--- zzzz-none-000/linux-4.4.60/arch/arm64/kernel/smp.c	2017-04-08 07:53:53.000000000 +0000
+++ scorpion-7490-727/linux-4.4.60/arch/arm64/kernel/smp.c	2021-02-04 17:41:59.000000000 +0000
@@ -57,6 +57,9 @@
 #define CREATE_TRACE_POINTS
 #include <trace/events/ipi.h>
 
+DEFINE_PER_CPU_READ_MOSTLY(int, cpu_number);
+EXPORT_PER_CPU_SYMBOL(cpu_number);
+
 /*
  * as from 2.5, kernels no longer have an init_tasks structure
  * so we need some other way of telling a new secondary core
@@ -70,6 +73,7 @@
 	IPI_CPU_STOP,
 	IPI_TIMER,
 	IPI_IRQ_WORK,
+	IPI_WAKEUP,
 };
 
 /*
@@ -94,6 +98,9 @@
 	 * We need to tell the secondary core where to find its stack and the
 	 * page tables.
 	 */
+#ifdef CONFIG_THREAD_INFO_IN_TASK
+	secondary_data.task = idle;
+#endif
 	secondary_data.stack = task_stack_page(idle) + THREAD_START_SP;
 	__flush_dcache_area(&secondary_data, sizeof(secondary_data));
 
@@ -116,7 +123,9 @@
 	} else {
 		pr_err("CPU%u: failed to boot: %d\n", cpu, ret);
 	}
-
+#ifdef CONFIG_THREAD_INFO_IN_TASK
+	secondary_data.task = NULL;
+#endif
 	secondary_data.stack = NULL;
 
 	return ret;
@@ -134,7 +143,10 @@
 asmlinkage void secondary_start_kernel(void)
 {
 	struct mm_struct *mm = &init_mm;
-	unsigned int cpu = smp_processor_id();
+	unsigned int cpu;
+
+	cpu = task_cpu(current);
+	set_my_cpu_offset(per_cpu_offset(cpu));
 
 	/*
 	 * All kernel threads share the same mm context; grab a
@@ -143,8 +155,6 @@
 	atomic_inc(&mm->mm_count);
 	current->active_mm = mm;
 
-	set_my_cpu_offset(per_cpu_offset(smp_processor_id()));
-
 	/*
 	 * TTBR0 is only used for the identity mapping at this stage. Make it
 	 * point to zero page to avoid speculatively fetching new entries.
@@ -597,6 +607,8 @@
 		if (max_cpus == 0)
 			break;
 
+		per_cpu(cpu_number, cpu) = cpu;
+
 		if (cpu == smp_processor_id())
 			continue;
 
@@ -626,6 +638,7 @@
 	S(IPI_CPU_STOP, "CPU stop interrupts"),
 	S(IPI_TIMER, "Timer broadcast interrupts"),
 	S(IPI_IRQ_WORK, "IRQ work interrupts"),
+	S(IPI_WAKEUP, "CPU wakeup interrupts"),
 };
 
 static void smp_cross_call(const struct cpumask *target, unsigned int ipinr)
@@ -669,6 +682,11 @@
 	smp_cross_call(cpumask_of(cpu), IPI_CALL_FUNC);
 }
 
+void arch_send_wakeup_ipi_mask(const struct cpumask *mask)
+{
+	smp_cross_call(mask, IPI_WAKEUP);
+}
+
 #ifdef CONFIG_IRQ_WORK
 void arch_irq_work_raise(void)
 {