| Message ID | 20220225141550.162490-1-tejaskumarx.surendrakumar.upadhyay@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [topic/core-for-CI] PCI: vmd: Prevent recursive locking on interrupt allocation | expand |
Please ignore this, patch https://cgit.freedesktop.org/drm-tip/commit/?id=ba1366f3d039e7c3ca1fc29ed00ce3ed2b8fd32f has already landed today in drm-tip. Thanks, Tejas > -----Original Message----- > From: Surendrakumar Upadhyay, TejaskumarX > <tejaskumarx.surendrakumar.upadhyay@intel.com> > Sent: 25 February 2022 19:46 > To: intel-gfx@lists.freedesktop.org > Cc: Thomas Gleixner <tglx@linutronix.de>; Surendrakumar Upadhyay, > TejaskumarX <tejaskumarx.surendrakumar.upadhyay@intel.com>; linux- > pci@vger.kernel.org > Subject: [PATCH topic/core-for-CI] PCI: vmd: Prevent recursive locking on > interrupt allocation > > From: Thomas Gleixner <tglx@linutronix.de> > > Tejas reported the following recursive locking issue: > > swapper/0/1 is trying to acquire lock: > ffff8881074fd0a0 (&md->mutex){+.+.}-{3:3}, at: msi_get_virq+0x30/0xc0 > > but task is already holding lock: > ffff8881017cd6a0 (&md->mutex){+.+.}-{3:3}, at: > __pci_enable_msi_range+0xf2/0x290 > > stack backtrace: > __mutex_lock+0x9d/0x920 > msi_get_virq+0x30/0xc0 > pci_irq_vector+0x26/0x30 > vmd_msi_init+0xcc/0x210 > msi_domain_alloc+0xbf/0x150 > msi_domain_alloc_irqs_descs_locked+0x3e/0xb0 > __pci_enable_msi_range+0x155/0x290 > pci_alloc_irq_vectors_affinity+0xba/0x100 > pcie_port_device_register+0x307/0x550 > pcie_portdrv_probe+0x3c/0xd0 > pci_device_probe+0x95/0x110 > > This is caused by the VMD MSI code which does a lookup of the Linux > interrupt number for an VMD managed MSI[X] vector. The lookup function > tries to acquire the already held mutex. > > Avoid that by caching the Linux interrupt number at initialization time instead > of looking it up over and over. > > Fixes: 82ff8e6b78fc ("PCI/MSI: Use msi_get_virq() in pci_get_vector()") > Reported-by: "Surendrakumar Upadhyay, TejaskumarX" > <tejaskumarx.surendrakumar.upadhyay@intel.com> > Signed-off-by: Thomas Gleixner <tglx@linutronix.de> > Tested-by: "Surendrakumar Upadhyay, TejaskumarX" > <tejaskumarx.surendrakumar.upadhyay@intel.com> > Cc: linux-pci@vger.kernel.org > Link: https://lore.kernel.org/r/87a6euub2a.ffs@tglx > --- > drivers/pci/controller/vmd.c | 14 +++++++------- > 1 file changed, 7 insertions(+), 7 deletions(-) > > diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c index > cc166c683638..eb05cceab964 100644 > --- a/drivers/pci/controller/vmd.c > +++ b/drivers/pci/controller/vmd.c > @@ -99,11 +99,13 @@ struct vmd_irq { > * @srcu: SRCU struct for local synchronization. > * @count: number of child IRQs assigned to this vector; used to track > * sharing. > + * @virq: The underlying VMD Linux interrupt number > */ > struct vmd_irq_list { > struct list_head irq_list; > struct srcu_struct srcu; > unsigned int count; > + unsigned int virq; > }; > > struct vmd_dev { > @@ -253,7 +255,6 @@ static int vmd_msi_init(struct irq_domain *domain, > struct msi_domain_info *info, > struct msi_desc *desc = arg->desc; > struct vmd_dev *vmd = vmd_from_bus(msi_desc_to_pci_dev(desc)- > >bus); > struct vmd_irq *vmdirq = kzalloc(sizeof(*vmdirq), GFP_KERNEL); > - unsigned int index, vector; > > if (!vmdirq) > return -ENOMEM; > @@ -261,10 +262,8 @@ static int vmd_msi_init(struct irq_domain *domain, > struct msi_domain_info *info, > INIT_LIST_HEAD(&vmdirq->node); > vmdirq->irq = vmd_next_irq(vmd, desc); > vmdirq->virq = virq; > - index = index_from_irqs(vmd, vmdirq->irq); > - vector = pci_irq_vector(vmd->dev, index); > > - irq_domain_set_info(domain, virq, vector, info->chip, vmdirq, > + irq_domain_set_info(domain, virq, vmdirq->irq->virq, info->chip, > +vmdirq, > handle_untracked_irq, vmd, NULL); > return 0; > } > @@ -685,7 +684,8 @@ static int vmd_alloc_irqs(struct vmd_dev *vmd) > return err; > > INIT_LIST_HEAD(&vmd->irqs[i].irq_list); > - err = devm_request_irq(&dev->dev, pci_irq_vector(dev, i), > + vmd->irqs[i].virq = pci_irq_vector(dev, i); > + err = devm_request_irq(&dev->dev, vmd->irqs[i].virq, > vmd_irq, IRQF_NO_THREAD, > vmd->name, &vmd->irqs[i]); > if (err) > @@ -969,7 +969,7 @@ static int vmd_suspend(struct device *dev) > int i; > > for (i = 0; i < vmd->msix_count; i++) > - devm_free_irq(dev, pci_irq_vector(pdev, i), &vmd->irqs[i]); > + devm_free_irq(dev, vmd->irqs[i].virq, &vmd->irqs[i]); > > return 0; > } > @@ -981,7 +981,7 @@ static int vmd_resume(struct device *dev) > int err, i; > > for (i = 0; i < vmd->msix_count; i++) { > - err = devm_request_irq(dev, pci_irq_vector(pdev, i), > + err = devm_request_irq(dev, vmd->irqs[i].virq, > vmd_irq, IRQF_NO_THREAD, > vmd->name, &vmd->irqs[i]); > if (err) > -- > 2.34.1
diff --git a/drivers/pci/controller/vmd.c b/drivers/pci/controller/vmd.c index cc166c683638..eb05cceab964 100644 --- a/drivers/pci/controller/vmd.c +++ b/drivers/pci/controller/vmd.c @@ -99,11 +99,13 @@ struct vmd_irq { * @srcu: SRCU struct for local synchronization. * @count: number of child IRQs assigned to this vector; used to track * sharing. + * @virq: The underlying VMD Linux interrupt number */ struct vmd_irq_list { struct list_head irq_list; struct srcu_struct srcu; unsigned int count; + unsigned int virq; }; struct vmd_dev { @@ -253,7 +255,6 @@ static int vmd_msi_init(struct irq_domain *domain, struct msi_domain_info *info, struct msi_desc *desc = arg->desc; struct vmd_dev *vmd = vmd_from_bus(msi_desc_to_pci_dev(desc)->bus); struct vmd_irq *vmdirq = kzalloc(sizeof(*vmdirq), GFP_KERNEL); - unsigned int index, vector; if (!vmdirq) return -ENOMEM; @@ -261,10 +262,8 @@ static int vmd_msi_init(struct irq_domain *domain, struct msi_domain_info *info, INIT_LIST_HEAD(&vmdirq->node); vmdirq->irq = vmd_next_irq(vmd, desc); vmdirq->virq = virq; - index = index_from_irqs(vmd, vmdirq->irq); - vector = pci_irq_vector(vmd->dev, index); - irq_domain_set_info(domain, virq, vector, info->chip, vmdirq, + irq_domain_set_info(domain, virq, vmdirq->irq->virq, info->chip, vmdirq, handle_untracked_irq, vmd, NULL); return 0; } @@ -685,7 +684,8 @@ static int vmd_alloc_irqs(struct vmd_dev *vmd) return err; INIT_LIST_HEAD(&vmd->irqs[i].irq_list); - err = devm_request_irq(&dev->dev, pci_irq_vector(dev, i), + vmd->irqs[i].virq = pci_irq_vector(dev, i); + err = devm_request_irq(&dev->dev, vmd->irqs[i].virq, vmd_irq, IRQF_NO_THREAD, vmd->name, &vmd->irqs[i]); if (err) @@ -969,7 +969,7 @@ static int vmd_suspend(struct device *dev) int i; for (i = 0; i < vmd->msix_count; i++) - devm_free_irq(dev, pci_irq_vector(pdev, i), &vmd->irqs[i]); + devm_free_irq(dev, vmd->irqs[i].virq, &vmd->irqs[i]); return 0; } @@ -981,7 +981,7 @@ static int vmd_resume(struct device *dev) int err, i; for (i = 0; i < vmd->msix_count; i++) { - err = devm_request_irq(dev, pci_irq_vector(pdev, i), + err = devm_request_irq(dev, vmd->irqs[i].virq, vmd_irq, IRQF_NO_THREAD, vmd->name, &vmd->irqs[i]); if (err)