[PATCH v5 1/3] PCI: trace: Add PCI controller LTSSM transition tracepoint

[Shawn Lin <shawn.lin@rock-chips.com>]

Some platforms may provide LTSSM trace functionality, recording historical
LTSSM state transition information. This is very useful for debugging, such
as when certain devices cannot be recognized or link broken during test.
Implement the pci controller tracepoint for recording LTSSM and rate.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
---

Changes in v5:
- use EM/EMe instead
- remove reg/unreg function and back to use TRACE_EVENT

Changes in v4:
- use TRACE_EVENT_FN to notify when to start and stop the tracepoint,
  and export pci_ltssm_tp_enabled() for host drivers to use

Changes in v3:
- add TRACE_DEFINE_ENUM for all enums(Steven Rostedt)

Changes in v2: None

 drivers/pci/trace.c                   |  1 +
 include/trace/events/pci_controller.h | 58 +++++++++++++++++++++++++++++++++++
 2 files changed, 59 insertions(+)
 create mode 100644 include/trace/events/pci_controller.h

diff --git a/drivers/pci/trace.c b/drivers/pci/trace.c
index cf11abc..c1da9d3 100644
--- a/drivers/pci/trace.c
+++ b/drivers/pci/trace.c
@@ -9,3 +9,4 @@
 
 #define CREATE_TRACE_POINTS
 #include <trace/events/pci.h>
+#include <trace/events/pci_controller.h>
diff --git a/include/trace/events/pci_controller.h b/include/trace/events/pci_controller.h
new file mode 100644
index 0000000..a4b387c
--- /dev/null
+++ b/include/trace/events/pci_controller.h
@@ -0,0 +1,58 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM pci_controller
+
+#if !defined(_TRACE_HW_EVENT_PCI_CONTROLLER_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_HW_EVENT_PCI_CONTROLLER_H
+
+#include <uapi/linux/pci_regs.h>
+#include <linux/tracepoint.h>
+
+#define RATE					\
+	EM(PCIE_SPEED_2_5GT,  "2.5 GT/s")	\
+	EM(PCIE_SPEED_5_0GT,  "5.0 GT/s")	\
+	EM(PCIE_SPEED_8_0GT,  "8.0 GT/s")	\
+	EM(PCIE_SPEED_16_0GT, "16.0 GT/s")	\
+	EM(PCIE_SPEED_32_0GT, "32.0 GT/s")	\
+	EM(PCIE_SPEED_64_0GT, "64.0 GT/s")	\
+	EMe(PCI_SPEED_UNKNOWN, "Unknown")
+
+
+#undef EM
+#undef EMe
+#define EM(a, b)	TRACE_DEFINE_ENUM(a);
+#define EMe(a, b)	TRACE_DEFINE_ENUM(a);
+
+RATE
+
+#undef EM
+#undef EMe
+#define EM(a, b)	{a, b},
+#define EMe(a, b)	{a, b}
+
+TRACE_EVENT(pcie_ltssm_state_transition,
+	TP_PROTO(const char *dev_name, const char *state, u32 rate),
+	TP_ARGS(dev_name, state, rate),
+
+	TP_STRUCT__entry(
+		__string(dev_name, dev_name)
+		__string(state, state)
+		__field(u32, rate)
+	),
+
+	TP_fast_assign(
+		__assign_str(dev_name);
+		__assign_str(state);
+		__entry->rate = rate;
+	),
+
+	TP_printk("dev: %s state: %s rate: %s",
+		__get_str(dev_name), __get_str(state),
+		__print_symbolic(__entry->rate, RATE)
+	)
+);
+
+#endif /* _TRACE_HW_EVENT_PCI_CONTROLLER_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>
-- 
2.7.4