powerpc: Prepare xmon_save_regs for use with kdump

Today the arch/powerpc/xmon/setjmp.S file contains only the
xmon_save_regs function.  We want to use it for kdump purposes, so
let's move the file into arch/powerpc/kernel/ and give the function a
more generic name (ppc_save_regs).

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/ppc_save_regs.S b/arch/powerpc/kernel/ppc_save_regs.S
new file mode 100644
index 0000000..5113bd2
--- /dev/null
+++ b/arch/powerpc/kernel/ppc_save_regs.S
@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 1996 Paul Mackerras.
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ *
+ * NOTE: assert(sizeof(buf) > 23 * sizeof(long))
+ */
+#include <asm/processor.h>
+#include <asm/ppc_asm.h>
+#include <asm/asm-offsets.h>
+
+/*
+ * Grab the register values as they are now.
+ * This won't do a particularily good job because we really
+ * want our caller's caller's registers, and our caller has
+ * already executed its prologue.
+ * ToDo: We could reach back into the caller's save area to do
+ * a better job of representing the caller's state (note that
+ * that will be different for 32-bit and 64-bit, because of the
+ * different ABIs, though).
+ */
+_GLOBAL(ppc_save_regs)
+	PPC_STL	r0,0*SZL(r3)
+	PPC_STL	r2,2*SZL(r3)
+	PPC_STL	r3,3*SZL(r3)
+	PPC_STL	r4,4*SZL(r3)
+	PPC_STL	r5,5*SZL(r3)
+	PPC_STL	r6,6*SZL(r3)
+	PPC_STL	r7,7*SZL(r3)
+	PPC_STL	r8,8*SZL(r3)
+	PPC_STL	r9,9*SZL(r3)
+	PPC_STL	r10,10*SZL(r3)
+	PPC_STL	r11,11*SZL(r3)
+	PPC_STL	r12,12*SZL(r3)
+	PPC_STL	r13,13*SZL(r3)
+	PPC_STL	r14,14*SZL(r3)
+	PPC_STL	r15,15*SZL(r3)
+	PPC_STL	r16,16*SZL(r3)
+	PPC_STL	r17,17*SZL(r3)
+	PPC_STL	r18,18*SZL(r3)
+	PPC_STL	r19,19*SZL(r3)
+	PPC_STL	r20,20*SZL(r3)
+	PPC_STL	r21,21*SZL(r3)
+	PPC_STL	r22,22*SZL(r3)
+	PPC_STL	r23,23*SZL(r3)
+	PPC_STL	r24,24*SZL(r3)
+	PPC_STL	r25,25*SZL(r3)
+	PPC_STL	r26,26*SZL(r3)
+	PPC_STL	r27,27*SZL(r3)
+	PPC_STL	r28,28*SZL(r3)
+	PPC_STL	r29,29*SZL(r3)
+	PPC_STL	r30,30*SZL(r3)
+	PPC_STL	r31,31*SZL(r3)
+	/* go up one stack frame for SP */
+	PPC_LL	r4,0(r1)
+	PPC_STL	r4,1*SZL(r3)
+	/* get caller's LR */
+	PPC_LL	r0,LRSAVE(r4)
+	PPC_STL	r0,_NIP-STACK_FRAME_OVERHEAD(r3)
+	PPC_STL	r0,_LINK-STACK_FRAME_OVERHEAD(r3)
+	mfmsr	r0
+	PPC_STL	r0,_MSR-STACK_FRAME_OVERHEAD(r3)
+	mfctr	r0
+	PPC_STL	r0,_CTR-STACK_FRAME_OVERHEAD(r3)
+	mfxer	r0
+	PPC_STL	r0,_XER-STACK_FRAME_OVERHEAD(r3)
+	mfcr	r0
+	PPC_STL	r0,_CCR-STACK_FRAME_OVERHEAD(r3)
+	li	r0,0
+	PPC_STL	r0,_TRAP-STACK_FRAME_OVERHEAD(r3)
+	blr