habanalabs: fix nullifying of destroyed mmu pgt pool

In case of host-resident MMU, when the page tables pool is destroyed,
its pointer is not nullified correctly.
As a result, on a device fini which happens after a failing reset, the
already destroyed pool is accessed, which leads to a kernel panic.
The patch fixes the setting of the pool pointer to NULL.

Signed-off-by: Tomer Tayar <ttayar@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

diff --git a/drivers/misc/habanalabs/common/mmu/mmu_v1.c b/drivers/misc/habanalabs/common/mmu/mmu_v1.c
index c5e93ff325866298750fd51a783825b602206d7f..0f536f79dd9c9ab35ace651deb08369f225f68bb 100644 (file)
--- a/drivers/misc/habanalabs/common/mmu/mmu_v1.c
+++ b/drivers/misc/habanalabs/common/mmu/mmu_v1.c
@@ -470,13 +470,13 @@ static void hl_mmu_v1_fini(struct hl_device *hdev)
        if (!ZERO_OR_NULL_PTR(hdev->mmu_priv.hr.mmu_shadow_hop0)) {
                kvfree(hdev->mmu_priv.dr.mmu_shadow_hop0);
                gen_pool_destroy(hdev->mmu_priv.dr.mmu_pgt_pool);
-       }
 
-       /* Make sure that if we arrive here again without init was called we
-        * won't cause kernel panic. This can happen for example if we fail
-        * during hard reset code at certain points
-        */
-       hdev->mmu_priv.dr.mmu_shadow_hop0 = NULL;
+               /* Make sure that if we arrive here again without init was
+                * called we won't cause kernel panic. This can happen for
+                * example if we fail during hard reset code at certain points
+                */
+               hdev->mmu_priv.dr.mmu_shadow_hop0 = NULL;
+       }
 }
 
 /**