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Subject[PATCH 9/9] iommu/amd: Don't call the inv_ctx_cb when pasid is not set up
Date
From: Joerg Roedel <jroedel@suse.de>

On the error path of amd_iommu_bind_pasid() we call
mmu_notifier_unregister() for cleanup. This calls
mn_release() which calls the users inv_ctx_cb function if
one is available. Since the pasid is not set up yet there is
nothing the user can to tear down in this call-back. So
don't call inv_ctx_cb on the error path of
amd_iommu_unbind_pasid() and make life of the users simpler.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Tested-by: Oded Gabbay <Oded.Gabbay@amd.com>
---
drivers/iommu/amd_iommu_v2.c | 17 ++++++++++++-----
1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c
index f7ca009..a195c78 100644
--- a/drivers/iommu/amd_iommu_v2.c
+++ b/drivers/iommu/amd_iommu_v2.c
@@ -52,7 +52,8 @@ 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 */
+ bool invalid; /* Used during setup and
+ teardown of the pasid */
spinlock_t lock; /* Protect pri_queues and
mmu_notifer_count */
wait_queue_head_t wq; /* To wait for count == 0 */
@@ -473,13 +474,15 @@ static void mn_release(struct mmu_notifier *mn, struct mm_struct *mm)
{
struct pasid_state *pasid_state;
struct device_state *dev_state;
+ bool run_inv_ctx_cb;

might_sleep();

- pasid_state = mn_to_state(mn);
- dev_state = pasid_state->device_state;
+ pasid_state = mn_to_state(mn);
+ dev_state = pasid_state->device_state;
+ run_inv_ctx_cb = !pasid_state->invalid;

- if (pasid_state->device_state->inv_ctx_cb)
+ if (run_inv_ctx_cb && pasid_state->device_state->inv_ctx_cb)
dev_state->inv_ctx_cb(dev_state->pdev, pasid_state->pasid);

unbind_pasid(pasid_state);
@@ -674,7 +677,8 @@ int amd_iommu_bind_pasid(struct pci_dev *pdev, int pasid,
pasid_state->mm = mm;
pasid_state->device_state = dev_state;
pasid_state->pasid = pasid;
- pasid_state->invalid = false;
+ pasid_state->invalid = true; /* Mark as valid only if we are
+ done with setting up the pasid */
pasid_state->mn.ops = &iommu_mn;

if (pasid_state->mm == NULL)
@@ -691,6 +695,9 @@ int amd_iommu_bind_pasid(struct pci_dev *pdev, int pasid,
if (ret)
goto out_clear_state;

+ /* Now we are ready to handle faults */
+ pasid_state->invalid = false;
+
/*
* Drop the reference to the mm_struct here. We rely on the
* mmu_notifier release call-back to inform us when the mm
--
1.7.9.5



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