Hi Samuel,
On Wed, Mar 27, 2024 at 12:51 PM Samuel Holland
<samuel.holland@xxxxxxxxxx> 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@xxxxxxxxxxxx>
> Signed-off-by: Samuel Holland <samuel.holland@xxxxxxxxxx>
> ---
>
> (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@xxxxxxxxxxxxx>
Thanks,
Yunhui
