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Diffstat (limited to 'drivers/s390/char/sclp_early_core.c')
-rw-r--r--drivers/s390/char/sclp_early_core.c26
1 files changed, 25 insertions, 1 deletions
diff --git a/drivers/s390/char/sclp_early_core.c b/drivers/s390/char/sclp_early_core.c
index 676634de65a8..ac1d00980fa6 100644
--- a/drivers/s390/char/sclp_early_core.c
+++ b/drivers/s390/char/sclp_early_core.c
@@ -17,7 +17,7 @@
static struct read_info_sccb __bootdata(sclp_info_sccb);
static int __bootdata(sclp_info_sccb_valid);
-char *__bootdata(sclp_early_sccb);
+char *__bootdata_preserved(sclp_early_sccb);
int sclp_init_state = sclp_init_state_uninitialized;
/*
* Used to keep track of the size of the event masks. Qemu until version 2.11
@@ -241,6 +241,30 @@ void sclp_early_printk(const char *str)
}
/*
+ * Use sclp_emergency_printk() to print a string when the system is in a
+ * state where regular console drivers cannot be assumed to work anymore.
+ *
+ * Callers must make sure that no concurrent SCLP requests are outstanding
+ * and all other CPUs are stopped, or at least disabled for external
+ * interrupts.
+ */
+void sclp_emergency_printk(const char *str)
+{
+ int have_linemode, have_vt220;
+ unsigned int len;
+
+ len = strlen(str);
+ /*
+ * Don't care about return values; if requests fail, just ignore and
+ * continue to have a rather high chance that anything is printed.
+ */
+ sclp_early_setup(0, &have_linemode, &have_vt220);
+ sclp_early_print_lm(str, len);
+ sclp_early_print_vt220(str, len);
+ sclp_early_setup(1, &have_linemode, &have_vt220);
+}
+
+/*
* We can't pass sclp_info_sccb to sclp_early_cmd() here directly,
* because it might not fulfil the requiremets for a SCLP communication buffer:
* - lie below 2G in memory