drm/msm: Reference count address spaces

There are reasons for a memory object to outlive the file descriptor
that created it and so the address space that a buffer object is
attached to must also outlive the file descriptor. Reference count
the address space so that it can remain viable until all the objects
have released their addresses.

Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/mdp/mdp4/mdp4_kms.c

@@ -169,7 +169,7 @@ static void mdp4_destroy(struct msm_kms *kms)
 	if (aspace) {
 		aspace->mmu->funcs->detach(aspace->mmu,
 				iommu_ports, ARRAY_SIZE(iommu_ports));
-		msm_gem_address_space_destroy(aspace);
+		msm_gem_address_space_put(aspace);
 	}
 
 	if (mdp4_kms->rpm_enabled)

drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c

@@ -175,7 +175,7 @@ static void mdp5_kms_destroy(struct msm_kms *kms)
 	if (aspace) {
 		aspace->mmu->funcs->detach(aspace->mmu,
 				iommu_ports, ARRAY_SIZE(iommu_ports));
-		msm_gem_address_space_destroy(aspace);
+		msm_gem_address_space_put(aspace);
 	}
 }