habanalabs: fix nullifying of destroyed mmu pgt pool

[mirror_ubuntu-hirsute-kernel.git] / drivers / misc / habanalabs / common / mmu_v1.c

diff --git a/drivers/misc/habanalabs/common/mmu_v1.c b/drivers/misc/habanalabs/common/mmu_v1.c
index 2ce6ea89d4fa22930aef8e325e2db9ce1b193d49..a5be1c096e390818883e3fd0170cdf28e607aef4 100644 (file)
--- a/drivers/misc/habanalabs/common/mmu_v1.c
+++ b/drivers/misc/habanalabs/common/mmu_v1.c
@@ -467,8 +467,16 @@ static void hl_mmu_v1_fini(struct hl_device *hdev)
 {
        /* MMU H/W fini was already done in device hw_fini() */
 
-       kvfree(hdev->mmu_priv.dr.mmu_shadow_hop0);
-       gen_pool_destroy(hdev->mmu_priv.dr.mmu_pgt_pool);
+       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;
+       }
 }
 
 /**