From: Lu Baolu <baolu.lu@linux.intel.com>
To: Joerg Roedel <joro@8bytes.org>, Kevin Tian <kevin.tian@intel.com>,
Ashok Raj <ashok.raj@intel.com>,
Christoph Hellwig <hch@infradead.org>,
Jason Gunthorpe <jgg@nvidia.com>
Cc: Will Deacon <will@kernel.org>,
Robin Murphy <robin.murphy@arm.com>,
Liu Yi L <yi.l.liu@intel.com>,
Jacob jun Pan <jacob.jun.pan@intel.com>,
iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
Lu Baolu <baolu.lu@linux.intel.com>
Subject: [PATCH v2 06/12] iommu/vt-d: Acquiring lock in domain ID allocation helpers
Date: Tue, 14 Jun 2022 10:51:31 +0800 [thread overview]
Message-ID: <20220614025137.1632762-7-baolu.lu@linux.intel.com> (raw)
In-Reply-To: <20220614025137.1632762-1-baolu.lu@linux.intel.com>
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.
On the other hand, the iommu->lock is never used in interrupt context,
there's no need to use the irqsave variant of the spinlock calls.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
drivers/iommu/intel/iommu.c | 25 +++++++++----------------
1 file changed, 9 insertions(+), 16 deletions(-)
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index b2ef8af0c3f3..8fdaa01ef10d 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -1782,16 +1782,13 @@ 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);
@@ -1800,7 +1797,8 @@ 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);
@@ -1809,7 +1807,9 @@ 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,
@@ -1817,9 +1817,7 @@ 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];
@@ -1827,6 +1825,7 @@ 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)
@@ -2479,9 +2478,7 @@ static int domain_add_dev_info(struct dmar_domain *domain, struct device *dev)
spin_lock_irqsave(&device_domain_lock, flags);
info->domain = domain;
- spin_lock(&iommu->lock);
ret = domain_attach_iommu(domain, iommu);
- spin_unlock(&iommu->lock);
if (ret) {
spin_unlock_irqrestore(&device_domain_lock, flags);
return ret;
@@ -4166,7 +4163,6 @@ static void __dmar_remove_one_dev_info(struct device_domain_info *info)
{
struct dmar_domain *domain;
struct intel_iommu *iommu;
- unsigned long flags;
assert_spin_locked(&device_domain_lock);
@@ -4187,10 +4183,7 @@ static void __dmar_remove_one_dev_info(struct device_domain_info *info)
}
list_del(&info->link);
-
- spin_lock_irqsave(&iommu->lock, flags);
domain_detach_iommu(domain, iommu);
- spin_unlock_irqrestore(&iommu->lock, flags);
}
static void dmar_remove_one_dev_info(struct device *dev)
--
2.25.1
next prev parent reply other threads:[~2022-06-14 2:59 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-06-14 2:51 [PATCH v2 00/12] iommu/vt-d: Optimize the use of locks Lu Baolu
2022-06-14 2:51 ` [PATCH v2 01/12] iommu/vt-d: debugfs: Remove device_domain_lock usage Lu Baolu
2022-06-14 6:43 ` Tian, Kevin
2022-06-14 7:15 ` Baolu Lu
2022-06-15 1:53 ` Baolu Lu
2022-06-15 6:13 ` Tian, Kevin
2022-06-15 13:02 ` Baolu Lu
2022-06-14 2:51 ` [PATCH v2 02/12] iommu/vt-d: Remove for_each_device_domain() Lu Baolu
2022-06-14 2:51 ` [PATCH v2 03/12] iommu/vt-d: Remove clearing translation data in disable_dmar_iommu() Lu Baolu
2022-06-14 6:49 ` Tian, Kevin
2022-06-14 7:21 ` Baolu Lu
2022-06-15 6:22 ` Tian, Kevin
2022-06-15 13:10 ` Baolu Lu
2022-06-16 4:00 ` Tian, Kevin
2022-06-14 2:51 ` [PATCH v2 04/12] iommu/vt-d: Use pci_get_domain_bus_and_slot() in pgtable_walk() Lu Baolu
2022-06-14 2:51 ` [PATCH v2 05/12] iommu/vt-d: Unnecessary spinlock for root table alloc and free Lu Baolu
2022-06-14 2:51 ` Lu Baolu [this message]
2022-06-14 6:52 ` [PATCH v2 06/12] iommu/vt-d: Acquiring lock in domain ID allocation helpers Tian, Kevin
2022-06-14 7:22 ` Baolu Lu
2022-06-14 2:51 ` [PATCH v2 07/12] iommu/vt-d: Acquiring lock in pasid manipulation helpers Lu Baolu
2022-06-14 2:51 ` [PATCH v2 08/12] iommu/vt-d: Replace spin_lock_irqsave() with spin_lock() Lu Baolu
2022-06-14 6:56 ` Tian, Kevin
2022-06-14 2:51 ` [PATCH v2 09/12] iommu/vt-d: Check device list of domain in domain free path Lu Baolu
2022-06-14 6:57 ` Tian, Kevin
2022-06-14 2:51 ` [PATCH v2 10/12] iommu/vt-d: Fold __dmar_remove_one_dev_info() into its caller Lu Baolu
2022-06-14 7:07 ` Tian, Kevin
2022-06-14 7:44 ` Baolu Lu
2022-06-14 2:51 ` [PATCH v2 11/12] iommu/vt-d: Use device_domain_lock accurately Lu Baolu
2022-06-14 7:16 ` Tian, Kevin
2022-06-14 7:47 ` Baolu Lu
2022-06-14 2:51 ` [PATCH v2 12/12] iommu/vt-d: Convert global spinlock into per domain ones Lu Baolu
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