The device_domain_lock is used to protect the device tracking list of a domain. Remove unnecessary spin_lock/unlock()'s and move the necessary ones around the list access.
Signed-off-by: Lu Baolu <baolu...@linux.intel.com> --- drivers/iommu/intel/iommu.c | 68 +++++++++++++++---------------------- 1 file changed, 27 insertions(+), 41 deletions(-) diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index d02ddd338afd..f8aa8649dc6f 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -534,16 +534,10 @@ static int domain_update_device_node(struct dmar_domain *domain) { struct device_domain_info *info; int nid = NUMA_NO_NODE; + unsigned long flags; - assert_spin_locked(&device_domain_lock); - - if (list_empty(&domain->devices)) - return NUMA_NO_NODE; - + spin_lock_irqsave(&device_domain_lock, flags); list_for_each_entry(info, &domain->devices, link) { - if (!info->dev) - continue; - /* * There could possibly be multiple device numa nodes as devices * within the same domain may sit behind different IOMMUs. There @@ -554,6 +548,7 @@ static int domain_update_device_node(struct dmar_domain *domain) if (nid != NUMA_NO_NODE) break; } + spin_unlock_irqrestore(&device_domain_lock, flags); return nid; } @@ -1376,49 +1371,50 @@ static void __iommu_flush_iotlb(struct intel_iommu *iommu, u16 did, } static struct device_domain_info * -iommu_support_dev_iotlb (struct dmar_domain *domain, struct intel_iommu *iommu, - u8 bus, u8 devfn) +iommu_support_dev_iotlb(struct dmar_domain *domain, struct intel_iommu *iommu, + u8 bus, u8 devfn) { - struct device_domain_info *info; - - assert_spin_locked(&device_domain_lock); + struct device_domain_info *info = NULL, *tmp; + unsigned long flags; if (!iommu->qi) return NULL; - list_for_each_entry(info, &domain->devices, link) - if (info->iommu == iommu && info->bus == bus && - info->devfn == devfn) { - if (info->ats_supported && info->dev) - return info; + spin_lock_irqsave(&device_domain_lock, flags); + list_for_each_entry(tmp, &domain->devices, link) { + if (tmp->iommu == iommu && tmp->bus == bus && + tmp->devfn == devfn) { + if (tmp->ats_supported) + info = tmp; break; } + } + spin_unlock_irqrestore(&device_domain_lock, flags); - return NULL; + return info; } static void domain_update_iotlb(struct dmar_domain *domain) { struct device_domain_info *info; bool has_iotlb_device = false; + unsigned long flags; - assert_spin_locked(&device_domain_lock); - - list_for_each_entry(info, &domain->devices, link) + spin_lock_irqsave(&device_domain_lock, flags); + list_for_each_entry(info, &domain->devices, link) { if (info->ats_enabled) { has_iotlb_device = true; break; } - + } domain->has_iotlb_device = has_iotlb_device; + spin_unlock_irqrestore(&device_domain_lock, flags); } static void iommu_enable_dev_iotlb(struct device_domain_info *info) { struct pci_dev *pdev; - assert_spin_locked(&device_domain_lock); - if (!info || !dev_is_pci(info->dev)) return; @@ -1464,8 +1460,6 @@ static void iommu_disable_dev_iotlb(struct device_domain_info *info) { struct pci_dev *pdev; - assert_spin_locked(&device_domain_lock); - if (!dev_is_pci(info->dev)) return; @@ -1900,11 +1894,11 @@ static int domain_context_mapping_one(struct dmar_domain *domain, struct pasid_table *table, u8 bus, u8 devfn) { + struct device_domain_info *info = + iommu_support_dev_iotlb(domain, iommu, bus, devfn); u16 did = domain->iommu_did[iommu->seq_id]; int translation = CONTEXT_TT_MULTI_LEVEL; - struct device_domain_info *info = NULL; struct context_entry *context; - unsigned long flags; int ret; WARN_ON(did == 0); @@ -1917,7 +1911,6 @@ static int domain_context_mapping_one(struct dmar_domain *domain, BUG_ON(!domain->pgd); - spin_lock_irqsave(&device_domain_lock, flags); spin_lock(&iommu->lock); ret = -ENOMEM; @@ -1970,7 +1963,6 @@ static int domain_context_mapping_one(struct dmar_domain *domain, * Setup the Device-TLB enable bit and Page request * Enable bit: */ - info = iommu_support_dev_iotlb(domain, iommu, bus, devfn); if (info && info->ats_supported) context_set_sm_dte(context); if (info && info->pri_supported) @@ -1993,7 +1985,6 @@ static int domain_context_mapping_one(struct dmar_domain *domain, goto out_unlock; } - info = iommu_support_dev_iotlb(domain, iommu, bus, devfn); if (info && info->ats_supported) translation = CONTEXT_TT_DEV_IOTLB; else @@ -2039,7 +2030,6 @@ static int domain_context_mapping_one(struct dmar_domain *domain, out_unlock: spin_unlock(&iommu->lock); - spin_unlock_irqrestore(&device_domain_lock, flags); return ret; } @@ -2452,15 +2442,14 @@ static int domain_add_dev_info(struct dmar_domain *domain, struct device *dev) if (!iommu) return -ENODEV; - spin_lock_irqsave(&device_domain_lock, flags); - info->domain = domain; ret = domain_attach_iommu(domain, iommu); - if (ret) { - spin_unlock_irqrestore(&device_domain_lock, flags); + if (ret) return ret; - } + + spin_lock_irqsave(&device_domain_lock, flags); list_add(&info->link, &domain->devices); spin_unlock_irqrestore(&device_domain_lock, flags); + info->domain = domain; /* PASID table is mandatory for a PCI device in scalable mode. */ if (sm_supported(iommu) && !dev_is_real_dma_subdevice(dev)) { @@ -4629,7 +4618,6 @@ int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct device *dev) struct device_domain_info *info = dev_iommu_priv_get(dev); struct context_entry *context; struct dmar_domain *domain; - unsigned long flags; u64 ctx_lo; int ret; @@ -4637,7 +4625,6 @@ int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct device *dev) if (!domain) return -EINVAL; - spin_lock_irqsave(&device_domain_lock, flags); spin_lock(&iommu->lock); ret = -EINVAL; @@ -4669,7 +4656,6 @@ int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct device *dev) out: spin_unlock(&iommu->lock); - spin_unlock_irqrestore(&device_domain_lock, flags); return ret; } -- 2.25.1 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu