From d746bab9411ab55c6382c8be33ee2c2654f59d67 Mon Sep 17 00:00:00 2001
From: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Date: Tue, 28 May 2019 11:06:26 +0530
Subject: [PATCH] powerpc/mm/hugetlb: Don't enable HugeTLB if we don't have a
 page table cache

commit ac25ba68fa4001c85395f0488b1c7a2421c5aada upstream.

This makes sure we don't enable HugeTLB if the cache is not configured.
I am still not sure about this. IMHO hugetlb support should be a hardware
support derivative and any cache allocation failure should be handled as I did
in the earlier patch. But then if we were not able to create hugetlb page table
cache, we can as well declare hugetlb support disabled thereby avoiding calling
into allocation routines.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 1de0f43a68e5..1f24b768daa0 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -596,6 +596,7 @@ __setup("hugepagesz=", hugepage_setup_sz);
 
 static int __init hugetlbpage_init(void)
 {
+	bool configured = false;
 	int psize;
 
 	if (hugetlb_disabled) {
@@ -646,10 +647,15 @@ static int __init hugetlbpage_init(void)
 			pgtable_cache_add(pdshift - shift);
 		else if (IS_ENABLED(CONFIG_PPC_FSL_BOOK3E) || IS_ENABLED(CONFIG_PPC_8xx))
 			pgtable_cache_add(PTE_T_ORDER);
+
+		configured = true;
 	}
 
-	if (IS_ENABLED(CONFIG_HUGETLB_PAGE_SIZE_VARIABLE))
-		hugetlbpage_init_default();
+	if (configured) {
+		if (IS_ENABLED(CONFIG_HUGETLB_PAGE_SIZE_VARIABLE))
+			hugetlbpage_init_default();
+	} else
+		pr_info("Failed to initialize. Disabling HugeTLB");
 
 	return 0;
 }
-- 
2.7.4