linux-kernel - Re: [External] [PATCH 2/4] riscv: tlb: convert __p*d_free

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Message-ID: <ZYLksMHfzH1usBAb@xhacker>
Date: Wed, 20 Dec 2023 20:57:20 +0800
From: Jisheng Zhang <jszhang@...nel.org>
To: yunhui cui <cuiyunhui@...edance.com>
Cc: Paul Walmsley <paul.walmsley@...ive.com>,
	Palmer Dabbelt <palmer@...belt.com>,
	Albert Ou <aou@...s.berkeley.edu>, Will Deacon <will@...nel.org>,
	"Aneesh Kumar K . V" <aneesh.kumar@...ux.ibm.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Nick Piggin <npiggin@...il.com>,
	Peter Zijlstra <peterz@...radead.org>,
	linux-riscv@...ts.infradead.org, linux-kernel@...r.kernel.org,
	linux-arch@...r.kernel.org, linux-mm@...ck.org
Subject: Re: [External] [PATCH 2/4] riscv: tlb: convert __p*d_free_tlb() to
 inline functions

On Wed, Dec 20, 2023 at 10:59:22AM +0800, yunhui cui wrote:
> Hi Jisheng,

Hi,

> 
> On Wed, Dec 20, 2023 at 2:04 AM Jisheng Zhang <jszhang@...nel.org> wrote:
> >
> > This is to prepare for enabling MMU_GATHER_RCU_TABLE_FREE.
> > No functionality changes.
> >
> > Signed-off-by: Jisheng Zhang <jszhang@...nel.org>
> > ---
> >  arch/riscv/include/asm/pgalloc.h | 54 +++++++++++++++++++-------------
> >  1 file changed, 32 insertions(+), 22 deletions(-)
> >
> > diff --git a/arch/riscv/include/asm/pgalloc.h b/arch/riscv/include/asm/pgalloc.h
> > index a12fb83fa1f5..3c5e3bd15f46 100644
> > --- a/arch/riscv/include/asm/pgalloc.h
> > +++ b/arch/riscv/include/asm/pgalloc.h
> > @@ -95,13 +95,16 @@ static inline void pud_free(struct mm_struct *mm, pud_t *pud)
> >                 __pud_free(mm, pud);
> >  }
> >
> > -#define __pud_free_tlb(tlb, pud, addr)                                 \
> > -do {                                                                   \
> > -       if (pgtable_l4_enabled) {                                       \
> > -               pagetable_pud_dtor(virt_to_ptdesc(pud));                \
> > -               tlb_remove_page_ptdesc((tlb), virt_to_ptdesc(pud));     \
> > -       }                                                               \
> > -} while (0)
> > +static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pud,
> > +                                 unsigned long addr)
> > +{
> > +       if (pgtable_l4_enabled) {
> > +               struct ptdesc *ptdesc = virt_to_ptdesc(pud);
> > +
> > +               pagetable_pud_dtor(ptdesc);
> > +               tlb_remove_page_ptdesc(tlb, ptdesc);
> > +       }
> > +}
> >
> >  #define p4d_alloc_one p4d_alloc_one
> >  static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr)
> > @@ -130,11 +133,12 @@ static inline void p4d_free(struct mm_struct *mm, p4d_t *p4d)
> >                 __p4d_free(mm, p4d);
> >  }
> >
> > -#define __p4d_free_tlb(tlb, p4d, addr)                                 \
> > -do {                                                                   \
> > -       if (pgtable_l5_enabled)                                         \
> > -               tlb_remove_page_ptdesc((tlb), virt_to_ptdesc(p4d));     \
> > -} while (0)
> > +static inline void __p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d,
> > +                                 unsigned long addr)
> > +{
> > +       if (pgtable_l5_enabled)
> > +               tlb_remove_page_ptdesc(tlb, virt_to_ptdesc(p4d));
> > +}
> >  #endif /* __PAGETABLE_PMD_FOLDED */
> >
> >  static inline void sync_kernel_mappings(pgd_t *pgd)
> > @@ -159,19 +163,25 @@ static inline pgd_t *pgd_alloc(struct mm_struct *mm)
> >
> >  #ifndef __PAGETABLE_PMD_FOLDED
> >
> > -#define __pmd_free_tlb(tlb, pmd, addr)                         \
> > -do {                                                           \
> > -       pagetable_pmd_dtor(virt_to_ptdesc(pmd));                \
> > -       tlb_remove_page_ptdesc((tlb), virt_to_ptdesc(pmd));     \
> > -} while (0)
> > +static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd,
> > +                                 unsigned long addr)
> > +{
> > +       struct ptdesc *ptdesc = virt_to_ptdesc(pmd);
> > +
> > +       pagetable_pmd_dtor(ptdesc);
> > +       tlb_remove_page_ptdesc(tlb, ptdesc);
> > +}
> >
> >  #endif /* __PAGETABLE_PMD_FOLDED */
> >
> > -#define __pte_free_tlb(tlb, pte, buf)                  \
> > -do {                                                   \
> > -       pagetable_pte_dtor(page_ptdesc(pte));           \
> > -       tlb_remove_page_ptdesc((tlb), page_ptdesc(pte));\
> > -} while (0)
> > +static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte,
> > +                                 unsigned long addr)
> > +{
> > +       struct ptdesc *ptdesc = page_ptdesc(pte);
> > +
> > +       pagetable_pte_dtor(ptdesc);
> > +       tlb_remove_page_ptdesc(tlb, ptdesc);
> > +}
> >  #endif /* CONFIG_MMU */
> >
> >  #endif /* _ASM_RISCV_PGALLOC_H */
> > --
> > 2.40.0
> >
> 
> Why is it necessary to convert to inline functions?

Hmm, it's not necessary but a plus, the inline version's readability and
maintainability is better than macros

Regards