Commit b6170188 authored by Lu Baolu's avatar Lu Baolu Committed by Joerg Roedel
Browse files

iommu/vt-d: Remove pasid_mutex 



The pasid_mutex was used to protect the paths of set/remove_dev_pasid().
It's duplicate with iommu_sva_lock. Remove it to avoid duplicate code.

Signed-off-by: default avatarLu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: default avatarJacob Pan <jacob.jun.pan@linux.intel.com>
Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20230802212427.1497170-5-jacob.jun.pan@linux.intel.com


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent ac1a3483

drivers/iommu/intel/svm.c

+5 −40
Original line number Diff line number Diff line
@@ -259,8 +259,6 @@ static const struct mmu_notifier_ops intel_mmuops = { 
	.invalidate_range = intel_invalidate_range,

};



static DEFINE_MUTEX(pasid_mutex);



static int pasid_to_svm_sdev(struct device *dev, unsigned int pasid,

			     struct intel_svm **rsvm,

			     struct intel_svm_dev **rsdev)
@@ -268,10 +266,6 @@ static int pasid_to_svm_sdev(struct device *dev, unsigned int pasid, 
	struct intel_svm_dev *sdev = NULL;

	struct intel_svm *svm;



	/* The caller should hold the pasid_mutex lock */

	if (WARN_ON(!mutex_is_locked(&pasid_mutex)))

		return -EINVAL;



	if (pasid == IOMMU_PASID_INVALID || pasid >= PASID_MAX)

		return -EINVAL;
@@ -371,22 +365,19 @@ static int intel_svm_bind_mm(struct intel_iommu *iommu, struct device *dev, 
	return ret;

}



/* Caller must hold pasid_mutex */

static int intel_svm_unbind_mm(struct device *dev, u32 pasid)

void intel_svm_remove_dev_pasid(struct device *dev, u32 pasid)

{

	struct intel_svm_dev *sdev;

	struct intel_iommu *iommu;

	struct intel_svm *svm;

	struct mm_struct *mm;

	int ret = -EINVAL;



	iommu = device_to_iommu(dev, NULL, NULL);

	if (!iommu)

		goto out;

		return;



	ret = pasid_to_svm_sdev(dev, pasid, &svm, &sdev);

	if (ret)

		goto out;

	if (pasid_to_svm_sdev(dev, pasid, &svm, &sdev))

		return;

	mm = svm->mm;



	if (sdev) {
@@ -418,8 +409,6 @@ static int intel_svm_unbind_mm(struct device *dev, u32 pasid) 
			kfree(svm);

		}

	}

out:

	return ret;

}



/* Page request queue descriptor */
@@ -520,19 +509,7 @@ static void intel_svm_drain_prq(struct device *dev, u32 pasid) 
		goto prq_retry;

	}



	/*

	 * A work in IO page fault workqueue may try to lock pasid_mutex now.

	 * Holding pasid_mutex while waiting in iopf_queue_flush_dev() for

	 * all works in the workqueue to finish may cause deadlock.

	 *

	 * It's unnecessary to hold pasid_mutex in iopf_queue_flush_dev().

	 * Unlock it to allow the works to be handled while waiting for

	 * them to finish.

	 */

	lockdep_assert_held(&pasid_mutex);

	mutex_unlock(&pasid_mutex);

	iopf_queue_flush_dev(dev);

	mutex_lock(&pasid_mutex);



	/*

	 * Perform steps described in VT-d spec CH7.10 to drain page
@@ -827,26 +804,14 @@ int intel_svm_page_response(struct device *dev, 
	return ret;

}



void intel_svm_remove_dev_pasid(struct device *dev, ioasid_t pasid)

{

	mutex_lock(&pasid_mutex);

	intel_svm_unbind_mm(dev, pasid);

	mutex_unlock(&pasid_mutex);

}



static int intel_svm_set_dev_pasid(struct iommu_domain *domain,

				   struct device *dev, ioasid_t pasid)

{

	struct device_domain_info *info = dev_iommu_priv_get(dev);

	struct intel_iommu *iommu = info->iommu;

	struct mm_struct *mm = domain->mm;

	int ret;



	mutex_lock(&pasid_mutex);

	ret = intel_svm_bind_mm(iommu, dev, mm);

	mutex_unlock(&pasid_mutex);



	return ret;

	return intel_svm_bind_mm(iommu, dev, mm);

}



static void intel_svm_domain_free(struct iommu_domain *domain)