linux/drivers/misc/mei/init.c
Tomas Winkler 6009595a66 mei: bus: link client devices instead of host clients
MEI bus was designed around nfc and was hard to extend.
Instead of the hard coded way of adding the devices on the mei bus
we scan the whole me client list and create a device for each
eligible me client (mei_cl_bus_rescan); currently we support
only clients with single connection and fixed address clients.
NFC radio name detection is run as a fixup routine

The patch replaces handling the device list based on struct me_cl
to device list based on me_cl_devices. The creating a connection
is pushed from the device creation time to device enablement.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-03 17:24:48 -07:00

430 lines
9.9 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/export.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/delay.h>
#include <linux/mei.h>
#include "mei_dev.h"
#include "hbm.h"
#include "client.h"
const char *mei_dev_state_str(int state)
{
#define MEI_DEV_STATE(state) case MEI_DEV_##state: return #state
switch (state) {
MEI_DEV_STATE(INITIALIZING);
MEI_DEV_STATE(INIT_CLIENTS);
MEI_DEV_STATE(ENABLED);
MEI_DEV_STATE(RESETTING);
MEI_DEV_STATE(DISABLED);
MEI_DEV_STATE(POWER_DOWN);
MEI_DEV_STATE(POWER_UP);
default:
return "unknown";
}
#undef MEI_DEV_STATE
}
const char *mei_pg_state_str(enum mei_pg_state state)
{
#define MEI_PG_STATE(state) case MEI_PG_##state: return #state
switch (state) {
MEI_PG_STATE(OFF);
MEI_PG_STATE(ON);
default:
return "unknown";
}
#undef MEI_PG_STATE
}
/**
* mei_fw_status2str - convert fw status registers to printable string
*
* @fw_status: firmware status
* @buf: string buffer at minimal size MEI_FW_STATUS_STR_SZ
* @len: buffer len must be >= MEI_FW_STATUS_STR_SZ
*
* Return: number of bytes written or -EINVAL if buffer is to small
*/
ssize_t mei_fw_status2str(struct mei_fw_status *fw_status,
char *buf, size_t len)
{
ssize_t cnt = 0;
int i;
buf[0] = '\0';
if (len < MEI_FW_STATUS_STR_SZ)
return -EINVAL;
for (i = 0; i < fw_status->count; i++)
cnt += scnprintf(buf + cnt, len - cnt, "%08X ",
fw_status->status[i]);
/* drop last space */
buf[cnt] = '\0';
return cnt;
}
EXPORT_SYMBOL_GPL(mei_fw_status2str);
/**
* mei_cancel_work - Cancel mei background jobs
*
* @dev: the device structure
*/
void mei_cancel_work(struct mei_device *dev)
{
cancel_work_sync(&dev->init_work);
cancel_work_sync(&dev->reset_work);
cancel_delayed_work(&dev->timer_work);
}
EXPORT_SYMBOL_GPL(mei_cancel_work);
/**
* mei_reset - resets host and fw.
*
* @dev: the device structure
*
* Return: 0 on success or < 0 if the reset hasn't succeeded
*/
int mei_reset(struct mei_device *dev)
{
enum mei_dev_state state = dev->dev_state;
bool interrupts_enabled;
int ret;
if (state != MEI_DEV_INITIALIZING &&
state != MEI_DEV_DISABLED &&
state != MEI_DEV_POWER_DOWN &&
state != MEI_DEV_POWER_UP) {
char fw_sts_str[MEI_FW_STATUS_STR_SZ];
mei_fw_status_str(dev, fw_sts_str, MEI_FW_STATUS_STR_SZ);
dev_warn(dev->dev, "unexpected reset: dev_state = %s fw status = %s\n",
mei_dev_state_str(state), fw_sts_str);
}
/* we're already in reset, cancel the init timer
* if the reset was called due the hbm protocol error
* we need to call it before hw start
* so the hbm watchdog won't kick in
*/
mei_hbm_idle(dev);
/* enter reset flow */
interrupts_enabled = state != MEI_DEV_POWER_DOWN;
dev->dev_state = MEI_DEV_RESETTING;
dev->reset_count++;
if (dev->reset_count > MEI_MAX_CONSEC_RESET) {
dev_err(dev->dev, "reset: reached maximal consecutive resets: disabling the device\n");
dev->dev_state = MEI_DEV_DISABLED;
return -ENODEV;
}
ret = mei_hw_reset(dev, interrupts_enabled);
/* fall through and remove the sw state even if hw reset has failed */
/* no need to clean up software state in case of power up */
if (state != MEI_DEV_INITIALIZING &&
state != MEI_DEV_POWER_UP) {
/* remove all waiting requests */
mei_cl_all_write_clear(dev);
mei_cl_all_disconnect(dev);
/* wake up all readers and writers so they can be interrupted */
mei_cl_all_wakeup(dev);
/* remove entry if already in list */
dev_dbg(dev->dev, "remove iamthif and wd from the file list.\n");
mei_cl_unlink(&dev->wd_cl);
mei_cl_unlink(&dev->iamthif_cl);
mei_amthif_reset_params(dev);
}
mei_hbm_reset(dev);
dev->rd_msg_hdr = 0;
dev->wd_pending = false;
if (ret) {
dev_err(dev->dev, "hw_reset failed ret = %d\n", ret);
return ret;
}
if (state == MEI_DEV_POWER_DOWN) {
dev_dbg(dev->dev, "powering down: end of reset\n");
dev->dev_state = MEI_DEV_DISABLED;
return 0;
}
ret = mei_hw_start(dev);
if (ret) {
dev_err(dev->dev, "hw_start failed ret = %d\n", ret);
return ret;
}
dev_dbg(dev->dev, "link is established start sending messages.\n");
dev->dev_state = MEI_DEV_INIT_CLIENTS;
ret = mei_hbm_start_req(dev);
if (ret) {
dev_err(dev->dev, "hbm_start failed ret = %d\n", ret);
dev->dev_state = MEI_DEV_RESETTING;
return ret;
}
return 0;
}
EXPORT_SYMBOL_GPL(mei_reset);
/**
* mei_start - initializes host and fw to start work.
*
* @dev: the device structure
*
* Return: 0 on success, <0 on failure.
*/
int mei_start(struct mei_device *dev)
{
int ret;
mutex_lock(&dev->device_lock);
/* acknowledge interrupt and stop interrupts */
mei_clear_interrupts(dev);
mei_hw_config(dev);
dev_dbg(dev->dev, "reset in start the mei device.\n");
dev->reset_count = 0;
do {
dev->dev_state = MEI_DEV_INITIALIZING;
ret = mei_reset(dev);
if (ret == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
dev_err(dev->dev, "reset failed ret = %d", ret);
goto err;
}
} while (ret);
/* we cannot start the device w/o hbm start message completed */
if (dev->dev_state == MEI_DEV_DISABLED) {
dev_err(dev->dev, "reset failed");
goto err;
}
if (mei_hbm_start_wait(dev)) {
dev_err(dev->dev, "HBM haven't started");
goto err;
}
if (!mei_host_is_ready(dev)) {
dev_err(dev->dev, "host is not ready.\n");
goto err;
}
if (!mei_hw_is_ready(dev)) {
dev_err(dev->dev, "ME is not ready.\n");
goto err;
}
if (!mei_hbm_version_is_supported(dev)) {
dev_dbg(dev->dev, "MEI start failed.\n");
goto err;
}
dev_dbg(dev->dev, "link layer has been established.\n");
mutex_unlock(&dev->device_lock);
return 0;
err:
dev_err(dev->dev, "link layer initialization failed.\n");
dev->dev_state = MEI_DEV_DISABLED;
mutex_unlock(&dev->device_lock);
return -ENODEV;
}
EXPORT_SYMBOL_GPL(mei_start);
/**
* mei_restart - restart device after suspend
*
* @dev: the device structure
*
* Return: 0 on success or -ENODEV if the restart hasn't succeeded
*/
int mei_restart(struct mei_device *dev)
{
int err;
mutex_lock(&dev->device_lock);
mei_clear_interrupts(dev);
dev->dev_state = MEI_DEV_POWER_UP;
dev->reset_count = 0;
err = mei_reset(dev);
mutex_unlock(&dev->device_lock);
if (err == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
dev_err(dev->dev, "device disabled = %d\n", err);
return -ENODEV;
}
/* try to start again */
if (err)
schedule_work(&dev->reset_work);
return 0;
}
EXPORT_SYMBOL_GPL(mei_restart);
static void mei_reset_work(struct work_struct *work)
{
struct mei_device *dev =
container_of(work, struct mei_device, reset_work);
int ret;
mutex_lock(&dev->device_lock);
ret = mei_reset(dev);
mutex_unlock(&dev->device_lock);
if (dev->dev_state == MEI_DEV_DISABLED) {
dev_err(dev->dev, "device disabled = %d\n", ret);
return;
}
/* retry reset in case of failure */
if (ret)
schedule_work(&dev->reset_work);
}
void mei_stop(struct mei_device *dev)
{
dev_dbg(dev->dev, "stopping the device.\n");
mei_cancel_work(dev);
mei_cl_bus_remove_devices(dev);
mutex_lock(&dev->device_lock);
mei_wd_stop(dev);
dev->dev_state = MEI_DEV_POWER_DOWN;
mei_reset(dev);
/* move device to disabled state unconditionally */
dev->dev_state = MEI_DEV_DISABLED;
mutex_unlock(&dev->device_lock);
mei_watchdog_unregister(dev);
}
EXPORT_SYMBOL_GPL(mei_stop);
/**
* mei_write_is_idle - check if the write queues are idle
*
* @dev: the device structure
*
* Return: true of there is no pending write
*/
bool mei_write_is_idle(struct mei_device *dev)
{
bool idle = (dev->dev_state == MEI_DEV_ENABLED &&
list_empty(&dev->ctrl_wr_list.list) &&
list_empty(&dev->write_list.list) &&
list_empty(&dev->write_waiting_list.list));
dev_dbg(dev->dev, "write pg: is idle[%d] state=%s ctrl=%01d write=%01d wwait=%01d\n",
idle,
mei_dev_state_str(dev->dev_state),
list_empty(&dev->ctrl_wr_list.list),
list_empty(&dev->write_list.list),
list_empty(&dev->write_waiting_list.list));
return idle;
}
EXPORT_SYMBOL_GPL(mei_write_is_idle);
/**
* mei_device_init -- initialize mei_device structure
*
* @dev: the mei device
* @device: the device structure
* @hw_ops: hw operations
*/
void mei_device_init(struct mei_device *dev,
struct device *device,
const struct mei_hw_ops *hw_ops)
{
/* setup our list array */
INIT_LIST_HEAD(&dev->file_list);
INIT_LIST_HEAD(&dev->device_list);
INIT_LIST_HEAD(&dev->me_clients);
mutex_init(&dev->device_lock);
init_rwsem(&dev->me_clients_rwsem);
mutex_init(&dev->cl_bus_lock);
init_waitqueue_head(&dev->wait_hw_ready);
init_waitqueue_head(&dev->wait_pg);
init_waitqueue_head(&dev->wait_hbm_start);
init_waitqueue_head(&dev->wait_stop_wd);
dev->dev_state = MEI_DEV_INITIALIZING;
dev->reset_count = 0;
mei_io_list_init(&dev->write_list);
mei_io_list_init(&dev->write_waiting_list);
mei_io_list_init(&dev->ctrl_wr_list);
mei_io_list_init(&dev->ctrl_rd_list);
INIT_DELAYED_WORK(&dev->timer_work, mei_timer);
INIT_WORK(&dev->init_work, mei_host_client_init);
INIT_WORK(&dev->reset_work, mei_reset_work);
INIT_LIST_HEAD(&dev->wd_cl.link);
INIT_LIST_HEAD(&dev->iamthif_cl.link);
mei_io_list_init(&dev->amthif_cmd_list);
mei_io_list_init(&dev->amthif_rd_complete_list);
bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX);
dev->open_handle_count = 0;
/*
* Reserving the first client ID
* 0: Reserved for MEI Bus Message communications
*/
bitmap_set(dev->host_clients_map, 0, 1);
dev->pg_event = MEI_PG_EVENT_IDLE;
dev->ops = hw_ops;
dev->dev = device;
}
EXPORT_SYMBOL_GPL(mei_device_init);