interface.c

Go to the documentation of this file.

/*
 *
 * Intel Management Engine Interface (Intel MEI) Linux driver
 * Copyright (c) 2003-2012, 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 <linux/mei.h>
#include "interface.h"



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);
}

void mei_enable_interrupts(struct mei_device *dev)
{
    dev->host_hw_state |= H_IE;
    mei_hcsr_set(dev);
}

void mei_disable_interrupts(struct mei_device *dev)
{
    dev->host_hw_state &= ~H_IE;
    mei_hcsr_set(dev);
}

static unsigned char mei_hbuf_filled_slots(struct mei_device *dev)
{
    char read_ptr, write_ptr;

    dev->host_hw_state = mei_hcsr_read(dev);

    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);
}

bool mei_hbuf_is_empty(struct mei_device *dev)
{
    return mei_hbuf_filled_slots(dev) == 0;
}

int mei_hbuf_empty_slots(struct mei_device *dev)
{
    unsigned char filled_slots, empty_slots;

    filled_slots = mei_hbuf_filled_slots(dev);
    empty_slots = dev->hbuf_depth - filled_slots;

    /* check for overflow */
    if (filled_slots > dev->hbuf_depth)
        return -EOVERFLOW;

    return empty_slots;
}

int mei_write_message(struct mei_device *dev, struct mei_msg_hdr *header,
              unsigned char *buf, unsigned long length)
{
    unsigned long rem, dw_cnt;
    u32 *reg_buf = (u32 *)buf;
    int i;
    int empty_slots;


    dev_dbg(&dev->pdev->dev,
            "mei_write_message header=%08x.\n",
            *((u32 *) header));

    empty_slots = mei_hbuf_empty_slots(dev);
    dev_dbg(&dev->pdev->dev, "empty slots = %hu.\n", empty_slots);

    dw_cnt = mei_data2slots(length);
    if (empty_slots < 0 || dw_cnt > empty_slots)
        return -EIO;

    mei_reg_write(dev, H_CB_WW, *((u32 *) header));

    for (i = 0; i < length / 4; i++)
        mei_reg_write(dev, H_CB_WW, reg_buf[i]);

    rem = length & 0x3;
    if (rem > 0) {
        u32 reg = 0;
        memcpy(&reg, &buf[length - rem], rem);
        mei_reg_write(dev, H_CB_WW, reg);
    }

    dev->host_hw_state = mei_hcsr_read(dev);
    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 -EIO;

    return 0;
}

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;
}

void mei_read_slots(struct mei_device *dev, unsigned char *buffer,
            unsigned long buffer_length)
{
    u32 *reg_buf = (u32 *)buffer;

    for (; buffer_length >= sizeof(u32); buffer_length -= sizeof(u32))
        *reg_buf++ = mei_mecbrw_read(dev);

    if (buffer_length > 0) {
        u32 reg = mei_mecbrw_read(dev);
        memcpy(reg_buf, &reg, buffer_length);
    }

    dev->host_hw_state |= H_IG;
    mei_hcsr_set(dev);
}

int mei_flow_ctrl_creds(struct mei_device *dev, struct mei_cl *cl)
{
    int i;

    if (!dev->me_clients_num)
        return 0;

    if (cl->mei_flow_ctrl_creds > 0)
        return 1;

    for (i = 0; i < dev->me_clients_num; 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;
}

int mei_flow_ctrl_reduce(struct mei_device *dev, struct mei_cl *cl)
{
    int i;

    if (!dev->me_clients_num)
        return -ENOENT;

    for (i = 0; i < dev->me_clients_num; 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;
}

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->hbm_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);

    return mei_write_message(dev, mei_hdr,
                (unsigned char *) mei_flow_control,
                sizeof(struct hbm_flow_control));
}

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;
}

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->hbm_cmd = CLIENT_DISCONNECT_REQ_CMD;
    mei_cli_disconnect->reserved[0] = 0;

    return mei_write_message(dev, mei_hdr,
                (unsigned char *) mei_cli_disconnect,
                sizeof(struct hbm_client_disconnect_request));
}

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->hbm_cmd = CLIENT_CONNECT_REQ_CMD;
    mei_cli_connect->reserved = 0;

    return mei_write_message(dev, mei_hdr,
                (unsigned char *) mei_cli_connect,
                sizeof(struct hbm_client_connect_request));
}