From 74d33dedc2fb8d98821bcf7df9800ce59456502e Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Wed, 21 Sep 2011 17:04:47 -0400 Subject: [PATCH] xen/pciback: use mutex rather than spinlock in vpci backend Similar to the "xen/pciback: use mutex rather than spinlock in passthrough backend" this patch converts the vpci backend to use a mutex instead of a spinlock. Note that the code taking the lock won't ever get called from non-sleepable context Signed-off-by: Konrad Rzeszutek Wilk --- drivers/xen/xen-pciback/vpci.c | 26 +++++++++++--------------- 1 file changed, 11 insertions(+), 15 deletions(-) diff --git a/drivers/xen/xen-pciback/vpci.c b/drivers/xen/xen-pciback/vpci.c index a778552..01222d7 100644 --- a/drivers/xen/xen-pciback/vpci.c +++ b/drivers/xen/xen-pciback/vpci.c @@ -8,7 +8,7 @@ #include #include #include -#include +#include #include "pciback.h" #define PCI_SLOT_MAX 32 @@ -16,7 +16,7 @@ struct vpci_dev_data { /* Access to dev_list must be protected by lock */ struct list_head dev_list[PCI_SLOT_MAX]; - spinlock_t lock; + struct mutex lock; }; static inline struct list_head *list_first(struct list_head *head) @@ -32,13 +32,12 @@ static struct pci_dev *__xen_pcibk_get_pci_dev(struct xen_pcibk_device *pdev, struct pci_dev_entry *entry; struct pci_dev *dev = NULL; struct vpci_dev_data *vpci_dev = pdev->pci_dev_data; - unsigned long flags; if (domain != 0 || bus != 0) return NULL; if (PCI_SLOT(devfn) < PCI_SLOT_MAX) { - spin_lock_irqsave(&vpci_dev->lock, flags); + mutex_lock(&vpci_dev->lock); list_for_each_entry(entry, &vpci_dev->dev_list[PCI_SLOT(devfn)], @@ -49,7 +48,7 @@ static struct pci_dev *__xen_pcibk_get_pci_dev(struct xen_pcibk_device *pdev, } } - spin_unlock_irqrestore(&vpci_dev->lock, flags); + mutex_unlock(&vpci_dev->lock); } return dev; } @@ -70,7 +69,6 @@ static int __xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev, int err = 0, slot, func = -1; struct pci_dev_entry *t, *dev_entry; struct vpci_dev_data *vpci_dev = pdev->pci_dev_data; - unsigned long flags; if ((dev->class >> 24) == PCI_BASE_CLASS_BRIDGE) { err = -EFAULT; @@ -89,7 +87,7 @@ static int __xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev, dev_entry->dev = dev; - spin_lock_irqsave(&vpci_dev->lock, flags); + mutex_lock(&vpci_dev->lock); /* Keep multi-function devices together on the virtual PCI bus */ for (slot = 0; slot < PCI_SLOT_MAX; slot++) { @@ -128,7 +126,7 @@ static int __xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev, "No more space on root virtual PCI bus"); unlock: - spin_unlock_irqrestore(&vpci_dev->lock, flags); + mutex_unlock(&vpci_dev->lock); /* Publish this device. */ if (!err) @@ -144,9 +142,8 @@ static void __xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev, int slot; struct vpci_dev_data *vpci_dev = pdev->pci_dev_data; struct pci_dev *found_dev = NULL; - unsigned long flags; - spin_lock_irqsave(&vpci_dev->lock, flags); + mutex_lock(&vpci_dev->lock); for (slot = 0; slot < PCI_SLOT_MAX; slot++) { struct pci_dev_entry *e; @@ -162,7 +159,7 @@ static void __xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev, } out: - spin_unlock_irqrestore(&vpci_dev->lock, flags); + mutex_unlock(&vpci_dev->lock); if (found_dev) pcistub_put_pci_dev(found_dev); @@ -177,7 +174,7 @@ static int __xen_pcibk_init_devices(struct xen_pcibk_device *pdev) if (!vpci_dev) return -ENOMEM; - spin_lock_init(&vpci_dev->lock); + mutex_init(&vpci_dev->lock); for (slot = 0; slot < PCI_SLOT_MAX; slot++) INIT_LIST_HEAD(&vpci_dev->dev_list[slot]); @@ -221,10 +218,9 @@ static int __xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev, struct pci_dev_entry *entry; struct pci_dev *dev = NULL; struct vpci_dev_data *vpci_dev = pdev->pci_dev_data; - unsigned long flags; int found = 0, slot; - spin_lock_irqsave(&vpci_dev->lock, flags); + mutex_lock(&vpci_dev->lock); for (slot = 0; slot < PCI_SLOT_MAX; slot++) { list_for_each_entry(entry, &vpci_dev->dev_list[slot], @@ -242,7 +238,7 @@ static int __xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev, } } } - spin_unlock_irqrestore(&vpci_dev->lock, flags); + mutex_lock(&vpci_dev->lock); return found; } -- 2.7.4