git: 9342ec5077f4 - stable/13 - LinuxKPI: add read_poll_timeout()

The branch stable/13 has been updated by bz:

URL: https://cgit.FreeBSD.org/src/commit/?id=9342ec5077f4e198394ec8648a3834524c684d6d

commit 9342ec5077f4e198394ec8648a3834524c684d6d
Author:     Bjoern A. Zeeb <bz@FreeBSD.org>
AuthorDate: 2021-07-01 13:29:49 +0000
Commit:     Bjoern A. Zeeb <bz@FreeBSD.org>
CommitDate: 2021-11-19 00:01:23 +0000

    LinuxKPI: add read_poll_timeout()
    
    Add an implementation of read_poll_timeout() and the atomic variant
    which I did at some point last year for rtw88 and now updated based
    on feedback.
    
    (cherry picked from commit fed248a6acb33cf6d51880be8d5c774d89e75110)
---
 sys/compat/linuxkpi/common/include/linux/iopoll.h | 91 +++++++++++++++++++++++
 1 file changed, 91 insertions(+)

diff --git a/sys/compat/linuxkpi/common/include/linux/iopoll.h b/sys/compat/linuxkpi/common/include/linux/iopoll.h
new file mode 100644
index 000000000000..ea876042eab6
--- /dev/null
+++ b/sys/compat/linuxkpi/common/include/linux/iopoll.h
@@ -0,0 +1,91 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2020-2021 Bjoern A. Zeeb
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef	__LINUXKPI_LINUX_IOPOLL_H
+#define	__LINUXKPI_LINUX_IOPOLL_H
+
+#include <sys/types.h>
+#include <sys/time.h>
+#include <linux/delay.h>
+
+#define	read_poll_timeout(_pollfp, _var, _cond, _us, _to, _early_sleep, ...)	\
+({										\
+	struct timeval __now, __end;						\
+	if (_to) {								\
+		__end.tv_sec = (_to) / USEC_PER_SEC;				\
+		__end.tv_usec = (_to) % USEC_PER_SEC;				\
+		microtime(&__now);						\
+		timevaladd(&__end, &__now);					\
+	}									\
+										\
+	if ((_early_sleep) && (_us) > 0)					\
+		usleep_range(_us, _us);						\
+	do {									\
+		(_var) = _pollfp(__VA_ARGS__);					\
+		if (_cond)							\
+			break;							\
+		if (_to) {							\
+			microtime(&__now);					\
+			if (timevalcmp(&__now, &__end, >))			\
+				break;						\
+		}								\
+		if ((_us) != 0)							\
+			usleep_range(_us, _us);					\
+	} while (1);								\
+	(_cond) ? 0 : (-ETIMEDOUT);						\
+})
+
+#define	read_poll_timeout_atomic(_pollfp, _var, _cond, _us, _to, _early_sleep, ...)	\
+({										\
+	struct timeval __now, __end;						\
+	if (_to) {								\
+		__end.tv_sec = (_to) / USEC_PER_SEC;				\
+		__end.tv_usec = (_to) % USEC_PER_SEC;				\
+		microtime(&__now);						\
+		timevaladd(&__end, &__now);					\
+	}									\
+										\
+	if ((_early_sleep) && (_us) > 0)					\
+		DELAY(_us);							\
+	do {									\
+		(_var) = _pollfp(__VA_ARGS__);					\
+		if (_cond)							\
+			break;							\
+		if (_to) {							\
+			microtime(&__now);					\
+			if (timevalcmp(&__now, &__end, >))			\
+				break;						\
+		}								\
+		if ((_us) != 0)							\
+			DELAY(_us);						\
+	} while (1);								\
+	(_cond) ? 0 : (-ETIMEDOUT);						\
+})
+
+#endif	/* __LINUXKPI_LINUX_IOPOLL_H */