Index: kernel/arch/sparc64/include/asm.h
===================================================================
--- kernel/arch/sparc64/include/asm.h	(revision 989d3c289c17f32d29f1f6518aa347b0f9da85fd)
+++ kernel/arch/sparc64/include/asm.h	(revision 2ee907e74a1d87d148ea499f185a9d7ca1af4b61)
@@ -433,4 +433,5 @@
 extern void asm_delay_loop(const uint32_t usec);
 
+extern uint64_t read_from_ag_g6(void);
 extern uint64_t read_from_ag_g7(void);
 extern void write_to_ag_g6(uint64_t val);
Index: kernel/arch/sparc64/src/sun4u/asm.S
===================================================================
--- kernel/arch/sparc64/src/sun4u/asm.S	(revision 989d3c289c17f32d29f1f6518aa347b0f9da85fd)
+++ kernel/arch/sparc64/src/sun4u/asm.S	(revision 2ee907e74a1d87d148ea499f185a9d7ca1af4b61)
@@ -67,4 +67,8 @@
 	WRITE_ALTERNATE_REGISTER %g6, PSTATE_IG_BIT
 
+.global read_from_ag_g6
+read_from_ag_g6:
+	READ_ALTERNATE_REGISTER %g6, PSTATE_AG_BIT
+
 .global read_from_ag_g7
 read_from_ag_g7: