Subject: [PATCH 3/4] sparc64: Register hugepages during arch init

From: Nitin Gupta <[email-masked]>
Date: Wed, 19 Jul 2017 17:12:54 -0700

[ Upstream commit 8399e4b88a93fc7bc00fff3b8da9b2e718b7f45e ]

Add hstate for each supported hugepage size using
arch initcall. This change fixes some hugepage
parameter parsing inconsistencies:

case 1: no hugepage parameters

 Without hugepage parameters, only a hugepages-8192kB entry is visible
 in sysfs.  It's different from x86_64 where both 2M and 1G hugepage
 sizes are available.

case 2: default_hugepagesz=[64K|256M|2G]

 When specifying only a default_hugepagesz parameter, the default
 hugepage size isn't really changed and it stays at 8M. This is again
 different from x86_64.

Orabug: 25869946

Reviewed-by: Bob Picco <[email-masked]>
Signed-off-by: Nitin Gupta <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 arch/sparc/mm/init_64.c | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
index 3c40ebd50f92..fed73f14aa49 100644
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -325,6 +325,29 @@ static void __update_mmu_tsb_insert(struct mm_struct *mm, unsigned long tsb_inde
 }
 
 #ifdef CONFIG_HUGETLB_PAGE
+static void __init add_huge_page_size(unsigned long size)
+{
+	unsigned int order;
+
+	if (size_to_hstate(size))
+		return;
+
+	order = ilog2(size) - PAGE_SHIFT;
+	hugetlb_add_hstate(order);
+}
+
+static int __init hugetlbpage_init(void)
+{
+	add_huge_page_size(1UL << HPAGE_64K_SHIFT);
+	add_huge_page_size(1UL << HPAGE_SHIFT);
+	add_huge_page_size(1UL << HPAGE_256MB_SHIFT);
+	add_huge_page_size(1UL << HPAGE_2GB_SHIFT);
+
+	return 0;
+}
+
+arch_initcall(hugetlbpage_init);
+
 static int __init setup_hugepagesz(char *string)
 {
 	unsigned long long hugepage_size;
@@ -364,7 +387,7 @@ static int __init setup_hugepagesz(char *string)
 		goto out;
 	}
 
-	hugetlb_add_hstate(hugepage_shift - PAGE_SHIFT);
+	add_huge_page_size(hugepage_size);
 	rc = 1;
 
 out:
-- 
2.13.4