Commit b5f687f9 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

genirq/msi: Add mutex for MSI list protection 



For upcoming runtime extensions of MSI-X interrupts it's required to
protect the MSI descriptor list. Add a mutex to struct msi_device_data and
provide lock/unlock functions.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Tested-by: default avatarMichael Kelley <mikelley@microsoft.com>
Tested-by: default avatarNishanth Menon <nm@ti.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20211206210747.708877269@linutronix.de
parent 125282cd

include/linux/msi.h

+5 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ 
#define LINUX_MSI_H



#include <linux/cpumask.h>

#include <linux/mutex.h>

#include <linux/list.h>

#include <asm/msi.h>
@@ -145,17 +146,21 @@ struct msi_desc { 
 * @attrs:		Pointer to the sysfs attribute group

 * @platform_data:	Platform-MSI specific data

 * @list:		List of MSI descriptors associated to the device

 * @mutex:		Mutex protecting the MSI list

 */

struct msi_device_data {

	unsigned long			properties;

	const struct attribute_group    **attrs;

	struct platform_msi_priv_data	*platform_data;

	struct list_head		list;

	struct mutex			mutex;

};



int msi_setup_device_data(struct device *dev);



unsigned int msi_get_virq(struct device *dev, unsigned int index);

void msi_lock_descs(struct device *dev);

void msi_unlock_descs(struct device *dev);



/* Helpers to hide struct msi_desc implementation details */

#define msi_desc_to_dev(desc)		((desc)->dev)

kernel/irq/msi.c

+21 −0
Original line number Diff line number Diff line
@@ -103,11 +103,32 @@ int msi_setup_device_data(struct device *dev) 
		return -ENOMEM;



	INIT_LIST_HEAD(&md->list);

	mutex_init(&md->mutex);

	dev->msi.data = md;

	devres_add(dev, md);

	return 0;

}



/**

 * msi_lock_descs - Lock the MSI descriptor storage of a device

 * @dev:	Device to operate on

 */

void msi_lock_descs(struct device *dev)

{

	mutex_lock(&dev->msi.data->mutex);

}

EXPORT_SYMBOL_GPL(msi_lock_descs);



/**

 * msi_unlock_descs - Unlock the MSI descriptor storage of a device

 * @dev:	Device to operate on

 */

void msi_unlock_descs(struct device *dev)

{

	mutex_unlock(&dev->msi.data->mutex);

}

EXPORT_SYMBOL_GPL(msi_unlock_descs);



/**

 * msi_get_virq - Return Linux interrupt number of a MSI interrupt

 * @dev:	Device to operate on