM_MINOR_VERSION;
+
+	/*
+	 * (!) Response to HBM start may be so quick that this thread would get
+	 * preempted BEFORE managing to set hbm_state = ISHTP_HBM_START.
+	 * So set it at first, change back to ISHTP_HBM_IDLE upon failure
+	 */
+	dev->hbm_state = ISHTP_HBM_START;
+	if (ishtp_write_message(dev, ishtp_hdr, data)) {
+		dev_err(dev->devc, "version message send failed\n");
+		dev->dev_state = ISHTP_DEV_RESETTING;
+		dev->hbm_state = ISHTP_HBM_IDLE;
+		ish_hw_reset(dev);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+/**
+ * ishtp_hbm_enum_clients_req() - Send client enum req
+ * @dev: ISHTP device instance
+ *
+ * Send enumeration client request message
+ *
+ * Return: 0 if success else error code
+ */
+void ishtp_hbm_enum_clients_req(struct ishtp_device *dev)
+{
+	struct ishtp_msg_hdr hdr;
+	unsigned char data[128];
+	struct ishtp_msg_hdr *ishtp_hdr = &hdr;
+	struct hbm_host_enum_request *enum_req;
+	const size_t len = sizeof(struct hbm_host_enum_request);
+
+	/* enumerate clients */
+	ishtp_hbm_hdr(ishtp_hdr, len);
+
+	enum_req = (struct hbm_host_enum_request *)data;
+	memset(enum_req, 0, len);
+	enum_req->hbm_cmd = HOST_ENUM_REQ_CMD;
+
+	if (ishtp_write_message(dev, ishtp_hdr, data)) {
+		dev->dev_state = ISHTP_DEV_RESETTING;
+		dev_err(dev->devc, "enumeration request send failed\n");
+		ish_hw_reset(dev);
+	}
+	dev->hbm_state = ISHTP_HBM_ENUM_CLIENTS;
+}
+
+/**
+ * ishtp_hbm_prop_req() - Request property
+ * @dev: ISHTP device instance
+ *
+ * Request property for a single client
+ *
+ * Return: 0 if success else error code
+ */
+static int ishtp_hbm_prop_req(struct ishtp_device *dev)
+{
+
+	struct ishtp_msg_hdr hdr;
+	unsigned char data[128];
+	struct ishtp_msg_hdr *ishtp_hdr = &hdr;
+	struct hbm_props_request *prop_req;
+	const size_t len = sizeof(struct hbm_props_request);
+	unsigned long next_client_index;
+	uint8_t client_num;
+
+	client_num = dev->fw_client_presentation_num;
+
+	next_client_index = find_next_bit(dev->fw_clients_map,
+		ISHTP_CLIENTS_MAX, dev->fw_client_index);
+
+	/* We got all client properties */
+	if (next_client_index == ISHTP_CLIENTS_MAX) {
+		dev->hbm_state = ISHTP_HBM_WORKING;
+		dev->dev_state = ISHTP_DEV_ENABLED;
+
+		for (dev->fw_client_presentation_num = 1;
+			dev->fw_client_presentation_num < client_num + 1;
+				++dev->fw_client_presentation_num)
+			/* Add new client device */
+			ishtp_bus_new_client(dev);
+		return 0;
+	}
+
+	dev->fw_clients[client_num].client_id = next_client_index;
+
+	ishtp_hbm_hdr(ishtp_hdr, len);
+	prop_req = (struct hbm_props_request *)data;
+
+	memset(prop_req, 0, sizeof(struct hbm_props_request));
+
+	prop_req->hbm_cmd = HOST_CLIENT_PROPERTIES_REQ_CMD;
+	prop_req->address = next_client_index;
+
+	if (ishtp_write_message(dev, ishtp_hdr, data)) {
+		dev->dev_state = ISHTP_DEV_RESETTING;
+		dev_err(dev->devc, "properties request send failed\n");
+		ish_hw_reset(dev);
+		return -EIO;
+	}
+
+	dev->fw_client_index = next_client_index;
+
+	return 0;
+}
+
+/**
+ * ishtp_hbm_stop_req() - Send HBM stop
+ * @dev: ISHTP device instance
+ *
+ * Send stop request message
+ */
+static void ishtp_hbm_stop_req(struct ishtp_device *dev)
+{
+	struct ishtp_msg_hdr hdr;
+	unsigned char data[128];
+	struct ishtp_msg_hdr *ishtp_hdr = &hdr;
+	struct hbm_host_stop_request *req;
+	const size_t len = sizeof(struct hbm_host_stop_request);
+
+	ishtp_hbm_hdr(ishtp_hdr, len);
+	req = (struct hbm_host_stop_request *)data;
+
+	memset(req, 0, sizeof(struct hbm_host_stop_request));
+	req->hbm_cmd = HOST_STOP_REQ_CMD;
+	req->reason = DRIVER_STOP_REQUEST;
+
+	ishtp_write_message(dev, ishtp_hdr, data);
+}
+
+/**
+ * ishtp_hbm_cl_flow_control_req() - Send flow control request
+ * @dev: ISHTP device instance
+ * @cl: ISHTP client instance
+ *
+ * Send flow control request
+ *
+ * Return: 0 if success else error code
+ */
+int ishtp_hbm_cl_flow_control_req(struct ishtp_device *dev,
+				  struct ishtp_cl *cl)
+{
+	struct ishtp_msg_hdr hdr;
+	unsigned char data[128];
+	struct ishtp_msg_hdr *ishtp_hdr = &hdr;
+	const size_t len = sizeof(struct hbm_flow_control);
+	int	rv;
+	unsigned long	flags;
+
+	spin_lock_irqsave(&cl->fc_spinlock, flags);
+	ishtp_hbm_hdr(ishtp_hdr, len);
+	ishtp_hbm_cl_hdr(cl, ISHTP_FLOW_CONTROL_CMD, data, len);
+
+	/*
+	 * Sync possible race when RB recycle and packet receive paths
+	 * both try to send an out FC
+	 */
+	if (cl->out_flow_ctrl_creds) {
+		spin_unlock_irqrestore(&cl->fc_spinlock, flags);
+		return	0;
+	}
+
+	cl->recv_msg_num_frags = 0;
+
+	rv = ishtp_write_message(dev, ishtp_hdr, data);
+	if (!rv) {
+		++cl->out_flow_ctrl_creds;
+		++cl->out_flow_ctrl_cnt;
+		cl->ts_out_fc = ktime_get();
+		if (cl->ts_rx) {
+			ktime_t ts_diff = ktime_sub(cl->ts_out_fc, cl->ts_rx);
+			if (ktime_after(ts_diff, cl->ts_max_fc_delay))
+				cl->ts_max_fc_delay = ts_diff;
+		}
+	} else {
+		++cl->err_send_fc;
+	}
+
+	spin_unlock_irqrestore(&cl->fc_spinlock, flags);
+	return	rv;
+}
+
+/**
+ * ishtp_hbm_cl_disconnect_req() - Send disconnect request
+ * @dev: ISHTP device instance
+ * @cl: ISHTP client instance
+ *
+ * Send disconnect message to fw
+ *
+ * Return: 0 if success else error code
+ */
+int ishtp_hbm_cl_disconnect_req(struct ishtp_device *dev, struct ishtp_cl *cl)
+{
+	struct ishtp_msg_hdr hdr;
+	unsigned char data[128];
+	struct ishtp_msg_hdr *ishtp_hdr = &hdr;
+	const size_t len = sizeof(struct hbm_client_connect_request);
+
+	ishtp_hbm_hdr(ishtp_hdr, len);
+	ishtp_hbm_cl_hdr(cl, CLIENT_DISCONNECT_REQ_CMD, data, len);
+
+	return ishtp_write_message(dev, ishtp_hdr, data);
+}
+
+/**
+ * ishtp_hbm_cl_disconnect_res() - Get disconnect response
+ * @dev: ISHTP device instance
+ * @rs: Response message
+ *
+ * Received disconnect response from fw
+ */
+static void ishtp_hbm_cl_disconnect_res(struct ishtp_device *dev,
+	struct hbm_client_connect_response *rs)
+{
+	struct ishtp_cl *cl = NULL;
+	unsigned long	flags;
+
+	spin_lock_irqsave(&dev->cl_list_lock, flags);
+	list_for_each_entry(cl, &dev->cl_list, link) {
+		if (!rs->status && ishtp_hbm_cl_addr_equal(cl, rs)) {
+			cl->state = ISHTP_CL_DISCONNECTED;
+			wake_up_interruptible(&cl->wait_ctrl_res);
+			break;
+		}
+	}
+	spin_unlock_irqrestore(&dev->cl_list_lock, flags);
+}
+
+/**
+ * ishtp_hbm_cl_connect_req() - Send connect request
+ * @dev: ISHTP device instance
+ * @cl: client device instance
+ *
+ * Send connection request to specific fw client
+ *
+ * Return: 0 if success else error code
+ */
+int ishtp_hbm_cl_connect_req(struct ishtp_device *dev, struct ishtp_cl *cl)
+{
+	struct ishtp_msg_hdr hdr;
+	unsigned char data[128];
+	struct ishtp_msg_hdr *ishtp_hdr = &hdr;
+	const size_t len = sizeof(struct hbm_client_connect_request);
+
+	ishtp_hbm_hdr(ishtp_hdr, len);
+	ishtp_hbm_cl_hdr(cl, CLIENT_CONNECT_REQ_CMD, data, len);
+
+	return ishtp_write_message(dev, ishtp_hdr, data);
+}
+
+/**
+ * ishtp_hbm_cl_connect_res() - Get connect response
+ * @dev: ISHTP device instance
+ * @rs: Response message
+ *
+ * Received connect response from fw
+ */
+static void ishtp_hbm_cl_connect_res(struct ishtp_device *dev,
+	struct hbm_client_connect_response *rs)
+{
+	struct ishtp_cl *cl = NULL;
+	unsigned long	flags;
+
+	spin_lock_irqsave(&dev->cl_list_lock, flags);
+	list_for_each_entry(cl, &dev->cl_list, link) {
+		if (ishtp_hbm_cl_addr_equal(cl, rs)) {
+			if (!rs->status) {
+				cl->state = ISHTP_CL_CONNECTED;
+				cl->status = 0;
+			} else {
+				cl->state = ISHTP_CL_DISCONNECTED;
+				cl->status = -ENODEV;
+			}
+			wake_up_interruptible(&cl->wait_ctrl_res);
+			break;
+		}
+	}
+	spin_unlock_irqrestore(&dev->cl_list_lock, flags);
+}
+
+/**
+ * ishtp_client_disconnect_request() - Receive disconnect request
+ * @dev: ISHTP device instance
+ * @disconnect_req: disconnect request structure
+ *
+ * Disconnect request bus message from the fw. Send diconnect response.
+ */
+static void ishtp_hbm_fw_disconnect_req(struct ishtp_device *dev,
+	struct hbm_client_connect_request *disconnect_req)
+{
+	struct ishtp_cl *cl;
+	const size_t len = sizeof(struct hbm_client_connect_response);
+	unsigned long	flags;
+	struct ishtp_msg_hdr hdr;
+	unsigned char data[4];	/* All HBM messages are 4 bytes */
+
+	spin_lock_irqsave(&dev->cl_list_lock, flags);
+	list_for_each_entry(cl, &dev->cl_list, link) {
+		if (ishtp_hbm_cl_addr_equal(cl, disconnect_req)) {
+			cl->state = ISHTP_CL_DISCONNECTED;
+
+			/* send disconnect response */
+			ishtp_hbm_hdr(&hdr, len);
+			ishtp_hbm_cl_hdr(cl, CLIENT_DISCONNECT_RES_CMD, data,
+				len);
+			ishtp_write_message(dev, &hdr, data);
+			break;
+		}
+	}
+	spin_unlock_irqrestore(&dev->cl_list_lock, flags);
+}
+
+/**
+ * ishtp_hbm_dma_xfer_ack(() - Receive transfer ACK
+ * @dev: ISHTP device instance
+ * @dma_xfer: HBM transfer message
+ *
+ * Receive ack for ISHTP-over-DMA client message
+ */
+static void ishtp_hbm_dma_xfer_ack(struct ishtp_device *dev,
+				   struct dma_xfer_hbm *dma_xfer)
+{
+	void	*msg;
+	uint64_t	offs;
+	struct ishtp_msg_hdr	*ishtp_hdr =
+		(struct ishtp_msg_hdr *)&dev->ishtp_msg_hdr;
+	unsigned int	msg_offs;
+	struct ishtp_cl *cl;
+
+	for (msg_offs = 0; msg_offs < ishtp_hdr->length;
+		msg_offs += sizeof(struct dma_xfer_hbm)) {
+		offs = dma_xfer->msg_addr - dev->ishtp_host_dma_tx_buf_phys;
+		if (offs > dev->ishtp_host_dma_tx_buf_size) {
+			dev_err(dev->devc, "Bad DMA Tx ack message address\n");
+			return;
+		}
+		if (dma_xfer->msg_length >
+				dev->ishtp_host_dma_tx_buf_size - offs) {
+			dev_err(dev->devc, "Bad DMA Tx ack message size\n");
+			return;
+		}
+
+		/* logical address of the acked mem */
+		msg = (unsigned char *)dev->ishtp_host_dma_tx_buf + offs;
+		ishtp_cl_release_dma_acked_mem(dev, msg, dma_xfer->msg_length);
+
+		list_for_each_entry(cl, &dev->cl_list, link) {
+			if (cl->fw_client_id == dma_xfer->fw_client_id &&
+			    cl->host_client_id == dma_xfer->host_client_id)
+				/*
+				 * in case that a single ack may be sent
+				 * over several dma transfers, and the last msg
+				 * addr was inside the acked memory, but not in
+				 * its start
+				 */
+				if (cl->last_dma_addr >=
+							(unsigned char *)msg &&
+						cl->last_dma_addr <
+						(unsigned char *)msg +
+						dma_xfer->msg_length) {
+					cl->last_dma_acked = 1;
+
+					if (!list_empty(&cl->tx_list.list) &&
+						cl->ishtp_flow_ctrl_creds) {
+						/*
+						 * start sending the first msg
+						 */
+						ishtp_cl_send_msg(dev, cl);
+					}
+				}
+		}
+		++dma_xfer;
+	}
+}
+
+/**
+ * ishtp_hbm_dma_xfer() - Receive DMA transfer message
+ * @dev: ISHTP device instance
+ * @dma_xfer: HBM transfer message
+ *
+ * Receive ISHTP-over-DMA client message
+ */
+static void ishtp_hbm_dma_xfer(struct ishtp_device *dev,
+			       struct dma_xfer_hbm *dma_xfer)
+{
+	void	*msg;
+	uint64_t	offs;
+	struct ishtp_msg_hdr	hdr;
+	struct ishtp_msg_hdr	*ishtp_hdr =
+		(struct ishtp_msg_hdr *) &dev->ishtp_msg_hdr;
+	struct dma_xfer_hbm	*prm = dma_xfer;
+	unsigned int	msg_offs;
+
+	for (msg_offs = 0; msg_offs < ishtp_hdr->length;
+		msg_offs += sizeof(struct dma_xfer_hbm)) {
+
+		offs = dma_xfer->msg_addr - dev->ishtp_host_dma_rx_buf_phys;
+		if (offs > dev->ishtp_host_dma_rx_buf_size) {
+			dev_err(dev->devc, "Bad DMA Rx message address\n");
+			return;
+		}
+		if (dma_xfer->msg_length >
+				dev->ishtp_host_dma_rx_buf_size - offs) {
+			dev_err(dev->devc, "Bad DMA Rx message size\n");
+			return;
+		}
+		msg = dev->ishtp_host_dma_rx_buf + offs;
+		recv_ishtp_cl_msg_dma(dev, msg, dma_xfer);
+		dma_xfer->hbm = DMA_XFER_ACK;	/* Prepare for response */
+		++dma_xfer;
+	}
+
+	/* Send DMA_XFER_ACK [...] */
+	ishtp_hbm_hdr(&hdr, ishtp_hdr->length);
+	ishtp_write_message(dev, &hdr, (unsigned char *)prm);
+}
+
+/**
+ * ishtp_hbm_dispatch() - HBM dispatch function
+ * @dev: ISHTP device instance
+ * @hdr: bus message
+ *
+ * Bottom half read routine after ISR to handle the read bus message cmd
+ * processing
+ */
+void ishtp_hbm_dispatch(struct ishtp_device *dev,
+			struct ishtp_bus_message *hdr)
+{
+	struct ishtp_bus_message *ishtp_msg;
+	struct ishtp_fw_client *fw_client;
+	struct hbm_host_version_response *version_res;
+	struct hbm_client_connect_response *connect_res;
+	struct hbm_client_connect_response *disconnect_res;
+	struct hbm_client_connect_request *disconnect_req;
+	struct hbm_props_response *props_res;
+	struct hbm_host_enum_response *enum_res;
+	struct ishtp_msg_hdr ishtp_hdr;
+	struct dma_alloc_notify	dma_alloc_notify;
+	struct dma_xfer_hbm	*dma_xfer;
+
+	ishtp_msg = hdr;
+
+	switch (ishtp_msg->hbm_cmd) {
+	case HOST_START_RES_CMD:
+		version_res = (struct hbm_host_version_response *)ishtp_msg;
+		if (!version_res->host_version_supported) {
+			dev->version = version_res->fw_max_version;
+
+			dev->hbm_state = ISHTP_HBM_STOPPED;
+			ishtp_hbm_stop_req(dev);
+			return;
+		}
+
+		dev->version.major_version = HBM_MAJOR_VERSION;
+		dev->version.minor_version = HBM_MINOR_VERSION;
+		if (dev->dev_state == ISHTP_DEV_INIT_CLIENTS &&
+				dev->hbm_state == ISHTP_HBM_START) {
+			dev->hbm_state = ISHTP_HBM_STARTED;
+			ishtp_hbm_enum_clients_req(dev);
+		} else {
+			dev_err(dev->devc,
+				"reset: wrong host start response\n");
+			/* BUG: why do we arrive here? */
+			ish_hw_reset(dev);
+			return;
+		}
+
+		wake_up_interruptible(&dev->wait_hbm_recvd_msg);
+		break;
+
+	case CLIENT_CONNECT_RES_CMD:
+		connect_res = (struct hbm_client_connect_response *)ishtp_msg;
+		ishtp_hbm_cl_connect_res(dev, connect_res);
+		break;
+
+	case CLIENT_DISCONNECT_RES_CMD:
+		disconnect_res =
+			(struct hbm_client_connect_response *)ishtp_msg;
+		ishtp_hbm_cl_disconnect_res(dev, disconnect_res);
+		break;
+
+	case HOST_CLIENT_PROPERTIES_RES_CMD:
+		props_res = (struct hbm_props_response *)ishtp_msg;
+		fw_client = &dev->fw_clients[dev->fw_client_presentation_num];
+
+		if (props_res->status || !dev->fw_clients) {
+			dev_err(dev->devc,
+			"reset: properties response hbm wrong status\n");
+			ish_hw_reset(dev);
+			return;
+		}
+
+		if (fw_client->client_id != props_res->address) {
+			dev_err(dev->devc,
+				"reset: host properties response address mismatch [%02X %02X]\n",
+				fw_client->client_id, props_res->address);
+			ish_hw_reset(dev);
+			return;
+		}
+
+		if (dev->dev_state != ISHTP_DEV_INIT_CLIENTS ||
+			dev->hbm_state != ISHTP_HBM_CLIENT_PROPERTIES) {
+			dev_err(dev->devc,
+				"reset: unexpected properties response\n");
+			ish_hw_reset(dev);
+			return;
+		}
+
+		fw_client->props = props_res->client_properties;
+		dev->fw_client_index++;
+		dev->fw_client_presentation_num++;
+
+		/* request property for the next client */
+		ishtp_hbm_prop_req(dev);
+
+		if (dev->dev_state != ISHTP_DEV_ENABLED)
+			break;
+
+		if (!ishtp_use_dma_transfer())
+			break;
+
+		dev_dbg(dev->devc, "Requesting to use DMA\n");
+		ishtp_cl_alloc_dma_buf(dev);
+		if (dev->ishtp_host_dma_rx_buf) {
+			const size_t len = sizeof(dma_alloc_notify);
+
+			memset(&dma_alloc_notify, 0, sizeof(dma_alloc_notify));
+			dma_alloc_notify.hbm = DMA_BUFFER_ALLOC_NOTIFY;
+			dma_alloc_notify.buf_size =
+					dev->ishtp_host_dma_rx_buf_size;
+			dma_alloc_notify.buf_address =
+					dev->ishtp_host_dma_rx_buf_phys;
+			ishtp_hbm_hdr(&ishtp_hdr, len);
+			ishtp_write_message(dev, &ishtp_hdr,
+				(unsigned char *)&dma_alloc_notify);
+		}
+
+		break;
+
+	case HOST_ENUM_RES_CMD:
+		enum_res = (struct hbm_host_enum_response *) ishtp_msg;
+		memcpy(dev->fw_clients_map, enum_res->valid_addresses, 32);
+		if (dev->dev_state == ISHTP_DEV_INIT_CLIENTS &&
+			dev->hbm_state == ISHTP_HBM_ENUM_CLIENTS) {
+			dev->fw_client_presentation_num = 0;
+			dev->fw_client_index = 0;
+
+			ishtp_hbm_fw_cl_allocate(dev);
+			dev->hbm_state = ISHTP_HBM_CLIENT_PROPERTIES;
+
+			/* first property request */
+			ishtp_hbm_prop_req(dev);
+		} else {
+			dev_err(dev->devc,
+			      "reset: unexpected enumeration response hbm\n");
+			ish_hw_reset(dev);
+			return;
+		}
+		break;
+
+	case HOST_STOP_RES_CMD:
+		if (dev->hbm_state != ISHTP_HBM_STOPPED)
+			dev_err(dev->devc, "unexpected stop response\n");
+
+		dev->dev_state = ISHTP_DEV_DISABLED;
+		dev_info(dev->devc, "reset: FW stop response\n");
+		ish_hw_reset(dev);
+		break;
+
+	case CLIENT_DISCONNECT_REQ_CMD:
+		/* search for client */
+		disconnect_req =
+			(struct hbm_client_connect_request *)ishtp_msg;
+		ishtp_hbm_fw_disconnect_req(dev, disconnect_req);
+		break;
+
+	case FW_STOP_REQ_CMD:
+		dev->hbm_state = ISHTP_HBM_STOPPED;
+		break;
+
+	case DMA_BUFFER_ALLOC_RESPONSE:
+		dev->ishtp_host_dma_enabled = 1;
+		break;
+
+	case DMA_XFER:
+		dma_xfer = (struct dma_xfer_hbm *)ishtp_msg;
+		if (!dev->ishtp_host_dma_enabled) {
+			dev_err(dev->devc,
+				"DMA XFER requested but DMA is not enabled\n");
+			break;
+		}
+		ishtp_hbm_dma_xfer(dev, dma_xfer);
+		break;
+
+	case DMA_XFER_ACK:
+		dma_xfer = (struct dma_xfer_hbm *)ishtp_msg;
+		if (!dev->ishtp_host_dma_enabled ||
+		    !dev->ishtp_host_dma_tx_buf) {
+			dev_err(dev->devc,
+				"DMA XFER acked but DMA Tx is not enabled\n");
+			break;
+		}
+		ishtp_hbm_dma_xfer_ack(dev, dma_xfer);
+		break;
+
+	default:
+		dev_err(dev->devc, "unknown HBM: %u\n",
+			(unsigned int)ishtp_msg->hbm_cmd);
+
+		break;
+	}
+}
+
+/**
+ * bh_hbm_work_fn() - HBM work function
+ * @work: work struct
+ *
+ * Bottom half processing work function (instead of thread handler)
+ * for processing hbm messages
+ */
+void	bh_hbm_work_fn(struct work_struct *work)
+{
+	unsigned long	flags;
+	struct ishtp_device	*dev;
+	unsigned char	hbm[IPC_PAYLOAD_SIZE];
+
+	dev = container_of(work, struct ishtp_device, bh_hbm_work);
+	spin_lock_irqsave(&dev->rd_msg_spinlock, flags);
+	if (dev->rd_msg_fifo_head != dev->rd_msg_fifo_tail) {
+		memcpy(hbm, dev->rd_msg_fifo + dev->rd_msg_fifo_head,
+			IPC_PAYLOAD_SIZE);
+		dev->rd_msg_fifo_head =
+			(dev->rd_msg_fifo_head + IPC_PAYLOAD_SIZE) %
+			(RD_INT_FIFO_SIZE * IPC_PAYLOAD_SIZE);
+		spin_unlock_irqrestore(&dev->rd_msg_spinlock, flags);
+		ishtp_hbm_dispatch(dev, (struct ishtp_bus_message *)hbm);
+	} else {
+		spin_unlock_irqrestore(&dev->rd_msg_spinlock, flags);
+	}
+}
+
+/**
+ * recv_hbm() - Receive HBM message
+ * @dev: ISHTP device instance
+ * @ishtp_hdr: received bus message
+ *
+ * Receive and process ISHTP bus messages in ISR context. This will schedule
+ * work function to process message
+ */
+void	recv_hbm(struct ishtp_device *dev, struct ishtp_msg_hdr *ishtp_hdr)
+{
+	uint8_t	rd_msg_buf[ISHTP_RD_MSG_BUF_SIZE];
+	struct ishtp_bus_message	*ishtp_msg =
+		(struct ishtp_bus_message *)rd_msg_buf;
+	unsigned long	flags;
+
+	dev->ops->ishtp_read(dev, rd_msg_buf, ishtp_hdr->length);
+
+	/* Flow control - handle in place */
+	if (ishtp_msg->hbm_cmd == ISHTP_FLOW_CONTROL_CMD) {
+		struct hbm_flow_control *flow_control =
+			(struct hbm_flow_control *)ishtp_msg;
+		struct ishtp_cl *cl = NULL;
+		unsigned long	flags, tx_flags;
+
+		spin_lock_irqsave(&dev->cl_list_lock, flags);
+		list_for_each_entry(cl, &dev->cl_list, link) {
+			if (cl->host_client_id == flow_control->host_addr &&
+					cl->fw_client_id ==
+					flow_control->fw_addr) {
+				/*
+				 * NOTE: It's valid only for counting
+				 * flow-control implementation to receive a
+				 * FC in the middle of sending. Meanwhile not
+				 * supported
+				 */
+				if (cl->ishtp_flow_ctrl_creds)
+					dev_err(dev->devc,
+					 "recv extra FC from FW client %u (host client %u) (FC count was %d)\n",
+					 (unsigned int)cl->fw_client_id,
+					 (unsigned int)cl->host_client_id,
+					 cl->ishtp_flow_ctrl_creds);
+				else {
+					++cl->ishtp_flow_ctrl_creds;
+					++cl->ishtp_flow_ctrl_cnt;
+					cl->last_ipc_acked = 1;
+					spin_lock_irqsave(
+							&cl->tx_list_spinlock,
+							tx_flags);
+					if (!list_empty(&cl->tx_list.list)) {
+						/*
+						 * start sending the first msg
+						 *	= the callback function
+						 */
+						spin_unlock_irqrestore(
+							&cl->tx_list_spinlock,
+							tx_flags);
+						ishtp_cl_send_msg(dev, cl);
+					} else {
+						spin_unlock_irqrestore(
+							&cl->tx_list_spinlock,
+							tx_flags);
+					}
+				}
+				break;
+			}
+		}
+		spin_unlock_irqrestore(&dev->cl_list_lock, flags);
+		goto	eoi;
+	}
+
+	/*
+	 * Some messages that are safe for ISR processing and important
+	 * to be done "quickly" and in-order, go here
+	 */
+	if (ishtp_msg->hbm_cmd == CLIENT_CONNECT_RES_CMD ||
+			ishtp_msg->hbm_cmd == CLIENT_DISCONNECT_RES_CMD ||
+			ishtp_msg->hbm_cmd == CLIENT_DISCONNECT_REQ_CMD ||
+			ishtp_msg->hbm_cmd == DMA_XFER) {
+		ishtp_hbm_dispatch(dev, ishtp_msg);
+		goto	eoi;
+	}
+
+	/*
+	 * All other HBMs go here.
+	 * We schedule HBMs for processing serially by using system wq,
+	 * possibly there will be multiple HBMs scheduled at the same time.
+	 */
+	spin_lock_irqsave(&dev->rd_msg_spinlock, flags);
+	if ((dev->rd_msg_fifo_tail + IPC_PAYLOAD_SIZE) %
+			(RD_INT_FIFO_SIZE * IPC_PAYLOAD_SIZE) ==
+			dev->rd_msg_fifo_head) {
+		spin_unlock_irqrestore(&dev->rd_msg_spinlock, flags);
+		dev_err(dev->devc, "BH buffer overflow, dropping HBM %u\n",
+			(unsigned int)ishtp_msg->hbm_cmd);
+		goto	eoi;
+	}
+	memcpy(dev->rd_msg_fifo + dev->rd_msg_fifo_tail, ishtp_msg,
+		ishtp_hdr->length);
+	dev->rd_msg_fifo_tail = (dev->rd_msg_fifo_tail + IPC_PAYLOAD_SIZE) %
+		(RD_INT_FIFO_SIZE * IPC_PAYLOAD_SIZE);
+	spin_unlock_irqrestore(&dev->rd_msg_spinlock, flags);
+	schedule_work(&dev->bh_hbm_work);
+eoi:
+	return;
+}
+
+/**
+ * recv_fixed_cl_msg() - Receive fixed client message
+ * @dev: ISHTP device instance
+ * @ishtp_hdr: received bus message
+ *
+ * Receive and process ISHTP fixed client messages (address == 0)
+ * in ISR context
+ */
+void recv_fixed_cl_msg(struct ishtp_device *dev,
+	struct ishtp_msg_hdr *ishtp_hdr)
+{
+	uint8_t rd_msg_buf[ISHTP_RD_MSG_BUF_SIZE];
+
+	dev->print_log(dev,
+		"%s() got fixed client msg from client #%d\n",
+		__func__, ishtp_hdr->fw_addr);
+	dev->ops->ishtp_read(dev, rd_msg_buf, ishtp_hdr->length);
+	if (ishtp_hdr->fw_addr == ISHTP_SYSTEM_STATE_CLIENT_ADDR) {
+		struct ish_system_states_header *msg_hdr =
+			(struct ish_system_states_header *)rd_msg_buf;
+		if (msg_hdr->cmd == SYSTEM_STATE_SUBSCRIBE)
+			ishtp_send_resume(dev);
+		/* if FW request arrived here, the system is not suspended */
+		else
+			dev_err(dev->devc, "unknown fixed client msg [%02X]\n",
+				msg_hdr->cmd);
+	}
+}
+
+/**
+ * fix_cl_hdr() - Initialize fixed client header
+ * @hdr: message header
+ * @length: length of message
+ * @cl_addr: Client address
+ *
+ * Initialize message header for fixed client
+ */
+static inline void fix_cl_hdr(struct ishtp_msg_hdr *hdr, size_t length,
+	uint8_t cl_addr)
+{
+	hdr->host_addr = 0;
+	hdr->fw_addr = cl_addr;
+	hdr->length = length;
+	hdr->msg_complete = 1;
+	hdr->reserved = 0;
+}
+
+/*** Suspend and resume notification ***/
+
+static uint32_t current_state;
+static uint32_t supported_states = 0 | SUSPEND_STATE_BIT;
+
+/**
+ * ishtp_send_suspend() - Send suspend message to FW
+ * @dev: ISHTP device instance
+ *
+ * Send suspend message to FW. This is useful for system freeze (non S3) case
+ */
+void ishtp_send_suspend(struct ishtp_device *dev)
+{
+	struct ishtp_msg_hdr	ishtp_hdr;
+	struct ish_system_states_status state_status_msg;
+	const size_t len = sizeof(struct ish_system_states_status);
+
+	fix_cl_hdr(&ishtp_hdr, len, ISHTP_SYSTEM_STATE_CLIENT_ADDR);
+
+	memset(&state_status_msg, 0, len);
+	state_status_msg.hdr.cmd = SYSTEM_STATE_STATUS;
+	state_status_msg.supported_states = supported_states;
+	current_state |= SUSPEND_STATE_BIT;
+	dev->print_log(dev, "%s() sends SUSPEND notification\n", __func__);
+	state_status_msg.states_status = current_state;
+
+	ishtp_write_message(dev, &ishtp_hdr,
+		(unsigned char *)&state_status_msg);
+}
+EXPORT_SYMBOL(ishtp_send_suspend);
+
+/**
+ * ishtp_send_resume() - Send resume message to FW
+ * @dev: ISHTP device instance
+ *
+ * Send resume message to FW. This is useful for system freeze (non S3) case
+ */
+void ishtp_send_resume(struct ishtp_device *dev)
+{
+	struct ishtp_msg_hdr	ishtp_hdr;
+	struct ish_system_states_status state_status_msg;
+	const size_t len = sizeof(struct ish_system_states_status);
+
+	fix_cl_hdr(&ishtp_hdr, len, ISHTP_SYSTEM_STATE_CLIENT_ADDR);
+
+	memset(&state_status_msg, 0, len);
+	state_status_msg.hdr.cmd = SYSTEM_STATE_STATUS;
+	state_status_msg.supported_states = supported_states;
+	current_state &= ~SUSPEND_STATE_BIT;
+	dev->print_log(dev, "%s() sends RESUME notification\n", __func__);
+	state_status_msg.states_status = current_state;
+
+	ishtp_write_message(dev, &ishtp_hdr,
+		(unsigned char *)&state_status_msg);
+}
+EXPORT_SYMBOL(ishtp_send_resume);
+
+/**
+ * ishtp_query_subscribers() - Send query subscribers message
+ * @dev: ISHTP device instance
+ *
+ * Send message to query subscribers
+ */
+void ishtp_query_subscribers(struct ishtp_device *dev)
+{
+	struct ishtp_msg_hdr	ishtp_hdr;
+	struct ish_system_states_query_subscribers query_subscribers_msg;
+	const size_t len = sizeof(struct ish_system_states_query_subscribers);
+
+	fix_cl_hdr(&ishtp_hdr, len, ISHTP_SYSTEM_STATE_CLIENT_ADDR);
+
+	memset(&query_subscribers_msg, 0, len);
+	query_subscribers_msg.hdr.cmd = SYSTEM_STATE_QUERY_SUBSCRIBERS;
+
+	ishtp_write_message(dev, &ishtp_hdr,
+		(unsigned char *)&query_subscribers_msg);
+}