git: a609ed795943 - main - linuxkpi: Define `synchronize_hardirq()`

The branch main has been updated by dumbbell (ports committer):

URL: https://cgit.FreeBSD.org/src/commit/?id=a609ed795943673074b71aeafafabe46d08f1a6d

commit a609ed795943673074b71aeafafabe46d08f1a6d
Author:     Jean-Sébastien Pédron <dumbbell@FreeBSD.org>
AuthorDate: 2023-01-11 00:27:40 +0000
Commit:     Jean-Sébastien Pédron <dumbbell@FreeBSD.org>
CommitDate: 2023-01-25 21:26:53 +0000

    linuxkpi: Define `synchronize_hardirq()`
    
    It currently does the same as `synchronize_irq()`.
    
    Reviewed by:    manu
    Approved by:    manu
    Differential Revision:  https://reviews.freebsd.org/D38079
---
 sys/compat/linuxkpi/common/include/linux/hardirq.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/sys/compat/linuxkpi/common/include/linux/hardirq.h b/sys/compat/linuxkpi/common/include/linux/hardirq.h
index 07f00f076860..9e7baec1b213 100644
--- a/sys/compat/linuxkpi/common/include/linux/hardirq.h
+++ b/sys/compat/linuxkpi/common/include/linux/hardirq.h
@@ -40,4 +40,14 @@
 
 #define	synchronize_irq(irq)	_intr_drain((irq))
 
+/*
+ * FIXME: In the i915 driver's `intel_engine_cs.c` file,
+ * `synchronize_hardirq()` was replaced by `synchronize_rcu()` with the
+ * following comment:
+ *   "Is it enough to wait that all cpu have context-switched?"
+ *
+ * See commit f6d50b7af554e21c380486d6f41c8537b265c777 in drm-kmod.
+ */
+#define	synchronize_hardirq(irq) _intr_drain((irq))
+
 #endif	/* _LINUXKPI_LINUX_HARDIRQ_H_ */