1 files changed, 28 insertions, 29 deletions

diff --git a/arch/arm/mm/context.c b/arch/arm/mm/context.c
index ee9bb363d60..806cc4f6351 100644
--- a/arch/arm/mm/context.c
+++ b/arch/arm/mm/context.c
@@ -18,30 +18,39 @@
 
 static DEFINE_RAW_SPINLOCK(cpu_asid_lock);
 unsigned int cpu_last_asid = ASID_FIRST_VERSION;
-#ifdef CONFIG_SMP
-DEFINE_PER_CPU(struct mm_struct *, current_mm);
-#endif
 
 #ifdef CONFIG_ARM_LPAE
-#define cpu_set_asid(asid) {						\
-	unsigned long ttbl, ttbh;					\
-	asm volatile(							\
-	"	mrrc	p15, 0, %0, %1, c2		@ read TTBR0\n"	\
-	"	mov	%1, %2, lsl #(48 - 32)		@ set ASID\n"	\
-	"	mcrr	p15, 0, %0, %1, c2		@ set TTBR0\n"	\
-	: "=&r" (ttbl), "=&r" (ttbh)					\
-	: "r" (asid & ~ASID_MASK));					\
+void cpu_set_reserved_ttbr0(void)
+{
+	unsigned long ttbl = __pa(swapper_pg_dir);
+	unsigned long ttbh = 0;
+
+	/*
+	 * Set TTBR0 to swapper_pg_dir which contains only global entries. The
+	 * ASID is set to 0.
+	 */
+	asm volatile(
+	"	mcrr	p15, 0, %0, %1, c2		@ set TTBR0\n"
+	:
+	: "r" (ttbl), "r" (ttbh));
+	isb();
 }
 #else
-#define cpu_set_asid(asid) \
-	asm("	mcr	p15, 0, %0, c13, c0, 1\n" : : "r" (asid))
+void cpu_set_reserved_ttbr0(void)
+{
+	u32 ttb;
+	/* Copy TTBR1 into TTBR0 */
+	asm volatile(
+	"	mrc	p15, 0, %0, c2, c0, 1		@ read TTBR1\n"
+	"	mcr	p15, 0, %0, c2, c0, 0		@ set TTBR0\n"
+	: "=r" (ttb));
+	isb();
+}
 #endif
 
 /*
  * We fork()ed a process, and we need a new context for the child
- * to run in.  We reserve version 0 for initial tasks so we will
- * always allocate an ASID. The ASID 0 is reserved for the TTBR
- * register changing sequence.
+ * to run in.
  */
 void __init_new_context(struct task_struct *tsk, struct mm_struct *mm)
 {
@@ -51,9 +60,7 @@ void __init_new_context(struct task_struct *tsk, struct mm_struct *mm)
 
 static void flush_context(void)
 {
-	/* set the reserved ASID before flushing the TLB */
-	cpu_set_asid(0);
-	isb();
+	cpu_set_reserved_ttbr0();
 	local_flush_tlb_all();
 	if (icache_is_vivt_asid_tagged()) {
 		__flush_icache_all();
@@ -98,14 +105,7 @@ static void reset_context(void *info)
 {
 	unsigned int asid;
 	unsigned int cpu = smp_processor_id();
-	struct mm_struct *mm = per_cpu(current_mm, cpu);
-
-	/*
-	 * Check if a current_mm was set on this CPU as it might still
-	 * be in the early booting stages and using the reserved ASID.
-	 */
-	if (!mm)
-		return;
+	struct mm_struct *mm = current->active_mm;
 
 	smp_rmb();
 	asid = cpu_last_asid + cpu + 1;
@@ -114,8 +114,7 @@ static void reset_context(void *info)
 	set_mm_context(mm, asid);
 
 	/* set the new ASID */
-	cpu_set_asid(mm->context.id);
-	isb();
+	cpu_switch_mm(mm->pgd, mm);
 }
 
 #else