PCI: trace: Add PCI controller tracepoint feature

Some PCI controllers may provide debug functionalities to track PCI bus
activities like LTSSM state transitions and data rate changes. These will
be very useful for debugging PCI link specific issues such as endpoint not
getting detected or performance issues.

Hence, implement the PCI controller tracepoint feature for recording LTSSM
state transitions and data rate changes.

Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com>
[mani: commit log and maintainers entry]
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Tested-by: Anand Moon <linux.amoon@gmail.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://patch.msgid.link/1774403912-210670-2-git-send-email-shawn.lin@rock-chips.com

diff --git a/MAINTAINERS b/MAINTAINERS
index 55af015174a54e17cc7449e5a80b6cdc83aa6fde..b5a83f0b4211230dab828387bb53c1a11b2e5c83 100644 (file)
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -20399,6 +20399,7 @@ F:      Documentation/devicetree/bindings/pci/
 F:     drivers/pci/controller/
 F:     drivers/pci/pci-bridge-emul.c
 F:     drivers/pci/pci-bridge-emul.h
+F:     include/trace/events/pci_controller.h
 
 PCI PEER-TO-PEER DMA (P2PDMA)
 M:     Bjorn Helgaas <bhelgaas@google.com>

diff --git a/drivers/pci/trace.c b/drivers/pci/trace.c
index cf11abca8602f11b24cc57c75197d91e58e0e8f5..c1da9d3d39d64d1934a56e1150de7ff078c584f9 100644 (file)
--- 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 (file)
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>