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-rw-r--r--arch/powerpc/platforms/powernv/Makefile1
-rw-r--r--arch/powerpc/platforms/powernv/opal-kmsg.c68
-rw-r--r--arch/powerpc/platforms/powernv/opal-wrappers.S1
-rw-r--r--arch/powerpc/platforms/powernv/opal.c3
4 files changed, 73 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/Makefile b/arch/powerpc/platforms/powernv/Makefile
index ee774e8a4837..f1516b5ecec9 100644
--- a/arch/powerpc/platforms/powernv/Makefile
+++ b/arch/powerpc/platforms/powernv/Makefile
@@ -2,6 +2,7 @@ obj-y += setup.o opal-wrappers.o opal.o opal-async.o idle.o
obj-y += opal-rtc.o opal-nvram.o opal-lpc.o opal-flash.o
obj-y += rng.o opal-elog.o opal-dump.o opal-sysparam.o opal-sensor.o
obj-y += opal-msglog.o opal-hmi.o opal-power.o opal-irqchip.o
+obj-y += opal-kmsg.o
obj-$(CONFIG_SMP) += smp.o subcore.o subcore-asm.o
obj-$(CONFIG_PCI) += pci.o pci-p5ioc2.o pci-ioda.o npu-dma.o
diff --git a/arch/powerpc/platforms/powernv/opal-kmsg.c b/arch/powerpc/platforms/powernv/opal-kmsg.c
new file mode 100644
index 000000000000..bd3b2ee1ba1d
--- /dev/null
+++ b/arch/powerpc/platforms/powernv/opal-kmsg.c
@@ -0,0 +1,68 @@
+/*
+ * kmsg dumper that ensures the OPAL console fully flushes panic messages
+ *
+ * Author: Russell Currey <ruscur@russell.cc>
+ *
+ * Copyright 2015 IBM Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <linux/kmsg_dump.h>
+
+#include <asm/opal.h>
+#include <asm/opal-api.h>
+
+/*
+ * Console output is controlled by OPAL firmware. The kernel regularly calls
+ * OPAL_POLL_EVENTS, which flushes some console output. In a panic state,
+ * however, the kernel no longer calls OPAL_POLL_EVENTS and the panic message
+ * may not be completely printed. This function does not actually dump the
+ * message, it just ensures that OPAL completely flushes the console buffer.
+ */
+static void force_opal_console_flush(struct kmsg_dumper *dumper,
+ enum kmsg_dump_reason reason)
+{
+ int i;
+
+ /*
+ * Outside of a panic context the pollers will continue to run,
+ * so we don't need to do any special flushing.
+ */
+ if (reason != KMSG_DUMP_PANIC)
+ return;
+
+ if (opal_check_token(OPAL_CONSOLE_FLUSH)) {
+ opal_console_flush();
+ } else {
+ /*
+ * If OPAL_CONSOLE_FLUSH is not implemented in the firmware,
+ * the console can still be flushed by calling the polling
+ * function enough times to flush the buffer. We don't know
+ * how much output still needs to be flushed, but we can be
+ * generous since the kernel is in panic and doesn't need
+ * to do much else.
+ */
+ printk(KERN_NOTICE "opal: OPAL_CONSOLE_FLUSH missing.\n");
+ for (i = 0; i < 1024; i++) {
+ opal_poll_events(NULL);
+ }
+ }
+}
+
+static struct kmsg_dumper opal_kmsg_dumper = {
+ .dump = force_opal_console_flush
+};
+
+void __init opal_kmsg_init(void)
+{
+ int rc;
+
+ /* Add our dumper to the list */
+ rc = kmsg_dump_register(&opal_kmsg_dumper);
+ if (rc != 0)
+ pr_err("opal: kmsg_dump_register failed; returned %d\n", rc);
+}
diff --git a/arch/powerpc/platforms/powernv/opal-wrappers.S b/arch/powerpc/platforms/powernv/opal-wrappers.S
index b7a464fef7a7..e45b88a5d7e0 100644
--- a/arch/powerpc/platforms/powernv/opal-wrappers.S
+++ b/arch/powerpc/platforms/powernv/opal-wrappers.S
@@ -301,3 +301,4 @@ OPAL_CALL(opal_flash_erase, OPAL_FLASH_ERASE);
OPAL_CALL(opal_prd_msg, OPAL_PRD_MSG);
OPAL_CALL(opal_leds_get_ind, OPAL_LEDS_GET_INDICATOR);
OPAL_CALL(opal_leds_set_ind, OPAL_LEDS_SET_INDICATOR);
+OPAL_CALL(opal_console_flush, OPAL_CONSOLE_FLUSH);
diff --git a/arch/powerpc/platforms/powernv/opal.c b/arch/powerpc/platforms/powernv/opal.c
index aad0033d65d1..b349dd3e76ea 100644
--- a/arch/powerpc/platforms/powernv/opal.c
+++ b/arch/powerpc/platforms/powernv/opal.c
@@ -748,6 +748,9 @@ static int __init opal_init(void)
opal_pdev_init(opal_node, "ibm,opal-flash");
opal_pdev_init(opal_node, "ibm,opal-prd");
+ /* Initialise OPAL kmsg dumper for flushing console on panic */
+ opal_kmsg_init();
+
return 0;
}
machine_subsys_initcall(powernv, opal_init);