1 files changed, 95 insertions, 0 deletions
diff --git a/arch/parisc/include/asm/mmu_context.h b/arch/parisc/include/asm/mmu_context.h
new file mode 100644
index 000000000..697a906ab
--- /dev/null
+++ b/arch/parisc/include/asm/mmu_context.h
@@ -0,0 +1,95 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __PARISC_MMU_CONTEXT_H
+#define __PARISC_MMU_CONTEXT_H
+
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/atomic.h>
+#include <asm/pgalloc.h>
+#include <asm/pgtable.h>
+#include <asm-generic/mm_hooks.h>
+
+static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
+{
+}
+
+/* on PA-RISC, we actually have enough contexts to justify an allocator
+ * for them.  prumpf */
+
+extern unsigned long alloc_sid(void);
+extern void free_sid(unsigned long);
+
+static inline int
+init_new_context(struct task_struct *tsk, struct mm_struct *mm)
+{
+	BUG_ON(atomic_read(&mm->mm_users) != 1);
+
+	mm->context = alloc_sid();
+	return 0;
+}
+
+static inline void
+destroy_context(struct mm_struct *mm)
+{
+	free_sid(mm->context);
+	mm->context = 0;
+}
+
+static inline unsigned long __space_to_prot(mm_context_t context)
+{
+#if SPACEID_SHIFT == 0
+	return context << 1;
+#else
+	return context >> (SPACEID_SHIFT - 1);
+#endif
+}
+
+static inline void load_context(mm_context_t context)
+{
+	mtsp(context, 3);
+	mtctl(__space_to_prot(context), 8);
+}
+
+static inline void switch_mm_irqs_off(struct mm_struct *prev,
+		struct mm_struct *next, struct task_struct *tsk)
+{
+	if (prev != next) {
+		mtctl(__pa(next->pgd), 25);
+		load_context(next->context);
+	}
+}
+
+static inline void switch_mm(struct mm_struct *prev,
+		struct mm_struct *next, struct task_struct *tsk)
+{
+	unsigned long flags;
+
+	if (prev == next)
+		return;
+
+	local_irq_save(flags);
+	switch_mm_irqs_off(prev, next, tsk);
+	local_irq_restore(flags);
+}
+#define switch_mm_irqs_off switch_mm_irqs_off
+
+#define deactivate_mm(tsk,mm)	do { } while (0)
+
+static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
+{
+	/*
+	 * Activate_mm is our one chance to allocate a space id
+	 * for a new mm created in the exec path. There's also
+	 * some lazy tlb stuff, which is currently dead code, but
+	 * we only allocate a space id if one hasn't been allocated
+	 * already, so we should be OK.
+	 */
+
+	BUG_ON(next == &init_mm); /* Should never happen */
+
+	if (next->context == 0)
+	    next->context = alloc_sid();
+
+	switch_mm(prev,next,current);
+}
+#endif