git: 74bde725ad81 - main - linuxkpi: Add <linux/ref_tracker.h>

From: Jean-Sébastien Pédron <dumbbell_at_FreeBSD.org>
Date: Sat, 12 Apr 2025 10:35:55 UTC
The branch main has been updated by dumbbell:

URL: https://cgit.FreeBSD.org/src/commit/?id=74bde725ad81f457a9b4a04a98f1acac6b93e929

commit 74bde725ad81f457a9b4a04a98f1acac6b93e929
Author:     Jean-Sébastien Pédron <dumbbell@FreeBSD.org>
AuthorDate: 2025-02-24 21:04:34 +0000
Commit:     Jean-Sébastien Pédron <dumbbell@FreeBSD.org>
CommitDate: 2025-04-12 10:34:17 +0000

    linuxkpi: Add <linux/ref_tracker.h>
    
    This currently implements the empty stubs when `CONFIG_REF_TRACKER` is
    not defined.
    
    This is used by the i915 DRM driver starting with Linux 6.8.
    
    Reviewed by:    bz, emaste
    Sponsored by:   The FreeBSD Foundation
    Differential Revision: https://reviews.freebsd.org/D49376
---
 .../linuxkpi/common/include/linux/ref_tracker.h    | 93 ++++++++++++++++++++++
 1 file changed, 93 insertions(+)

diff --git a/sys/compat/linuxkpi/common/include/linux/ref_tracker.h b/sys/compat/linuxkpi/common/include/linux/ref_tracker.h
new file mode 100644
index 000000000000..fa510b2498e1
--- /dev/null
+++ b/sys/compat/linuxkpi/common/include/linux/ref_tracker.h
@@ -0,0 +1,93 @@
+/*-
+ * Copyright (c) 2025 The FreeBSD Foundation
+ * Copyright (c) 2025 Jean-Sébastien Pédron
+ *
+ * This software was developed by Jean-Sébastien Pédron under sponsorship
+ * from the FreeBSD Foundation.
+ *
+ * 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_REF_TRACKER_H_
+#define	_LINUXKPI_LINUX_REF_TRACKER_H_
+
+#include <linux/refcount.h>
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/stackdepot.h>
+
+struct ref_tracker;
+
+struct ref_tracker_dir {
+};
+
+/*
+ * The following functions currently have dummy implementations that, on Linux,
+ * are used when CONFIG_REF_TRACKER is not set at compile time.
+ *
+ * The ref tracker is a tool to associate a refcount increase to a refcount
+ * decrease. This helps developers track, document and debug refcounts. We
+ * don't need this feature for now in linuxkpi.
+ */
+
+static inline void
+ref_tracker_dir_init(struct ref_tracker_dir *dir,
+    unsigned int quarantine_count, const char *name)
+{
+}
+
+static inline void
+ref_tracker_dir_exit(struct ref_tracker_dir *dir)
+{
+}
+
+static inline void
+ref_tracker_dir_print_locked(struct ref_tracker_dir *dir,
+    unsigned int display_limit)
+{
+}
+
+static inline void
+ref_tracker_dir_print(struct ref_tracker_dir *dir, unsigned int display_limit)
+{
+}
+
+static inline int
+ref_tracker_dir_snprint(struct ref_tracker_dir *dir, char *buf, size_t size)
+{
+	return (0);
+}
+
+static inline int
+ref_tracker_alloc(struct ref_tracker_dir *dir, struct ref_tracker **trackerp,
+    gfp_t gfp)
+{
+	return (0);
+}
+
+static inline int
+ref_tracker_free(struct ref_tracker_dir *dir, struct ref_tracker **trackerp)
+{
+	return (0);
+}
+
+#endif /* !defined(_LINUXKPI_LINUX_REF_TRACKER_H_) */