s390/kexec_file: Load new kernel to absolute 0

The leading 64 kB of a kernel image doesn't contain any data needed to boot
the new kernel when it was loaded via kexec_file. Thus kexec_file currently
strips them off before loading the image. Keep the leading 64 kB in order
to be able to pass a ipl_report to the next kernel.

Signed-off-by: Philipp Rudo <prudo@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/include/asm/kexec.h

@@ -43,6 +43,9 @@
 /* The native architecture */
 #define KEXEC_ARCH KEXEC_ARCH_S390
 
+/* Allow kexec_file to load a segment to 0 */
+#define KEXEC_BUF_MEM_UNKNOWN -1
+
 /* Provide a dummy definition to avoid build failures. */
 static inline void crash_setup_regs(struct pt_regs *newregs,
 					struct pt_regs *oldregs) { }
@@ -52,6 +55,9 @@ struct s390_load_data {
 	/* Pointer to the kernel buffer. Used to register cmdline etc.. */
 	void *kernel_buf;
 
+	/* Load address of the kernel_buf. */
+	unsigned long kernel_mem;
+
 	/* Parmarea in the kernel buffer. */
 	struct parmarea *parm;