/*
*
* 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 "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
*
* This function returns -EIO if write has failed
*/
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 -EIO;
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 -EIO;
return 0;
}
/**
* 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 *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, ®, 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->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;
}
/**
* 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 when ctrl credits are <= 0
*/
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;
}
/**
* mei_send_flow_control - sends flow control to fw.
*
* @dev: the device structure
* @cl: private data of the file object
*
* This function returns -EIO on write failure
*/
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));
}
/**
* 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
*
* This function returns -EIO on write failure
*/
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));
}
/**
* mei_connect - sends connect message to fw.
*
* @dev: the device structure
* @cl: private data of the file object
*
* This function returns -EIO on write failure
*/
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));
}