Subject: [RFC PATCH 3/3] powerpc/mm/hugetlb: Don't enable HugeTLB if we don't have a page table cache

From: "Aneesh Kumar K.V" <[email-masked]>
Date: Tue, 14 May 2019 20:20:41 +0530

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 <[email-masked]>
---
 arch/powerpc/mm/hugetlbpage.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index ee16a3fb788a..4bf8bc659cc7 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -602,6 +602,7 @@ __setup("hugepagesz=", hugepage_setup_sz);
 static int __init hugetlbpage_init(void)
 {
 	int psize;
+	bool configured = false;
 
 	if (hugetlb_disabled) {
 		pr_info("HugeTLB support is disabled!\n");
@@ -651,10 +652,16 @@ 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);
+
+		if (!configured)
+			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("Disabling HugeTLB");
 
 	return 0;
 }
-- 
2.21.0