Merge tag 'driver-core-7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-coregrafted

Pull driver core fixes from Danilo Krummrich:

 - Fix kernfs listxattr() not returning security xattr names (e.g.
   SELinux labels) when the kernfs node has no allocated kernfs_iattrs

 - Fix silent truncation of IRQ vector indices in the Rust PCI
   abstractions

 - Don't select OF from DRIVER_PE_KUNIT_TEST; skip the test when OF is
   disabled instead of silently enabling extra kernel functionality

 - Russ Weight is retiring from kernel development; update the Firmware
   Loader sysfs contact to the driver-core mailing list, add a CREDITS
   entry for Firmware Upload, and update MAINTAINERS accordingly

* tag 'driver-core-7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core:
  MAINTAINERS: Remove Russ Weight from Firmware Loader
  CREDITS: Add CREDITS entry for Firmware Upload
  firmware_loader: Change contact for sysfs nodes
  rust: pci: reject IRQ vector indices that do not fit in u32
  kernfs: preserve security xattrs without allocating iattrs
  drivers: base: test: DRIVER_PE_KUNIT_TEST should not select OF

1 files changed, 95 insertions, 0 deletions

diff --git a/tools/perf/util/trigger.h b/tools/perf/util/trigger.h
new file mode 100644
index 000000000..33e997f9c
--- /dev/null
+++ b/tools/perf/util/trigger.h
@@ -0,0 +1,95 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __TRIGGER_H_
+#define __TRIGGER_H_ 1
+
+#include "asm/bug.h"
+
+/*
+ * Use trigger to model operations which need to be executed when
+ * an event (a signal, for example) is observed.
+ *
+ * States and transits:
+ *
+ *
+ *  OFF--> ON --> READY --(hit)--> HIT
+ *                 ^               |
+ *                 |            (ready)
+ *                 |               |
+ *                  \_____________/
+ *
+ * is_hit and is_ready are two key functions to query the state of
+ * a trigger. is_hit means the event already happen; is_ready means the
+ * trigger is waiting for the event.
+ */
+
+struct trigger {
+	volatile enum {
+		TRIGGER_ERROR		= -2,
+		TRIGGER_OFF		= -1,
+		TRIGGER_ON		= 0,
+		TRIGGER_READY		= 1,
+		TRIGGER_HIT		= 2,
+	} state;
+	const char *name;
+};
+
+#define TRIGGER_WARN_ONCE(t, exp) \
+	WARN_ONCE(t->state != exp, "trigger '%s' state transist error: %d in %s()\n", \
+		  t->name, t->state, __func__)
+
+static inline bool trigger_is_available(struct trigger *t)
+{
+	return t->state >= 0;
+}
+
+static inline bool trigger_is_error(struct trigger *t)
+{
+	return t->state <= TRIGGER_ERROR;
+}
+
+static inline void trigger_on(struct trigger *t)
+{
+	TRIGGER_WARN_ONCE(t, TRIGGER_OFF);
+	t->state = TRIGGER_ON;
+}
+
+static inline void trigger_ready(struct trigger *t)
+{
+	if (!trigger_is_available(t))
+		return;
+	t->state = TRIGGER_READY;
+}
+
+static inline void trigger_hit(struct trigger *t)
+{
+	if (!trigger_is_available(t))
+		return;
+	TRIGGER_WARN_ONCE(t, TRIGGER_READY);
+	t->state = TRIGGER_HIT;
+}
+
+static inline void trigger_off(struct trigger *t)
+{
+	if (!trigger_is_available(t))
+		return;
+	t->state = TRIGGER_OFF;
+}
+
+static inline void trigger_error(struct trigger *t)
+{
+	t->state = TRIGGER_ERROR;
+}
+
+static inline bool trigger_is_ready(struct trigger *t)
+{
+	return t->state == TRIGGER_READY;
+}
+
+static inline bool trigger_is_hit(struct trigger *t)
+{
+	return t->state == TRIGGER_HIT;
+}
+
+#define DEFINE_TRIGGER(n) \
+struct trigger n = {.state = TRIGGER_OFF, .name = #n}
+#endif