Commit 43b8a7ed authored by Alexander Usyskin's avatar Alexander Usyskin Committed by Greg Kroah-Hartman
Browse files

mei: expose device state in sysfs 



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: default avatarAlexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: default avatarTomas Winkler <tomas.winkler@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent d65bf042

Documentation/ABI/testing/sysfs-class-mei

+15 −0
Original line number Diff line number Diff line
@@ -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

drivers/misc/mei/client.c

+1 −1
Original line number Diff line number Diff line
@@ -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);

drivers/misc/mei/init.c

+10 −10
Original line number Diff line number Diff line
@@ -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;

	}
@@ -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;

	}
@@ -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;

	}
@@ -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) {
@@ -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;

}
@@ -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);
@@ -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);
@@ -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);

}

drivers/misc/mei/main.c

+59 −6
Original line number Diff line number Diff line
@@ -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

 *
@@ -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);
@@ -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

 *

drivers/misc/mei/mei_dev.h

+2 −1
Original line number Diff line number Diff line
@@ -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 *));

};
@@ -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);

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