1 files changed, 43 insertions, 0 deletions
diff --git a/arch/arm/include/asm/percpu.h b/arch/arm/include/asm/percpu.h
new file mode 100644
index 000000000..e2fcb3cfd
--- /dev/null
+++ b/arch/arm/include/asm/percpu.h
@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2012 Calxeda, Inc.
+ */
+#ifndef _ASM_ARM_PERCPU_H_
+#define _ASM_ARM_PERCPU_H_
+
+register unsigned long current_stack_pointer asm ("sp");
+
+/*
+ * Same as asm-generic/percpu.h, except that we store the per cpu offset
+ * in the TPIDRPRW. TPIDRPRW only exists on V6K and V7
+ */
+#if defined(CONFIG_SMP) && !defined(CONFIG_CPU_V6)
+static inline void set_my_cpu_offset(unsigned long off)
+{
+	/* Set TPIDRPRW */
+	asm volatile("mcr p15, 0, %0, c13, c0, 4" : : "r" (off) : "memory");
+}
+
+static inline unsigned long __my_cpu_offset(void)
+{
+	unsigned long off;
+
+	/*
+	 * Read TPIDRPRW.
+	 * We want to allow caching the value, so avoid using volatile and
+	 * instead use a fake stack read to hazard against barrier().
+	 */
+	asm("mrc p15, 0, %0, c13, c0, 4" : "=r" (off)
+		: "Q" (*(const unsigned long *)current_stack_pointer));
+
+	return off;
+}
+#define __my_cpu_offset __my_cpu_offset()
+#else
+#define set_my_cpu_offset(x)	do {} while(0)
+
+#endif /* CONFIG_SMP */
+
+#include <asm-generic/percpu.h>
+
+#endif /* _ASM_ARM_PERCPU_H_ */