--- /dev/null
+/*
+ *
+ * Intel Management Engine Interface (Intel MEI) Linux driver
+ * Copyright (c) 2003-2011, 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/pci.h>
+#include "mei_dev.h"
+#include "mei.h"
+#include "interface.h"
+
+
+
+/**
+ * mei_set_csr_register - writes H_CSR register to the mei device,
+ * and ignores the H_IS bit for it is write-one-to-zero.
+ *
+ * @dev: the device structure
+ */
+void mei_hcsr_set(struct mei_device *dev)
+{
+       if ((dev->host_hw_state & H_IS) == H_IS)
+               dev->host_hw_state &= ~H_IS;
+       mei_reg_write(dev, H_CSR, dev->host_hw_state);
+       dev->host_hw_state = mei_hcsr_read(dev);
+}
+
+/**
+ * mei_csr_enable_interrupts - enables mei device interrupts
+ *
+ * @dev: the device structure
+ */
+void mei_enable_interrupts(struct mei_device *dev)
+{
+       dev->host_hw_state |= H_IE;
+       mei_hcsr_set(dev);
+}
+
+/**
+ * mei_csr_disable_interrupts - disables mei device interrupts
+ *
+ * @dev: the device structure
+ */
+void mei_disable_interrupts(struct mei_device *dev)
+{
+       dev->host_hw_state &= ~H_IE;
+       mei_hcsr_set(dev);
+}
+
+/**
+ * _host_get_filled_slots - gets number of device filled buffer slots
+ *
+ * @device: the device structure
+ *
+ * returns number of filled slots
+ */
+static unsigned char _host_get_filled_slots(const struct mei_device *dev)
+{
+       char read_ptr, write_ptr;
+
+       read_ptr = (char) ((dev->host_hw_state & H_CBRP) >> 8);
+       write_ptr = (char) ((dev->host_hw_state & H_CBWP) >> 16);
+
+       return (unsigned char) (write_ptr - read_ptr);
+}
+
+/**
+ * mei_host_buffer_is_empty - checks if host buffer is empty.
+ *
+ * @dev: the device structure
+ *
+ * returns 1 if empty, 0 - otherwise.
+ */
+int mei_host_buffer_is_empty(struct mei_device *dev)
+{
+       unsigned char filled_slots;
+
+       dev->host_hw_state = mei_hcsr_read(dev);
+       filled_slots = _host_get_filled_slots(dev);
+
+       if (filled_slots == 0)
+               return 1;
+
+       return 0;
+}
+
+/**
+ * mei_count_empty_write_slots - counts write empty slots.
+ *
+ * @dev: the device structure
+ *
+ * returns -1(ESLOTS_OVERFLOW) if overflow, otherwise empty slots count
+ */
+int mei_count_empty_write_slots(struct mei_device *dev)
+{
+       unsigned char buffer_depth, filled_slots, empty_slots;
+
+       dev->host_hw_state = mei_hcsr_read(dev);
+       buffer_depth = (unsigned char) ((dev->host_hw_state & H_CBD) >> 24);
+       filled_slots = _host_get_filled_slots(dev);
+       empty_slots = buffer_depth - filled_slots;
+
+       /* check for overflow */
+       if (filled_slots > buffer_depth)
+               return -EOVERFLOW;
+
+       return empty_slots;
+}
+
+/**
+ * mei_write_message - writes a message to mei device.
+ *
+ * @dev: the device structure
+ * @header: header of message
+ * @write_buffer: message buffer will be written
+ * @write_length: message size will be written
+ *
+ * returns 1 if success, 0 - otherwise.
+ */
+int mei_write_message(struct mei_device *dev,
+                            struct mei_msg_hdr *header,
+                            unsigned char *write_buffer,
+                            unsigned long write_length)
+{
+       u32 temp_msg = 0;
+       unsigned long bytes_written = 0;
+       unsigned char buffer_depth, filled_slots, empty_slots;
+       unsigned long dw_to_write;
+
+       dev->host_hw_state = mei_hcsr_read(dev);
+
+       dev_dbg(&dev->pdev->dev,
+                       "host_hw_state = 0x%08x.\n",
+                       dev->host_hw_state);
+
+       dev_dbg(&dev->pdev->dev,
+                       "mei_write_message header=%08x.\n",
+                       *((u32 *) header));
+
+       buffer_depth = (unsigned char) ((dev->host_hw_state & H_CBD) >> 24);
+       filled_slots = _host_get_filled_slots(dev);
+       empty_slots = buffer_depth - filled_slots;
+       dev_dbg(&dev->pdev->dev,
+                       "filled = %hu, empty = %hu.\n",
+                       filled_slots, empty_slots);
+
+       dw_to_write = ((write_length + 3) / 4);
+
+       if (dw_to_write > empty_slots)
+               return 0;
+
+       mei_reg_write(dev, H_CB_WW, *((u32 *) header));
+
+       while (write_length >= 4) {
+               mei_reg_write(dev, H_CB_WW,
+                               *(u32 *) (write_buffer + bytes_written));
+               bytes_written += 4;
+               write_length -= 4;
+       }
+
+       if (write_length > 0) {
+               memcpy(&temp_msg, &write_buffer[bytes_written], write_length);
+               mei_reg_write(dev, H_CB_WW, temp_msg);
+       }
+
+       dev->host_hw_state |= H_IG;
+       mei_hcsr_set(dev);
+       dev->me_hw_state = mei_mecsr_read(dev);
+       if ((dev->me_hw_state & ME_RDY_HRA) != ME_RDY_HRA)
+               return 0;
+
+       dev->write_hang = 0;
+       return 1;
+}
+
+/**
+ * mei_count_full_read_slots - counts read full slots.
+ *
+ * @dev: the device structure
+ *
+ * returns -1(ESLOTS_OVERFLOW) if overflow, otherwise filled slots count
+ */
+int mei_count_full_read_slots(struct mei_device *dev)
+{
+       char read_ptr, write_ptr;
+       unsigned char buffer_depth, filled_slots;
+
+       dev->me_hw_state = mei_mecsr_read(dev);
+       buffer_depth = (unsigned char)((dev->me_hw_state & ME_CBD_HRA) >> 24);
+       read_ptr = (char) ((dev->me_hw_state & ME_CBRP_HRA) >> 8);
+       write_ptr = (char) ((dev->me_hw_state & ME_CBWP_HRA) >> 16);
+       filled_slots = (unsigned char) (write_ptr - read_ptr);
+
+       /* check for overflow */
+       if (filled_slots > buffer_depth)
+               return -EOVERFLOW;
+
+       dev_dbg(&dev->pdev->dev, "filled_slots =%08x\n", filled_slots);
+       return (int)filled_slots;
+}
+
+/**
+ * mei_read_slots - reads a message from mei device.
+ *
+ * @dev: the device structure
+ * @buffer: message buffer will be written
+ * @buffer_length: message size will be read
+ */
+void mei_read_slots(struct mei_device *dev,
+                    unsigned char *buffer, unsigned long buffer_length)
+{
+       u32 i = 0;
+       unsigned char temp_buf[sizeof(u32)];
+
+       while (buffer_length >= sizeof(u32)) {
+               ((u32 *) buffer)[i] = mei_mecbrw_read(dev);
+
+               dev_dbg(&dev->pdev->dev,
+                               "buffer[%d]= %d\n",
+                               i, ((u32 *) buffer)[i]);
+
+               i++;
+               buffer_length -= sizeof(u32);
+       }
+
+       if (buffer_length > 0) {
+               *((u32 *) &temp_buf) = mei_mecbrw_read(dev);
+               memcpy(&buffer[i * 4], temp_buf, buffer_length);
+       }
+
+       dev->host_hw_state |= H_IG;
+       mei_hcsr_set(dev);
+}
+
+/**
+ * mei_flow_ctrl_creds - checks flow_control credentials.
+ *
+ * @dev: the device structure
+ * @cl: private data of the file object
+ *
+ * returns 1 if mei_flow_ctrl_creds >0, 0 - otherwise.
+ *     -ENOENT if mei_cl is not present
+ *     -EINVAL if single_recv_buf == 0
+ */
+int mei_flow_ctrl_creds(struct mei_device *dev, struct mei_cl *cl)
+{
+       int i;
+
+       if (!dev->num_mei_me_clients)
+               return 0;
+
+       if (cl->mei_flow_ctrl_creds > 0)
+               return 1;
+
+       for (i = 0; i < dev->num_mei_me_clients; i++) {
+               struct mei_me_client  *me_cl = &dev->me_clients[i];
+               if (me_cl->client_id == cl->me_client_id) {
+                       if (me_cl->mei_flow_ctrl_creds) {
+                               if (WARN_ON(me_cl->props.single_recv_buf == 0))
+                                       return -EINVAL;
+                               return 1;
+                       } else {
+                               return 0;
+                       }
+               }
+       }
+       return -ENOENT;
+}
+
+/**
+ * mei_flow_ctrl_reduce - reduces flow_control.
+ *
+ * @dev: the device structure
+ * @cl: private data of the file object
+ * @returns
+ *     0 on success
+ *     -ENOENT when me client is not found
+ *     -EINVAL wehn ctrl credits are <= 0
+ */
+int mei_flow_ctrl_reduce(struct mei_device *dev, struct mei_cl *cl)
+{
+       int i;
+
+       if (!dev->num_mei_me_clients)
+               return -ENOENT;
+
+       for (i = 0; i < dev->num_mei_me_clients; i++) {
+               struct mei_me_client  *me_cl = &dev->me_clients[i];
+               if (me_cl->client_id == cl->me_client_id) {
+                       if (me_cl->props.single_recv_buf != 0) {
+                               if (WARN_ON(me_cl->mei_flow_ctrl_creds <= 0))
+                                       return -EINVAL;
+                               dev->me_clients[i].mei_flow_ctrl_creds--;
+                       } else {
+                               if (WARN_ON(cl->mei_flow_ctrl_creds <= 0))
+                                       return -EINVAL;
+                               cl->mei_flow_ctrl_creds--;
+                       }
+                       return 0;
+               }
+       }
+       return -ENOENT;
+}
+
+/**
+ * mei_send_flow_control - sends flow control to fw.
+ *
+ * @dev: the device structure
+ * @cl: private data of the file object
+ *
+ * returns 1 if success, 0 - otherwise.
+ */
+int mei_send_flow_control(struct mei_device *dev, struct mei_cl *cl)
+{
+       struct mei_msg_hdr *mei_hdr;
+       struct hbm_flow_control *mei_flow_control;
+
+       mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
+       mei_hdr->host_addr = 0;
+       mei_hdr->me_addr = 0;
+       mei_hdr->length = sizeof(struct hbm_flow_control);
+       mei_hdr->msg_complete = 1;
+       mei_hdr->reserved = 0;
+
+       mei_flow_control = (struct hbm_flow_control *) &dev->wr_msg_buf[1];
+       memset(mei_flow_control, 0, sizeof(mei_flow_control));
+       mei_flow_control->host_addr = cl->host_client_id;
+       mei_flow_control->me_addr = cl->me_client_id;
+       mei_flow_control->cmd.cmd = MEI_FLOW_CONTROL_CMD;
+       memset(mei_flow_control->reserved, 0,
+                       sizeof(mei_flow_control->reserved));
+       dev_dbg(&dev->pdev->dev, "sending flow control host client = %d, ME client = %d\n",
+           cl->host_client_id, cl->me_client_id);
+       if (!mei_write_message(dev, mei_hdr,
+                               (unsigned char *) mei_flow_control,
+                               sizeof(struct hbm_flow_control)))
+               return 0;
+
+       return 1;
+
+}
+
+/**
+ * mei_other_client_is_connecting - checks if other
+ *    client with the same client id is connected.
+ *
+ * @dev: the device structure
+ * @cl: private data of the file object
+ *
+ * returns 1 if other client is connected, 0 - otherwise.
+ */
+int mei_other_client_is_connecting(struct mei_device *dev,
+                               struct mei_cl *cl)
+{
+       struct mei_cl *cl_pos = NULL;
+       struct mei_cl *cl_next = NULL;
+
+       list_for_each_entry_safe(cl_pos, cl_next, &dev->file_list, link) {
+               if ((cl_pos->state == MEI_FILE_CONNECTING) &&
+                       (cl_pos != cl) &&
+                       cl->me_client_id == cl_pos->me_client_id)
+                       return 1;
+
+       }
+       return 0;
+}
+
+/**
+ * mei_disconnect - sends disconnect message to fw.
+ *
+ * @dev: the device structure
+ * @cl: private data of the file object
+ *
+ * returns 1 if success, 0 - otherwise.
+ */
+int mei_disconnect(struct mei_device *dev, struct mei_cl *cl)
+{
+       struct mei_msg_hdr *mei_hdr;
+       struct hbm_client_disconnect_request *mei_cli_disconnect;
+
+       mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
+       mei_hdr->host_addr = 0;
+       mei_hdr->me_addr = 0;
+       mei_hdr->length = sizeof(struct hbm_client_disconnect_request);
+       mei_hdr->msg_complete = 1;
+       mei_hdr->reserved = 0;
+
+       mei_cli_disconnect =
+           (struct hbm_client_disconnect_request *) &dev->wr_msg_buf[1];
+       memset(mei_cli_disconnect, 0, sizeof(mei_cli_disconnect));
+       mei_cli_disconnect->host_addr = cl->host_client_id;
+       mei_cli_disconnect->me_addr = cl->me_client_id;
+       mei_cli_disconnect->cmd.cmd = CLIENT_DISCONNECT_REQ_CMD;
+       mei_cli_disconnect->reserved[0] = 0;
+
+       if (!mei_write_message(dev, mei_hdr,
+                               (unsigned char *) mei_cli_disconnect,
+                               sizeof(struct hbm_client_disconnect_request)))
+               return 0;
+
+       return 1;
+}
+
+/**
+ * mei_connect - sends connect message to fw.
+ *
+ * @dev: the device structure
+ * @cl: private data of the file object
+ *
+ * returns 1 if success, 0 - otherwise.
+ */
+int mei_connect(struct mei_device *dev, struct mei_cl *cl)
+{
+       struct mei_msg_hdr *mei_hdr;
+       struct hbm_client_connect_request *mei_cli_connect;
+
+       mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
+       mei_hdr->host_addr = 0;
+       mei_hdr->me_addr = 0;
+       mei_hdr->length = sizeof(struct hbm_client_connect_request);
+       mei_hdr->msg_complete = 1;
+       mei_hdr->reserved = 0;
+
+       mei_cli_connect =
+           (struct hbm_client_connect_request *) &dev->wr_msg_buf[1];
+       mei_cli_connect->host_addr = cl->host_client_id;
+       mei_cli_connect->me_addr = cl->me_client_id;
+       mei_cli_connect->cmd.cmd = CLIENT_CONNECT_REQ_CMD;
+       mei_cli_connect->reserved = 0;
+
+       if (!mei_write_message(dev, mei_hdr,
+                               (unsigned char *) mei_cli_connect,
+                               sizeof(struct hbm_client_connect_request)))
+               return 0;
+
+       return 1;
+}