ARM: 6117/1: kdump: implement crash_setup_regs()

Implement machine specific function crash_setup_regs() which is
responsible for storing machine state when crash occured.
Signed-off-by: NMika Westerberg <ext-mika.1.westerberg@nokia.com>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/include/asm/kexec.h

@@ -19,10 +19,26 @@
 
 #ifndef __ASSEMBLY__
 
-struct kimage;
-/* Provide a dummy definition to avoid build failures. */
+/**
+ * crash_setup_regs() - save registers for the panic kernel
+ * @newregs: registers are saved here
+ * @oldregs: registers to be saved (may be %NULL)
+ *
+ * Function copies machine registers from @oldregs to @newregs. If @oldregs is
+ * %NULL then current registers are stored there.
+ */
 static inline void crash_setup_regs(struct pt_regs *newregs,
-                                        struct pt_regs *oldregs) { }
+				    struct pt_regs *oldregs)
+{
+	if (oldregs) {
+		memcpy(newregs, oldregs, sizeof(*newregs));
+	} else {
+		__asm__ __volatile__ ("stmia %0, {r0 - r15}"
+				      : : "r" (&newregs->ARM_r0));
+		__asm__ __volatile__ ("mrs %0, cpsr"
+				      : "=r" (newregs->ARM_cpsr));
+	}
+}
 
 #endif /* __ASSEMBLY__ */