1 files changed, 184 insertions, 0 deletions

diff --git a/arch/s390/include/asm/hugetlb.h b/arch/s390/include/asm/hugetlb.h
new file mode 100644
index 000000000000..670a1d1745d2
--- /dev/null
+++ b/arch/s390/include/asm/hugetlb.h
@@ -0,0 +1,184 @@
+/*
+ *  IBM System z Huge TLB Page Support for Kernel.
+ *
+ *    Copyright IBM Corp. 2008
+ *    Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
+ */
+
+#ifndef _ASM_S390_HUGETLB_H
+#define _ASM_S390_HUGETLB_H
+
+#include <asm/page.h>
+#include <asm/pgtable.h>
+
+
+#define is_hugepage_only_range(mm, addr, len)   0
+#define hugetlb_free_pgd_range                  free_pgd_range
+
+void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
+                     pte_t *ptep, pte_t pte);
+
+/*
+ * If the arch doesn't supply something else, assume that hugepage
+ * size aligned regions are ok without further preparation.
+ */
+static inline int prepare_hugepage_range(struct file *file,
+                        unsigned long addr, unsigned long len)
+{
+        if (len & ~HPAGE_MASK)
+                return -EINVAL;
+        if (addr & ~HPAGE_MASK)
+                return -EINVAL;
+        return 0;
+}
+
+#define hugetlb_prefault_arch_hook(mm)          do { } while (0)
+
+int arch_prepare_hugepage(struct page *page);
+void arch_release_hugepage(struct page *page);
+
+static inline pte_t pte_mkhuge(pte_t pte)
+{
+        /*
+         * PROT_NONE needs to be remapped from the pte type to the ste type.
+         * The HW invalid bit is also different for pte and ste. The pte
+         * invalid bit happens to be the same as the ste _SEGMENT_ENTRY_LARGE
+         * bit, so we don't have to clear it.
+         */
+        if (pte_val(pte) & _PAGE_INVALID) {
+                if (pte_val(pte) & _PAGE_SWT)
+                        pte_val(pte) |= _HPAGE_TYPE_NONE;
+                pte_val(pte) |= _SEGMENT_ENTRY_INV;
+        }
+        /*
+         * Clear SW pte bits SWT and SWX, there are no SW bits in a segment
+         * table entry.
+         */
+        pte_val(pte) &= ~(_PAGE_SWT | _PAGE_SWX);
+        /*
+         * Also set the change-override bit because we don't need dirty bit
+         * tracking for hugetlbfs pages.
+         */
+        pte_val(pte) |= (_SEGMENT_ENTRY_LARGE | _SEGMENT_ENTRY_CO);
+        return pte;
+}
+
+static inline pte_t huge_pte_wrprotect(pte_t pte)
+{
+        pte_val(pte) |= _PAGE_RO;
+        return pte;
+}
+
+static inline int huge_pte_none(pte_t pte)
+{
+        return (pte_val(pte) & _SEGMENT_ENTRY_INV) &&
+                !(pte_val(pte) & _SEGMENT_ENTRY_RO);
+}
+
+static inline pte_t huge_ptep_get(pte_t *ptep)
+{
+        pte_t pte = *ptep;
+        unsigned long mask;
+
+        if (!MACHINE_HAS_HPAGE) {
+                ptep = (pte_t *) (pte_val(pte) & _SEGMENT_ENTRY_ORIGIN);
+                if (ptep) {
+                        mask = pte_val(pte) &
+                                (_SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO);
+                        pte = pte_mkhuge(*ptep);
+                        pte_val(pte) |= mask;
+                }
+        }
+        return pte;
+}
+
+static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
+                                            unsigned long addr, pte_t *ptep)
+{
+        pte_t pte = huge_ptep_get(ptep);
+
+        pmd_clear((pmd_t *) ptep);
+        return pte;
+}
+
+static inline void __pmd_csp(pmd_t *pmdp)
+{
+        register unsigned long reg2 asm("2") = pmd_val(*pmdp);
+        register unsigned long reg3 asm("3") = pmd_val(*pmdp) |
+                                               _SEGMENT_ENTRY_INV;
+        register unsigned long reg4 asm("4") = ((unsigned long) pmdp) + 5;
+
+        asm volatile(
+                "       csp %1,%3"
+                : "=m" (*pmdp)
+                : "d" (reg2), "d" (reg3), "d" (reg4), "m" (*pmdp) : "cc");
+        pmd_val(*pmdp) = _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY;
+}
+
+static inline void __pmd_idte(unsigned long address, pmd_t *pmdp)
+{
+        unsigned long sto = (unsigned long) pmdp -
+                                pmd_index(address) * sizeof(pmd_t);
+
+        if (!(pmd_val(*pmdp) & _SEGMENT_ENTRY_INV)) {
+                asm volatile(
+                        "       .insn   rrf,0xb98e0000,%2,%3,0,0"
+                        : "=m" (*pmdp)
+                        : "m" (*pmdp), "a" (sto),
+                          "a" ((address & HPAGE_MASK))
+                );
+        }
+        pmd_val(*pmdp) = _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY;
+}
+
+static inline void huge_ptep_invalidate(struct mm_struct *mm,
+                                        unsigned long address, pte_t *ptep)
+{
+        pmd_t *pmdp = (pmd_t *) ptep;
+
+        if (!MACHINE_HAS_IDTE) {
+                __pmd_csp(pmdp);
+                if (mm->context.noexec) {
+                        pmdp = get_shadow_table(pmdp);
+                        __pmd_csp(pmdp);
+                }
+                return;
+        }
+
+        __pmd_idte(address, pmdp);
+        if (mm->context.noexec) {
+                pmdp = get_shadow_table(pmdp);
+                __pmd_idte(address, pmdp);
+        }
+        return;
+}
+
+#define huge_ptep_set_access_flags(__vma, __addr, __ptep, __entry, __dirty) \
+({                                                                          \
+        int __changed = !pte_same(huge_ptep_get(__ptep), __entry);          \
+        if (__changed) {                                                    \
+                huge_ptep_invalidate((__vma)->vm_mm, __addr, __ptep);       \
+                set_huge_pte_at((__vma)->vm_mm, __addr, __ptep, __entry);   \
+        }                                                                   \
+        __changed;                                                          \
+})
+
+#define huge_ptep_set_wrprotect(__mm, __addr, __ptep)                   \
+({                                                                      \
+        pte_t __pte = huge_ptep_get(__ptep);                            \
+        if (pte_write(__pte)) {                                         \
+                if (atomic_read(&(__mm)->mm_users) > 1 ||               \
+                    (__mm) != current->active_mm)                       \
+                        huge_ptep_invalidate(__mm, __addr, __ptep);     \
+                set_huge_pte_at(__mm, __addr, __ptep,                   \
+                                huge_pte_wrprotect(__pte));             \
+        }                                                               \
+})
+
+static inline void huge_ptep_clear_flush(struct vm_area_struct *vma,
+                                         unsigned long address, pte_t *ptep)
+{
+        huge_ptep_invalidate(vma->vm_mm, address, ptep);
+}
+
+#endif /* _ASM_S390_HUGETLB_H */