From 5e8d2850cbc55b43960d737e27bfd7dcb4a3e02e Mon Sep 17 00:00:00 2001
From: Peter Xu <peterx@redhat.com>
Date: Thu, 12 May 2022 20:22:54 -0700
Subject: [PATCH] mm/hugetlb: introduce huge pte version of uffd-wp helpers

They will be used in the follow up patches to either check/set/clear
uffd-wp bit of a huge pte.

So far it reuses all the small pte helpers.  Archs can overwrite these
versions when necessary (with __HAVE_ARCH_HUGE_PTE_UFFD_WP* macros) in the
future.

Link: https://lkml.kernel.org/r/20220405014858.14531-1-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: "Kirill A . Shutemov" <kirill@shutemov.name>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 arch/s390/include/asm/hugetlb.h | 15 +++++++++++++++
 include/asm-generic/hugetlb.h   | 15 +++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/arch/s390/include/asm/hugetlb.h b/arch/s390/include/asm/hugetlb.h
index f0bc4d31e852f..32c3fd6e878ee 100644
--- a/arch/s390/include/asm/hugetlb.h
+++ b/arch/s390/include/asm/hugetlb.h
@@ -120,6 +120,21 @@ static inline pte_t huge_pte_modify(pte_t pte, pgprot_t newprot)
 	return pte_modify(pte, newprot);
 }
 
+static inline pte_t huge_pte_mkuffd_wp(pte_t pte)
+{
+	return pte;
+}
+
+static inline pte_t huge_pte_clear_uffd_wp(pte_t pte)
+{
+	return pte;
+}
+
+static inline int huge_pte_uffd_wp(pte_t pte)
+{
+	return 0;
+}
+
 static inline bool gigantic_page_runtime_supported(void)
 {
 	return true;
diff --git a/include/asm-generic/hugetlb.h b/include/asm-generic/hugetlb.h
index f39cad20ffc6c..896f341f614d4 100644
--- a/include/asm-generic/hugetlb.h
+++ b/include/asm-generic/hugetlb.h
@@ -35,6 +35,21 @@ static inline pte_t huge_pte_modify(pte_t pte, pgprot_t newprot)
 	return pte_modify(pte, newprot);
 }
 
+static inline pte_t huge_pte_mkuffd_wp(pte_t pte)
+{
+	return pte_mkuffd_wp(pte);
+}
+
+static inline pte_t huge_pte_clear_uffd_wp(pte_t pte)
+{
+	return pte_clear_uffd_wp(pte);
+}
+
+static inline int huge_pte_uffd_wp(pte_t pte)
+{
+	return pte_uffd_wp(pte);
+}
+
 #ifndef __HAVE_ARCH_HUGE_PTE_CLEAR
 static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
 		    pte_t *ptep, unsigned long sz)
-- 
2.39.5