From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from galois.linutronix.de (Galois.linutronix.de. [193.142.43.55]) by gmr-mx.google.com with ESMTPS id e10si970619edz.5.2021.12.06.14.51.06 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 06 Dec 2021 14:51:06 -0800 (PST) Message-ID: <20211206210747.708877269@linutronix.de> From: Thomas Gleixner Subject: [patch V2 02/31] genirq/msi: Add mutex for MSI list protection References: <20211206210600.123171746@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Date: Mon, 6 Dec 2021 23:51:05 +0100 (CET) To: LKML Cc: Bjorn Helgaas , Marc Zygnier , Alex Williamson , Kevin Tian , Jason Gunthorpe , Megha Dey , Ashok Raj , linux-pci@vger.kernel.org, Cedric Le Goater , xen-devel@lists.xenproject.org, Juergen Gross , Greg Kroah-Hartman , Niklas Schnelle , linux-s390@vger.kernel.org, Heiko Carstens , Christian Borntraeger , Logan Gunthorpe , Jon Mason , Dave Jiang , Allen Hubbe , linux-ntb@googlegroups.com List-ID: 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: Thomas Gleixner --- include/linux/msi.h | 5 +++++ kernel/irq/msi.c | 25 +++++++++++++++++++++++++ 2 files changed, 30 insertions(+) --- a/include/linux/msi.h +++ b/include/linux/msi.h @@ -3,6 +3,7 @@ #define LINUX_MSI_H #include +#include #include #include #include @@ -146,12 +147,14 @@ 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); @@ -173,6 +176,8 @@ static inline void msi_device_set_proper #endif 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) --- a/kernel/irq/msi.c +++ b/kernel/irq/msi.c @@ -127,12 +127,37 @@ int msi_setup_device_data(struct device 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) +{ + if (WARN_ON_ONCE(!dev->msi.data)) + return; + 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) +{ + if (WARN_ON_ONCE(!dev->msi.data)) + return; + 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 * @index: MSI interrupt index to look for (0-based)