s390/kernel: Remove OS info init function call and diag 308 for kdump

Because of a design change for stand-alone kdump the function that
was done by the OS info init function is moved to the boot loader
code. This has two implications that are implemented by this patch:
a) The OS info init function is no longer called by the kernel
b) The diag 308 subcode 1 reset is no longer done by the kdump boot code.
This is necessary because otherwise the operation that is done now
by the boot loader would be reversed. For the normal kexec based
kdump mechansim the reset is already done by the kdump trigger code
(e.g. panic or PSW restart).

Signed-off-by: Michael Holzheu <[e-mail]>
Signed-off-by: Martin Schwidefsky <[e-mail]>

arch/s390/include/asm/os_info.h

···
 
 #define OS_INFO_VMCOREINFO	0
 #define OS_INFO_REIPL_BLOCK	1
-#define OS_INFO_INIT_FN		2
 
 struct os_info_entry {
 	u64	addr;
···
 	u16	version_minor;
 	u64	crashkernel_addr;
 	u64	crashkernel_size;
-	struct os_info_entry entry[3];
-	u8	reserved[4004];
+	struct os_info_entry entry[2];
+	u8	reserved[4024];
 } __packed;
 
 void os_info_init(void);

arch/s390/kernel/head_kdump.S

···
 	basr	%r13,0
 0:
 	mvc	0(8,%r0),.Lrestart_psw-0b(%r13)	# Setup restart PSW
-	mvc	464(16,%r0),.Lpgm_psw-0b(%r13)	# Setup pgm check PSW
-	lhi	%r1,1				# Start new kernel
-	diag	%r1,%r1,0x308			# with diag 308
-
-.Lno_diag308:					# No diag 308
 	sam31					# Switch to 31 bit addr mode
 	sr	%r1,%r1				# Erase register r1
 	sr	%r2,%r2				# Erase register r2
···
 .align	8
 .Lrestart_psw:
 	.long	0x00080000,0x80000000 + startup
-.Lpgm_psw:
-	.quad	0x0000000180000000,0x0000000000000000 + .Lno_diag308
 #else
 .align 2
 .Lep_startup_kdump:

arch/s390/kernel/os_info.c

···
 		goto fail_free;
 	os_info_old_alloc(OS_INFO_VMCOREINFO, 1);
 	os_info_old_alloc(OS_INFO_REIPL_BLOCK, 1);
-	os_info_old_alloc(OS_INFO_INIT_FN, PAGE_SIZE);
 	pr_info("crashkernel: addr=0x%lx size=%lu\n",
 		(unsigned long) os_info_old->crashkernel_addr,
 		(unsigned long) os_info_old->crashkernel_size);

arch/s390/kernel/smp.c

···
 
 #endif /* CONFIG_HOTPLUG_CPU */
 
-static void smp_call_os_info_init_fn(void)
-{
-	int (*init_fn)(void);
-	unsigned long size;
-
-	init_fn = os_info_old_entry(OS_INFO_INIT_FN, &size);
-	if (!init_fn)
-		return;
-	init_fn();
-}
-
 void __init smp_prepare_cpus(unsigned int max_cpus)
 {
 	/* request the 0x1201 emergency signal external interrupt */
···
 	/* request the 0x1202 external call external interrupt */
 	if (register_external_interrupt(0x1202, do_ext_call_interrupt) != 0)
 		panic("Couldn't request external interrupt 0x1202");
-	smp_call_os_info_init_fn();
 	smp_detect_cpus();
 }