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-rw-r--r--arch/s390/mm/hugetlbpage.c134
1 files changed, 134 insertions, 0 deletions
diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c
new file mode 100644
index 00000000000..f4b6124fdb7
--- /dev/null
+++ b/arch/s390/mm/hugetlbpage.c
@@ -0,0 +1,134 @@
+/*
+ * IBM System z Huge TLB Page Support for Kernel.
+ *
+ * Copyright 2007 IBM Corp.
+ * Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
+ */
+
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+
+
+void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
+ pte_t *pteptr, pte_t pteval)
+{
+ pmd_t *pmdp = (pmd_t *) pteptr;
+ pte_t shadow_pteval = pteval;
+ unsigned long mask;
+
+ if (!MACHINE_HAS_HPAGE) {
+ pteptr = (pte_t *) pte_page(pteval)[1].index;
+ mask = pte_val(pteval) &
+ (_SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO);
+ pte_val(pteval) = (_SEGMENT_ENTRY + __pa(pteptr)) | mask;
+ if (mm->context.noexec) {
+ pteptr += PTRS_PER_PTE;
+ pte_val(shadow_pteval) =
+ (_SEGMENT_ENTRY + __pa(pteptr)) | mask;
+ }
+ }
+
+ pmd_val(*pmdp) = pte_val(pteval);
+ if (mm->context.noexec) {
+ pmdp = get_shadow_table(pmdp);
+ pmd_val(*pmdp) = pte_val(shadow_pteval);
+ }
+}
+
+int arch_prepare_hugepage(struct page *page)
+{
+ unsigned long addr = page_to_phys(page);
+ pte_t pte;
+ pte_t *ptep;
+ int i;
+
+ if (MACHINE_HAS_HPAGE)
+ return 0;
+
+ ptep = (pte_t *) pte_alloc_one(&init_mm, address);
+ if (!ptep)
+ return -ENOMEM;
+
+ pte = mk_pte(page, PAGE_RW);
+ for (i = 0; i < PTRS_PER_PTE; i++) {
+ set_pte_at(&init_mm, addr + i * PAGE_SIZE, ptep + i, pte);
+ pte_val(pte) += PAGE_SIZE;
+ }
+ page[1].index = (unsigned long) ptep;
+ return 0;
+}
+
+void arch_release_hugepage(struct page *page)
+{
+ pte_t *ptep;
+
+ if (MACHINE_HAS_HPAGE)
+ return;
+
+ ptep = (pte_t *) page[1].index;
+ if (!ptep)
+ return;
+ pte_free(&init_mm, ptep);
+ page[1].index = 0;
+}
+
+pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr)
+{
+ pgd_t *pgdp;
+ pud_t *pudp;
+ pmd_t *pmdp = NULL;
+
+ pgdp = pgd_offset(mm, addr);
+ pudp = pud_alloc(mm, pgdp, addr);
+ if (pudp)
+ pmdp = pmd_alloc(mm, pudp, addr);
+ return (pte_t *) pmdp;
+}
+
+pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
+{
+ pgd_t *pgdp;
+ pud_t *pudp;
+ pmd_t *pmdp = NULL;
+
+ pgdp = pgd_offset(mm, addr);
+ if (pgd_present(*pgdp)) {
+ pudp = pud_offset(pgdp, addr);
+ if (pud_present(*pudp))
+ pmdp = pmd_offset(pudp, addr);
+ }
+ return (pte_t *) pmdp;
+}
+
+int huge_pmd_unshare(struct mm_struct *mm, unsigned long *addr, pte_t *ptep)
+{
+ return 0;
+}
+
+struct page *follow_huge_addr(struct mm_struct *mm, unsigned long address,
+ int write)
+{
+ return ERR_PTR(-EINVAL);
+}
+
+int pmd_huge(pmd_t pmd)
+{
+ if (!MACHINE_HAS_HPAGE)
+ return 0;
+
+ return !!(pmd_val(pmd) & _SEGMENT_ENTRY_LARGE);
+}
+
+struct page *follow_huge_pmd(struct mm_struct *mm, unsigned long address,
+ pmd_t *pmdp, int write)
+{
+ struct page *page;
+
+ if (!MACHINE_HAS_HPAGE)
+ return NULL;
+
+ page = pmd_page(*pmdp);
+ if (page)
+ page += ((address & ~HPAGE_MASK) >> PAGE_SHIFT);
+ return page;
+}