s390/ipl: add REIPL_CLEAR flag to os_info

Introduce new OS_INFO_FLAGS_ENTRY to os_info pointing to the field
with bit flags.
Add OS_INFO_FLAGS_ENTRY upon dump_reipl shutdown action processing and
set OS_INFO_FLAG_REIPL_CLEAR flag indicating 'clear' sysfs attribute has
been set on the panicked system for specified ipl type. This flag can be
used to inform the dumper whether LOAD_CLEAR or LOAD_NORMAL diag308
subcode to be used for ipl after dumping the memory.
Signed-off-by: Mikhail Zaslonko <zaslonko@linux.ibm.com>
Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>

arch/s390/include/asm/os_info.h

@@ -16,6 +16,9 @@
 
 #define OS_INFO_VMCOREINFO	0
 #define OS_INFO_REIPL_BLOCK	1
+#define OS_INFO_FLAGS_ENTRY	2
+
+#define OS_INFO_FLAG_REIPL_CLEAR	(1UL << 0)
 
 struct os_info_entry {
 	u64	addr;
@@ -30,8 +33,8 @@ struct os_info {
 	u16	version_minor;
 	u64	crashkernel_addr;
 	u64	crashkernel_size;
-	struct os_info_entry entry[2];
-	u8	reserved[4024];
+	struct os_info_entry entry[3];
+	u8	reserved[4004];
 } __packed;
 
 void os_info_init(void);

arch/s390/kernel/ipl.c

@@ -176,6 +176,8 @@ static bool reipl_fcp_clear;
 static bool reipl_ccw_clear;
 static bool reipl_eckd_clear;
 
+static unsigned long os_info_flags;
+
 static inline int __diag308(unsigned long subcode, unsigned long addr)
 {
 	union register_pair r1;
@@ -1939,6 +1941,20 @@ static void dump_reipl_run(struct shutdown_trigger *trigger)
 	struct lowcore *abs_lc;
 	unsigned int csum;
 
+	/*
+	 * Set REIPL_CLEAR flag in os_info flags entry indicating
+	 * 'clear' sysfs attribute has been set on the panicked system
+	 * for specified reipl type.
+	 * Always set for IPL_TYPE_NSS and IPL_TYPE_UNKNOWN.
+	 */
+	if ((reipl_type == IPL_TYPE_CCW && reipl_ccw_clear) ||
+	    (reipl_type == IPL_TYPE_ECKD && reipl_eckd_clear) ||
+	    (reipl_type == IPL_TYPE_FCP && reipl_fcp_clear) ||
+	    (reipl_type == IPL_TYPE_NVME && reipl_nvme_clear) ||
+	    reipl_type == IPL_TYPE_NSS ||
+	    reipl_type == IPL_TYPE_UNKNOWN)
+		os_info_flags |= OS_INFO_FLAG_REIPL_CLEAR;
+	os_info_entry_add(OS_INFO_FLAGS_ENTRY, &os_info_flags, sizeof(os_info_flags));
 	csum = (__force unsigned int)
 	       csum_partial(reipl_block_actual, reipl_block_actual->hdr.len, 0);
 	abs_lc = get_abs_lowcore();