Architectures like ppc64 support faster mremap only with radix
translation. Hence allow a runtime check w.r.t support for fast mremap.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
---
arch/powerpc/include/asm/tlb.h | 6 ++++++
mm/mremap.c | 15 ++++++++++++++-
2 files changed, 20 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm/tlb.h b/arch/powerpc/include/asm/tlb.h
index 160422a439aa..09a9ae5f3656 100644
--- a/arch/powerpc/include/asm/tlb.h
+++ b/arch/powerpc/include/asm/tlb.h
@@ -83,5 +83,11 @@ static inline int mm_is_thread_local(struct mm_struct *mm)
}
#endif
+#define arch_supports_page_table_move arch_supports_page_table_move
+static inline bool arch_supports_page_table_move(void)
+{
+ return radix_enabled();
+}
+
#endif /* __KERNEL__ */
#endif /* __ASM_POWERPC_TLB_H */
diff --git a/mm/mremap.c b/mm/mremap.c
index dacfa9111ab1..9cd352fb9cf8 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -25,7 +25,7 @@
#include <linux/userfaultfd_k.h>
#include <asm/cacheflush.h>
-#include <asm/tlbflush.h>
+#include <asm/tlb.h>
#include <asm/pgalloc.h>
#include "internal.h"
@@ -210,6 +210,15 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd,
drop_rmap_locks(vma);
}
+#ifndef arch_supports_page_table_move
+#define arch_supports_page_table_move arch_supports_page_table_move
+static inline bool arch_supports_page_table_move(void)
+{
+ return IS_ENABLED(CONFIG_HAVE_MOVE_PMD) ||
+ IS_ENABLED(CONFIG_HAVE_MOVE_PUD);
+}
+#endif
+
#ifdef CONFIG_HAVE_MOVE_PMD
static bool move_normal_pmd(struct vm_area_struct *vma, unsigned long old_addr,
unsigned long new_addr, pmd_t *old_pmd, pmd_t *new_pmd)
@@ -218,6 +227,8 @@ static bool move_normal_pmd(struct vm_area_struct *vma, unsigned long old_addr,
struct mm_struct *mm = vma->vm_mm;
pmd_t pmd;
+ if (!arch_supports_page_table_move())
+ return false;
/*
* The destination pmd shouldn't be established, free_pgtables()
* should have released it.
@@ -284,6 +295,8 @@ static bool move_normal_pud(struct vm_area_struct *vma, unsigned long old_addr,
struct mm_struct *mm = vma->vm_mm;
pud_t pud;
+ if (!arch_supports_page_table_move())
+ return false;
/*
* The destination pud shouldn't be established, free_pgtables()
* should have released it.
--
2.31.1
