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 18 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, 19 pte_t *ptep, pte_t pte); 20 21 /* 22 * If the arch doesn't supply something else, assume that hugepage 23 * size aligned regions are ok without further preparation. 24 */ 25 static inline int prepare_hugepage_range(struct file *file, 26 unsigned long addr, unsigned long len) 27 { 28 if (len & ~HPAGE_MASK) 29 return -EINVAL; 30 if (addr & ~HPAGE_MASK) 31 return -EINVAL; 32 return 0; 33 } 34 35 #define hugetlb_prefault_arch_hook(mm) do { } while (0) 36 #define arch_clear_hugepage_flags(page) do { } while (0) 37 38 int arch_prepare_hugepage(struct page *page); 39 void arch_release_hugepage(struct page *page); 40 41 static inline pte_t huge_pte_wrprotect(pte_t pte) 42 { 43 pte_val(pte) |= _PAGE_RO; 44 return pte; 45 } 46 47 static inline int huge_pte_none(pte_t pte) 48 { 49 return (pte_val(pte) & _SEGMENT_ENTRY_INV) && 50 !(pte_val(pte) & _SEGMENT_ENTRY_RO); 51 } 52 53 static inline pte_t huge_ptep_get(pte_t *ptep) 54 { 55 pte_t pte = *ptep; 56 unsigned long mask; 57 58 if (!MACHINE_HAS_HPAGE) { 59 ptep = (pte_t *) (pte_val(pte) & _SEGMENT_ENTRY_ORIGIN); 60 if (ptep) { 61 mask = pte_val(pte) & 62 (_SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO); 63 pte = pte_mkhuge(*ptep); 64 pte_val(pte) |= mask; 65 } 66 } 67 return pte; 68 } 69 70 static inline void __pmd_csp(pmd_t *pmdp) 71 { 72 register unsigned long reg2 asm("2") = pmd_val(*pmdp); 73 register unsigned long reg3 asm("3") = pmd_val(*pmdp) | 74 _SEGMENT_ENTRY_INV; 75 register unsigned long reg4 asm("4") = ((unsigned long) pmdp) + 5; 76 77 asm volatile( 78 " csp %1,%3" 79 : "=m" (*pmdp) 80 : "d" (reg2), "d" (reg3), "d" (reg4), "m" (*pmdp) : "cc"); 81 } 82 83 static inline void huge_ptep_invalidate(struct mm_struct *mm, 84 unsigned long address, pte_t *ptep) 85 { 86 pmd_t *pmdp = (pmd_t *) ptep; 87 88 if (MACHINE_HAS_IDTE) 89 __pmd_idte(address, pmdp); 90 else 91 __pmd_csp(pmdp); 92 pmd_val(*pmdp) = _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY; 93 } 94 95 static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm, 96 unsigned long addr, pte_t *ptep) 97 { 98 pte_t pte = huge_ptep_get(ptep); 99 100 huge_ptep_invalidate(mm, addr, ptep); 101 return pte; 102 } 103 104 #define huge_ptep_set_access_flags(__vma, __addr, __ptep, __entry, __dirty) \ 105 ({ \ 106 int __changed = !pte_same(huge_ptep_get(__ptep), __entry); \ 107 if (__changed) { \ 108 huge_ptep_invalidate((__vma)->vm_mm, __addr, __ptep); \ 109 set_huge_pte_at((__vma)->vm_mm, __addr, __ptep, __entry); \ 110 } \ 111 __changed; \ 112 }) 113 114 #define huge_ptep_set_wrprotect(__mm, __addr, __ptep) \ 115 ({ \ 116 pte_t __pte = huge_ptep_get(__ptep); \ 117 if (pte_write(__pte)) { \ 118 huge_ptep_invalidate(__mm, __addr, __ptep); \ 119 set_huge_pte_at(__mm, __addr, __ptep, \ 120 huge_pte_wrprotect(__pte)); \ 121 } \ 122 }) 123 124 static inline void huge_ptep_clear_flush(struct vm_area_struct *vma, 125 unsigned long address, pte_t *ptep) 126 { 127 huge_ptep_invalidate(vma->vm_mm, address, ptep); 128 } 129 130 #endif /* _ASM_S390_HUGETLB_H */ 131