git: 6d8dc6c97157 - stable/13 - linuxkpi: Add circ_buf.h

The branch stable/13 has been updated by manu:

URL: https://cgit.FreeBSD.org/src/commit/?id=6d8dc6c9715700c9281c9f0eac763ffc346e8477

commit 6d8dc6c9715700c9281c9f0eac763ffc346e8477
Author:     Emmanuel Vadot <manu@FreeBSD.org>
AuthorDate: 2022-06-23 07:46:03 +0000
Commit:     Emmanuel Vadot <manu@FreeBSD.org>
CommitDate: 2022-09-07 15:09:02 +0000

    linuxkpi: Add circ_buf.h
    
    Provide macros needed for drm-kmod.
    
    Reviewed by:    bz
    MFC after:      1 week
    Sponsored by:   Beckhoff Automation GmbH & Co. KG
    Differential Revision:  https://reviews.freebsd.org/D35561
    
    (cherry picked from commit 7674baeb37870b05539a0214c99ce55d9f199fb0)
---
 .../linuxkpi/common/include/linux/circ_buf.h       | 34 ++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/sys/compat/linuxkpi/common/include/linux/circ_buf.h b/sys/compat/linuxkpi/common/include/linux/circ_buf.h
new file mode 100644
index 000000000000..53d7fa736ef8
--- /dev/null
+++ b/sys/compat/linuxkpi/common/include/linux/circ_buf.h
@@ -0,0 +1,34 @@
+/*-
+ * Copyright (c) 2022 Beckhoff Automation GmbH & Co. KG
+ *
+ * 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.
+ *
+ */
+
+#ifndef _LINUXKPI_LINUX_CIRC_BUF_H_
+#define	_LINUXKPI_LINUX_CIRC_BUF_H_
+
+#define CIRC_CNT(head,tail,size)	(((head) - (tail)) & ((size) - 1))
+#define CIRC_SPACE(head,tail,size)	CIRC_CNT((tail),((head) + 1),(size))
+
+#endif	/* _LINUXKPI_LINUX_CIRC_BUF_H_ */
+