From: Lu Baolu <baolu.lu@linux.intel.com>
Date: Tue, 12 Jul 2022 08:08:57 +0800
Subject: iommu/vt-d: Acquiring lock in domain ID allocation helpers
Git-commit: 2c3262f9e881ae403b6d92a7e4824531cdb63829
Patch-mainline: v6.0-rc1
References: bsc#1200301
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 <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20220706025524.2904370-7-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
drivers/iommu/intel/iommu.c | 29 +++++++++--------------------
1 file changed, 9 insertions(+), 20 deletions(-)
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -1837,16 +1837,13 @@ static struct dmar_domain *alloc_domain(
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);
@@ -1855,7 +1852,8 @@ static int domain_attach_iommu(struct dm
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);
@@ -1864,7 +1862,9 @@ static int domain_attach_iommu(struct dm
domain_update_iommu_cap(domain);
}
- return 0;
+out_unlock:
+ spin_unlock(&iommu->lock);
+ return ret;
}
static void domain_detach_iommu(struct dmar_domain *domain,
@@ -1872,9 +1872,7 @@ static void domain_detach_iommu(struct d
{
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];
@@ -1882,6 +1880,7 @@ static void domain_detach_iommu(struct d
domain_update_iommu_cap(domain);
domain->iommu_did[iommu->seq_id] = 0;
}
+ spin_unlock(&iommu->lock);
}
static inline int guestwidth_to_adjustwidth(int gaw)
@@ -2565,9 +2564,7 @@ static struct dmar_domain *dmar_insert_o
return found;
}
- spin_lock(&iommu->lock);
ret = domain_attach_iommu(domain, iommu);
- spin_unlock(&iommu->lock);
if (ret) {
spin_unlock_irqrestore(&device_domain_lock, flags);
@@ -4378,7 +4375,6 @@ static void __dmar_remove_one_dev_info(s
{
struct dmar_domain *domain;
struct intel_iommu *iommu;
- unsigned long flags;
assert_spin_locked(&device_domain_lock);
@@ -4400,9 +4396,7 @@ static void __dmar_remove_one_dev_info(s
unlink_domain_info(info);
- spin_lock_irqsave(&iommu->lock, flags);
domain_detach_iommu(domain, iommu);
- spin_unlock_irqrestore(&iommu->lock, flags);
free_devinfo_mem(info);
}
@@ -4598,7 +4592,6 @@ static int aux_domain_add_dev(struct dma
* iommu->lock must be held to attach domain to iommu and setup the
* pasid entry for second level translation.
*/
- spin_lock(&iommu->lock);
ret = domain_attach_iommu(domain, iommu);
if (ret)
goto attach_failed;
@@ -4613,7 +4606,6 @@ static int aux_domain_add_dev(struct dma
if (ret)
goto table_failed;
- spin_unlock(&iommu->lock);
out:
spin_unlock_irqrestore(&device_domain_lock, flags);
@@ -4622,7 +4614,6 @@ out:
table_failed:
domain_detach_iommu(domain, iommu);
attach_failed:
- spin_unlock(&iommu->lock);
auxiliary_unlink_device(domain, dev);
link_failed:
spin_unlock_irqrestore(&device_domain_lock, flags);
@@ -4647,11 +4638,9 @@ static void aux_domain_remove_dev(struct
iommu = info->iommu;
if (!auxiliary_unlink_device(domain, dev)) {
- spin_lock(&iommu->lock);
intel_pasid_tear_down_entry(iommu, dev,
domain->default_pasid, false);
domain_detach_iommu(domain, iommu);
- spin_unlock(&iommu->lock);
}
spin_unlock_irqrestore(&device_domain_lock, flags);