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Commit 53d340ef authored by Joerg Roedel's avatar Joerg Roedel
Browse files

iommu/amd: Add pasid_state->invalid flag 



This is used to signal the ppr_notifer function that no more
faults should be processes on this pasid_state. This way we
can keep the pasid_state safely in the state-table so that
it can be freed in the amd_iommu_unbind_pasid() function.

This allows us to not hold a reference to the mm_struct
during the whole pasid-binding-time.

Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
Tested-by: default avatarOded Gabbay <Oded.Gabbay@amd.com>
parent dc88db7e

drivers/iommu/amd_iommu_v2.c

+16 −2
Original line number Diff line number Diff line
@@ -53,6 +53,7 @@ struct pasid_state { 
	struct pri_queue pri[PRI_QUEUE_SIZE];	/* PRI tag states */

	struct device_state *device_state;	/* Link to our device_state */

	int pasid;				/* PASID index */

	bool invalid;				/* Used during teardown */

	spinlock_t lock;			/* Protect pri_queues and

						   mmu_notifer_count */

	wait_queue_head_t wq;			/* To wait for count == 0 */
@@ -306,8 +307,17 @@ static void unbind_pasid(struct pasid_state *pasid_state) 


	domain = pasid_state->device_state->domain;



	/*

	 * Mark pasid_state as invalid, no more faults will we added to the

	 * work queue after this is visible everywhere.

	 */

	pasid_state->invalid = true;



	/* Make sure this is visible */

	smp_wmb();



	/* After this the device/pasid can't access the mm anymore */

	amd_iommu_domain_clear_gcr3(domain, pasid_state->pasid);

	clear_pasid_state(pasid_state->device_state, pasid_state->pasid);



	/* Make sure no more pending faults are in the queue */

	flush_workqueue(iommu_wq);
@@ -573,7 +583,7 @@ static int ppr_notifier(struct notifier_block *nb, unsigned long e, void *data) 
		goto out;



	pasid_state = get_pasid_state(dev_state, iommu_fault->pasid);

	if (pasid_state == NULL) {

	if (pasid_state == NULL || pasid_state->invalid) {

		/* We know the device but not the PASID -> send INVALID */

		amd_iommu_complete_ppr(dev_state->pdev, iommu_fault->pasid,

				       PPR_INVALID, tag);
@@ -657,6 +667,7 @@ int amd_iommu_bind_pasid(struct pci_dev *pdev, int pasid, 
	pasid_state->mm           = get_task_mm(task);

	pasid_state->device_state = dev_state;

	pasid_state->pasid        = pasid;

	pasid_state->invalid      = false;

	pasid_state->mn.ops       = &iommu_mn;



	if (pasid_state->mm == NULL)
@@ -720,6 +731,9 @@ void amd_iommu_unbind_pasid(struct pci_dev *pdev, int pasid) 
	 */

	put_pasid_state(pasid_state);



	/* Clear the pasid state so that the pasid can be re-used */

	clear_pasid_state(dev_state, pasid_state->pasid);



	/* This will call the mn_release function and unbind the PASID */

	mmu_notifier_unregister(&pasid_state->mn, pasid_state->mm);