diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index e9b408343c5d..b1e780a465b5 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -417,6 +417,8 @@ static void cpa_collapse_large_pages(struct cpa_data *cpa)
 	int collapsed = 0;
 	int i;
 
+	spin_lock(&cpa_lock);
+
 	if (cpa->flags & (CPA_PAGES_ARRAY | CPA_ARRAY)) {
 		for (i = 0; i < cpa->numpages; i++)
 			collapsed += collapse_large_pages(__cpa_addr(cpa, i),
@@ -430,8 +432,10 @@ static void cpa_collapse_large_pages(struct cpa_data *cpa)
 			collapsed += collapse_large_pages(addr, &pgtables);
 	}
 
-	if (!collapsed)
+	if (!collapsed) {
+		spin_unlock(&cpa_lock);
 		return;
+	}
 
 	flush_tlb_all();
 
@@ -439,6 +443,8 @@ static void cpa_collapse_large_pages(struct cpa_data *cpa)
 		list_del(&ptdesc->pt_list);
 		pagetable_free(ptdesc);
 	}
+
+	spin_unlock(&cpa_lock);
 }
 
 static void cpa_flush(struct cpa_data *cpa, int cache)