git: 995c3b88d485 - main - linuxkpi: Add mmap_lock.h

The branch main has been updated by manu:

URL: https://cgit.FreeBSD.org/src/commit/?id=995c3b88d485b9b64ab94efe270d424b2526ade7

commit 995c3b88d485b9b64ab94efe270d424b2526ade7
Author:     Emmanuel Vadot <manu@FreeBSD.org>
AuthorDate: 2022-02-16 10:26:14 +0000
Commit:     Emmanuel Vadot <manu@FreeBSD.org>
CommitDate: 2022-02-17 08:31:51 +0000

    linuxkpi: Add mmap_lock.h
    
    This contain mmap_read_lock, mmap_read_unlock and mmap_write_lock_killable
    which are abstraction around down_read, up_read and down_write_killable.
    Note that in Linux 5.8 mmap_sem was renamed to mmap_lock.
    We might want to do the same at some point but some drivers still uses
    the old mmap locking API.
    
    Reviewed by:    bz
    MFC after:      2 weeks
    Sponsored by:   Beckhoff Automation GmbH & Co. KG
    Differential Revision:  https://reviews.freebsd.org/D34297
---
 sys/compat/linuxkpi/common/include/linux/mm.h      |  1 +
 .../linuxkpi/common/include/linux/mm_types.h       |  1 +
 .../linuxkpi/common/include/linux/mmap_lock.h      | 54 ++++++++++++++++++++++
 3 files changed, 56 insertions(+)

diff --git a/sys/compat/linuxkpi/common/include/linux/mm.h b/sys/compat/linuxkpi/common/include/linux/mm.h
index bb230b4fbbe9..5a16cf0d0a58 100644
--- a/sys/compat/linuxkpi/common/include/linux/mm.h
+++ b/sys/compat/linuxkpi/common/include/linux/mm.h
@@ -39,6 +39,7 @@
 #include <linux/mm_types.h>
 #include <linux/pfn.h>
 #include <linux/list.h>
+#include <linux/mmap_lock.h>
 
 #include <asm/pgtable.h>
 
diff --git a/sys/compat/linuxkpi/common/include/linux/mm_types.h b/sys/compat/linuxkpi/common/include/linux/mm_types.h
index a59c1e535b45..2a7b33d15054 100644
--- a/sys/compat/linuxkpi/common/include/linux/mm_types.h
+++ b/sys/compat/linuxkpi/common/include/linux/mm_types.h
@@ -45,6 +45,7 @@ struct mm_struct {
 	atomic_t mm_count;
 	atomic_t mm_users;
 	size_t pinned_vm;
+	/* Renamed to mmap_lock in v5.8 */
 	struct rw_semaphore mmap_sem;
 };
 
diff --git a/sys/compat/linuxkpi/common/include/linux/mmap_lock.h b/sys/compat/linuxkpi/common/include/linux/mmap_lock.h
new file mode 100644
index 000000000000..de6b2a029b1f
--- /dev/null
+++ b/sys/compat/linuxkpi/common/include/linux/mmap_lock.h
@@ -0,0 +1,54 @@
+/*-
+ * 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_MMAP_LOCK_H_
+#define	_LINUXKPI_LINUX_MMAP_LOCK_H_
+
+#include <linux/mm_types.h>
+#include <linux/rwsem.h>
+
+static inline void
+mmap_read_lock(struct mm_struct *mm)
+{
+
+	down_read(&mm->mmap_sem);
+}
+
+static inline void
+mmap_read_unlock(struct mm_struct *mm)
+{
+
+	up_read(&mm->mmap_sem);
+}
+
+static inline void
+mmap_write_lock_killable(struct mm_struct *mm)
+{
+
+	down_write_killable(&mm->mmap_sem);
+}
+
+#endif	/* _LINUXKPI_LINUX_MMAP_LOCK_H_ */