Re: [PATCH v3 1/3] ioremap: Update pgtable free interfaces with addr

[Chintan Pandya]

On 3/20/2018 12:31 AM, Kani, Toshi wrote:
> On Mon, 2018-03-19 at 18:10 +0530, Chintan Pandya wrote:
> > This patch ("mm/vmalloc: Add interfaces to free unmapped
> > page table") adds following 2 interfaces to free the page
> > table in case we implement huge mapping.
> >
> > pud_free_pmd_page() and pmd_free_pte_page()
> >
> > Some architectures (like arm64) needs to do proper TLB
> > maintanance after updating pagetable entry even in map.
> > Why ? Read this,
> > https://patchwork.kernel.org/patch/10134581/
> >
> > Pass 'addr' in these interfaces so that proper TLB ops
> > can be performed.
> >
> > Signed-off-by: Chintan Pandya <cpandya@xxxxxxxxxxxxxx>
>   :
> > diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
> > index 34cda7e..20b0322 100644
> > --- a/arch/x86/mm/pgtable.c
> > +++ b/arch/x86/mm/pgtable.c
> > @@ -710,7 +710,7 @@ int pmd_clear_huge(pmd_t *pmd)
> >    * Context: The pud range has been unmaped and TLB purged.
> >    * Return: 1 if clearing the entry succeeded. 0 otherwise.
> >    */
> > -int pud_free_pmd_page(pud_t *pud)
> > +int pud_free_pmd_page(pud_t *pud, unsigned long addr)
>
> Please update the function header as well.  Same for pmd.
>
> + * @addr: Virtual address associated with pud.
Noted.
> --- a/include/asm-generic/pgtable.h
> > +++ b/include/asm-generic/pgtable.h
> > @@ -983,8 +983,8 @@ static inline int p4d_clear_huge(p4d_t *p4d)
> >   int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot);
> >   int pud_clear_huge(pud_t *pud);
> >   int pmd_clear_huge(pmd_t *pmd);
> > -int pud_free_pmd_page(pud_t *pud);
> > -int pmd_free_pte_page(pmd_t *pmd);
> > +int pud_free_pmd_page(pud_t *pud, unsigned long addr);
> > +int pmd_free_pte_page(pmd_t *pmd, unsigned long addr);
> >   #else	/* !CONFIG_HAVE_ARCH_HUGE_VMAP */
> >   static inline int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t
> prot)
> >   {
> > @@ -1010,11 +1010,11 @@ static inline int pmd_clear_huge(pmd_t *pmd)
> >   {
> >   	return 0;
> >   }
> > -static inline int pud_free_pmd_page(pud_t *pud)
> > +static inline int pud_free_pmd_page(pud_t *pud, unsigned long addr)
> >   {
> >   	return 0;
> >   }
> > -static inline int pmd_free_pte_page(pud_t *pmd)
> > +static inline int pmd_free_pte_page(pud_t *pmd, unsigned long addr)
>
> Please base your patches on top of the mm tree or at least pick up
> 8cab93de994f6 in the mm tree.  Andrew fixed the typo; the 'pud_t' above
> should have been 'pmd_t'.

Right. Noted.

> Thanks,
> -Toshi

Chintan
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