[S390] kdump backend code

This patch provides the architecture specific part of the s390 kdump
support.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/Kconfig

@@ -569,6 +569,16 @@ config KEXEC
 	  current kernel, and to start another kernel.  It is like a reboot
 	  but is independent of hardware/microcode support.
 
+config CRASH_DUMP
+	bool "kernel crash dumps"
+	depends on 64BIT
+	help
+	  Generate crash dump after being started by kexec.
+	  Crash dump kernels are loaded in the main kernel with kexec-tools
+	  into a specially reserved region and then later executed after
+	  a crash by kdump/kexec.
+	  For more details see Documentation/kdump/kdump.txt
+
 config ZFCPDUMP
 	def_bool n
 	prompt "zfcpdump support"

arch/s390/include/asm/ipl.h

@@ -168,5 +168,6 @@ enum diag308_rc {
 
 extern int diag308(unsigned long subcode, void *addr);
 extern void diag308_reset(void);
+extern void store_status(void);
 
 #endif /* _ASM_S390_IPL_H */

arch/s390/include/asm/kexec.h

@@ -30,6 +30,9 @@
 /* Not more than 2GB */
 #define KEXEC_CONTROL_MEMORY_LIMIT (1UL<<31)
 
+/* Maximum address we can use for the crash control pages */
+#define KEXEC_CRASH_CONTROL_MEMORY_LIMIT (-1UL)
+
 /* Allocate one page for the pdp and the second for the code */
 #define KEXEC_CONTROL_PAGE_SIZE 4096
 

arch/s390/include/asm/reset.h

@@ -17,5 +17,5 @@ struct reset_call {
 
 extern void register_reset_call(struct reset_call *reset);
 extern void unregister_reset_call(struct reset_call *reset);
-extern void s390_reset_system(void);
+extern void s390_reset_system(void (*func)(void *), void *data);
 #endif /* _ASM_S390_RESET_H */

arch/s390/include/asm/setup.h

@@ -26,15 +26,21 @@
 #define IPL_DEVICE        (*(unsigned long *)  (0x10404))
 #define INITRD_START      (*(unsigned long *)  (0x1040C))
 #define INITRD_SIZE       (*(unsigned long *)  (0x10414))
+#define OLDMEM_BASE	  (*(unsigned long *)  (0x1041C))
+#define OLDMEM_SIZE	  (*(unsigned long *)  (0x10424))
 #else /* __s390x__ */
 #define IPL_DEVICE        (*(unsigned long *)  (0x10400))
 #define INITRD_START      (*(unsigned long *)  (0x10408))
 #define INITRD_SIZE       (*(unsigned long *)  (0x10410))
+#define OLDMEM_BASE	  (*(unsigned long *)  (0x10418))
+#define OLDMEM_SIZE	  (*(unsigned long *)  (0x10420))
 #endif /* __s390x__ */
 #define COMMAND_LINE      ((char *)            (0x10480))
 
 #define CHUNK_READ_WRITE 0
 #define CHUNK_READ_ONLY  1
+#define CHUNK_OLDMEM	 4
+#define CHUNK_CRASHK	 5
 
 struct mem_chunk {
 	unsigned long addr;
@@ -48,6 +54,8 @@ extern int memory_end_set;
 extern unsigned long memory_end;
 
 void detect_memory_layout(struct mem_chunk chunk[]);
+void create_mem_hole(struct mem_chunk memory_chunk[], unsigned long addr,
+		     unsigned long size, int type);
 
 #define PRIMARY_SPACE_MODE	0
 #define ACCESS_REGISTER_MODE	1
@@ -106,6 +114,7 @@ extern unsigned int user_mode;
 #endif /* __s390x__ */
 
 #define ZFCPDUMP_HSA_SIZE	(32UL<<20)
+#define ZFCPDUMP_HSA_SIZE_MAX	(64UL<<20)
 
 /*
  * Console mode. Override with conmode=
@@ -134,10 +143,14 @@ extern char kernel_nss_name[];
 #define IPL_DEVICE        0x10404
 #define INITRD_START      0x1040C
 #define INITRD_SIZE       0x10414
+#define OLDMEM_BASE	  0x1041C
+#define OLDMEM_SIZE	  0x10424
 #else /* __s390x__ */
 #define IPL_DEVICE        0x10400
 #define INITRD_START      0x10408
 #define INITRD_SIZE       0x10410
+#define OLDMEM_BASE	  0x10418
+#define OLDMEM_SIZE	  0x10420
 #endif /* __s390x__ */
 #define COMMAND_LINE      0x10480
 

arch/s390/kernel/Makefile

@@ -48,6 +48,7 @@ obj-$(CONFIG_FUNCTION_TRACER)	+= $(if $(CONFIG_64BIT),mcount64.o,mcount.o)
 obj-$(CONFIG_DYNAMIC_FTRACE)	+= ftrace.o
 obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o
 obj-$(CONFIG_FTRACE_SYSCALLS)  += ftrace.o
+obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o
 
 # Kexec part
 S390_KEXEC_OBJS := machine_kexec.o crash.o

arch/s390/kernel/base.S

@@ -86,6 +86,8 @@ s390_base_pgm_handler_fn:
 ENTRY(diag308_reset)
 	larl	%r4,.Lctlregs		# Save control registers
 	stctg	%c0,%c15,0(%r4)
+	larl	%r4,.Lfpctl		# Floating point control register
+	stfpc	0(%r4)
 	larl	%r4,.Lrestart_psw	# Setup restart PSW at absolute 0
 	lghi	%r3,0
 	lg	%r4,0(%r4)		# Save PSW
@@ -99,6 +101,8 @@ ENTRY(diag308_reset)
 	sam64				# Switch to 64 bit addressing mode
 	larl	%r4,.Lctlregs		# Restore control registers
 	lctlg	%c0,%c15,0(%r4)
+	larl	%r4,.Lfpctl		# Restore floating point ctl register
+	lfpc	0(%r4)
 	br	%r14
 .align 16
 .Lrestart_psw:
@@ -110,6 +114,8 @@ ENTRY(diag308_reset)
 	.rept	16
 	.quad	0
 	.endr
+.Lfpctl:
+	.long	0
 	.previous
 
 #else /* CONFIG_64BIT */