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 37 int arch_prepare_hugepage(struct page *page); 38 void arch_release_hugepage(struct page *page); 39 40 static inline pte_t huge_pte_wrprotect(pte_t pte) 41 { 42 pte_val(pte) |= _PAGE_RO; 43 return pte; 44 } 45 46 static inline int huge_pte_none(pte_t pte) 47 { 48 return (pte_val(pte) & _SEGMENT_ENTRY_INV) && 49 !(pte_val(pte) & _SEGMENT_ENTRY_RO); 50 } 51 52 static inline pte_t huge_ptep_get(pte_t *ptep) 53 { 54 pte_t pte = *ptep; 55 unsigned long mask; 56 57 if (!MACHINE_HAS_HPAGE) { 58 ptep = (pte_t *) (pte_val(pte) & _SEGMENT_ENTRY_ORIGIN); 59 if (ptep) { 60 mask = pte_val(pte) & 61 (_SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO); 62 pte = pte_mkhuge(*ptep); 63 pte_val(pte) |= mask; 64 } 65 } 66 return pte; 67 } 68 69 static inline void __pmd_csp(pmd_t *pmdp) 70 { 71 register unsigned long reg2 asm("2") = pmd_val(*pmdp); 72 register unsigned long reg3 asm("3") = pmd_val(*pmdp) | 73 _SEGMENT_ENTRY_INV; 74 register unsigned long reg4 asm("4") = ((unsigned long) pmdp) + 5; 75 76 asm volatile( 77 " csp %1,%3" 78 : "=m" (*pmdp) 79 : "d" (reg2), "d" (reg3), "d" (reg4), "m" (*pmdp) : "cc"); 80 pmd_val(*pmdp) = _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY; 81 } 82 83 static inline void __pmd_idte(unsigned long address, pmd_t *pmdp) 84 { 85 unsigned long sto = (unsigned long) pmdp - 86 pmd_index(address) * sizeof(pmd_t); 87 88 if (!(pmd_val(*pmdp) & _SEGMENT_ENTRY_INV)) { 89 asm volatile( 90 " .insn rrf,0xb98e0000,%2,%3,0,0" 91 : "=m" (*pmdp) 92 : "m" (*pmdp), "a" (sto), 93 "a" ((address & HPAGE_MASK)) 94 ); 95 } 96 pmd_val(*pmdp) = _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY; 97 } 98 99 static inline void huge_ptep_invalidate(struct mm_struct *mm, 100 unsigned long address, pte_t *ptep) 101 { 102 pmd_t *pmdp = (pmd_t *) ptep; 103 104 if (MACHINE_HAS_IDTE) 105 __pmd_idte(address, pmdp); 106 else 107 __pmd_csp(pmdp); 108 } 109 110 static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm, 111 unsigned long addr, pte_t *ptep) 112 { 113 pte_t pte = huge_ptep_get(ptep); 114 115 huge_ptep_invalidate(mm, addr, ptep); 116 return pte; 117 } 118 119 #define huge_ptep_set_access_flags(__vma, __addr, __ptep, __entry, __dirty) \ 120 ({ \ 121 int __changed = !pte_same(huge_ptep_get(__ptep), __entry); \ 122 if (__changed) { \ 123 huge_ptep_invalidate((__vma)->vm_mm, __addr, __ptep); \ 124 set_huge_pte_at((__vma)->vm_mm, __addr, __ptep, __entry); \ 125 } \ 126 __changed; \ 127 }) 128 129 #define huge_ptep_set_wrprotect(__mm, __addr, __ptep) \ 130 ({ \ 131 pte_t __pte = huge_ptep_get(__ptep); \ 132 if (pte_write(__pte)) { \ 133 huge_ptep_invalidate(__mm, __addr, __ptep); \ 134 set_huge_pte_at(__mm, __addr, __ptep, \ 135 huge_pte_wrprotect(__pte)); \ 136 } \ 137 }) 138 139 static inline void huge_ptep_clear_flush(struct vm_area_struct *vma, 140 unsigned long address, pte_t *ptep) 141 { 142 huge_ptep_invalidate(vma->vm_mm, address, ptep); 143 } 144 145 #endif /* _ASM_S390_HUGETLB_H */ 146