coresight: abort coresight tracing on kernel crash

Add trace events to control aborting CoreSight trace
dynamically based on module parameter.
Coresight driver will dump any trace present in the current sink
in case we hit a kernel panic, user fault or an undefined instruction.

Change-Id: Iee1ccf5cbd7b767753a3115c0570e63fbe2aa8f3
Signed-off-by: Satyajit Desai <sadesai@codeaurora.org>

2 files changed, 128 insertions, 0 deletions

diff --git a/include/linux/coresight.h b/include/linux/coresight.h
index 903a8e852f5d..66bf56640fe1 100644
--- a/include/linux/coresight.h
+++ b/include/linux/coresight.h
@@ -194,10 +194,12 @@ struct coresight_device {
  * Operations available for sinks
  * @enable:	enables the sink.
  * @disable:	disables the sink.
+ * @abort:	captures sink trace on abort
  */
 struct coresight_ops_sink {
 	int (*enable)(struct coresight_device *csdev);
 	void (*disable)(struct coresight_device *csdev);
+	void (*abort)(struct coresight_device *csdev);
 };
 
 /**
@@ -239,6 +241,7 @@ extern int coresight_enable(struct coresight_device *csdev);
 extern void coresight_disable(struct coresight_device *csdev);
 extern int coresight_timeout(void __iomem *addr, u32 offset,
 			     int position, int value);
+extern void coresight_abort(void);
 #else
 static inline struct coresight_device *
 coresight_register(struct coresight_desc *desc) { return NULL; }
@@ -248,6 +251,7 @@ coresight_enable(struct coresight_device *csdev) { return -ENOSYS; }
 static inline void coresight_disable(struct coresight_device *csdev) {}
 static inline int coresight_timeout(void __iomem *addr, u32 offset,
 				     int position, int value) { return 1; }
+static inline void coresight_abort(void) {}
 #endif
 
 #if defined(CONFIG_OF) && defined(CONFIG_CORESIGHT)
diff --git a/include/trace/events/exception.h b/include/trace/events/exception.h
new file mode 100644
index 000000000000..6b525da1432e
--- /dev/null
+++ b/include/trace/events/exception.h
@@ -0,0 +1,124 @@
+/* Copyright (c) 2012-2016, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM exception
+
+#if !defined(_TRACE_EXCEPTION_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_EXCEPTION_H
+
+#include <linux/tracepoint.h>
+
+struct task_struct;
+
+TRACE_EVENT(user_fault,
+
+	TP_PROTO(struct task_struct *tsk, unsigned long addr, unsigned int fsr),
+
+	TP_ARGS(tsk, addr, fsr),
+
+	TP_STRUCT__entry(
+		__string(task_name, tsk->comm)
+		__field(unsigned long, addr)
+		__field(unsigned int, fsr)
+	),
+
+	TP_fast_assign(
+	__assign_str(task_name, tsk->comm)
+		__entry->addr	= addr;
+		__entry->fsr	= fsr;
+	),
+
+	TP_printk("task_name:%s addr:%lu, fsr:%u", __get_str(task_name),
+		__entry->addr, __entry->fsr)
+);
+
+
+struct pt_regs;
+
+TRACE_EVENT(undef_instr,
+
+	TP_PROTO(struct pt_regs *regs, void *prog_cnt),
+
+	TP_ARGS(regs, prog_cnt),
+
+	TP_STRUCT__entry(
+		__field(void *, prog_cnt)
+		__field(struct pt_regs *, regs)
+	),
+
+	TP_fast_assign(
+		__entry->regs		= regs;
+		__entry->prog_cnt	= prog_cnt;
+	),
+
+	TP_printk("pc:%p", __entry->prog_cnt)
+);
+
+TRACE_EVENT(unhandled_abort,
+
+	TP_PROTO(struct pt_regs *regs, unsigned long addr, unsigned int fsr),
+
+	TP_ARGS(regs, addr, fsr),
+
+	TP_STRUCT__entry(
+		__field(struct pt_regs *, regs)
+		__field(unsigned long, addr)
+		__field(unsigned int, fsr)
+	),
+
+	TP_fast_assign(
+		__entry->regs	= regs;
+		__entry->addr	= addr;
+		__entry->fsr	= fsr;
+	),
+
+	TP_printk("addr:%lu, fsr:%u", __entry->addr, __entry->fsr)
+);
+
+TRACE_EVENT(kernel_panic,
+
+	TP_PROTO(long dummy),
+
+	TP_ARGS(dummy),
+
+	TP_STRUCT__entry(
+		__field(long, dummy)
+	),
+
+	TP_fast_assign(
+		__entry->dummy	= dummy;
+	),
+
+	TP_printk("dummy:%ld", __entry->dummy)
+);
+
+TRACE_EVENT(kernel_panic_late,
+
+	TP_PROTO(long dummy),
+
+	TP_ARGS(dummy),
+
+	TP_STRUCT__entry(
+		__field(long, dummy)
+	),
+
+	TP_fast_assign(
+		__entry->dummy	= dummy;
+	),
+
+	TP_printk("dummy:%ld", __entry->dummy)
+);
+
+#endif
+
+#include <trace/define_trace.h>