release-request-65fa9893-af48-4e1d-bbfd-0ad00ce88026-for-git_nyc-iot-release-4273224 snap-temp-L21600000093073568android-n-iot-release-smart-display-r2android-n-iot-release-smart-displayandroid-n-iot-release-polk-at1android-n-iot-release-lg-thinq-wk7android-n-iot-release-ihome-igv1nougat-iot-release

Change-Id: I9624021a4a6df994f06c0dcbee05ce5a15a11cfa

1 files changed, 13 insertions, 1 deletions

diff --git a/arch/arm64/include/asm/smp.h b/arch/arm64/include/asm/smp.h
index 2013a4dc5124..a05033beb2a2 100644
--- a/arch/arm64/include/asm/smp.h
+++ b/arch/arm64/include/asm/smp.h
@@ -16,11 +16,20 @@
 #ifndef __ASM_SMP_H
 #define __ASM_SMP_H
 
+#include <asm/percpu.h>
+
 #include <linux/threads.h>
 #include <linux/cpumask.h>
 #include <linux/thread_info.h>
 
-#define raw_smp_processor_id() (current_thread_info()->cpu)
+DECLARE_PER_CPU_READ_MOSTLY(int, cpu_number);
+
+/*
+ * We don't use this_cpu_read(cpu_number) as that has implicit writes to
+ * preempt_count, and associated (compiler) barriers, that we'd like to avoid
+ * the expense of. If we're preemptible, the value can be stale at use anyway.
+ */
+#define raw_smp_processor_id() (*this_cpu_ptr(&cpu_number))
 
 struct seq_file;
 
@@ -57,6 +66,9 @@ asmlinkage void secondary_start_kernel(void);
  */
 struct secondary_data {
 	void *stack;
+#ifdef CONFIG_THREAD_INFO_IN_TASK
+	struct task_struct *task;
+#endif
 };
 extern struct secondary_data secondary_data;
 extern void secondary_entry(void);