[PATCH 4/5] s390/hugetlb: remove dead code for sw emulated huge pages

From: Dominik Dingel
Date: Thu May 28 2015 - 07:53:20 EST


We now support only hugepages on hardware with EDAT1 support.
So we remove the prepare/release_hugepage hooks and
simplify set_huge_pte_at and huge_ptep_get.

Acked-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Signed-off-by: Dominik Dingel <dingel@xxxxxxxxxxxxxxxxxx>
---
arch/s390/include/asm/hugetlb.h | 3 ---
arch/s390/mm/hugetlbpage.c | 60 +++--------------------------------------
2 files changed, 3 insertions(+), 60 deletions(-)

diff --git a/arch/s390/include/asm/hugetlb.h b/arch/s390/include/asm/hugetlb.h
index dfb542a..0130d03 100644
--- a/arch/s390/include/asm/hugetlb.h
+++ b/arch/s390/include/asm/hugetlb.h
@@ -37,9 +37,6 @@ static inline int prepare_hugepage_range(struct file *file,

#define arch_clear_hugepage_flags(page) do { } while (0)

-int arch_prepare_hugepage(struct page *page);
-void arch_release_hugepage(struct page *page);
-
static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
pte_t *ptep)
{
diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c
index fa6e1bc..999616b 100644
--- a/arch/s390/mm/hugetlbpage.c
+++ b/arch/s390/mm/hugetlbpage.c
@@ -80,31 +80,16 @@ static inline pte_t __pmd_to_pte(pmd_t pmd)
void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pte)
{
- pmd_t pmd;
+ pmd_t pmd = __pte_to_pmd(pte);

- pmd = __pte_to_pmd(pte);
- if (!MACHINE_HAS_HPAGE) {
- /* Emulated huge ptes loose the dirty and young bit */
- pmd_val(pmd) &= ~_SEGMENT_ENTRY_ORIGIN;
- pmd_val(pmd) |= pte_page(pte)[1].index;
- } else
- pmd_val(pmd) |= _SEGMENT_ENTRY_LARGE;
+ pmd_val(pmd) |= _SEGMENT_ENTRY_LARGE;
*(pmd_t *) ptep = pmd;
}

pte_t huge_ptep_get(pte_t *ptep)
{
- unsigned long origin;
- pmd_t pmd;
+ pmd_t pmd = *(pmd_t *) ptep;

- pmd = *(pmd_t *) ptep;
- if (!MACHINE_HAS_HPAGE && pmd_present(pmd)) {
- origin = pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN;
- pmd_val(pmd) &= ~_SEGMENT_ENTRY_ORIGIN;
- pmd_val(pmd) |= *(unsigned long *) origin;
- /* Emulated huge ptes are young and dirty by definition */
- pmd_val(pmd) |= _SEGMENT_ENTRY_YOUNG | _SEGMENT_ENTRY_DIRTY;
- }
return __pmd_to_pte(pmd);
}

@@ -119,45 +104,6 @@ pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
return pte;
}

-int arch_prepare_hugepage(struct page *page)
-{
- unsigned long addr = page_to_phys(page);
- pte_t pte;
- pte_t *ptep;
- int i;
-
- if (MACHINE_HAS_HPAGE)
- return 0;
-
- ptep = (pte_t *) pte_alloc_one(&init_mm, addr);
- if (!ptep)
- return -ENOMEM;
-
- pte_val(pte) = addr;
- for (i = 0; i < PTRS_PER_PTE; i++) {
- set_pte_at(&init_mm, addr + i * PAGE_SIZE, ptep + i, pte);
- pte_val(pte) += PAGE_SIZE;
- }
- page[1].index = (unsigned long) ptep;
- return 0;
-}
-
-void arch_release_hugepage(struct page *page)
-{
- pte_t *ptep;
-
- if (MACHINE_HAS_HPAGE)
- return;
-
- ptep = (pte_t *) page[1].index;
- if (!ptep)
- return;
- clear_table((unsigned long *) ptep, _PAGE_INVALID,
- PTRS_PER_PTE * sizeof(pte_t));
- page_table_free(&init_mm, (unsigned long *) ptep);
- page[1].index = 0;
-}
-
pte_t *huge_pte_alloc(struct mm_struct *mm,
unsigned long addr, unsigned long sz)
{
--
2.3.7

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