[PATCH 05/10] riscv: mm: Skip pgtable level check in {pud,p4d}_alloc_one

Kevin Brodsky
2024-12-19T16:53:33Z

{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>
---
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 f52264304f77..8ad0bbe838a2 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)
--
2.47.0