diff mbox series

[v6,06/13] riscv: mm: Combine the SMP and UP TLB flush code

Message ID 20240327045035.368512-7-samuel.holland@sifive.com (mailing list archive)
State New
Headers show
Series riscv: ASID-related and UP-related TLB flush enhancements | expand

Commit Message

Samuel Holland March 27, 2024, 4:49 a.m. UTC 
In SMP configurations, all TLB flushing narrower than flush_tlb_all()
goes through __flush_tlb_range(). Do the same in UP configurations.

This allows UP configurations to take advantage of recent improvements
to the code in tlbflush.c, such as support for huge pages and flushing
multiple-page ranges.

Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
---

(no changes since v4)

Changes in v4:
 - Merge the two copies of __flush_tlb_range() and rely on the compiler
   to optimize out the broadcast path (both clang and gcc do this)
 - Merge the two copies of flush_tlb_all() and rely on constant folding

Changes in v2:
 - Move the SMP/UP merge earlier in the series to avoid build issues
 - Make a copy of __flush_tlb_range() instead of adding ifdefs inside
 - local_flush_tlb_all() is the only function used on !MMU (smpboot.c)

 arch/riscv/Kconfig                |  2 +-
 arch/riscv/include/asm/tlbflush.h | 31 +++----------------------------
 arch/riscv/mm/Makefile            |  5 +----
 3 files changed, 5 insertions(+), 33 deletions(-)

Comments

yunhui cui March 27, 2024, 6:23 a.m. UTC | #1 
Hi Samuel,

On Wed, Mar 27, 2024 at 12:51 PM Samuel Holland
<samuel.holland@sifive.com> wrote:
>
> In SMP configurations, all TLB flushing narrower than flush_tlb_all()
> goes through __flush_tlb_range(). Do the same in UP configurations.
>
> This allows UP configurations to take advantage of recent improvements
> to the code in tlbflush.c, such as support for huge pages and flushing
> multiple-page ranges.
>
> Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
> Signed-off-by: Samuel Holland <samuel.holland@sifive.com>
> ---
>
> (no changes since v4)
>
> Changes in v4:
>  - Merge the two copies of __flush_tlb_range() and rely on the compiler
>    to optimize out the broadcast path (both clang and gcc do this)
>  - Merge the two copies of flush_tlb_all() and rely on constant folding
>
> Changes in v2:
>  - Move the SMP/UP merge earlier in the series to avoid build issues
>  - Make a copy of __flush_tlb_range() instead of adding ifdefs inside
>  - local_flush_tlb_all() is the only function used on !MMU (smpboot.c)
>
>  arch/riscv/Kconfig                |  2 +-
>  arch/riscv/include/asm/tlbflush.h | 31 +++----------------------------
>  arch/riscv/mm/Makefile            |  5 +----
>  3 files changed, 5 insertions(+), 33 deletions(-)
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index be09c8836d56..442532819a44 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -60,7 +60,7 @@ config RISCV
>         select ARCH_USE_MEMTEST
>         select ARCH_USE_QUEUED_RWLOCKS
>         select ARCH_USES_CFI_TRAPS if CFI_CLANG
> -       select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP && MMU
> +       select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if MMU
>         select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
>         select ARCH_WANT_FRAME_POINTERS
>         select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT
> diff --git a/arch/riscv/include/asm/tlbflush.h b/arch/riscv/include/asm/tlbflush.h
> index 4112cc8d1d69..4f86424b1ba5 100644
> --- a/arch/riscv/include/asm/tlbflush.h
> +++ b/arch/riscv/include/asm/tlbflush.h
> @@ -27,12 +27,7 @@ static inline void local_flush_tlb_page(unsigned long addr)
>  {
>         ALT_FLUSH_TLB_PAGE(__asm__ __volatile__ ("sfence.vma %0" : : "r" (addr) : "memory"));
>  }
> -#else /* CONFIG_MMU */
> -#define local_flush_tlb_all()                  do { } while (0)
> -#define local_flush_tlb_page(addr)             do { } while (0)
> -#endif /* CONFIG_MMU */
>
> -#if defined(CONFIG_SMP) && defined(CONFIG_MMU)
>  void flush_tlb_all(void);
>  void flush_tlb_mm(struct mm_struct *mm);
>  void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
> @@ -54,28 +49,8 @@ void arch_tlbbatch_add_pending(struct arch_tlbflush_unmap_batch *batch,
>                                unsigned long uaddr);
>  void arch_flush_tlb_batched_pending(struct mm_struct *mm);
>  void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch);
> -
> -#else /* CONFIG_SMP && CONFIG_MMU */
> -
> -#define flush_tlb_all() local_flush_tlb_all()
> -#define flush_tlb_page(vma, addr) local_flush_tlb_page(addr)
> -
> -static inline void flush_tlb_range(struct vm_area_struct *vma,
> -               unsigned long start, unsigned long end)
> -{
> -       local_flush_tlb_all();
> -}
> -
> -/* Flush a range of kernel pages */
> -static inline void flush_tlb_kernel_range(unsigned long start,
> -       unsigned long end)
> -{
> -       local_flush_tlb_all();
> -}
> -
> -#define flush_tlb_mm(mm) flush_tlb_all()
> -#define flush_tlb_mm_range(mm, start, end, page_size) flush_tlb_all()
> -#define local_flush_tlb_kernel_range(start, end) flush_tlb_all()
> -#endif /* !CONFIG_SMP || !CONFIG_MMU */
> +#else /* CONFIG_MMU */
> +#define local_flush_tlb_all()                  do { } while (0)
> +#endif /* CONFIG_MMU */
>
>  #endif /* _ASM_RISCV_TLBFLUSH_H */
> diff --git a/arch/riscv/mm/Makefile b/arch/riscv/mm/Makefile
> index 2c869f8026a8..cbe4d775ef56 100644
> --- a/arch/riscv/mm/Makefile
> +++ b/arch/riscv/mm/Makefile
> @@ -13,14 +13,11 @@ endif
>  KCOV_INSTRUMENT_init.o := n
>
>  obj-y += init.o
> -obj-$(CONFIG_MMU) += extable.o fault.o pageattr.o pgtable.o
> +obj-$(CONFIG_MMU) += extable.o fault.o pageattr.o pgtable.o tlbflush.o
>  obj-y += cacheflush.o
>  obj-y += context.o
>  obj-y += pmem.o
>
> -ifeq ($(CONFIG_MMU),y)
> -obj-$(CONFIG_SMP) += tlbflush.o
> -endif
>  obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
>  obj-$(CONFIG_PTDUMP_CORE) += ptdump.o
>  obj-$(CONFIG_KASAN)   += kasan_init.o
> --
> 2.43.1
>

This is cleaner than my previous modification to support UP __flush_tlb_range.
So:
Reviewed-by: Yunhui Cui <cuiyunhui@bytedance.com>

Thanks,
Yunhui
diff mbox series

Patch

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index be09c8836d56..442532819a44 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -60,7 +60,7 @@  config RISCV
 	select ARCH_USE_MEMTEST
 	select ARCH_USE_QUEUED_RWLOCKS
 	select ARCH_USES_CFI_TRAPS if CFI_CLANG
-	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if SMP && MMU
+	select ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH if MMU
 	select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
 	select ARCH_WANT_FRAME_POINTERS
 	select ARCH_WANT_GENERAL_HUGETLB if !RISCV_ISA_SVNAPOT
diff --git a/arch/riscv/include/asm/tlbflush.h b/arch/riscv/include/asm/tlbflush.h
index 4112cc8d1d69..4f86424b1ba5 100644
--- a/arch/riscv/include/asm/tlbflush.h
+++ b/arch/riscv/include/asm/tlbflush.h
@@ -27,12 +27,7 @@  static inline void local_flush_tlb_page(unsigned long addr)
 {
 	ALT_FLUSH_TLB_PAGE(__asm__ __volatile__ ("sfence.vma %0" : : "r" (addr) : "memory"));
 }
-#else /* CONFIG_MMU */
-#define local_flush_tlb_all()			do { } while (0)
-#define local_flush_tlb_page(addr)		do { } while (0)
-#endif /* CONFIG_MMU */
 
-#if defined(CONFIG_SMP) && defined(CONFIG_MMU)
 void flush_tlb_all(void);
 void flush_tlb_mm(struct mm_struct *mm);
 void flush_tlb_mm_range(struct mm_struct *mm, unsigned long start,
@@ -54,28 +49,8 @@  void arch_tlbbatch_add_pending(struct arch_tlbflush_unmap_batch *batch,
 			       unsigned long uaddr);
 void arch_flush_tlb_batched_pending(struct mm_struct *mm);
 void arch_tlbbatch_flush(struct arch_tlbflush_unmap_batch *batch);
-
-#else /* CONFIG_SMP && CONFIG_MMU */
-
-#define flush_tlb_all() local_flush_tlb_all()
-#define flush_tlb_page(vma, addr) local_flush_tlb_page(addr)
-
-static inline void flush_tlb_range(struct vm_area_struct *vma,
-		unsigned long start, unsigned long end)
-{
-	local_flush_tlb_all();
-}
-
-/* Flush a range of kernel pages */
-static inline void flush_tlb_kernel_range(unsigned long start,
-	unsigned long end)
-{
-	local_flush_tlb_all();
-}
-
-#define flush_tlb_mm(mm) flush_tlb_all()
-#define flush_tlb_mm_range(mm, start, end, page_size) flush_tlb_all()
-#define local_flush_tlb_kernel_range(start, end) flush_tlb_all()
-#endif /* !CONFIG_SMP || !CONFIG_MMU */
+#else /* CONFIG_MMU */
+#define local_flush_tlb_all()			do { } while (0)
+#endif /* CONFIG_MMU */
 
 #endif /* _ASM_RISCV_TLBFLUSH_H */
diff --git a/arch/riscv/mm/Makefile b/arch/riscv/mm/Makefile
index 2c869f8026a8..cbe4d775ef56 100644
--- a/arch/riscv/mm/Makefile
+++ b/arch/riscv/mm/Makefile
@@ -13,14 +13,11 @@  endif
 KCOV_INSTRUMENT_init.o := n
 
 obj-y += init.o
-obj-$(CONFIG_MMU) += extable.o fault.o pageattr.o pgtable.o
+obj-$(CONFIG_MMU) += extable.o fault.o pageattr.o pgtable.o tlbflush.o
 obj-y += cacheflush.o
 obj-y += context.o
 obj-y += pmem.o
 
-ifeq ($(CONFIG_MMU),y)
-obj-$(CONFIG_SMP) += tlbflush.o
-endif
 obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
 obj-$(CONFIG_PTDUMP_CORE) += ptdump.o
 obj-$(CONFIG_KASAN)   += kasan_init.o