Re: [PATCH] riscv: using page table index in setup_vm()

From: JaeJoon Jung <rgbi3307@gmail.com>
To: Mike Rapoport <rppt@linux.ibm.com>
Cc: linux-riscv@lists.infradead.org
Subject: Re: [PATCH] riscv: using page table index in setup_vm()
Date: Thu, 23 May 2019 19:12:14 +0900	[thread overview]
Message-ID: <CAHOvCC72URVWs8RswjqeewKn0rnoik2OespWkt+d+RNhdTHOAg@mail.gmail.com> (raw)
In-Reply-To: <20190523095214.GD23850@rapoport-lnx>

Thanks for your professional advice.
I'd like to take your appropriate suggestion.

Sincerely yours,
JaeJoon Jung.

On Thu, 23 May 2019 at 18:52, Mike Rapoport <rppt@linux.ibm.com> wrote:
>
> On Mon, May 20, 2019 at 05:48:24PM +0900, JaeJoon Jung wrote:
> > From: JaeJoon Jung <rgbi3307@gmail.com>
> >
> > The page table index macro are defined already in pgtable.h as below:
> > ///arch/riscv/include/asm/pgtable.h
> > #define pgd_index(addr)     (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
> > #define pte_index(addr)     (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
> > ///arch/riscv/include/asm/pgtable-64.h
> > #define pmd_index(addr)     (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
> >
> > But, In the arch/riscv/mm/init.c,
> > I found that it does not use above macro in setup_vm().
> > I wat to use this macro in setup_vm() as below:
>
> I'd suggest the following changelog:
> -----------------------------------------
> riscv: setup_vm: use p?d_index() instead of its open coded implementation
>
> The page table indexing macros are defined in include/asm/pgtable.h, but
> setup_vm() uses an open coded implementation.
>
> Replace it with the appropriate macros.
> -----------------------------------------
>
>
> > Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
> > Cc: Anup Patel <anup.patel@wdc.com>
> > Cc: linux-riscv@lists.infradead.org
>
> Otherwise
>
> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
>
> > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> > index bc7b77e34d09..785954b776ac 100644
> > --- a/arch/riscv/mm/init.c
> > +++ b/arch/riscv/mm/init.c
> >
> >  asmlinkage void __init setup_vm(void)
> >  {
> >         extern char _start;
> > @@ -223,13 +190,13 @@ asmlinkage void __init setup_vm(void)
> >         BUG_ON((pa % (PAGE_SIZE * PTRS_PER_PTE)) != 0);
> >
> >  #ifndef __PAGETABLE_PMD_FOLDED
> > -       trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
> > +       trampoline_pg_dir[pgd_index(PAGE_OFFSET)] =
> >                 pfn_pgd(PFN_DOWN((uintptr_t)trampoline_pmd),
> >                         __pgprot(_PAGE_TABLE));
> >         trampoline_pmd[0] = pfn_pmd(PFN_DOWN(pa), prot);
> >
> >         for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
> > -               size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
> > +               size_t o = pgd_index(PAGE_OFFSET) + i;
> >
> >                 swapper_pg_dir[o] =
> >                         pfn_pgd(PFN_DOWN((uintptr_t)swapper_pmd) + i,
> > @@ -238,24 +205,23 @@ asmlinkage void __init setup_vm(void)
> >         for (i = 0; i < ARRAY_SIZE(swapper_pmd); i++)
> >                 swapper_pmd[i] = pfn_pmd(PFN_DOWN(pa + i * PMD_SIZE), prot);
> >
> > -       swapper_pg_dir[(FIXADDR_START >> PGDIR_SHIFT) % PTRS_PER_PGD] =
> > +       swapper_pg_dir[pgd_index(FIXADDR_START)] =
> >                 pfn_pgd(PFN_DOWN((uintptr_t)fixmap_pmd),
> >                                 __pgprot(_PAGE_TABLE));
> > -       fixmap_pmd[(FIXADDR_START >> PMD_SHIFT) % PTRS_PER_PMD] =
> > +       fixmap_pmd[pmd_index(FIXADDR_START)] =
> >                 pfn_pmd(PFN_DOWN((uintptr_t)fixmap_pte),
> >                                 __pgprot(_PAGE_TABLE));
> >  #else
> > -       trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] =
> > +       trampoline_pg_dir[pgd_index(PAGE_OFFSET)] =
> >                 pfn_pgd(PFN_DOWN(pa), prot);
> >
> >         for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) {
> > -               size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i;
> > +               size_t o = pgd_index(PAGE_OFFSET) + i;
> >
> >                 swapper_pg_dir[o] =
> >                         pfn_pgd(PFN_DOWN(pa + i * PGDIR_SIZE), prot);
> >         }
> > -
> > -       swapper_pg_dir[(FIXADDR_START >> PGDIR_SHIFT) % PTRS_PER_PGD] =
> > +       swapper_pg_dir[pgd_index(FIXADDR_START)] =
> >                 pfn_pgd(PFN_DOWN((uintptr_t)fixmap_pte),
> >                                 __pgprot(_PAGE_TABLE));
> >  #endif
> >
> > _______________________________________________
> > linux-riscv mailing list
> > linux-riscv@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-riscv
> >
>
> --
> Sincerely yours,
> Mike.
>

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