From 2c3262f9e881ae403b6d92a7e4824531cdb63829 Mon Sep 17 00:00:00 2001 From: Lu Baolu Date: Tue, 12 Jul 2022 08:08:57 +0800 Subject: [PATCH] iommu/vt-d: Acquiring lock in domain ID allocation helpers The iommu->lock is used to protect the per-IOMMU domain ID resource. Moving the lock into the ID alloc/free helpers makes the code more compact. At the same time, the device_domain_lock is irrelevant to the domain ID resource, remove its assertion as well. Signed-off-by: Lu Baolu Reviewed-by: Kevin Tian Link: https://lore.kernel.org/r/20220706025524.2904370-7-baolu.lu@linux.intel.com Signed-off-by: Joerg Roedel --- drivers/iommu/intel/iommu.c | 24 +++++++++--------------- 1 file changed, 9 insertions(+), 15 deletions(-) diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 93f01082dce1..7f03576e72d7 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -1779,16 +1779,13 @@ static struct dmar_domain *alloc_domain(unsigned int type) return domain; } -/* Must be called with iommu->lock */ static int domain_attach_iommu(struct dmar_domain *domain, struct intel_iommu *iommu) { unsigned long ndomains; - int num; - - assert_spin_locked(&device_domain_lock); - assert_spin_locked(&iommu->lock); + int num, ret = 0; + spin_lock(&iommu->lock); domain->iommu_refcnt[iommu->seq_id] += 1; if (domain->iommu_refcnt[iommu->seq_id] == 1) { ndomains = cap_ndoms(iommu->cap); @@ -1797,7 +1794,8 @@ static int domain_attach_iommu(struct dmar_domain *domain, if (num >= ndomains) { pr_err("%s: No free domain ids\n", iommu->name); domain->iommu_refcnt[iommu->seq_id] -= 1; - return -ENOSPC; + ret = -ENOSPC; + goto out_unlock; } set_bit(num, iommu->domain_ids); @@ -1806,7 +1804,9 @@ static int domain_attach_iommu(struct dmar_domain *domain, domain_update_iommu_cap(domain); } - return 0; +out_unlock: + spin_unlock(&iommu->lock); + return ret; } static void domain_detach_iommu(struct dmar_domain *domain, @@ -1814,9 +1814,7 @@ static void domain_detach_iommu(struct dmar_domain *domain, { int num; - assert_spin_locked(&device_domain_lock); - assert_spin_locked(&iommu->lock); - + spin_lock(&iommu->lock); domain->iommu_refcnt[iommu->seq_id] -= 1; if (domain->iommu_refcnt[iommu->seq_id] == 0) { num = domain->iommu_did[iommu->seq_id]; @@ -1824,6 +1822,7 @@ static void domain_detach_iommu(struct dmar_domain *domain, domain_update_iommu_cap(domain); domain->iommu_did[iommu->seq_id] = 0; } + spin_unlock(&iommu->lock); } static inline int guestwidth_to_adjustwidth(int gaw) @@ -2472,9 +2471,7 @@ static int domain_add_dev_info(struct dmar_domain *domain, struct device *dev) spin_lock(&device_domain_lock); info->domain = domain; - spin_lock(&iommu->lock); ret = domain_attach_iommu(domain, iommu); - spin_unlock(&iommu->lock); if (ret) { spin_unlock(&device_domain_lock); return ret; @@ -4178,10 +4175,7 @@ static void __dmar_remove_one_dev_info(struct device_domain_info *info) } list_del(&info->link); - - spin_lock(&iommu->lock); domain_detach_iommu(domain, iommu); - spin_unlock(&iommu->lock); } static void dmar_remove_one_dev_info(struct device *dev) -- 2.25.1