From 9fcb109218b1374a8caa3cac62e83fbedb1f7f2f Mon Sep 17 00:00:00 2001
From: Stewart Smith <stewart@linux.vnet.ibm.com>
Date: Fri, 18 Nov 2016 14:58:28 +1100
Subject: [PATCH] fsp: Don't recurse pollers in ibm_fsp_terminate

If we were to terminate in a poller, we'd call op_display() which
called pollers which hit the recursive poller warning, which ended
in not much fun at all.

This patch will skip the running of pollers and instead run
the FSP poller to set the op-panel display before attn.

Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
---
 hw/fsp/fsp-op-panel.c |  8 +++++++-
 hw/fsp/fsp.c          | 31 +++++++++++++++++++++++++++++++
 include/fsp.h         |  7 +++++++
 3 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/hw/fsp/fsp-op-panel.c b/hw/fsp/fsp-op-panel.c
index eb61e8d62623..7063cbb3a335 100644
--- a/hw/fsp/fsp-op-panel.c
+++ b/hw/fsp/fsp-op-panel.c
@@ -40,7 +40,13 @@ static void fsp_op_display_fatal(uint32_t w0, uint32_t w1)
 
 	fsp_fillmsg(&op_msg, FSP_CMD_DISP_SRC_DIRECT, 3, 1, w0, w1);
 
-	fsp_sync_msg(&op_msg, false);
+	/*
+	 * A special way to send a message: it doesn't run pollers.
+	 * This means we can call it while in a poller, which we may
+	 * well be in when we're terminating (and thus displaying a *fatal*
+	 * message on the op-panel).
+	 */
+	fsp_fatal_msg(&op_msg);
 }
 
 void op_display(enum op_severity sev, enum op_module mod, uint16_t code)
diff --git a/hw/fsp/fsp.c b/hw/fsp/fsp.c
index 58219a0aca57..c25e42c8b347 100644
--- a/hw/fsp/fsp.c
+++ b/hw/fsp/fsp.c
@@ -1689,6 +1689,7 @@ void fsp_interrupt(void)
 	unlock(&fsp_lock);
 }
 
+
 int fsp_sync_msg(struct fsp_msg *msg, bool autofree)
 {
 	int rc;
@@ -1977,6 +1978,36 @@ static void fsp_opal_poll(void *data __unused)
 	}
 }
 
+int fsp_fatal_msg(struct fsp_msg *msg)
+{
+	int rc = 0;
+
+	rc = fsp_queue_msg(msg, NULL);
+	if (rc)
+		return rc;
+
+	while(fsp_msg_busy(msg)) {
+		cpu_relax();
+		fsp_opal_poll(NULL);
+	}
+
+	switch(msg->state) {
+	case fsp_msg_done:
+		rc = 0;
+		break;
+	case fsp_msg_timeout:
+		rc = -1; /* XXX to improve */
+		break;
+	default:
+		rc = -1; /* Should not happen... (assert ?) */
+	}
+
+	if (msg->resp)
+		rc = (msg->resp->word1 >> 8) & 0xff;
+
+	return rc;
+}
+
 static bool fsp_init_one(const char *compat)
 {
 	struct dt_node *fsp_node;
diff --git a/include/fsp.h b/include/fsp.h
index 7ea162db0146..6142ca39a9f9 100644
--- a/include/fsp.h
+++ b/include/fsp.h
@@ -697,6 +697,13 @@ extern void fsp_cancelmsg(struct fsp_msg *msg);
 extern int fsp_queue_msg(struct fsp_msg *msg,
 			 void (*comp)(struct fsp_msg *msg)) __warn_unused_result;
 
+/* Send a fatal message to FSP
+ *
+ * This will *not* run pollers.
+ * Use only when attempting to get the word out about how we died.
+ */
+extern int fsp_fatal_msg(struct fsp_msg *msg);
+
 /* Synchronously send a command. If there's a response, the status is
  * returned as a positive number. A negative result means an error
  * sending the message.