1 files changed, 40 insertions, 0 deletions
diff --git a/arch/arm64/kernel/scs.c b/arch/arm64/kernel/scs.c
new file mode 100644
index 000000000000..eaadf5430baa
--- /dev/null
+++ b/arch/arm64/kernel/scs.c
@@ -0,0 +1,40 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Shadow Call Stack support.
+ *
+ * Copyright (C) 2019 Google LLC
+ */
+
+#include <linux/percpu.h>
+#include <linux/vmalloc.h>
+#include <asm/pgtable.h>
+#include <asm/scs.h>
+
+DEFINE_PER_CPU(unsigned long *, irq_shadow_call_stack_ptr);
+
+#ifndef CONFIG_SHADOW_CALL_STACK_VMAP
+DEFINE_PER_CPU(unsigned long [SCS_SIZE/sizeof(long)], irq_shadow_call_stack)
+	__aligned(SCS_SIZE);
+#endif
+
+void scs_init_irq(void)
+{
+	int cpu;
+
+	for_each_possible_cpu(cpu) {
+#ifdef CONFIG_SHADOW_CALL_STACK_VMAP
+		unsigned long *p;
+
+		p = __vmalloc_node_range(PAGE_SIZE, SCS_SIZE,
+					 VMALLOC_START, VMALLOC_END,
+					 GFP_SCS, PAGE_KERNEL,
+					 0, cpu_to_node(cpu),
+					 __builtin_return_address(0));
+
+		per_cpu(irq_shadow_call_stack_ptr, cpu) = p;
+#else
+		per_cpu(irq_shadow_call_stack_ptr, cpu) =
+			per_cpu(irq_shadow_call_stack, cpu);
+#endif /* CONFIG_SHADOW_CALL_STACK_VMAP */
+	}
+}