git: 37e07609505e - stable/13 - linuxkpi: Add refcount_dec_and_test

The branch stable/13 has been updated by manu:

URL: https://cgit.FreeBSD.org/src/commit/?id=37e07609505e869831753bc7b25976c09bc3b52a

commit 37e07609505e869831753bc7b25976c09bc3b52a
Author:     Emmanuel Vadot <manu@FreeBSD.org>
AuthorDate: 2022-08-09 09:03:34 +0000
Commit:     Emmanuel Vadot <manu@FreeBSD.org>
CommitDate: 2022-09-07 15:09:05 +0000

    linuxkpi: Add refcount_dec_and_test
    
    In Linux this takes a refcount_t argument but in linuxkpi struct kref
    uses an atomic_t for the refcount and code in drm directly uses this
    function with a kref so use an atomic_t here.
    
    Reviewed by:    bz
    Sponsored by:   Beckhoff Automation GmbH & Co. KG
    Differential Revision:  https://reviews.freebsd.org/D36099
    
    (cherry picked from commit 1a6874e3a411c7876bee55bc631119a2e1cd09a2)
---
 sys/compat/linuxkpi/common/include/linux/kref.h     |  1 +
 sys/compat/linuxkpi/common/include/linux/refcount.h | 11 +++++++++++
 2 files changed, 12 insertions(+)

diff --git a/sys/compat/linuxkpi/common/include/linux/kref.h b/sys/compat/linuxkpi/common/include/linux/kref.h
index 2c59794f4ddc..3b5645bf139b 100644
--- a/sys/compat/linuxkpi/common/include/linux/kref.h
+++ b/sys/compat/linuxkpi/common/include/linux/kref.h
@@ -43,6 +43,7 @@
 #include <asm/atomic.h>
 
 struct kref {
+	/* XXX In Linux this is a refcount_t */
 	atomic_t refcount;
 };
 
diff --git a/sys/compat/linuxkpi/common/include/linux/refcount.h b/sys/compat/linuxkpi/common/include/linux/refcount.h
index 7c055fb32029..6a49da530c0a 100644
--- a/sys/compat/linuxkpi/common/include/linux/refcount.h
+++ b/sys/compat/linuxkpi/common/include/linux/refcount.h
@@ -79,4 +79,15 @@ refcount_dec_and_lock_irqsave(refcount_t *ref, spinlock_t *lock,
 	return (false);
 }
 
+/*
+ * struct kref uses atomic_t and not refcount_t so
+ * we differ from Linux here.
+ */
+static inline bool
+refcount_dec_and_test(atomic_t *r)
+{
+
+	return (atomic_dec_and_test(r));
+}
+
 #endif /* __LINUXKPI_LINUX_REFCOUNT_H__ */