New patch to review for coreboot: f276ba0 add poll-with-timeout macro

[Patrick Georgi]

Patrick Georgi ([e-mail]) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/6494

-gerrit

commit f276ba0d64bdf23efbe92af1e4b487db0f8ec8bf
Author: Patrick Georgi 
Date:   Mon Aug 4 18:49:52 2014 +0200

add poll-with-timeout macro

A new poll.h provides a macro to wait for a certain event
    to happen with a timeout.

Use: POLL(statement, expected value, max time in usecs)

Change-Id: Icbb57a47d8ca1cff504f01954c0693fb60b77656
    Signed-off-by: Patrick Georgi 
---
 src/include/poll.h | 45 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 45 insertions(+)

diff --git a/src/include/poll.h b/src/include/poll.h
new file mode 100644
index 0000000..1084731
--- /dev/null
+++ b/src/include/poll.h
@@ -0,0 +1,45 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright 2013 Google Inc.
+ *           2014 Patrick Georgi
+ *
+ * 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; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef _POLL_H_
+#define _POLL_H_
+
+#include <delay.h>
+
+#define POLL_DELAY 100 /* 100us */
+
+#define POLL(insn, exp_val, timeout) \
+	({\
+	u64 _try, _value; \
+	u64 _timeout = (timeout); \
+	u64 _exp_val = (exp_val); \
+	for (_try = 0; _try < (_timeout); _try += POLL_DELAY) { \
+		_value = insn; \
+		if (_value == _exp_val) \
+			break; \
+		udelay(POLL_DELAY); \
+	} \
+	if (_try >= _timeout) \
+		printk(BIOS_WARNING, "%s: POLL timeout waiting for " #insn \
+			" to return 0x%llx, got 0x%llx\n", \
+			__func__, _exp_val, _value); \
+	})
+
+#endif