diff options
Diffstat (limited to 'arch/s390/mm/hugetlbpage.c')
-rw-r--r-- | arch/s390/mm/hugetlbpage.c | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c new file mode 100644 index 00000000..597bb2d2 --- /dev/null +++ b/arch/s390/mm/hugetlbpage.c @@ -0,0 +1,130 @@ +/* + * IBM System z Huge TLB Page Support for Kernel. + * + * Copyright 2007 IBM Corp. + * Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com> + */ + +#include <linux/mm.h> +#include <linux/hugetlb.h> + + +void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, + pte_t *pteptr, pte_t pteval) +{ + pmd_t *pmdp = (pmd_t *) pteptr; + unsigned long mask; + + if (!MACHINE_HAS_HPAGE) { + pteptr = (pte_t *) pte_page(pteval)[1].index; + mask = pte_val(pteval) & + (_SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO); + pte_val(pteval) = (_SEGMENT_ENTRY + __pa(pteptr)) | mask; + } + + pmd_val(*pmdp) = pte_val(pteval); +} + +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 = mk_pte(page, PAGE_RW); + 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; + 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) +{ + pgd_t *pgdp; + pud_t *pudp; + pmd_t *pmdp = NULL; + + pgdp = pgd_offset(mm, addr); + pudp = pud_alloc(mm, pgdp, addr); + if (pudp) + pmdp = pmd_alloc(mm, pudp, addr); + return (pte_t *) pmdp; +} + +pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr) +{ + pgd_t *pgdp; + pud_t *pudp; + pmd_t *pmdp = NULL; + + pgdp = pgd_offset(mm, addr); + if (pgd_present(*pgdp)) { + pudp = pud_offset(pgdp, addr); + if (pud_present(*pudp)) + pmdp = pmd_offset(pudp, addr); + } + return (pte_t *) pmdp; +} + +int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep) +{ + return 0; +} + +struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address, + int write) +{ + return ERR_PTR(-EINVAL); +} + +int pmd_huge(pmd_t pmd) +{ + if (!MACHINE_HAS_HPAGE) + return 0; + + return !!(pmd_val(pmd) & _SEGMENT_ENTRY_LARGE); +} + +int pud_huge(pud_t pud) +{ + return 0; +} + +struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address, + pmd_t *pmdp, int write) +{ + struct page *page; + + if (!MACHINE_HAS_HPAGE) + return NULL; + + page = pmd_page(*pmdp); + if (page) + page += ((address & ~HPAGE_MASK) >> PAGE_SHIFT); + return page; +} |