[Devel] [PATCH RHEL8 COMMIT] userfaultfd: wp: add pmd_swp_*uffd_wp() helpers

[Konstantin Khorenko]

The commit is pushed to "branch-rh8-4.18.0-80.1.2.vz8.3.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh8-4.18.0-80.1.2.vz8.3.6
------>
commit cbb69eef0aa54e12c8ce122f44c59476d6f67b9f
Author: Peter Xu <peterx at redhat.com>
Date:   Mon Apr 20 10:34:40 2020 +0300

    userfaultfd: wp: add pmd_swp_*uffd_wp() helpers
    
    Adding these missing helpers for uffd-wp operations with pmd
    swap/migration entries.
    
    Signed-off-by: Peter Xu <peterx at redhat.com>
    Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
    Reviewed-by: Jerome Glisse <jglisse at redhat.com>
    Reviewed-by: Mike Rapoport <rppt at linux.vnet.ibm.com>
    Cc: Andrea Arcangeli <aarcange at redhat.com>
    Cc: Bobby Powers <bobbypowers at gmail.com>
    Cc: Brian Geffon <bgeffon at google.com>
    Cc: David Hildenbrand <david at redhat.com>
    Cc: Denis Plotnikov <dplotnikov at virtuozzo.com>
    Cc: "Dr . David Alan Gilbert" <dgilbert at redhat.com>
    Cc: Hugh Dickins <hughd at google.com>
    Cc: Johannes Weiner <hannes at cmpxchg.org>
    Cc: "Kirill A . Shutemov" <kirill at shutemov.name>
    Cc: Martin Cracauer <cracauer at cons.org>
    Cc: Marty McFadden <mcfadden8 at llnl.gov>
    Cc: Maya Gokhale <gokhale2 at llnl.gov>
    Cc: Mel Gorman <mgorman at suse.de>
    Cc: Mike Kravetz <mike.kravetz at oracle.com>
    Cc: Pavel Emelyanov <xemul at openvz.org>
    Cc: Rik van Riel <riel at redhat.com>
    Cc: Shaohua Li <shli at fb.com>
    Link: http://lkml.kernel.org/r/20200220163112.11409-10-peterx@redhat.com
    Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
    
    https://jira.sw.ru/browse/PSBM-102938
    (cherry picked from commit 2e3d5dc508cf001c4fb2d15515ebe6f30df88f76)
    Signed-off-by: Andrey Ryabinin <aryabinin at virtuozzo.com>
---
 arch/x86/include/asm/pgtable.h     | 15 +++++++++++++++
 include/asm-generic/pgtable_uffd.h | 15 +++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index f01d8e82167b..f15cc996b149 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -1312,6 +1312,21 @@ static inline pte_t pte_swp_clear_uffd_wp(pte_t pte)
 {
 	return pte_clear_flags(pte, _PAGE_SWP_UFFD_WP);
 }
+
+static inline pmd_t pmd_swp_mkuffd_wp(pmd_t pmd)
+{
+	return pmd_set_flags(pmd, _PAGE_SWP_UFFD_WP);
+}
+
+static inline int pmd_swp_uffd_wp(pmd_t pmd)
+{
+	return pmd_flags(pmd) & _PAGE_SWP_UFFD_WP;
+}
+
+static inline pmd_t pmd_swp_clear_uffd_wp(pmd_t pmd)
+{
+	return pmd_clear_flags(pmd, _PAGE_SWP_UFFD_WP);
+}
 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */
 
 #define PKRU_AD_BIT 0x1
diff --git a/include/asm-generic/pgtable_uffd.h b/include/asm-generic/pgtable_uffd.h
index 643d1bf559c2..828966d4c281 100644
--- a/include/asm-generic/pgtable_uffd.h
+++ b/include/asm-generic/pgtable_uffd.h
@@ -46,6 +46,21 @@ static __always_inline pte_t pte_swp_clear_uffd_wp(pte_t pte)
 {
 	return pte;
 }
+
+static inline pmd_t pmd_swp_mkuffd_wp(pmd_t pmd)
+{
+	return pmd;
+}
+
+static inline int pmd_swp_uffd_wp(pmd_t pmd)
+{
+	return 0;
+}
+
+static inline pmd_t pmd_swp_clear_uffd_wp(pmd_t pmd)
+{
+	return pmd;
+}
 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */
 
 #endif /* _ASM_GENERIC_PGTABLE_UFFD_H */