Re: [PATCH v4 13/15] mm: pgtable: introduce generic __tlb_remove_table()

[Alexander Gordeev <agordeev@linux.ibm.com>]

On Mon, Dec 30, 2024 at 05:07:48PM +0800, Qi Zheng wrote:
> Several architectures (arm, arm64, riscv and x86) define exactly the
> same __tlb_remove_table(), just introduce generic __tlb_remove_table() to
> eliminate these duplications.
> 
> The s390 __tlb_remove_table() is nearly the same, so also make s390
> __tlb_remove_table() version generic.
> 
> Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
> ---
>  arch/arm/include/asm/tlb.h      |  9 ---------
>  arch/arm64/include/asm/tlb.h    |  7 -------
>  arch/powerpc/include/asm/tlb.h  |  1 +
>  arch/riscv/include/asm/tlb.h    | 12 ------------
>  arch/s390/include/asm/tlb.h     |  9 ++++-----
>  arch/s390/mm/pgalloc.c          |  7 -------
>  arch/sparc/include/asm/tlb_32.h |  1 +
>  arch/sparc/include/asm/tlb_64.h |  1 +
>  arch/x86/include/asm/tlb.h      | 17 -----------------
>  include/asm-generic/tlb.h       | 15 +++++++++++++--
>  10 files changed, 20 insertions(+), 59 deletions(-)
...
> diff --git a/arch/s390/include/asm/tlb.h b/arch/s390/include/asm/tlb.h
> index 79df7c0932c56..da4a7d175f69c 100644
> --- a/arch/s390/include/asm/tlb.h
> +++ b/arch/s390/include/asm/tlb.h
> @@ -22,7 +22,6 @@
>   * Pages used for the page tables is a different story. FIXME: more
>   */
>  
> -void __tlb_remove_table(void *_table);
>  static inline void tlb_flush(struct mmu_gather *tlb);
>  static inline bool __tlb_remove_page_size(struct mmu_gather *tlb,
>  		struct page *page, bool delay_rmap, int page_size);
> @@ -87,7 +86,7 @@ static inline void pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte,
>  	tlb->cleared_pmds = 1;
>  	if (mm_alloc_pgste(tlb->mm))
>  		gmap_unlink(tlb->mm, (unsigned long *)pte, address);
> -	tlb_remove_ptdesc(tlb, pte);
> +	tlb_remove_ptdesc(tlb, virt_to_ptdesc(pte));
>  }
>  
>  /*
> @@ -106,7 +105,7 @@ static inline void pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd,
>  	tlb->mm->context.flush_mm = 1;
>  	tlb->freed_tables = 1;
>  	tlb->cleared_puds = 1;
> -	tlb_remove_ptdesc(tlb, pmd);
> +	tlb_remove_ptdesc(tlb, virt_to_ptdesc(pmd));
>  }
>  
>  /*
> @@ -124,7 +123,7 @@ static inline void pud_free_tlb(struct mmu_gather *tlb, pud_t *pud,
>  	tlb->mm->context.flush_mm = 1;
>  	tlb->freed_tables = 1;
>  	tlb->cleared_p4ds = 1;
> -	tlb_remove_ptdesc(tlb, pud);
> +	tlb_remove_ptdesc(tlb, virt_to_ptdesc(pud));
>  }
>  
>  /*
> @@ -142,7 +141,7 @@ static inline void p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d,
>  	__tlb_adjust_range(tlb, address, PAGE_SIZE);
>  	tlb->mm->context.flush_mm = 1;
>  	tlb->freed_tables = 1;
> -	tlb_remove_ptdesc(tlb, p4d);
> +	tlb_remove_ptdesc(tlb, virt_to_ptdesc(p4d));
>  }
>  
>  #endif /* _S390_TLB_H */
> diff --git a/arch/s390/mm/pgalloc.c b/arch/s390/mm/pgalloc.c
> index c73b89811a264..3e002dea6278f 100644
> --- a/arch/s390/mm/pgalloc.c
> +++ b/arch/s390/mm/pgalloc.c
> @@ -193,13 +193,6 @@ void page_table_free(struct mm_struct *mm, unsigned long *table)
>  	pagetable_dtor_free(ptdesc);
>  }
>  
> -void __tlb_remove_table(void *table)
> -{
> -	struct ptdesc *ptdesc = virt_to_ptdesc(table);
> -
> -	pagetable_dtor_free(ptdesc);
> -}
> -
>  #ifdef CONFIG_TRANSPARENT_HUGEPAGE
>  static void pte_free_now(struct rcu_head *head)
>  {
...
> diff --git a/include/asm-generic/tlb.h b/include/asm-generic/tlb.h
> index 709830274b756..69de47c7ef3c5 100644
> --- a/include/asm-generic/tlb.h
> +++ b/include/asm-generic/tlb.h
> @@ -153,8 +153,9 @@
>   *
>   *  Useful if your architecture has non-page page directories.
>   *
> - *  When used, an architecture is expected to provide __tlb_remove_table()
> - *  which does the actual freeing of these pages.
> + *  When used, an architecture is expected to provide __tlb_remove_table() or
> + *  use the generic __tlb_remove_table(), which does the actual freeing of these
> + *  pages.
>   *
>   *  MMU_GATHER_RCU_TABLE_FREE
>   *
> @@ -207,6 +208,16 @@ struct mmu_table_batch {
>  #define MAX_TABLE_BATCH		\
>  	((PAGE_SIZE - sizeof(struct mmu_table_batch)) / sizeof(void *))
>  
> +#ifndef __HAVE_ARCH_TLB_REMOVE_TABLE
> +static inline void __tlb_remove_table(void *table)
> +{
> +	struct ptdesc *ptdesc = (struct ptdesc *)table;
> +
> +	pagetable_dtor(ptdesc);
> +	pagetable_free(ptdesc);
> +}
> +#endif
> +
>  extern void tlb_remove_table(struct mmu_gather *tlb, void *table);
>  
>  #else /* !CONFIG_MMU_GATHER_HAVE_TABLE_FREE */

For s390:

Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>

Thanks!