From 969aaefbaaf2b444852c1980ac0cbbb66463fdae Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Tue, 12 Jul 2022 08:09:01 +0800 Subject: [PATCH] iommu/vt-d: Use device_domain_lock accurately 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 Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/20220706025524.2904370-11-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/iommu/intel/iommu.c | 57 +++++++++++++++------------------------------ 1 file changed, 19 insertions(+), 38 deletions(-) diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index ccddf63..ae42a9e 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -535,15 +535,8 @@ static int domain_update_device_node(struct dmar_domain *domain) struct device_domain_info *info; int nid = NUMA_NO_NODE; - assert_spin_locked(&device_domain_lock); - - if (list_empty(&domain->devices)) - return NUMA_NO_NODE; - + spin_lock(&device_domain_lock); 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 +547,7 @@ static int domain_update_device_node(struct dmar_domain *domain) if (nid != NUMA_NO_NODE) break; } + spin_unlock(&device_domain_lock); return nid; } @@ -1376,23 +1370,23 @@ 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); - if (!iommu->qi) return NULL; - list_for_each_entry(info, &domain->devices, link) + spin_lock(&device_domain_lock); + 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; - break; + spin_unlock(&device_domain_lock); + return info->ats_supported ? info : NULL; } + } + spin_unlock(&device_domain_lock); return NULL; } @@ -1402,23 +1396,21 @@ static void domain_update_iotlb(struct dmar_domain *domain) struct device_domain_info *info; bool has_iotlb_device = false; - assert_spin_locked(&device_domain_lock); - - list_for_each_entry(info, &domain->devices, link) + spin_lock(&device_domain_lock); + 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(&device_domain_lock); } 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 +1456,6 @@ 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; @@ -1906,9 +1896,10 @@ 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; int ret; @@ -1922,9 +1913,7 @@ static int domain_context_mapping_one(struct dmar_domain *domain, BUG_ON(!domain->pgd); - spin_lock(&device_domain_lock); spin_lock(&iommu->lock); - ret = -ENOMEM; context = iommu_context_addr(iommu, bus, devfn, 1); if (!context) @@ -1975,7 +1964,6 @@ 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) @@ -1998,7 +1986,6 @@ 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 @@ -2044,7 +2031,6 @@ static int domain_context_mapping_one(struct dmar_domain *domain, out_unlock: spin_unlock(&iommu->lock); - spin_unlock(&device_domain_lock); return ret; } @@ -2456,13 +2442,11 @@ static int domain_add_dev_info(struct dmar_domain *domain, struct device *dev) if (!iommu) return -ENODEV; - spin_lock(&device_domain_lock); - info->domain = domain; ret = domain_attach_iommu(domain, iommu); - if (ret) { - spin_unlock(&device_domain_lock); + if (ret) return ret; - } + info->domain = domain; + spin_lock(&device_domain_lock); list_add(&info->link, &domain->devices); spin_unlock(&device_domain_lock); @@ -4638,9 +4622,7 @@ int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct device *dev) if (!domain) return -EINVAL; - spin_lock(&device_domain_lock); spin_lock(&iommu->lock); - ret = -EINVAL; if (!info->pasid_supported) goto out; @@ -4670,7 +4652,6 @@ int intel_iommu_enable_pasid(struct intel_iommu *iommu, struct device *dev) out: spin_unlock(&iommu->lock); - spin_unlock(&device_domain_lock); return ret; } -- 2.7.4