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iommu/vt-d: Get rid of domain->iommu_lock

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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@suse.de>
This commit is contained in:
Joerg Roedel 2015-07-22 16:50:40 +02:00
parent de7e888646
commit 55d940430a
1 changed files with 49 additions and 38 deletions
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87
drivers/iommu/intel-iommu.c
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@ -406,7 +406,6 @@ struct dmar_domain {
int iommu_superpage;/* Level of superpages supported: int iommu_superpage;/* Level of superpages supported:
0 == 4KiB (no superpages), 1 == 2MiB, 0 == 4KiB (no superpages), 1 == 2MiB,
2 == 1GiB, 3 == 512GiB, 4 == 1TiB */ 2 == 1GiB, 3 == 512GiB, 4 == 1TiB */
spinlock_t iommu_lock; /* protect iommu set in domain */
u64 max_addr; /* maximum mapped address */ u64 max_addr; /* maximum mapped address */
struct iommu_domain domain; /* generic domain data structure for struct iommu_domain domain; /* generic domain data structure for
@ -476,6 +475,8 @@ static void dmar_remove_one_dev_info(struct dmar_domain *domain,
struct device *dev); struct device *dev);
static void domain_context_clear(struct intel_iommu *iommu, static void domain_context_clear(struct intel_iommu *iommu,
struct device *dev); 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, static int domain_detach_iommu(struct dmar_domain *domain,
struct intel_iommu *iommu); struct intel_iommu *iommu);
@ -1404,24 +1405,23 @@ iommu_support_dev_iotlb (struct dmar_domain *domain, struct intel_iommu *iommu,
u8 bus, u8 devfn) u8 bus, u8 devfn)
{ {
bool found = false; bool found = false;
unsigned long flags;
struct device_domain_info *info; struct device_domain_info *info;
struct pci_dev *pdev; struct pci_dev *pdev;
assert_spin_locked(&device_domain_lock);
if (!ecap_dev_iotlb_support(iommu->ecap)) if (!ecap_dev_iotlb_support(iommu->ecap))
return NULL; return NULL;
if (!iommu->qi) if (!iommu->qi)
return NULL; return NULL;
spin_lock_irqsave(&device_domain_lock, flags);
list_for_each_entry(info, &domain->devices, link) list_for_each_entry(info, &domain->devices, link)
if (info->iommu == iommu && info->bus == bus && if (info->iommu == iommu && info->bus == bus &&
info->devfn == devfn) { info->devfn == devfn) {
found = true; found = true;
break; break;
} }
spin_unlock_irqrestore(&device_domain_lock, flags);
if (!found || !info->dev || !dev_is_pci(info->dev)) if (!found || !info->dev || !dev_is_pci(info->dev))
return NULL; return NULL;
@ -1616,10 +1616,12 @@ static int iommu_init_domains(struct intel_iommu *iommu)
static void disable_dmar_iommu(struct intel_iommu *iommu) static void disable_dmar_iommu(struct intel_iommu *iommu)
{ {
struct device_domain_info *info, *tmp; struct device_domain_info *info, *tmp;
unsigned long flags;
if (!iommu->domains || !iommu->domain_ids) if (!iommu->domains || !iommu->domain_ids)
return; return;
spin_lock_irqsave(&device_domain_lock, flags);
list_for_each_entry_safe(info, tmp, &device_domain_list, global) { list_for_each_entry_safe(info, tmp, &device_domain_list, global) {
struct dmar_domain *domain; struct dmar_domain *domain;
@ -1636,6 +1638,7 @@ static void disable_dmar_iommu(struct intel_iommu *iommu)
if (!domain_type_is_vm_or_si(domain)) if (!domain_type_is_vm_or_si(domain))
domain_exit(domain); domain_exit(domain);
} }
spin_unlock_irqrestore(&device_domain_lock, flags);
if (iommu->gcmd & DMA_GCMD_TE) if (iommu->gcmd & DMA_GCMD_TE)
iommu_disable_translation(iommu); iommu_disable_translation(iommu);
@ -1672,7 +1675,6 @@ static struct dmar_domain *alloc_domain(int flags)
memset(domain, 0, sizeof(*domain)); memset(domain, 0, sizeof(*domain));
domain->nid = -1; domain->nid = -1;
domain->flags = flags; domain->flags = flags;
spin_lock_init(&domain->iommu_lock);
INIT_LIST_HEAD(&domain->devices); INIT_LIST_HEAD(&domain->devices);
return domain; return domain;
@ -1683,13 +1685,11 @@ static int domain_attach_iommu(struct dmar_domain *domain,
struct intel_iommu *iommu) struct intel_iommu *iommu)
{ {
unsigned long ndomains; unsigned long ndomains;
unsigned long flags; int num;
int ret, num;
assert_spin_locked(&device_domain_lock);
assert_spin_locked(&iommu->lock); assert_spin_locked(&iommu->lock);
spin_lock_irqsave(&domain->iommu_lock, flags);
domain->iommu_refcnt[iommu->seq_id] += 1; domain->iommu_refcnt[iommu->seq_id] += 1;
domain->iommu_count += 1; domain->iommu_count += 1;
if (domain->iommu_refcnt[iommu->seq_id] == 1) { if (domain->iommu_refcnt[iommu->seq_id] == 1) {
@ -1700,8 +1700,7 @@ static int domain_attach_iommu(struct dmar_domain *domain,
pr_err("%s: No free domain ids\n", iommu->name); pr_err("%s: No free domain ids\n", iommu->name);
domain->iommu_refcnt[iommu->seq_id] -= 1; domain->iommu_refcnt[iommu->seq_id] -= 1;
domain->iommu_count -= 1; domain->iommu_count -= 1;
ret = -ENOSPC; return -ENOSPC;
goto out_unlock;
} }
set_bit(num, iommu->domain_ids); set_bit(num, iommu->domain_ids);
@ -1713,22 +1712,17 @@ static int domain_attach_iommu(struct dmar_domain *domain,
domain_update_iommu_cap(domain); domain_update_iommu_cap(domain);
} }
ret = 0; return 0;
out_unlock:
spin_unlock_irqrestore(&domain->iommu_lock, flags);
return ret;
} }
static int domain_detach_iommu(struct dmar_domain *domain, static int domain_detach_iommu(struct dmar_domain *domain,
struct intel_iommu *iommu) struct intel_iommu *iommu)
{ {
int num, count = INT_MAX; int num, count = INT_MAX;
unsigned long flags;
assert_spin_locked(&device_domain_lock);
assert_spin_locked(&iommu->lock); assert_spin_locked(&iommu->lock);
spin_lock_irqsave(&domain->iommu_lock, flags);
domain->iommu_refcnt[iommu->seq_id] -= 1; domain->iommu_refcnt[iommu->seq_id] -= 1;
count = --domain->iommu_count; count = --domain->iommu_count;
if (domain->iommu_refcnt[iommu->seq_id] == 0) { if (domain->iommu_refcnt[iommu->seq_id] == 0) {
@ -1739,7 +1733,6 @@ static int domain_detach_iommu(struct dmar_domain *domain,
domain_update_iommu_cap(domain); domain_update_iommu_cap(domain);
domain->iommu_did[iommu->seq_id] = 0; domain->iommu_did[iommu->seq_id] = 0;
} }
spin_unlock_irqrestore(&domain->iommu_lock, flags);
return count; return count;
} }
@ -1894,7 +1887,7 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
struct context_entry *context; struct context_entry *context;
unsigned long flags; unsigned long flags;
struct dma_pte *pgd; struct dma_pte *pgd;
int agaw; int ret, agaw;
WARN_ON(did == 0); WARN_ON(did == 0);
@ -1906,16 +1899,17 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
BUG_ON(!domain->pgd); 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); context = iommu_context_addr(iommu, bus, devfn, 1);
spin_unlock_irqrestore(&iommu->lock, flags);
if (!context) if (!context)
return -ENOMEM; goto out_unlock;
spin_lock_irqsave(&iommu->lock, flags);
if (context_present(context)) { ret = 0;
spin_unlock_irqrestore(&iommu->lock, flags); if (context_present(context))
return 0; goto out_unlock;
}
pgd = domain->pgd; pgd = domain->pgd;
@ -1928,11 +1922,10 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
*/ */
if (translation != CONTEXT_TT_PASS_THROUGH) { if (translation != CONTEXT_TT_PASS_THROUGH) {
for (agaw = domain->agaw; agaw != iommu->agaw; agaw--) { for (agaw = domain->agaw; agaw != iommu->agaw; agaw--) {
ret = -ENOMEM;
pgd = phys_to_virt(dma_pte_addr(pgd)); pgd = phys_to_virt(dma_pte_addr(pgd));
if (!dma_pte_present(pgd)) { if (!dma_pte_present(pgd))
spin_unlock_irqrestore(&iommu->lock, flags); goto out_unlock;
return -ENOMEM;
}
} }
info = iommu_support_dev_iotlb(domain, iommu, bus, devfn); info = iommu_support_dev_iotlb(domain, iommu, bus, devfn);
@ -1971,7 +1964,12 @@ static int domain_context_mapping_one(struct dmar_domain *domain,
iommu_flush_write_buffer(iommu); iommu_flush_write_buffer(iommu);
} }
iommu_enable_dev_iotlb(info); 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; return 0;
} }
@ -2214,9 +2212,12 @@ static inline void unlink_domain_info(struct device_domain_info *info)
static void domain_remove_dev_info(struct dmar_domain *domain) static void domain_remove_dev_info(struct dmar_domain *domain)
{ {
struct device_domain_info *info, *tmp; 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) 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);
} }
/* /*
@ -4539,14 +4540,16 @@ 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); 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, static void __dmar_remove_one_dev_info(struct dmar_domain *domain,
struct device *dev) struct device *dev)
{ {
struct device_domain_info *info; struct device_domain_info *info;
struct intel_iommu *iommu; struct intel_iommu *iommu;
unsigned long flags; unsigned long flags;
u8 bus, devfn; u8 bus, devfn;
assert_spin_locked(&device_domain_lock);
iommu = device_to_iommu(dev, &bus, &devfn); iommu = device_to_iommu(dev, &bus, &devfn);
if (!iommu) if (!iommu)
return; return;
@ -4556,9 +4559,7 @@ static void dmar_remove_one_dev_info(struct dmar_domain *domain,
if (WARN_ON(!info)) if (WARN_ON(!info))
return; return;
spin_lock_irqsave(&device_domain_lock, flags);
unlink_domain_info(info); unlink_domain_info(info);
spin_unlock_irqrestore(&device_domain_lock, flags);
iommu_disable_dev_iotlb(info); iommu_disable_dev_iotlb(info);
domain_context_clear(iommu, dev); domain_context_clear(iommu, dev);
@ -4569,6 +4570,16 @@ static void dmar_remove_one_dev_info(struct dmar_domain *domain,
spin_unlock_irqrestore(&iommu->lock, flags); 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) static int md_domain_init(struct dmar_domain *domain, int guest_width)
{ {
int adjust_width; int adjust_width;