[PATCH v3 06/17] s390: pgtable: add statistics for PUD and P4D level page table

Qi Zheng
2024-12-23T09:44:20Z

Like PMD and PTE level page table, also add statistics for PUD and P4D
page table.

Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: linux-s390@vger.kernel.org
---
arch/s390/include/asm/pgalloc.h | 29 +++++++++++++++++++-------
arch/s390/include/asm/tlb.h | 37 +++++++++++++++++----------------
2 files changed, 40 insertions(+), 26 deletions(-)

diff --git a/arch/s390/include/asm/pgalloc.h b/arch/s390/include/asm/pgalloc.h
index 7b84ef6dc4b6d..a0c1ca5d8423c 100644
--- a/arch/s390/include/asm/pgalloc.h
+++ b/arch/s390/include/asm/pgalloc.h
@@ -53,29 +53,42 @@ static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long address)
{
unsigned long *table = crst_table_alloc(mm);

- if (table)
- crst_table_init(table, _REGION2_ENTRY_EMPTY);
+ if (!table)
+ return NULL;
+ crst_table_init(table, _REGION2_ENTRY_EMPTY);
+ pagetable_p4d_ctor(virt_to_ptdesc(table));
+
return (p4d_t *) table;
}

static inline void p4d_free(struct mm_struct *mm, p4d_t *p4d)
{
- if (!mm_p4d_folded(mm))
- crst_table_free(mm, (unsigned long *) p4d);
+ if (mm_p4d_folded(mm))
+ return;
+
+ pagetable_p4d_dtor(virt_to_ptdesc(p4d));
+ crst_table_free(mm, (unsigned long *) p4d);
}

static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address)
{
unsigned long *table = crst_table_alloc(mm);
- if (table)
- crst_table_init(table, _REGION3_ENTRY_EMPTY);
+
+ if (!table)
+ return NULL;
+ crst_table_init(table, _REGION3_ENTRY_EMPTY);
+ pagetable_pud_ctor(virt_to_ptdesc(table));
+
return (pud_t *) table;
}

static inline void pud_free(struct mm_struct *mm, pud_t *pud)
{
- if (!mm_pud_folded(mm))
- crst_table_free(mm, (unsigned long *) pud);
+ if (mm_pud_folded(mm))
+ return;
+
+ pagetable_pud_dtor(virt_to_ptdesc(pud));
+ crst_table_free(mm, (unsigned long *) pud);
}

static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long vmaddr)
diff --git a/arch/s390/include/asm/tlb.h b/arch/s390/include/asm/tlb.h
index e95b2c8081eb8..b946964afce8e 100644
--- a/arch/s390/include/asm/tlb.h
+++ b/arch/s390/include/asm/tlb.h
@@ -110,24 +110,6 @@ static inline void pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd,
tlb_remove_ptdesc(tlb, pmd);
}

-/*
- * p4d_free_tlb frees a pud table and clears the CRSTE for the
- * region second table entry from the tlb.
- * If the mm uses a four level page table the single p4d is freed
- * as the pgd. p4d_free_tlb checks the asce_limit against 8PB
- * to avoid the double free of the p4d in this case.
- */
-static inline void p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d,
- unsigned long address)
-{
- if (mm_p4d_folded(tlb->mm))
- return;
- __tlb_adjust_range(tlb, address, PAGE_SIZE);
- tlb->mm->context.flush_mm = 1;
- tlb->freed_tables = 1;
- tlb_remove_ptdesc(tlb, p4d);
-}
-
/*
* pud_free_tlb frees a pud table and clears the CRSTE for the
* region third table entry from the tlb.
@@ -140,11 +122,30 @@ static inline void pud_free_tlb(struct mmu_gather *tlb, pud_t *pud,
{
if (mm_pud_folded(tlb->mm))
return;
+ pagetable_pud_dtor(virt_to_ptdesc(pud));
tlb->mm->context.flush_mm = 1;
tlb->freed_tables = 1;
tlb->cleared_p4ds = 1;
tlb_remove_ptdesc(tlb, pud);
}

+/*
+ * p4d_free_tlb frees a p4d table and clears the CRSTE for the
+ * region second table entry from the tlb.
+ * If the mm uses a four level page table the single p4d is freed
+ * as the pgd. p4d_free_tlb checks the asce_limit against 8PB
+ * to avoid the double free of the p4d in this case.
+ */
+static inline void p4d_free_tlb(struct mmu_gather *tlb, p4d_t *p4d,
+ unsigned long address)
+{
+ if (mm_p4d_folded(tlb->mm))
+ return;
+ pagetable_p4d_dtor(virt_to_ptdesc(p4d));
+ __tlb_adjust_range(tlb, address, PAGE_SIZE);
+ tlb->mm->context.flush_mm = 1;
+ tlb->freed_tables = 1;
+ tlb_remove_ptdesc(tlb, p4d);
+}

#endif /* _S390_TLB_H */
--
2.20.1