1 files changed, 93 insertions, 0 deletions
diff --git a/include/linux/kcov.h b/include/linux/kcov.h
new file mode 100644
index 000000000..55dc338f6
--- /dev/null
+++ b/include/linux/kcov.h
@@ -0,0 +1,93 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_KCOV_H
+#define _LINUX_KCOV_H
+
+#include <linux/sched.h>
+#include <uapi/linux/kcov.h>
+
+struct task_struct;
+
+#ifdef CONFIG_KCOV
+
+enum kcov_mode {
+	/* Coverage collection is not enabled yet. */
+	KCOV_MODE_DISABLED = 0,
+	/* KCOV was initialized, but tracing mode hasn't been chosen yet. */
+	KCOV_MODE_INIT = 1,
+	/*
+	 * Tracing coverage collection mode.
+	 * Covered PCs are collected in a per-task buffer.
+	 */
+	KCOV_MODE_TRACE_PC = 2,
+	/* Collecting comparison operands mode. */
+	KCOV_MODE_TRACE_CMP = 3,
+};
+
+#define KCOV_IN_CTXSW	(1 << 30)
+
+void kcov_task_init(struct task_struct *t);
+void kcov_task_exit(struct task_struct *t);
+
+#define kcov_prepare_switch(t)			\
+do {						\
+	(t)->kcov_mode |= KCOV_IN_CTXSW;	\
+} while (0)
+
+#define kcov_finish_switch(t)			\
+do {						\
+	(t)->kcov_mode &= ~KCOV_IN_CTXSW;	\
+} while (0)
+
+/* See Documentation/dev-tools/kcov.rst for usage details. */
+void kcov_remote_start(u64 handle);
+void kcov_remote_stop(void);
+u64 kcov_common_handle(void);
+
+static inline void kcov_remote_start_common(u64 id)
+{
+	kcov_remote_start(kcov_remote_handle(KCOV_SUBSYSTEM_COMMON, id));
+}
+
+static inline void kcov_remote_start_usb(u64 id)
+{
+	kcov_remote_start(kcov_remote_handle(KCOV_SUBSYSTEM_USB, id));
+}
+
+/*
+ * The softirq flavor of kcov_remote_*() functions is introduced as a temporary
+ * work around for kcov's lack of nested remote coverage sections support in
+ * task context. Adding suport for nested sections is tracked in:
+ * https://bugzilla.kernel.org/show_bug.cgi?id=210337
+ */
+
+static inline void kcov_remote_start_usb_softirq(u64 id)
+{
+	if (in_serving_softirq())
+		kcov_remote_start_usb(id);
+}
+
+static inline void kcov_remote_stop_softirq(void)
+{
+	if (in_serving_softirq())
+		kcov_remote_stop();
+}
+
+#else
+
+static inline void kcov_task_init(struct task_struct *t) {}
+static inline void kcov_task_exit(struct task_struct *t) {}
+static inline void kcov_prepare_switch(struct task_struct *t) {}
+static inline void kcov_finish_switch(struct task_struct *t) {}
+static inline void kcov_remote_start(u64 handle) {}
+static inline void kcov_remote_stop(void) {}
+static inline u64 kcov_common_handle(void)
+{
+	return 0;
+}
+static inline void kcov_remote_start_common(u64 id) {}
+static inline void kcov_remote_start_usb(u64 id) {}
+static inline void kcov_remote_start_usb_softirq(u64 id) {}
+static inline void kcov_remote_stop_softirq(void) {}
+
+#endif /* CONFIG_KCOV */
+#endif /* _LINUX_KCOV_H */