arch/s390/include/asm/hugetlb.h

   1 /*
   2  *  IBM System z Huge TLB Page Support for Kernel.
   3  *
   4  *    Copyright IBM Corp. 2008
   5  *    Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
   6  */
   7
   8 #ifndef _ASM_S390_HUGETLB_H
   9 #define _ASM_S390_HUGETLB_H
  10
  11 #include <asm/page.h>
  12 #include <asm/pgtable.h>
  13
  14
  15 #define is_hugepage_only_range(mm, addr, len)   0
  16 #define hugetlb_free_pgd_range                  free_pgd_range
  17 #define hugepages_supported()                   (MACHINE_HAS_HPAGE)
  18
  19 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
  20                      pte_t *ptep, pte_t pte);
  21 pte_t huge_ptep_get(pte_t *ptep);
  22 pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
  23                               unsigned long addr, pte_t *ptep);
  24
  25 /*
  26  * If the arch doesn't supply something else, assume that hugepage
  27  * size aligned regions are ok without further preparation.
  28  */
  29 static inline int prepare_hugepage_range(struct file *file,
  30                         unsigned long addr, unsigned long len)
  31 {
  32         if (len & ~HPAGE_MASK)
  33                 return -EINVAL;
  34         if (addr & ~HPAGE_MASK)
  35                 return -EINVAL;
  36         return 0;
  37 }
  38
  39 #define arch_clear_hugepage_flags(page)         do { } while (0)
  40
  41 static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
  42                                   pte_t *ptep)
  43 {
  44         if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
  45                 pte_val(*ptep) = _REGION3_ENTRY_EMPTY;
  46         else
  47                 pte_val(*ptep) = _SEGMENT_ENTRY_EMPTY;
  48 }
  49
  50 static inline void huge_ptep_clear_flush(struct vm_area_struct *vma,
  51                                          unsigned long address, pte_t *ptep)
  52 {
  53         huge_ptep_get_and_clear(vma->vm_mm, address, ptep);
  54 }
  55
  56 static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
  57                                              unsigned long addr, pte_t *ptep,
  58                                              pte_t pte, int dirty)
  59 {
  60         int changed = !pte_same(huge_ptep_get(ptep), pte);
  61         if (changed) {
  62                 huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
  63                 set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
  64         }
  65         return changed;
  66 }
  67
  68 static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
  69                                            unsigned long addr, pte_t *ptep)
  70 {
  71         pte_t pte = huge_ptep_get_and_clear(mm, addr, ptep);
  72         set_huge_pte_at(mm, addr, ptep, pte_wrprotect(pte));
  73 }
  74
  75 static inline pte_t mk_huge_pte(struct page *page, pgprot_t pgprot)
  76 {
  77         return mk_pte(page, pgprot);
  78 }
  79
  80 static inline int huge_pte_none(pte_t pte)
  81 {
  82         return pte_none(pte);
  83 }
  84
  85 static inline int huge_pte_write(pte_t pte)
  86 {
  87         return pte_write(pte);
  88 }
  89
  90 static inline int huge_pte_dirty(pte_t pte)
  91 {
  92         return pte_dirty(pte);
  93 }
  94
  95 static inline pte_t huge_pte_mkwrite(pte_t pte)
  96 {
  97         return pte_mkwrite(pte);
  98 }
  99
 100 static inline pte_t huge_pte_mkdirty(pte_t pte)
 101 {
 102         return pte_mkdirty(pte);
 103 }
 104
 105 static inline pte_t huge_pte_wrprotect(pte_t pte)
 106 {
 107         return pte_wrprotect(pte);
 108 }
 109
 110 static inline pte_t huge_pte_modify(pte_t pte, pgprot_t newprot)
 111 {
 112         return pte_modify(pte, newprot);
 113 }
 114
 115 #endif /* _ASM_S390_HUGETLB_H */