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-rw-r--r--arch/s390/include/asm/hugetlb.h184
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 00000000000..670a1d1745d
--- /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 */