1 files changed, 79 insertions, 0 deletions
diff --git a/include/asm-x86_64/mmu_context.h b/include/asm-x86_64/mmu_context.h
new file mode 100644
index 0000000..b630d52
--- /dev/null
+++ b/include/asm-x86_64/mmu_context.h
@@ -0,0 +1,79 @@
+#ifndef __X86_64_MMU_CONTEXT_H
+#define __X86_64_MMU_CONTEXT_H
+
+#include <linux/config.h>
+#include <asm/desc.h>
+#include <asm/atomic.h>
+#include <asm/pgalloc.h>
+#include <asm/pda.h>
+#include <asm/pgtable.h>
+#include <asm/tlbflush.h>
+
+/*
+ * possibly do the LDT unload here?
+ */
+int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
+void destroy_context(struct mm_struct *mm);
+
+#ifdef CONFIG_SMP
+
+static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
+{
+	if (read_pda(mmu_state) == TLBSTATE_OK) 
+		write_pda(mmu_state, TLBSTATE_LAZY);
+}
+#else
+static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
+{
+}
+#endif
+
+static inline void load_cr3(pgd_t *pgd)
+{
+	asm volatile("movq %0,%%cr3" :: "r" (__pa(pgd)) : "memory");
+}
+
+static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, 
+			     struct task_struct *tsk)
+{
+	unsigned cpu = smp_processor_id();
+	if (likely(prev != next)) {
+		/* stop flush ipis for the previous mm */
+		clear_bit(cpu, &prev->cpu_vm_mask);
+#ifdef CONFIG_SMP
+		write_pda(mmu_state, TLBSTATE_OK);
+		write_pda(active_mm, next);
+#endif
+		set_bit(cpu, &next->cpu_vm_mask);
+		load_cr3(next->pgd);
+
+		if (unlikely(next->context.ldt != prev->context.ldt)) 
+			load_LDT_nolock(&next->context, cpu);
+	}
+#ifdef CONFIG_SMP
+	else {
+		write_pda(mmu_state, TLBSTATE_OK);
+		if (read_pda(active_mm) != next)
+			out_of_line_bug();
+		if(!test_and_set_bit(cpu, &next->cpu_vm_mask)) {
+			/* We were in lazy tlb mode and leave_mm disabled 
+			 * tlb flush IPI delivery. We must reload CR3
+			 * to make sure to use no freed page tables.
+			 */
+			load_cr3(next->pgd);
+			load_LDT_nolock(&next->context, cpu);
+		}
+	}
+#endif
+}
+
+#define deactivate_mm(tsk,mm)	do { \
+	load_gs_index(0); \
+	asm volatile("movl %0,%%fs"::"r"(0));  \
+} while(0)
+
+#define activate_mm(prev, next) \
+	switch_mm((prev),(next),NULL)
+
+
+#endif