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Date: Wed, 5 Aug 2015 17:18:53 +0200
From: Joerg Roedel <joro@...tes.org>
To: iommu@...ts.linux-foundation.org
Cc: David Woodhouse <dwmw2@...radead.org>,
Alex Williamson <alex.williamson@...hat.com>,
linux-kernel@...r.kernel.org, Joerg Roedel <joro@...tes.org>,
jroedel@...e.de
Subject: [PATCH 22/26] iommu/vt-d: Get rid of domain->iommu_lock
From: Joerg Roedel <jroedel@...e.de>
When this lock is held the device_domain_lock is also
required to make sure the device_domain_info does not vanish
while in use. So this lock can be removed as it gives no
additional protection.
Signed-off-by: Joerg Roedel <jroedel@...e.de>
---
drivers/iommu/intel-iommu.c | 87 +++++++++++++++++++++++++--------------------
1 file changed, 49 insertions(+), 38 deletions(-)
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index eb2a99a..1a9ecfe 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -404,7 +404,6 @@ struct dmar_domain {
int iommu_superpage;/* Level of superpages supported:
0 == 4KiB (no superpages), 1 == 2MiB,
2 == 1GiB, 3 == 512GiB, 4 == 1TiB */
- spinlock_t iommu_lock; /* protect iommu set in domain */
u64 max_addr; /* maximum mapped address */
struct iommu_domain domain; /* generic domain data structure for
@@ -474,6 +473,8 @@ static void dmar_remove_one_dev_info(struct dmar_domain *domain,
struct device *dev);
static void domain_context_clear(struct intel_iommu *iommu,
struct device *dev);
+static void __dmar_remove_one_dev_info(struct dmar_domain *domain,
+ struct device *dev);
static int domain_detach_iommu(struct dmar_domain *domain,
struct intel_iommu *iommu);
@@ -1402,24 +1403,23 @@ iommu_support_dev_iotlb (struct dmar_domain *domain, struct intel_iommu *iommu,
u8 bus, u8 devfn)
{
bool found = false;
- unsigned long flags;
struct device_domain_info *info;
struct pci_dev *pdev;
+ assert_spin_locked(&device_domain_lock);
+
if (!ecap_dev_iotlb_support(iommu->ecap))
return NULL;
if (!iommu->qi)
return NULL;
- spin_lock_irqsave(&device_domain_lock, flags);
list_for_each_entry(info, &domain->devices, link)
if (info->iommu == iommu && info->bus == bus &&
info->devfn == devfn) {
found = true;
break;
}
- spin_unlock_irqrestore(&device_domain_lock, flags);
if (!found || !info->dev || !dev_is_pci(info->dev))
return NULL;
@@ -1614,10 +1614,12 @@ static int iommu_init_domains(struct intel_iommu *iommu)
static void disable_dmar_iommu(struct intel_iommu *iommu)
{
struct device_domain_info *info, *tmp;
+ unsigned long flags;
if (!iommu->domains || !iommu->domain_ids)
return;
+ spin_lock_irqsave(&device_domain_lock, flags);
list_for_each_entry_safe(info, tmp, &device_domain_list, global) {
struct dmar_domain *domain;
@@ -1634,6 +1636,7 @@ static void disable_dmar_iommu(struct intel_iommu *iommu)
if (!domain_type_is_vm_or_si(domain))
domain_exit(domain);
}
+ spin_unlock_irqrestore(&device_domain_lock, flags);
if (iommu->gcmd & DMA_GCMD_TE)
iommu_disable_translation(iommu);
@@ -1670,7 +1673,6 @@ static struct dmar_domain *alloc_domain(int flags)
memset(domain, 0, sizeof(*domain));
domain->nid = -1;
domain->flags = flags;
- spin_lock_init(&domain->iommu_lock);
INIT_LIST_HEAD(&domain->devices);
return domain;
@@ -1681,13 +1683,11 @@ static int domain_attach_iommu(struct dmar_domain *domain,
struct intel_iommu *iommu)
{
unsigned long ndomains;
- unsigned long flags;
- int ret, num;
+ int num;
+ assert_spin_locked(&device_domain_lock);
assert_spin_locked(&iommu->lock);
- spin_lock_irqsave(&domain->iommu_lock, flags);
-
domain->iommu_refcnt[iommu->seq_id] += 1;
domain->iommu_count += 1;
if (domain->iommu_refcnt[iommu->seq_id] == 1) {
@@ -1698,8 +1698,7 @@ static int domain_attach_iommu(struct dmar_domain *domain,
pr_err("%s: No free domain ids\n", iommu->name);
domain->iommu_refcnt[iommu->seq_id] -= 1;
domain->iommu_count -= 1;
- ret = -ENOSPC;
- goto out_unlock;
+ return -ENOSPC;
}
set_bit(num, iommu->domain_ids);
@@ -1711,22 +1710,17 @@ static int domain_attach_iommu(struct dmar_domain *domain,
domain_update_iommu_cap(domain);
}
- ret = 0;
-out_unlock:
- spin_unlock_irqrestore(&domain->iommu_lock, flags);
-
- return ret;
+ return 0;
}
static int domain_detach_iommu(struct dmar_domain *domain,
struct intel_iommu *iommu)
{
int num, count = INT_MAX;
- unsigned long flags;
+ assert_spin_locked(&device_domain_lock);
assert_spin_locked(&iommu->lock);
- spin_lock_irqsave(&domain->iommu_lock, flags);
domain->iommu_refcnt[iommu->seq_id] -= 1;
count = --domain->iommu_count;
if (domain->iommu_refcnt[iommu->seq_id] == 0) {
@@ -1737,7 +1731,6 @@ static int domain_detach_iommu(struct dmar_domain *domain,
domain_update_iommu_cap(domain);
domain->iommu_did[iommu->seq_id] = 0;
}
- spin_unlock_irqrestore(&domain->iommu_lock, flags);
return count;
}
@@ -1892,7 +1885,7 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
struct context_entry *context;
unsigned long flags;
struct dma_pte *pgd;
- int agaw;
+ int ret, agaw;
WARN_ON(did == 0);
@@ -1905,16 +1898,17 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
BUG_ON(!domain->pgd);
- spin_lock_irqsave(&iommu->lock, flags);
+ spin_lock_irqsave(&device_domain_lock, flags);
+ spin_lock(&iommu->lock);
+
+ ret = -ENOMEM;
context = iommu_context_addr(iommu, bus, devfn, 1);
- spin_unlock_irqrestore(&iommu->lock, flags);
if (!context)
- return -ENOMEM;
- spin_lock_irqsave(&iommu->lock, flags);
- if (context_present(context)) {
- spin_unlock_irqrestore(&iommu->lock, flags);
- return 0;
- }
+ goto out_unlock;
+
+ ret = 0;
+ if (context_present(context))
+ goto out_unlock;
pgd = domain->pgd;
@@ -1927,11 +1921,10 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
*/
if (translation != CONTEXT_TT_PASS_THROUGH) {
for (agaw = domain->agaw; agaw != iommu->agaw; agaw--) {
+ ret = -ENOMEM;
pgd = phys_to_virt(dma_pte_addr(pgd));
- if (!dma_pte_present(pgd)) {
- spin_unlock_irqrestore(&iommu->lock, flags);
- return -ENOMEM;
- }
+ if (!dma_pte_present(pgd))
+ goto out_unlock;
}
info = iommu_support_dev_iotlb(domain, iommu, bus, devfn);
@@ -1970,7 +1963,12 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
iommu_flush_write_buffer(iommu);
}
iommu_enable_dev_iotlb(info);
- spin_unlock_irqrestore(&iommu->lock, flags);
+
+ ret = 0;
+
+out_unlock:
+ spin_unlock(&iommu->lock);
+ spin_unlock_irqrestore(&device_domain_lock, flags);
return 0;
}
@@ -2213,9 +2211,12 @@ static inline void unlink_domain_info(struct device_domain_info *info)
static void domain_remove_dev_info(struct dmar_domain *domain)
{
struct device_domain_info *info, *tmp;
+ unsigned long flags;
+ spin_lock_irqsave(&device_domain_lock, flags);
list_for_each_entry_safe(info, tmp, &domain->devices, link)
- dmar_remove_one_dev_info(domain, info->dev);
+ __dmar_remove_one_dev_info(domain, info->dev);
+ spin_unlock_irqrestore(&device_domain_lock, flags);
}
/*
@@ -4517,14 +4518,16 @@ static void domain_context_clear(struct intel_iommu *iommu, struct device *dev)
pci_for_each_dma_alias(to_pci_dev(dev), &domain_context_clear_one_cb, iommu);
}
-static void dmar_remove_one_dev_info(struct dmar_domain *domain,
- struct device *dev)
+static void __dmar_remove_one_dev_info(struct dmar_domain *domain,
+ struct device *dev)
{
struct device_domain_info *info;
struct intel_iommu *iommu;
unsigned long flags;
u8 bus, devfn;
+ assert_spin_locked(&device_domain_lock);
+
iommu = device_to_iommu(dev, &bus, &devfn);
if (!iommu)
return;
@@ -4534,9 +4537,7 @@ static void dmar_remove_one_dev_info(struct dmar_domain *domain,
if (WARN_ON(!info))
return;
- spin_lock_irqsave(&device_domain_lock, flags);
unlink_domain_info(info);
- spin_unlock_irqrestore(&device_domain_lock, flags);
iommu_disable_dev_iotlb(info);
domain_context_clear(iommu, dev);
@@ -4547,6 +4548,16 @@ static void dmar_remove_one_dev_info(struct dmar_domain *domain,
spin_unlock_irqrestore(&iommu->lock, flags);
}
+static void dmar_remove_one_dev_info(struct dmar_domain *domain,
+ struct device *dev)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&device_domain_lock, flags);
+ __dmar_remove_one_dev_info(domain, dev);
+ spin_unlock_irqrestore(&device_domain_lock, flags);
+}
+
static int md_domain_init(struct dmar_domain *domain, int guest_width)
{
int adjust_width;
--
1.9.1
--
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