KVM: x86/mmu: Consolidate "page" variant of memory cache helpers

Drop the "page" variants of the topup/free memory cache helpers, using
the existence of an associated kmem_cache to select the correct alloc
or free routine.

No functional change intended.
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200703023545.8771-3-sean.j.christopherson@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/mmu/mmu.c

@@ -1068,7 +1068,10 @@ static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache, int min)
 	if (cache->nobjs >= min)
 		return 0;
 	while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
-		obj = kmem_cache_zalloc(cache->kmem_cache, GFP_KERNEL_ACCOUNT);
+		if (cache->kmem_cache)
+			obj = kmem_cache_zalloc(cache->kmem_cache, GFP_KERNEL_ACCOUNT);
+		else
+			obj = (void *)__get_free_page(GFP_KERNEL_ACCOUNT);
 		if (!obj)
 			return cache->nobjs >= min ? 0 : -ENOMEM;
 		cache->objects[cache->nobjs++] = obj;
@@ -1083,30 +1086,12 @@ static int mmu_memory_cache_free_objects(struct kvm_mmu_memory_cache *cache)
 
 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
 {
-	while (mc->nobjs)
-		kmem_cache_free(mc->kmem_cache, mc->objects[--mc->nobjs]);
-}
-
-static int mmu_topup_memory_cache_page(struct kvm_mmu_memory_cache *cache,
-				       int min)
-{
-	void *page;
-
-	if (cache->nobjs >= min)
-		return 0;
-	while (cache->nobjs < ARRAY_SIZE(cache->objects)) {
-		page = (void *)__get_free_page(GFP_KERNEL_ACCOUNT);
-		if (!page)
-			return cache->nobjs >= min ? 0 : -ENOMEM;
-		cache->objects[cache->nobjs++] = page;
+	while (mc->nobjs) {
+		if (mc->kmem_cache)
+			kmem_cache_free(mc->kmem_cache, mc->objects[--mc->nobjs]);
+		else
+			free_page((unsigned long)mc->objects[--mc->nobjs]);
 	}
-	return 0;
-}
-
-static void mmu_free_memory_cache_page(struct kvm_mmu_memory_cache *mc)
-{
-	while (mc->nobjs)
-		free_page((unsigned long)mc->objects[--mc->nobjs]);
 }
 
 static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
@@ -1117,7 +1102,7 @@ static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
 				   8 + PTE_PREFETCH_NUM);
 	if (r)
 		goto out;
-	r = mmu_topup_memory_cache_page(&vcpu->arch.mmu_page_cache, 8);
+	r = mmu_topup_memory_cache(&vcpu->arch.mmu_page_cache, 8);
 	if (r)
 		goto out;
 	r = mmu_topup_memory_cache(&vcpu->arch.mmu_page_header_cache, 4);
@@ -1128,7 +1113,7 @@ static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
 static void mmu_free_memory_caches(struct kvm_vcpu *vcpu)
 {
 	mmu_free_memory_cache(&vcpu->arch.mmu_pte_list_desc_cache);
-	mmu_free_memory_cache_page(&vcpu->arch.mmu_page_cache);
+	mmu_free_memory_cache(&vcpu->arch.mmu_page_cache);
 	mmu_free_memory_cache(&vcpu->arch.mmu_page_header_cache);
 }