1 files changed, 164 insertions, 0 deletions
diff --git a/arch/m32r/include/asm/mmu_context.h b/arch/m32r/include/asm/mmu_context.h
new file mode 100644
index 00000000000..91909e5dd9d
--- /dev/null
+++ b/arch/m32r/include/asm/mmu_context.h
@@ -0,0 +1,164 @@
+#ifndef _ASM_M32R_MMU_CONTEXT_H
+#define _ASM_M32R_MMU_CONTEXT_H
+#ifdef __KERNEL__
+
+#include <asm/m32r.h>
+
+#define MMU_CONTEXT_ASID_MASK      (0x000000FF)
+#define MMU_CONTEXT_VERSION_MASK   (0xFFFFFF00)
+#define MMU_CONTEXT_FIRST_VERSION  (0x00000100)
+#define NO_CONTEXT                 (0x00000000)
+
+#ifndef __ASSEMBLY__
+
+#include <asm/atomic.h>
+#include <asm/pgalloc.h>
+#include <asm/mmu.h>
+#include <asm/tlbflush.h>
+#include <asm-generic/mm_hooks.h>
+
+/*
+ * Cache of MMU context last used.
+ */
+#ifndef CONFIG_SMP
+extern unsigned long mmu_context_cache_dat;
+#define mmu_context_cache	mmu_context_cache_dat
+#define mm_context(mm)		mm->context
+#else /* not CONFIG_SMP */
+extern unsigned long mmu_context_cache_dat[];
+#define mmu_context_cache	mmu_context_cache_dat[smp_processor_id()]
+#define mm_context(mm)		mm->context[smp_processor_id()]
+#endif /* not CONFIG_SMP */
+
+#define set_tlb_tag(entry, tag)		(*entry = (tag & PAGE_MASK)|get_asid())
+#define set_tlb_data(entry, data)	(*entry = (data | _PAGE_PRESENT))
+
+#ifdef CONFIG_MMU
+#define enter_lazy_tlb(mm, tsk)	do { } while (0)
+
+static inline void get_new_mmu_context(struct mm_struct *mm)
+{
+	unsigned long mc = ++mmu_context_cache;
+
+	if (!(mc & MMU_CONTEXT_ASID_MASK)) {
+		/* We exhaust ASID of this version.
+		   Flush all TLB and start new cycle. */
+		local_flush_tlb_all();
+		/* Fix version if needed.
+		   Note that we avoid version #0 to distingush NO_CONTEXT. */
+		if (!mc)
+			mmu_context_cache = mc = MMU_CONTEXT_FIRST_VERSION;
+	}
+	mm_context(mm) = mc;
+}
+
+/*
+ * Get MMU context if needed.
+ */
+static inline void get_mmu_context(struct mm_struct *mm)
+{
+	if (mm) {
+		unsigned long mc = mmu_context_cache;
+
+		/* Check if we have old version of context.
+		   If it's old, we need to get new context with new version. */
+		if ((mm_context(mm) ^ mc) & MMU_CONTEXT_VERSION_MASK)
+			get_new_mmu_context(mm);
+	}
+}
+
+/*
+ * Initialize the context related info for a new mm_struct
+ * instance.
+ */
+static inline int init_new_context(struct task_struct *tsk,
+	struct mm_struct *mm)
+{
+#ifndef CONFIG_SMP
+	mm->context = NO_CONTEXT;
+#else /* CONFIG_SMP */
+	int num_cpus = num_online_cpus();
+	int i;
+
+	for (i = 0 ; i < num_cpus ; i++)
+		mm->context[i] = NO_CONTEXT;
+#endif /* CONFIG_SMP */
+
+	return 0;
+}
+
+/*
+ * Destroy context related info for an mm_struct that is about
+ * to be put to rest.
+ */
+#define destroy_context(mm)	do { } while (0)
+
+static inline void set_asid(unsigned long asid)
+{
+	*(volatile unsigned long *)MASID = (asid & MMU_CONTEXT_ASID_MASK);
+}
+
+static inline unsigned long get_asid(void)
+{
+	unsigned long asid;
+
+	asid = *(volatile long *)MASID;
+	asid &= MMU_CONTEXT_ASID_MASK;
+
+	return asid;
+}
+
+/*
+ * After we have set current->mm to a new value, this activates
+ * the context for the new mm so we see the new mappings.
+ */
+static inline void activate_context(struct mm_struct *mm)
+{
+	get_mmu_context(mm);
+	set_asid(mm_context(mm) & MMU_CONTEXT_ASID_MASK);
+}
+
+static inline void switch_mm(struct mm_struct *prev,
+	struct mm_struct *next, struct task_struct *tsk)
+{
+#ifdef CONFIG_SMP
+	int cpu = smp_processor_id();
+#endif	/* CONFIG_SMP */
+
+	if (prev != next) {
+#ifdef CONFIG_SMP
+		cpu_set(cpu, next->cpu_vm_mask);
+#endif /* CONFIG_SMP */
+		/* Set MPTB = next->pgd */
+		*(volatile unsigned long *)MPTB = (unsigned long)next->pgd;
+		activate_context(next);
+	}
+#ifdef CONFIG_SMP
+	else
+		if (!cpu_test_and_set(cpu, next->cpu_vm_mask))
+			activate_context(next);
+#endif /* CONFIG_SMP */
+}
+
+#define deactivate_mm(tsk, mm)	do { } while (0)
+
+#define activate_mm(prev, next)	\
+	switch_mm((prev), (next), NULL)
+
+#else /* not CONFIG_MMU */
+#define get_mmu_context(mm)             do { } while (0)
+#define init_new_context(tsk,mm)        (0)
+#define destroy_context(mm)             do { } while (0)
+#define set_asid(asid)                  do { } while (0)
+#define get_asid()                      (0)
+#define activate_context(mm)            do { } while (0)
+#define switch_mm(prev,next,tsk)        do { } while (0)
+#define deactivate_mm(mm,tsk)           do { } while (0)
+#define activate_mm(prev,next)          do { } while (0)
+#define enter_lazy_tlb(mm,tsk)          do { } while (0)
+#endif /* not CONFIG_MMU */
+
+#endif /* not __ASSEMBLY__ */
+
+#endif /* __KERNEL__ */
+#endif /* _ASM_M32R_MMU_CONTEXT_H */