[RFC PATCH 5/6] mm/mremap: Allow arch runtime override
From: Aneesh Kumar K.V <hidden>
Date: 2021-02-02 09:11:50
Also in:
linux-mm
Subsystem:
arm64 port (aarch64 architecture), linux for powerpc (32-bit and 64-bit), memory management, memory mapping, mmu gather and tlb invalidation, the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Catalin Marinas, Will Deacon, Madhavan Srinivasan, Andrew Morton, Liam R. Howlett, Lorenzo Stoakes, "Aneesh Kumar K.V", Nick Piggin, Peter Zijlstra, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
Architectures like ppc64 can only 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 <redacted> --- 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 +++++++++++++- 4 files changed, 30 insertions(+), 1 deletion(-)
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 820082bd6880..62827553afd8 100644
--- a/arch/x86/include/asm/tlb.h
+++ b/arch/x86/include/asm/tlb.h@@ -38,4 +38,9 @@ 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 14778d215011..dd1244a410bb 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c@@ -26,7 +26,7 @@ #include <linux/userfaultfd_k.h> #include <asm/cacheflush.h> -#include <asm/tlbflush.h> +#include <asm/tlb.h> #include <asm/pgalloc.h> #include "internal.h"
@@ -211,6 +211,14 @@ static void move_ptes(struct vm_area_struct *vma, pmd_t *old_pmd, drop_rmap_locks(vma); } +#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; +} +#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)
@@ -220,6 +228,8 @@ static bool move_normal_pmd(struct vm_area_struct *vma, unsigned long old_addr, struct mmu_gather tlb; pmd_t pmd; + if (!arch_supports_page_tables_move()) + return false; /* * The destination pmd shouldn't be established, free_pgtables() * should have released it.
@@ -298,6 +308,8 @@ static bool move_normal_pud(struct vm_area_struct *vma, unsigned long old_addr, struct mmu_gather tlb; pud_t pud; + if (!arch_supports_page_tables_move()) + return false; /* * The destination pud shouldn't be established, free_pgtables() * should have released it.
--
2.29.2