Le 30/03/2021 à 08:07, Aneesh Kumar K.V a écrit :
Architectures like ppc64 can only support faster mremap only with radix
... only .... only ...
translation. Hence allow a runtime check w.r.t support for fast mremap.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
---
arch/arc/include/asm/tlb.h | 5 +++++
arch/arm64/include/asm/tlb.h | 6 ++++++
arch/powerpc/include/asm/tlb.h | 6 ++++++
arch/x86/include/asm/tlb.h | 5 +++++
mm/mremap.c | 14 +++++++++++++-
5 files changed, 35 insertions(+), 1 deletion(-)
diff --git a/arch/arc/include/asm/tlb.h b/arch/arc/include/asm/tlb.h
index 975b35d3738d..22b8cfb46cbf 100644
--- a/arch/arc/include/asm/tlb.h
+++ b/arch/arc/include/asm/tlb.h
@@ -9,4 +9,9 @@
#include <linux/pagemap.h>
#include <asm-generic/tlb.h>
+#define arch_supports_page_tables_move arch_supports_page_tables_move
+static inline bool arch_supports_page_tables_move(void)
+{
+ return true;
+}
I can't see why ARC arch needs that. It neither selects CONFIG_HAVE_MOVE_PMD nor CONFIG_HAVE_MOVE_PUD.
#endif /* _ASM_ARC_TLB_H */
diff --git a/arch/arm64/include/asm/tlb.h b/arch/arm64/include/asm/tlb.h
index 61c97d3b58c7..fe209efc6a10 100644
--- a/arch/arm64/include/asm/tlb.h
+++ b/arch/arm64/include/asm/tlb.h
@@ -94,4 +94,10 @@ static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pudp,
}
#endif
+#define arch_supports_page_tables_move arch_supports_page_tables_move
+static inline bool arch_supports_page_tables_move(void)
+{
+ return true;
+}
+
#endif
diff --git a/arch/powerpc/include/asm/tlb.h b/arch/powerpc/include/asm/tlb.h
index 160422a439aa..058918a7cd3c 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_tables_move arch_supports_page_tables_move
+static inline bool arch_supports_page_tables_move(void)
+{
+ return radix_enabled();
+}
+
#endif /* __KERNEL__ */
#endif /* __ASM_POWERPC_TLB_H */
diff --git a/arch/x86/include/asm/tlb.h b/arch/x86/include/asm/tlb.h
index 1bfe979bb9bc..62915238bb36 100644
--- a/arch/x86/include/asm/tlb.h
+++ b/arch/x86/include/asm/tlb.h
@@ -37,4 +37,9 @@ static inline void __tlb_remove_table(void *table)
free_page_and_swap_cache(table);
}
+#define arch_supports_page_tables_move arch_supports_page_tables_move
+static inline bool arch_supports_page_tables_move(void)
+{
+ return true;
+}
#endif /* _ASM_X86_TLB_H */
diff --git a/mm/mremap.c b/mm/mremap.c
index 7ac1df8e6d51..4d812af3e44b 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"
@@ -221,6 +221,14 @@ static inline void flush_pte_tlb_pwc_range(struct vm_area_struct *vma,
}
#endif
+#ifndef arch_supports_page_tables_move
+#define arch_supports_page_tables_move arch_supports_page_tables_move
+static inline bool arch_supports_page_tables_move(void)
+{
+ return false;
Can you do
return IS_ENABLED(CONFIG_HAVE_MOVE_PMD) || IS_ENABLED(CONFIG_HAVE_MOVE_PUD);
And then remove the arch_supports_page_tables_move() you have added for arc, arm64 and x86 ?
+}
+#endif
+
#ifdef CONFIG_HAVE_MOVE_PMD
Next step could be remove that #ifdef and the content of the matching #else
For that we'd just need a stub version of set_pmd_at() and set_pud_at().
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)
@@ -229,6 +237,8 @@ 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_tables_move())
+ return false;
/*
* The destination pmd shouldn't be established, free_pgtables()
* should have released it.
@@ -295,6 +305,8 @@ 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_tables_move())
+ return false;
/*
* The destination pud shouldn't be established, free_pgtables()
* should have released it.
