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-rw-r--r--kernel/arch/s390/include/asm/mmu_context.h133
1 files changed, 133 insertions, 0 deletions
diff --git a/kernel/arch/s390/include/asm/mmu_context.h b/kernel/arch/s390/include/asm/mmu_context.h
new file mode 100644
index 000000000..fb1b93ea3
--- /dev/null
+++ b/kernel/arch/s390/include/asm/mmu_context.h
@@ -0,0 +1,133 @@
+/*
+ * S390 version
+ *
+ * Derived from "include/asm-i386/mmu_context.h"
+ */
+
+#ifndef __S390_MMU_CONTEXT_H
+#define __S390_MMU_CONTEXT_H
+
+#include <asm/pgalloc.h>
+#include <asm/uaccess.h>
+#include <asm/tlbflush.h>
+#include <asm/ctl_reg.h>
+
+static inline int init_new_context(struct task_struct *tsk,
+ struct mm_struct *mm)
+{
+ cpumask_clear(&mm->context.cpu_attach_mask);
+ atomic_set(&mm->context.attach_count, 0);
+ mm->context.flush_mm = 0;
+ mm->context.asce_bits = _ASCE_TABLE_LENGTH | _ASCE_USER_BITS;
+ mm->context.asce_bits |= _ASCE_TYPE_REGION3;
+#ifdef CONFIG_PGSTE
+ mm->context.alloc_pgste = page_table_allocate_pgste;
+ mm->context.has_pgste = 0;
+ mm->context.use_skey = 0;
+#endif
+ mm->context.asce_limit = STACK_TOP_MAX;
+ crst_table_init((unsigned long *) mm->pgd, pgd_entry_type(mm));
+ return 0;
+}
+
+#define destroy_context(mm) do { } while (0)
+
+static inline void set_user_asce(struct mm_struct *mm)
+{
+ S390_lowcore.user_asce = mm->context.asce_bits | __pa(mm->pgd);
+ if (current->thread.mm_segment.ar4)
+ __ctl_load(S390_lowcore.user_asce, 7, 7);
+ set_cpu_flag(CIF_ASCE);
+}
+
+static inline void clear_user_asce(void)
+{
+ S390_lowcore.user_asce = S390_lowcore.kernel_asce;
+
+ __ctl_load(S390_lowcore.user_asce, 1, 1);
+ __ctl_load(S390_lowcore.user_asce, 7, 7);
+}
+
+static inline void load_kernel_asce(void)
+{
+ unsigned long asce;
+
+ __ctl_store(asce, 1, 1);
+ if (asce != S390_lowcore.kernel_asce)
+ __ctl_load(S390_lowcore.kernel_asce, 1, 1);
+ set_cpu_flag(CIF_ASCE);
+}
+
+static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
+ struct task_struct *tsk)
+{
+ int cpu = smp_processor_id();
+
+ S390_lowcore.user_asce = next->context.asce_bits | __pa(next->pgd);
+ if (prev == next)
+ return;
+ if (MACHINE_HAS_TLB_LC)
+ cpumask_set_cpu(cpu, &next->context.cpu_attach_mask);
+ /* Clear old ASCE by loading the kernel ASCE. */
+ __ctl_load(S390_lowcore.kernel_asce, 1, 1);
+ __ctl_load(S390_lowcore.kernel_asce, 7, 7);
+ atomic_inc(&next->context.attach_count);
+ atomic_dec(&prev->context.attach_count);
+ if (MACHINE_HAS_TLB_LC)
+ cpumask_clear_cpu(cpu, &prev->context.cpu_attach_mask);
+}
+
+#define finish_arch_post_lock_switch finish_arch_post_lock_switch
+static inline void finish_arch_post_lock_switch(void)
+{
+ struct task_struct *tsk = current;
+ struct mm_struct *mm = tsk->mm;
+
+ load_kernel_asce();
+ if (mm) {
+ preempt_disable();
+ while (atomic_read(&mm->context.attach_count) >> 16)
+ cpu_relax();
+
+ cpumask_set_cpu(smp_processor_id(), mm_cpumask(mm));
+ if (mm->context.flush_mm)
+ __tlb_flush_mm(mm);
+ preempt_enable();
+ }
+ set_fs(current->thread.mm_segment);
+}
+
+#define enter_lazy_tlb(mm,tsk) do { } while (0)
+#define deactivate_mm(tsk,mm) do { } while (0)
+
+static inline void activate_mm(struct mm_struct *prev,
+ struct mm_struct *next)
+{
+ switch_mm(prev, next, current);
+ cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
+ set_user_asce(next);
+}
+
+static inline void arch_dup_mmap(struct mm_struct *oldmm,
+ struct mm_struct *mm)
+{
+ if (oldmm->context.asce_limit < mm->context.asce_limit)
+ crst_table_downgrade(mm, oldmm->context.asce_limit);
+}
+
+static inline void arch_exit_mmap(struct mm_struct *mm)
+{
+}
+
+static inline void arch_unmap(struct mm_struct *mm,
+ struct vm_area_struct *vma,
+ unsigned long start, unsigned long end)
+{
+}
+
+static inline void arch_bprm_mm_init(struct mm_struct *mm,
+ struct vm_area_struct *vma)
+{
+}
+
+#endif /* __S390_MMU_CONTEXT_H */