s390/boot: convert parmarea to C

Convert parmarea to C, which makes it much easier to initialize it. No need
to keep offsets in assembler code in sync with struct parmarea anymore.

Reviewed-by: Vasily Gorbik <[e-mail]>
Signed-off-by: Heiko Carstens <[e-mail]>

arch/s390/boot/head.S

···
 	lmg	%r0,%r15,__LC_GPREGS_SAVE_AREA-4095(%r8)
 	lpswe	__LC_RETURN_PSW		# disabled wait
 SYM_CODE_END(startup_pgm_check_handler)
-
-#
-# params at 10400 (setup.h)
-# Must be keept in sync with struct parmarea in setup.h
-#
-	.org	PARMAREA - IPL_START
-SYM_DATA_START(parmarea)
-	.quad	0			# IPL_DEVICE
-	.quad	0			# INITRD_START
-	.quad	0			# INITRD_SIZE
-	.quad	0			# OLDMEM_BASE
-	.quad	0			# OLDMEM_SIZE
-	.quad	kernel_version		# points to kernel version string
-	.quad	COMMAND_LINE_SIZE
-
-	.org	COMMAND_LINE - IPL_START
-	.byte	"root=/dev/ram0 ro"
-	.byte	0
-	.org	PARMAREA+__PARMAREA_SIZE - IPL_START
-SYM_DATA_END(parmarea)

arch/s390/boot/ipl_data.c

···
  * that to succeed the two initial CCWs, and the 0x40 fill bytes must
  * be present.
  */
-struct ipl_lowcore ipl_lowcore __section(".ipldata") = {
+static struct ipl_lowcore ipl_lowcore __used __section(".ipldata") = {
 	.ipl_psw = { .mask = PSW32_MASK_BASE, .addr = PSW32_ADDR_AMODE | IPL_START },
 	.ccwpgm = {
 		[ 0] = CCW0(CCW_CMD_READ_IPL, 0x018, 0x50, CCW_FLAG_SLI | CCW_FLAG_CC),

arch/s390/boot/ipl_parm.c

···
 #include <asm/sections.h>
 #include <asm/boot_data.h>
 #include <asm/facility.h>
+#include <asm/setup.h>
 #include <asm/uv.h>
 #include "boot.h"
+
+struct parmarea parmarea __section(".parmarea") = {
+	.kernel_version		= (unsigned long)kernel_version,
+	.max_command_line_size	= COMMAND_LINE_SIZE,
+	.command_line		= "root=/dev/ram0 ro",
+};
 
 char __bootdata(early_command_line)[COMMAND_LINE_SIZE];
 int __bootdata(noexec_disabled);

arch/s390/boot/vmlinux.lds.S

···
 		HEAD_TEXT
 		_ehead = . ;
 	}
+	. = PARMAREA;
+	.parmarea : {
+		*(.parmarea)
+	}
 	.text :	{
 		_text = .;	/* Text */
 		*(.text)