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Commit 55d94043 authored by Joerg Roedel's avatar Joerg Roedel
Browse files

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



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: default avatarJoerg Roedel <jroedel@suse.de>
parent de7e8886

drivers/iommu/intel-iommu.c

+49 −38
Original line number Diff line number Diff line
@@ -406,7 +406,6 @@ 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
@@ -476,6 +475,8 @@ 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);
@@ -1404,24 +1405,23 @@ 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;
@@ -1616,10 +1616,12 @@ 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;
@@ -1636,6 +1638,7 @@ 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);
@@ -1672,7 +1675,6 @@ 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;
@@ -1683,13 +1685,11 @@ 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) {
@@ -1700,8 +1700,7 @@ 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);
@@ -1713,22 +1712,17 @@ 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) {
@@ -1739,7 +1733,6 @@ 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;

}
@@ -1894,7 +1887,7 @@ 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);
@@ -1906,16 +1899,17 @@ 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;
@@ -1928,11 +1922,10 @@ 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);
@@ -1971,7 +1964,12 @@ 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;

}
@@ -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)

{

	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);

}



/*
@@ -4539,7 +4540,7 @@ 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,

static void __dmar_remove_one_dev_info(struct dmar_domain *domain,

				       struct device *dev)

{

	struct device_domain_info *info;
@@ -4547,6 +4548,8 @@ static void dmar_remove_one_dev_info(struct dmar_domain *domain, 
	unsigned long flags;

	u8 bus, devfn;



	assert_spin_locked(&device_domain_lock);



	iommu = device_to_iommu(dev, &bus, &devfn);

	if (!iommu)

		return;
@@ -4556,9 +4559,7 @@ 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);
@@ -4569,6 +4570,16 @@ 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;