Skip to content

Commit

Permalink
mei: expose device state in sysfs
Browse files Browse the repository at this point in the history 
Expose mei device state to user-space through sysfs.
This gives indication to applications that driver is in transition,
usefully mostly to detect link reset state.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  • Loading branch information
Alexander Usyskin authored and Greg Kroah-Hartman committed Apr 25, 2019
1 parent d65bf04 commit 43b8a7e
Show file tree
Hide file tree
Showing 5 changed files with 87 additions and 18 deletions.
15 changes: 15 additions & 0 deletions Documentation/ABI/testing/sysfs-class-mei
View file
Original file line number Diff line number Diff line change
Expand Up @@ -65,3 +65,18 @@ Description: Display the ME firmware version.
<platform>:<major>.<minor>.<milestone>.<build_no>.
There can be up to three such blocks for different
FW components.

What: /sys/class/mei/meiN/dev_state
Date: Mar 2019
KernelVersion: 5.1
Contact: Tomas Winkler <tomas.winkler@intel.com>
Description: Display the ME device state.

The device state can have following values:
INITIALIZING
INIT_CLIENTS
ENABLED
RESETTING
DISABLED
POWER_DOWN
POWER_UP
2 changes: 1 addition & 1 deletion drivers/misc/mei/client.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -669,7 +669,7 @@ int mei_cl_unlink(struct mei_cl *cl)

void mei_host_client_init(struct mei_device *dev)
{
dev->dev_state = MEI_DEV_ENABLED;
mei_set_devstate(dev, MEI_DEV_ENABLED);
dev->reset_count = 0;

schedule_work(&dev->bus_rescan_work);
Expand Down
20 changes: 10 additions & 10 deletions drivers/misc/mei/init.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -123,12 +123,12 @@ int mei_reset(struct mei_device *dev)

/* enter reset flow */
interrupts_enabled = state != MEI_DEV_POWER_DOWN;
dev->dev_state = MEI_DEV_RESETTING;
mei_set_devstate(dev, 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;
mei_set_devstate(dev, MEI_DEV_DISABLED);
return -ENODEV;
}

Expand All @@ -150,7 +150,7 @@ int mei_reset(struct mei_device *dev)

if (state == MEI_DEV_POWER_DOWN) {
dev_dbg(dev->dev, "powering down: end of reset\n");
dev->dev_state = MEI_DEV_DISABLED;
mei_set_devstate(dev, MEI_DEV_DISABLED);
return 0;
}

Expand All @@ -162,11 +162,11 @@ int mei_reset(struct mei_device *dev)

dev_dbg(dev->dev, "link is established start sending messages.\n");

dev->dev_state = MEI_DEV_INIT_CLIENTS;
mei_set_devstate(dev, 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;
mei_set_devstate(dev, MEI_DEV_RESETTING);
return ret;
}

Expand Down Expand Up @@ -196,7 +196,7 @@ int mei_start(struct mei_device *dev)

dev->reset_count = 0;
do {
dev->dev_state = MEI_DEV_INITIALIZING;
mei_set_devstate(dev, MEI_DEV_INITIALIZING);
ret = mei_reset(dev);

if (ret == -ENODEV || dev->dev_state == MEI_DEV_DISABLED) {
Expand Down Expand Up @@ -231,7 +231,7 @@ int mei_start(struct mei_device *dev)
return 0;
err:
dev_err(dev->dev, "link layer initialization failed.\n");
dev->dev_state = MEI_DEV_DISABLED;
mei_set_devstate(dev, MEI_DEV_DISABLED);
mutex_unlock(&dev->device_lock);
return -ENODEV;
}
Expand All @@ -250,7 +250,7 @@ int mei_restart(struct mei_device *dev)

mutex_lock(&dev->device_lock);

dev->dev_state = MEI_DEV_POWER_UP;
mei_set_devstate(dev, MEI_DEV_POWER_UP);
dev->reset_count = 0;

err = mei_reset(dev);
Expand Down Expand Up @@ -301,7 +301,7 @@ void mei_stop(struct mei_device *dev)
dev_dbg(dev->dev, "stopping the device.\n");

mutex_lock(&dev->device_lock);
dev->dev_state = MEI_DEV_POWER_DOWN;
mei_set_devstate(dev, MEI_DEV_POWER_DOWN);
mutex_unlock(&dev->device_lock);
mei_cl_bus_remove_devices(dev);

Expand All @@ -314,7 +314,7 @@ void mei_stop(struct mei_device *dev)

mei_reset(dev);
/* move device to disabled state unconditionally */
dev->dev_state = MEI_DEV_DISABLED;
mei_set_devstate(dev, MEI_DEV_DISABLED);

mutex_unlock(&dev->device_lock);
}
Expand Down
65 changes: 59 additions & 6 deletions drivers/misc/mei/main.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -28,6 +28,12 @@
#include "mei_dev.h"
#include "client.h"

static struct class *mei_class;
static dev_t mei_devt;
#define MEI_MAX_DEVS MINORMASK
static DEFINE_MUTEX(mei_minor_lock);
static DEFINE_IDR(mei_idr);

/**
* mei_open - the open function
*
Expand Down Expand Up @@ -829,12 +835,65 @@ static ssize_t fw_ver_show(struct device *device,
}
static DEVICE_ATTR_RO(fw_ver);

/**
* dev_state_show - display device state
*
* @device: device pointer
* @attr: attribute pointer
* @buf: char out buffer
*
* Return: number of the bytes printed into buf or error
*/
static ssize_t dev_state_show(struct device *device,
struct device_attribute *attr, char *buf)
{
struct mei_device *dev = dev_get_drvdata(device);
enum mei_dev_state dev_state;

mutex_lock(&dev->device_lock);
dev_state = dev->dev_state;
mutex_unlock(&dev->device_lock);

return sprintf(buf, "%s", mei_dev_state_str(dev_state));
}
static DEVICE_ATTR_RO(dev_state);

static int match_devt(struct device *dev, const void *data)
{
const dev_t *devt = data;

return dev->devt == *devt;
}

/**
* dev_set_devstate: set to new device state and notify sysfs file.
*
* @dev: mei_device
* @state: new device state
*/
void mei_set_devstate(struct mei_device *dev, enum mei_dev_state state)
{
struct device *clsdev;

if (dev->dev_state == state)
return;

dev->dev_state = state;

clsdev = class_find_device(mei_class, NULL, &dev->cdev.dev, match_devt);
if (clsdev) {
sysfs_notify(&clsdev->kobj, NULL, "dev_state");
put_device(clsdev);
}
}

static struct attribute *mei_attrs[] = {
&dev_attr_fw_status.attr,
&dev_attr_hbm_ver.attr,
&dev_attr_hbm_ver_drv.attr,
&dev_attr_tx_queue_limit.attr,
&dev_attr_fw_ver.attr,
&dev_attr_dev_state.attr,
NULL
};
ATTRIBUTE_GROUPS(mei);
Expand All @@ -858,12 +917,6 @@ static const struct file_operations mei_fops = {
.llseek = no_llseek
};

static struct class *mei_class;
static dev_t mei_devt;
#define MEI_MAX_DEVS MINORMASK
static DEFINE_MUTEX(mei_minor_lock);
static DEFINE_IDR(mei_idr);

/**
* mei_minor_get - obtain next free device minor number
*
Expand Down
3 changes: 2 additions & 1 deletion drivers/misc/mei/mei_dev.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -525,7 +525,6 @@ struct mei_device {
struct dentry *dbgfs_dir;
#endif /* CONFIG_DEBUG_FS */


const struct mei_hw_ops *ops;
char hw[0] __aligned(sizeof(void *));
};
Expand Down Expand Up @@ -584,6 +583,8 @@ int mei_restart(struct mei_device *dev);
void mei_stop(struct mei_device *dev);
void mei_cancel_work(struct mei_device *dev);

void mei_set_devstate(struct mei_device *dev, enum mei_dev_state state);

int mei_dmam_ring_alloc(struct mei_device *dev);
void mei_dmam_ring_free(struct mei_device *dev);
bool mei_dma_ring_is_allocated(struct mei_device *dev);
Expand Down

0 comments on commit 43b8a7e

Please sign in to comment.