Patch "sparc64: Register hugepages during arch init" has been added to the 4.12-stable tree

This is a note to let you know that I've just added the patch titled

sparc64: Register hugepages during arch init

to the 4.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
sparc64-register-hugepages-during-arch-init.patch
and it can be found in the queue-4.12 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Nitin Gupta <[email protected]>
Date: Wed, 19 Jul 2017 17:12:54 -0700
Subject: sparc64: Register hugepages during arch init

From: Nitin Gupta <[email protected]>

[ 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

---
 arch/sparc/mm/init_64.c |   25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

@@ -325,6 +325,29 @@ static void __update_mmu_tsb_insert(stru
 }
 
 #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
 		goto out;
 	}
 
-	hugetlb_add_hstate(hugepage_shift - PAGE_SHIFT);
+	add_huge_page_size(hugepage_size);
 	rc = 1;
 
 out:

Patches currently in stable-queue which might be from [email protected] are

queue-4.12/sparc64-register-hugepages-during-arch-init.patch