Re: [PATCH v7 10/14] mips: move has_transparent_hugepage() out of THP guard

[Lance Yang <lance.yang@linux.dev>]

On 2026/9/1 11:12, Luiz Capitulino wrote:
> A future commit will introduce a kernel API to allow for checking if the
> CPU supports PMD-sized pages. This API will be based on the
> has_transparent_hugepage() implementation but will be orthogonal to THP
> and therefore must work when CONFIG_TRANSPARENT_HUGEPAGE=n.
> 
> Move its definition out of the THP guard.
> 
> Signed-off-by: Luiz Capitulino <luizcap@redhat.com>
> ---
>   arch/mips/include/asm/pgtable.h | 6 +++---
>   arch/mips/mm/tlb-r4k.c          | 4 ----
>   2 files changed, 3 insertions(+), 7 deletions(-)
> 
> diff --git a/arch/mips/include/asm/pgtable.h b/arch/mips/include/asm/pgtable.h
> index fa7b935f947c..b038da872ec6 100644
> --- a/arch/mips/include/asm/pgtable.h
> +++ b/arch/mips/include/asm/pgtable.h
> @@ -615,9 +615,6 @@ unsigned long io_remap_pfn_range_pfn(unsigned long pfn, unsigned long size);
>   /* We don't have hardware dirty/accessed bits, generic_pmdp_establish is fine.*/
>   #define pmdp_establish generic_pmdp_establish
>   
> -#define has_transparent_hugepage has_transparent_hugepage
> -extern int has_transparent_hugepage(void);

Assume a decstation_defconfig build. CPU_R3000 selects CPU_R3K_TLB, so the
Makefile builds tlb-r3k.o but not tlb-r4k.o IIUC ...

The only MIPS definition is in tlb-r4k.c, so R3000 would fail to link with
an undefined reference ... no?

Cheers, Lance

> -
>   static inline int pmd_trans_huge(pmd_t pmd)
>   {
>   	return !!(pmd_val(pmd) & _PAGE_HUGE);
> @@ -743,6 +740,9 @@ static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
>   
>   #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
>   
> +#define has_transparent_hugepage has_transparent_hugepage
> +extern int has_transparent_hugepage(void);
> +
>   #ifdef _PAGE_HUGE
>   #define pmd_leaf(pmd)	((pmd_val(pmd) & _PAGE_HUGE) != 0)
>   #define pud_leaf(pud)	((pud_val(pud) & _PAGE_HUGE) != 0)
> diff --git a/arch/mips/mm/tlb-r4k.c b/arch/mips/mm/tlb-r4k.c
> index 24fe85fa169d..f4e369342a56 100644
> --- a/arch/mips/mm/tlb-r4k.c
> +++ b/arch/mips/mm/tlb-r4k.c
> @@ -432,8 +432,6 @@ void add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
>   #endif
>   }
>   
> -#ifdef CONFIG_TRANSPARENT_HUGEPAGE
> -
>   int has_transparent_hugepage(void)
>   {
>   	static unsigned int mask = -1;
> @@ -452,8 +450,6 @@ int has_transparent_hugepage(void)
>   }
>   EXPORT_SYMBOL(has_transparent_hugepage);
>   
> -#endif /* CONFIG_TRANSPARENT_HUGEPAGE  */
> -
>   /*
>    * Used for loading TLB entries before trap_init() has started, when we
>    * don't actually want to add a wired entry which remains throughout the