[Skiboot] [BACKPORT PATCH 2/2] doc/opal-api: Add OPAL_CEC_REBOOT2 OPAL call description

[Mahesh J Salgaonkar]

From: Vipin K Parashar <vipin at linux.vnet.ibm.com>

This patch adds doc/opal-api/opal-cec-reboot-6-116.txt file
to add description for OPAL_CEC_REBOOT* OPAL call.

Signed-off-by: Vipin K Parashar <vipin at linux.vnet.ibm.com>
Signed-off-by: Mahesh Salgaonkar <mahesh at linux.vnet.ibm.com>
---
 doc/opal-api/opal-cec-reboot-6-116.txt |   54 ++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)
 create mode 100644 doc/opal-api/opal-cec-reboot-6-116.txt

diff --git a/doc/opal-api/opal-cec-reboot-6-116.txt b/doc/opal-api/opal-cec-reboot-6-116.txt
new file mode 100644
index 0000000..4d2b2ca
--- /dev/null
+++ b/doc/opal-api/opal-cec-reboot-6-116.txt
@@ -0,0 +1,54 @@
+OPAL_CEC_REBOOT and OPAL_CEC_REBOOT2
+------------------------------------
+
+#define OPAL_CEC_REBOOT		6
+#define OPAL_CEC_REBOOT2	116
+
+There are two opal calls to invoke system reboot.
+OPAL_CEC_REBOOT: Used for normal reboot by Linux host.
+
+OPAL_CEC_REBOOT2: Newly introduced to handle abnormal system reboots.
+The Linux kernel will make this OPAL call when it has to terminate
+abruptly due to an anomalous condition. The kernel will push some system
+state context to OPAL, which will in turn push it down to the BMC for
+further analysis.
+
+OPAL_CEC_REBOOT
+---------------
+Syntax:
+int64_t opal_cec_reboot(void)
+
+Input parameters:
+None.
+
+System reboots normally.
+
+OPAL_CEC_REBOOT2
+----------------
+Syntax:
+int64_t opal_cec_reboot2(uint32_t reboot_type, char *diag)
+
+Input parameters:
+	@reboot_type	Type of reboot. (see below)
+	@diag		Null-terminated string.
+
+Depending on reboot type, this call will carry out additional steps
+before triggering reboot.
+
+Supported reboot types:
+----------------------
+OPAL_REBOOT_NORMAL = 0
+	Behavior is as similar to that of opal_cec_reboot()
+
+OPAL_REBOOT_PLATFORM_ERROR = 1
+	Log an error to the BMC and then trigger a system checkstop, using
+	the information provided by 'ibm,sw-checkstop-fir' property in the
+	device-tree. Post the checkstop trigger, OCC/BMC will collect
+	relevant data for error analysis and trigger a reboot.
+
+	In absence of 'ibm,sw-checkstop-fir' device property, this function
+	will return with OPAL_UNSUPPORTED and no reboot will be triggered.
+
+Unsupported Reboot type
+	For unsupported reboot type, this function will return with
+	OPAL_UNSUPPORTED and no reboot will be triggered.