diff options
Diffstat (limited to 'arch/s390/mm/hugetlbpage.c')
| -rw-r--r-- | arch/s390/mm/hugetlbpage.c | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c new file mode 100644 index 00000000000..0ff66a7e29b --- /dev/null +++ b/arch/s390/mm/hugetlbpage.c @@ -0,0 +1,235 @@ +/* + * IBM System z Huge TLB Page Support for Kernel. + * + * Copyright IBM Corp. 2007 + * Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com> + */ + +#include <linux/mm.h> +#include <linux/hugetlb.h> + +static inline pmd_t __pte_to_pmd(pte_t pte) +{ + int none, young, prot; + pmd_t pmd; + + /* + * Convert encoding pte bits pmd bits + * .IR...wrdytp ..R...I...y. + * empty .10...000000 -> ..0...1...0. + * prot-none, clean, old .11...000001 -> ..0...1...1. + * prot-none, clean, young .11...000101 -> ..1...1...1. + * prot-none, dirty, old .10...001001 -> ..0...1...1. + * prot-none, dirty, young .10...001101 -> ..1...1...1. + * read-only, clean, old .11...010001 -> ..1...1...0. + * read-only, clean, young .01...010101 -> ..1...0...1. + * read-only, dirty, old .11...011001 -> ..1...1...0. + * read-only, dirty, young .01...011101 -> ..1...0...1. + * read-write, clean, old .11...110001 -> ..0...1...0. + * read-write, clean, young .01...110101 -> ..0...0...1. + * read-write, dirty, old .10...111001 -> ..0...1...0. + * read-write, dirty, young .00...111101 -> ..0...0...1. + * Huge ptes are dirty by definition, a clean pte is made dirty + * by the conversion. + */ + if (pte_present(pte)) { + pmd_val(pmd) = pte_val(pte) & PAGE_MASK; + if (pte_val(pte) & _PAGE_INVALID) + pmd_val(pmd) |= _SEGMENT_ENTRY_INVALID; + none = (pte_val(pte) & _PAGE_PRESENT) && + !(pte_val(pte) & _PAGE_READ) && + !(pte_val(pte) & _PAGE_WRITE); + prot = (pte_val(pte) & _PAGE_PROTECT) && + !(pte_val(pte) & _PAGE_WRITE); + young = pte_val(pte) & _PAGE_YOUNG; + if (none || young) + pmd_val(pmd) |= _SEGMENT_ENTRY_YOUNG; + if (prot || (none && young)) + pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT; + } else + pmd_val(pmd) = _SEGMENT_ENTRY_INVALID; + return pmd; +} + +static inline pte_t __pmd_to_pte(pmd_t pmd) +{ + pte_t pte; + + /* + * Convert encoding pmd bits pte bits + * ..R...I...y. .IR...wrdytp + * empty ..0...1...0. -> .10...000000 + * prot-none, old ..0...1...1. -> .10...001001 + * prot-none, young ..1...1...1. -> .10...001101 + * read-only, old ..1...1...0. -> .11...011001 + * read-only, young ..1...0...1. -> .01...011101 + * read-write, old ..0...1...0. -> .10...111001 + * read-write, young ..0...0...1. -> .00...111101 + * Huge ptes are dirty by definition + */ + if (pmd_present(pmd)) { + pte_val(pte) = _PAGE_PRESENT | _PAGE_LARGE | _PAGE_DIRTY | + (pmd_val(pmd) & PAGE_MASK); + if (pmd_val(pmd) & _SEGMENT_ENTRY_INVALID) + pte_val(pte) |= _PAGE_INVALID; + if (pmd_prot_none(pmd)) { + if (pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT) + pte_val(pte) |= _PAGE_YOUNG; + } else { + pte_val(pte) |= _PAGE_READ; + if (pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT) + pte_val(pte) |= _PAGE_PROTECT; + else + pte_val(pte) |= _PAGE_WRITE; + if (pmd_val(pmd) & _SEGMENT_ENTRY_YOUNG) + pte_val(pte) |= _PAGE_YOUNG; + } + } else + pte_val(pte) = _PAGE_INVALID; + return pte; +} + +void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, + pte_t *ptep, pte_t pte) +{ + pmd_t pmd; + + pmd = __pte_to_pmd(pte); + if (!MACHINE_HAS_HPAGE) { + pmd_val(pmd) &= ~_SEGMENT_ENTRY_ORIGIN; + pmd_val(pmd) |= pte_page(pte)[1].index; + } else + pmd_val(pmd) |= _SEGMENT_ENTRY_LARGE | _SEGMENT_ENTRY_CO; + *(pmd_t *) ptep = pmd; +} + +pte_t huge_ptep_get(pte_t *ptep) +{ + unsigned long origin; + pmd_t pmd; + + 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; + } + return __pmd_to_pte(pmd); +} + +pte_t huge_ptep_get_and_clear(struct mm_struct *mm, + unsigned long addr, pte_t *ptep) +{ + pmd_t *pmdp = (pmd_t *) ptep; + pte_t pte = huge_ptep_get(ptep); + + pmdp_flush_direct(mm, addr, pmdp); + pmd_val(*pmdp) = _SEGMENT_ENTRY_EMPTY; + 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) +{ + 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; +} |