diff mbox series

[v3,02/17] riscv: mm: Skip pgtable level check in {pud,p4d}_alloc_one

Message ID 84ddf857508b98a195a790bc6ff6ab8849b44633.1734945104.git.zhengqi.arch@bytedance.com (mailing list archive)
State New
Headers show
Series move pagetable_*_dtor() to __tlb_remove_table() | expand

Commit Message

Qi Zheng Dec. 23, 2024, 9:40 a.m. UTC
From: Kevin Brodsky <kevin.brodsky@arm.com>

{pmd,pud,p4d}_alloc_one() is never called if the corresponding page
table level is folded, as {pmd,pud,p4d}_alloc() already does the
required check. We can therefore remove the runtime page table level
checks in {pud,p4d}_alloc_one. The PUD helper becomes equivalent to
the generic version, so we remove it altogether.

This is consistent with the way arm64 and x86 handle this situation
(runtime check in p4d_free() only).

Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
---
 arch/riscv/include/asm/pgalloc.h | 22 ++++------------------
 1 file changed, 4 insertions(+), 18 deletions(-)

Comments

Palmer Dabbelt Dec. 27, 2024, 4:40 p.m. UTC | #1
On Mon, 23 Dec 2024 01:40:48 PST (-0800), zhengqi.arch@bytedance.com wrote:
> From: Kevin Brodsky <kevin.brodsky@arm.com>
>
> {pmd,pud,p4d}_alloc_one() is never called if the corresponding page
> table level is folded, as {pmd,pud,p4d}_alloc() already does the
> required check. We can therefore remove the runtime page table level
> checks in {pud,p4d}_alloc_one. The PUD helper becomes equivalent to
> the generic version, so we remove it altogether.
>
> This is consistent with the way arm64 and x86 handle this situation
> (runtime check in p4d_free() only).
>
> Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
> Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
> Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
> ---
>  arch/riscv/include/asm/pgalloc.h | 22 ++++------------------
>  1 file changed, 4 insertions(+), 18 deletions(-)
>
> diff --git a/arch/riscv/include/asm/pgalloc.h b/arch/riscv/include/asm/pgalloc.h
> index f52264304f772..8ad0bbe838a24 100644
> --- a/arch/riscv/include/asm/pgalloc.h
> +++ b/arch/riscv/include/asm/pgalloc.h
> @@ -12,7 +12,6 @@
>  #include <asm/tlb.h>
>
>  #ifdef CONFIG_MMU
> -#define __HAVE_ARCH_PUD_ALLOC_ONE
>  #define __HAVE_ARCH_PUD_FREE
>  #include <asm-generic/pgalloc.h>
>
> @@ -88,15 +87,6 @@ static inline void pgd_populate_safe(struct mm_struct *mm, pgd_t *pgd,
>  	}
>  }
>
> -#define pud_alloc_one pud_alloc_one
> -static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
> -{
> -	if (pgtable_l4_enabled)
> -		return __pud_alloc_one(mm, addr);
> -
> -	return NULL;
> -}
> -
>  #define pud_free pud_free
>  static inline void pud_free(struct mm_struct *mm, pud_t *pud)
>  {
> @@ -118,15 +108,11 @@ static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pud,
>  #define p4d_alloc_one p4d_alloc_one
>  static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr)
>  {
> -	if (pgtable_l5_enabled) {
> -		gfp_t gfp = GFP_PGTABLE_USER;
> -
> -		if (mm == &init_mm)
> -			gfp = GFP_PGTABLE_KERNEL;
> -		return (p4d_t *)get_zeroed_page(gfp);
> -	}
> +	gfp_t gfp = GFP_PGTABLE_USER;
>
> -	return NULL;
> +	if (mm == &init_mm)
> +		gfp = GFP_PGTABLE_KERNEL;
> +	return (p4d_t *)get_zeroed_page(gfp);
>  }
>
>  static inline void __p4d_free(struct mm_struct *mm, p4d_t *p4d)

Acked-by: Palmer Dabbelt <palmer@rivosinc.com>

Are you trying to keep these together, or do you want me to try and pick 
up the RISC-V bits on their own?
diff mbox series

Patch

diff --git a/arch/riscv/include/asm/pgalloc.h b/arch/riscv/include/asm/pgalloc.h
index f52264304f772..8ad0bbe838a24 100644
--- a/arch/riscv/include/asm/pgalloc.h
+++ b/arch/riscv/include/asm/pgalloc.h
@@ -12,7 +12,6 @@ 
 #include <asm/tlb.h>
 
 #ifdef CONFIG_MMU
-#define __HAVE_ARCH_PUD_ALLOC_ONE
 #define __HAVE_ARCH_PUD_FREE
 #include <asm-generic/pgalloc.h>
 
@@ -88,15 +87,6 @@  static inline void pgd_populate_safe(struct mm_struct *mm, pgd_t *pgd,
 	}
 }
 
-#define pud_alloc_one pud_alloc_one
-static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long addr)
-{
-	if (pgtable_l4_enabled)
-		return __pud_alloc_one(mm, addr);
-
-	return NULL;
-}
-
 #define pud_free pud_free
 static inline void pud_free(struct mm_struct *mm, pud_t *pud)
 {
@@ -118,15 +108,11 @@  static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pud,
 #define p4d_alloc_one p4d_alloc_one
 static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long addr)
 {
-	if (pgtable_l5_enabled) {
-		gfp_t gfp = GFP_PGTABLE_USER;
-
-		if (mm == &init_mm)
-			gfp = GFP_PGTABLE_KERNEL;
-		return (p4d_t *)get_zeroed_page(gfp);
-	}
+	gfp_t gfp = GFP_PGTABLE_USER;
 
-	return NULL;
+	if (mm == &init_mm)
+		gfp = GFP_PGTABLE_KERNEL;
+	return (p4d_t *)get_zeroed_page(gfp);
 }
 
 static inline void __p4d_free(struct mm_struct *mm, p4d_t *p4d)