s390/kexec_file: Simplify parmarea access

Access the parmarea in head.S via a struct instead of individual offsets.

While at it make the fields in the parmarea .quads.

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

arch/s390/boot/head.S

@@ -323,13 +323,14 @@ ENTRY(startup_kdump)
 
 #
 # params at 10400 (setup.h)
+# Must be keept in sync with struct parmarea in setup.h
 #
 	.org	PARMAREA
-	.long	0,0			# IPL_DEVICE
-	.long	0,0			# INITRD_START
-	.long	0,0			# INITRD_SIZE
-	.long	0,0			# OLDMEM_BASE
-	.long	0,0			# OLDMEM_SIZE
+	.quad	0			# IPL_DEVICE
+	.quad	0			# INITRD_START
+	.quad	0			# INITRD_SIZE
+	.quad	0			# OLDMEM_BASE
+	.quad	0			# OLDMEM_SIZE
 
 	.org	COMMAND_LINE
 	.byte	"root=/dev/ram0 ro"

arch/s390/include/asm/kexec.h

@@ -11,6 +11,7 @@
 
 #include <asm/processor.h>
 #include <asm/page.h>
+#include <asm/setup.h>
 /*
  * KEXEC_SOURCE_MEMORY_LIMIT maximum page get_free_page can return.
  * I.e. Maximum page that is mapped directly into kernel memory,
@@ -51,11 +52,11 @@ struct s390_load_data {
 	/* Pointer to the kernel buffer. Used to register cmdline etc.. */
 	void *kernel_buf;
 
+	/* Parmarea in the kernel buffer. */
+	struct parmarea *parm;
+
 	/* Total size of loaded segments in memory. Used as an offset. */
 	size_t memsz;
-
-	/* Load address of initrd. Used to register INITRD_START in kernel. */
-	unsigned long initrd_load_addr;
 };
 
 int kexec_file_add_purgatory(struct kimage *image,

arch/s390/include/asm/setup.h

@@ -65,6 +65,16 @@
 #define OLDMEM_SIZE	(*(unsigned long *)  (OLDMEM_SIZE_OFFSET))
 #define COMMAND_LINE	((char *)	     (COMMAND_LINE_OFFSET))
 
+struct parmarea {
+	unsigned long ipl_device;			/* 0x10400 */
+	unsigned long initrd_start;			/* 0x10408 */
+	unsigned long initrd_size;			/* 0x10410 */
+	unsigned long oldmem_base;			/* 0x10418 */
+	unsigned long oldmem_size;			/* 0x10420 */
+	char pad1[0x10480 - 0x10428];			/* 0x10428 - 0x10480 */
+	char command_line[ARCH_COMMAND_LINE_SIZE];	/* 0x10480 */
+};
+
 extern int noexec_disabled;
 extern int memory_end_set;
 extern unsigned long memory_end;

arch/s390/kernel/kexec_elf.c

@@ -42,6 +42,7 @@ static int kexec_file_add_elf_kernel(struct kimage *image,
 
 		if (entry - phdr->p_paddr < phdr->p_memsz) {
 			data->kernel_buf = buf.buffer;
+			data->parm = buf.buffer + PARMAREA;
 			data->memsz += STARTUP_NORMAL_OFFSET;
 
 			buf.buffer += STARTUP_NORMAL_OFFSET;

arch/s390/kernel/kexec_image.c

@@ -32,6 +32,7 @@ static int kexec_file_add_image_kernel(struct kimage *image,
 	ret = kexec_add_buffer(&buf);
 
 	data->kernel_buf = kernel;
+	data->parm = (void *)kernel + PARMAREA;
 	data->memsz += buf.memsz + STARTUP_NORMAL_OFFSET;
 
 	return ret;

arch/s390/kernel/machine_kexec_file.c

@@ -25,24 +25,12 @@ int *kexec_file_update_kernel(struct kimage *image,
 	if (image->cmdline_buf_len >= ARCH_COMMAND_LINE_SIZE)
 		return ERR_PTR(-EINVAL);
 
-	if (image->cmdline_buf_len)
-		memcpy(data->kernel_buf + COMMAND_LINE_OFFSET,
-		       image->cmdline_buf, image->cmdline_buf_len);
+	memcpy(data->parm->command_line, image->cmdline_buf,
+	       image->cmdline_buf_len);
 
 	if (image->type == KEXEC_TYPE_CRASH) {
-		loc = (unsigned long *)(data->kernel_buf + OLDMEM_BASE_OFFSET);
-		*loc = crashk_res.start;
-
-		loc = (unsigned long *)(data->kernel_buf + OLDMEM_SIZE_OFFSET);
-		*loc = crashk_res.end - crashk_res.start + 1;
-	}
-
-	if (image->initrd_buf) {
-		loc = (unsigned long *)(data->kernel_buf + INITRD_START_OFFSET);
-		*loc = data->initrd_load_addr;
-
-		loc = (unsigned long *)(data->kernel_buf + INITRD_SIZE_OFFSET);
-		*loc = image->initrd_buf_len;
+		data->parm->oldmem_base = crashk_res.start;
+		data->parm->oldmem_size = crashk_res.end - crashk_res.start + 1;
 	}
 
 	return NULL;
@@ -127,7 +115,8 @@ int kexec_file_add_initrd(struct kimage *image, struct s390_load_data *data,
 		buf.mem += crashk_res.start;
 	buf.memsz = buf.bufsz;
 
-	data->initrd_load_addr = buf.mem;
+	data->parm->initrd_start = buf.mem;
+	data->parm->initrd_size = buf.memsz;
 	data->memsz += buf.memsz;
 
 	ret = kexec_add_buffer(&buf);