linux/drivers/misc/mei/interface.c
Tomas Winkler 5bd6471441 mei: compact code for mei bus message creation
1. replace boilerplate code for filling up the bus message header
 with a common wrapper function
2. shorten variable names and use temporal variables
 to save some screen space

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-21 12:43:57 -08:00

389 lines
9.5 KiB
C

/*
*
* 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"
/**
* 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);
}
/**
* mei_hbuf_filled_slots - gets number of device filled buffer slots
*
* @device: the device structure
*
* returns number of filled slots
*/
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);
}
/**
* mei_hbuf_is_empty - checks if host buffer is empty.
*
* @dev: the device structure
*
* returns true if empty, false - otherwise.
*/
bool mei_hbuf_is_empty(struct mei_device *dev)
{
return mei_hbuf_filled_slots(dev) == 0;
}
/**
* mei_hbuf_empty_slots - counts write empty slots.
*
* @dev: the device structure
*
* returns -1(ESLOTS_OVERFLOW) if overflow, otherwise empty slots count
*/
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;
}
/**
* 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 *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;
}
/**
* 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, &reg, 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 *flow_ctrl;
const size_t len = sizeof(struct hbm_flow_control);
mei_hdr = mei_hbm_hdr(&dev->wr_msg_buf[0], len);
flow_ctrl = (struct hbm_flow_control *)&dev->wr_msg_buf[1];
memset(flow_ctrl, 0, len);
flow_ctrl->hbm_cmd = MEI_FLOW_CONTROL_CMD;
flow_ctrl->host_addr = cl->host_client_id;
flow_ctrl->me_addr = cl->me_client_id;
/* FIXME: reserved !? */
memset(flow_ctrl->reserved, 0, sizeof(flow_ctrl->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 *) flow_ctrl, len);
}
/**
* 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_connect_request *req;
const size_t len = sizeof(struct hbm_client_connect_request);
mei_hdr = mei_hbm_hdr(&dev->wr_msg_buf[0], len);
req = (struct hbm_client_connect_request *)&dev->wr_msg_buf[1];
memset(req, 0, len);
req->hbm_cmd = CLIENT_DISCONNECT_REQ_CMD;
req->host_addr = cl->host_client_id;
req->me_addr = cl->me_client_id;
req->reserved = 0;
return mei_write_message(dev, mei_hdr, (unsigned char *)req, len);
}
/**
* 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 *req;
const size_t len = sizeof(struct hbm_client_connect_request);
mei_hdr = mei_hbm_hdr(&dev->wr_msg_buf[0], len);
req = (struct hbm_client_connect_request *) &dev->wr_msg_buf[1];
req->hbm_cmd = CLIENT_CONNECT_REQ_CMD;
req->host_addr = cl->host_client_id;
req->me_addr = cl->me_client_id;
req->reserved = 0;
return mei_write_message(dev, mei_hdr, (unsigned char *) req, len);
}