[S390] zfcpdump support.

s390 machines provide hardware support for creating Linux dumps on SCSI
disks. For creating a dump a special purpose dump Linux is used. The first
32 MB of memory are saved by the hardware before the dump Linux is
booted. Via an SCLP interface, the saved memory can be accessed from
Linux. This patch exports memory and registers of the crashed Linux to
userspace via a debugfs file. For more information refer to
Documentation/s390/zfcpdump.txt, which is included in this patch.

Signed-off-by: Michael Holzheu <holzheu@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

1 files changed, 46 insertions, 0 deletions

diff --git a/include/asm-s390/lowcore.h b/include/asm-s390/lowcore.h
index 4a31d0a7ee83..ffc9788a21a7 100644
--- a/include/asm-s390/lowcore.h
+++ b/include/asm-s390/lowcore.h
@@ -147,6 +147,52 @@ void pgm_check_handler(void);
 void mcck_int_handler(void);
 void io_int_handler(void);
 
+struct save_area_s390 {
+	u32	ext_save;
+	u64	timer;
+	u64	clk_cmp;
+	u8	pad1[24];
+	u8	psw[8];
+	u32	pref_reg;
+	u8	pad2[20];
+	u32	acc_regs[16];
+	u64	fp_regs[4];
+	u32	gp_regs[16];
+	u32	ctrl_regs[16];
+}  __attribute__((packed));
+
+struct save_area_s390x {
+	u64	fp_regs[16];
+	u64	gp_regs[16];
+	u8	psw[16];
+	u8	pad1[8];
+	u32	pref_reg;
+	u32	fp_ctrl_reg;
+	u8	pad2[4];
+	u32	tod_reg;
+	u64	timer;
+	u64	clk_cmp;
+	u8	pad3[8];
+	u32	acc_regs[16];
+	u64	ctrl_regs[16];
+}  __attribute__((packed));
+
+union save_area {
+	struct save_area_s390	s390;
+	struct save_area_s390x	s390x;
+};
+
+#define SAVE_AREA_BASE_S390	0xd4
+#define SAVE_AREA_BASE_S390X	0x1200
+
+#ifndef __s390x__
+#define SAVE_AREA_SIZE sizeof(struct save_area_s390)
+#define SAVE_AREA_BASE SAVE_AREA_BASE_S390
+#else
+#define SAVE_AREA_SIZE sizeof(struct save_area_s390x)
+#define SAVE_AREA_BASE SAVE_AREA_BASE_S390X
+#endif
+
 struct _lowcore
 {
 #ifndef __s390x__