Commit d160aca5 authored by Joerg Roedel's avatar Joerg Roedel
Browse files

iommu/vt-d: Unify domain->iommu attach/detachment 



Move the code to attach/detach domains to iommus and vice
verce into a single function to make sure there are no
dangling references.

Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent c6c2cebd

drivers/iommu/intel-iommu.c

+49 −76
Original line number Diff line number Diff line
@@ -1678,90 +1678,64 @@ static struct dmar_domain *alloc_domain(int flags) 
	return domain;

}



static int __iommu_attach_domain(struct dmar_domain *domain,

/* Must be called with iommu->lock */

static int domain_attach_iommu(struct dmar_domain *domain,

			       struct intel_iommu *iommu)

{

	int num;

	unsigned long ndomains;

	unsigned long flags;

	int ret, num;



	num = domain->iommu_did[iommu->seq_id];

	if (num)

		return num;

	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) {

		ndomains = cap_ndoms(iommu->cap);

		num      = find_first_zero_bit(iommu->domain_ids, ndomains);



	if (num < ndomains) {

		set_bit(num, iommu->domain_ids);

		set_iommu_domain(iommu, num, domain);

		domain->iommu_did[iommu->seq_id] = num;

	} else {

		num = -ENOSPC;

	}



	if (num < 0)

		if (num >= ndomains) {

			pr_err("%s: No free domain ids\n", iommu->name);



	return num;

}



static int iommu_attach_domain(struct dmar_domain *domain,

			       struct intel_iommu *iommu)

{

	int num;

	unsigned long flags;



	spin_lock_irqsave(&iommu->lock, flags);

	num = __iommu_attach_domain(domain, iommu);

	spin_unlock_irqrestore(&iommu->lock, flags);



	return num;

}



static void iommu_detach_domain(struct dmar_domain *domain,

				struct intel_iommu *iommu)

{

	unsigned long flags;

	int num;



	spin_lock_irqsave(&iommu->lock, flags);



	num = domain->iommu_did[iommu->seq_id];



	if (num == 0)

		return;



	clear_bit(num, iommu->domain_ids);

	set_iommu_domain(iommu, num, NULL);



	spin_unlock_irqrestore(&iommu->lock, flags);

			domain->iommu_refcnt[iommu->seq_id] -= 1;

			domain->iommu_count -= 1;

			ret = -ENOSPC;

			goto out_unlock;

		}



static void domain_attach_iommu(struct dmar_domain *domain,

			       struct intel_iommu *iommu)

{

	unsigned long flags;

		set_bit(num, iommu->domain_ids);

		set_iommu_domain(iommu, num, domain);



	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) {

		domain->iommu_did[iommu->seq_id] = num;

		domain->nid			 = iommu->node;



		domain_update_iommu_cap(domain);

	}



	ret = 0;

out_unlock:

	spin_unlock_irqrestore(&domain->iommu_lock, flags);



	return ret;

}



static int domain_detach_iommu(struct dmar_domain *domain,

			       struct intel_iommu *iommu)

{

	int num, count = INT_MAX;

	unsigned long flags;

	int count = INT_MAX;



	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) {

		num = domain->iommu_did[iommu->seq_id];

		clear_bit(num, iommu->domain_ids);

		set_iommu_domain(iommu, num, NULL);



		domain_update_iommu_cap(domain);

		domain->iommu_did[iommu->seq_id] = 0;

	}
@@ -1886,7 +1860,6 @@ static int domain_init(struct dmar_domain *domain, struct intel_iommu *iommu, 
static void domain_exit(struct dmar_domain *domain)

{

	struct page *freelist = NULL;

	int i;



	/* Domain 0 is reserved, so dont process it */

	if (!domain)
@@ -1896,20 +1869,16 @@ static void domain_exit(struct dmar_domain *domain) 
	if (!intel_iommu_strict)

		flush_unmaps_timeout(0);



	/* remove associated devices */

	/* Remove associated devices and clear attached or cached domains */

	rcu_read_lock();

	domain_remove_dev_info(domain);

	rcu_read_unlock();



	/* destroy iovas */

	put_iova_domain(&domain->iovad);



	freelist = domain_unmap(domain, 0, DOMAIN_MAX_PFN(domain->gaw));



	/* clear attached or cached domains */

	rcu_read_lock();

	for_each_domain_iommu(i, domain)

		iommu_detach_domain(domain, g_iommus[i]);

	rcu_read_unlock();



	dma_free_pagelist(freelist);



	free_domain_mem(domain);
@@ -2286,6 +2255,7 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu, 
	struct dmar_domain *found = NULL;

	struct device_domain_info *info;

	unsigned long flags;

	int ret;



	info = alloc_devinfo_mem();

	if (!info)
@@ -2313,11 +2283,14 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu, 
		return found;

	}



	if (iommu_attach_domain(domain, iommu) < 0) {

	spin_lock(&iommu->lock);

	ret = domain_attach_iommu(domain, iommu);

	spin_unlock(&iommu->lock);



	if (ret) {

		spin_unlock_irqrestore(&device_domain_lock, flags);

		return NULL;

	}

	domain_attach_iommu(domain, iommu);



	list_add(&info->link, &domain->devices);

	list_add(&info->global, &device_domain_list);
@@ -4590,12 +4563,10 @@ static void dmar_remove_one_dev_info(struct dmar_domain *domain, 
	iommu_disable_dev_iotlb(info);

	domain_context_clear(iommu, dev);

	free_devinfo_mem(info);

	domain_detach_iommu(domain, iommu);



	spin_lock_irqsave(&domain->iommu_lock, flags);

	if (!domain->iommu_refcnt[iommu->seq_id])

		iommu_detach_domain(domain, iommu);

	spin_unlock_irqrestore(&domain->iommu_lock, flags);

	spin_lock_irqsave(&iommu->lock, flags);

	domain_detach_iommu(domain, iommu);

	spin_unlock_irqrestore(&iommu->lock, flags);

}



static int md_domain_init(struct dmar_domain *domain, int guest_width)
@@ -4676,10 +4647,12 @@ static int intel_iommu_attach_device(struct iommu_domain *domain, 


		old_domain = find_domain(dev);

		if (old_domain) {

			rcu_read_lock();

			if (domain_type_is_vm_or_si(dmar_domain))

				dmar_remove_one_dev_info(old_domain, dev);

			else

				domain_remove_dev_info(old_domain);

			rcu_read_unlock();



			if (!domain_type_is_vm_or_si(old_domain) &&

			     list_empty(&old_domain->devices))