[PATCH v2] bus: mhi: host: Add tracing support

[Krishna chaitanya chundru]

This change adds ftrace support for following functions which
helps in debugging the issues when there is Channel state & MHI
state change and also when we receive data and control events:
1. mhi_intvec_threaded_handler
2. mhi_process_data_event_ring
3. mhi_process_ctrl_ev_ring
4. mhi_gen_tre
5. mhi_update_channel_state
6. mhi_tryset_pm_state
7. mhi_pm_st_worker

Signed-off-by: Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx>
---
Changes in v2:
- Passing the raw state into the trace event and using  __print_symbolic() as suggested by bjorn.
- Change mhi_pm_st_worker to mhi_pm_st_transition as suggested by bjorn.
- Fixed the kernel test rebot issues.
- Link to v1: https://lore.kernel.org/r/20231005-ftrace_support-v1-1-23a2f394fa49@xxxxxxxxxxx
---
 MAINTAINERS                     |   1 +
 drivers/bus/mhi/host/init.c     |   3 +
 drivers/bus/mhi/host/internal.h |   1 +
 drivers/bus/mhi/host/main.c     |  32 +++--
 drivers/bus/mhi/host/pm.c       |   6 +-
 include/trace/events/mhi_host.h | 287 ++++++++++++++++++++++++++++++++++++++++
 6 files changed, 317 insertions(+), 13 deletions(-)

diff --git a/MAINTAINERS b/MAINTAINERS
index 35977b269d5e..4339c668a6ab 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13862,6 +13862,7 @@ F:	Documentation/mhi/
 F:	drivers/bus/mhi/
 F:	drivers/pci/endpoint/functions/pci-epf-mhi.c
 F:	include/linux/mhi.h
+F:	include/trace/events/mhi_host.h
 
 MICROBLAZE ARCHITECTURE
 M:	Michal Simek <monstr@xxxxxxxxx>
diff --git a/drivers/bus/mhi/host/init.c b/drivers/bus/mhi/host/init.c
index f78aefd2d7a3..3afa90a204fd 100644
--- a/drivers/bus/mhi/host/init.c
+++ b/drivers/bus/mhi/host/init.c
@@ -20,6 +20,9 @@
 #include <linux/wait.h>
 #include "internal.h"
 
+#define CREATE_TRACE_POINTS
+#include <trace/events/mhi_host.h>
+
 static DEFINE_IDA(mhi_controller_ida);
 
 const char * const mhi_ee_str[MHI_EE_MAX] = {
diff --git a/drivers/bus/mhi/host/internal.h b/drivers/bus/mhi/host/internal.h
index 2e139e76de4c..a80a317a59a9 100644
--- a/drivers/bus/mhi/host/internal.h
+++ b/drivers/bus/mhi/host/internal.h
@@ -7,6 +7,7 @@
 #ifndef _MHI_INT_H
 #define _MHI_INT_H
 
+#include <trace/events/mhi_host.h>
 #include "../common.h"
 
 extern struct bus_type mhi_bus_type;
diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c
index dcf627b36e82..fcdb728ba49f 100644
--- a/drivers/bus/mhi/host/main.c
+++ b/drivers/bus/mhi/host/main.c
@@ -246,6 +246,11 @@ static void *mhi_to_virtual(struct mhi_ring *ring, dma_addr_t addr)
 	return (addr - ring->iommu_base) + ring->base;
 }
 
+dma_addr_t mhi_to_physical(struct mhi_ring *ring, void *addr)
+{
+	return (addr - ring->base) + ring->iommu_base;
+}
+
 static void mhi_add_ring_element(struct mhi_controller *mhi_cntrl,
 				 struct mhi_ring *ring)
 {
@@ -491,11 +496,9 @@ irqreturn_t mhi_intvec_threaded_handler(int irq_number, void *priv)
 
 	state = mhi_get_mhi_state(mhi_cntrl);
 	ee = mhi_get_exec_env(mhi_cntrl);
-	dev_dbg(dev, "local ee: %s state: %s device ee: %s state: %s\n",
-		TO_MHI_EXEC_STR(mhi_cntrl->ee),
-		mhi_state_str(mhi_cntrl->dev_state),
-		TO_MHI_EXEC_STR(ee), mhi_state_str(state));
 
+	trace_mhi_intvec_threaded_handler(mhi_cntrl->mhi_dev->name, mhi_cntrl->ee,
+					  mhi_cntrl->dev_state, ee, state);
 	if (state == MHI_STATE_SYS_ERR) {
 		dev_dbg(dev, "System error detected\n");
 		pm_state = mhi_tryset_pm_state(mhi_cntrl,
@@ -832,6 +835,12 @@ int mhi_process_ctrl_ev_ring(struct mhi_controller *mhi_cntrl,
 	while (dev_rp != local_rp) {
 		enum mhi_pkt_type type = MHI_TRE_GET_EV_TYPE(local_rp);
 
+		trace_mhi_process_ctrl_ev_ring(mhi_cntrl->mhi_dev->name,
+					       mhi_to_physical(ev_ring, local_rp),
+					       local_rp->ptr, local_rp->dword[0],
+					       local_rp->dword[1],
+					       MHI_TRE_GET_EV_STATE(local_rp));
+
 		switch (type) {
 		case MHI_PKT_TYPE_BW_REQ_EVENT:
 		{
@@ -997,6 +1006,9 @@ int mhi_process_data_event_ring(struct mhi_controller *mhi_cntrl,
 	while (dev_rp != local_rp && event_quota > 0) {
 		enum mhi_pkt_type type = MHI_TRE_GET_EV_TYPE(local_rp);
 
+		trace_mhi_process_data_event_ring(mhi_cntrl->mhi_dev->name, local_rp->ptr,
+						  local_rp->dword[0], local_rp->dword[1]);
+
 		chan = MHI_TRE_GET_EV_CHID(local_rp);
 
 		WARN_ON(chan >= mhi_cntrl->max_chan);
@@ -1235,6 +1247,9 @@ int mhi_gen_tre(struct mhi_controller *mhi_cntrl, struct mhi_chan *mhi_chan,
 	mhi_tre->dword[0] = MHI_TRE_DATA_DWORD0(info->len);
 	mhi_tre->dword[1] = MHI_TRE_DATA_DWORD1(bei, eot, eob, chain);
 
+	trace_mhi_gen_tre(mhi_cntrl->mhi_dev->name, mhi_chan->chan,
+			  mhi_to_physical(tre_ring, mhi_tre),
+			  mhi_tre->ptr, mhi_tre->dword[0], mhi_tre->dword[1]);
 	/* increment WP */
 	mhi_add_ring_element(mhi_cntrl, tre_ring);
 	mhi_add_ring_element(mhi_cntrl, buf_ring);
@@ -1327,9 +1342,8 @@ static int mhi_update_channel_state(struct mhi_controller *mhi_cntrl,
 	enum mhi_cmd_type cmd = MHI_CMD_NOP;
 	int ret;
 
-	dev_dbg(dev, "%d: Updating channel state to: %s\n", mhi_chan->chan,
-		TO_CH_STATE_TYPE_STR(to_state));
-
+	trace_mhi_update_channel_state_start(mhi_cntrl->mhi_dev->name, mhi_chan->chan,
+					     to_state);
 	switch (to_state) {
 	case MHI_CH_STATE_TYPE_RESET:
 		write_lock_irq(&mhi_chan->lock);
@@ -1396,9 +1410,7 @@ static int mhi_update_channel_state(struct mhi_controller *mhi_cntrl,
 		write_unlock_irq(&mhi_chan->lock);
 	}
 
-	dev_dbg(dev, "%d: Channel state change to %s successful\n",
-		mhi_chan->chan, TO_CH_STATE_TYPE_STR(to_state));
-
+	trace_mhi_update_channel_state_end(mhi_cntrl->mhi_dev->name, mhi_chan->chan, to_state);
 exit_channel_update:
 	mhi_cntrl->runtime_put(mhi_cntrl);
 	mhi_device_put(mhi_cntrl->mhi_dev);
diff --git a/drivers/bus/mhi/host/pm.c b/drivers/bus/mhi/host/pm.c
index 8a4362d75fc4..e32afdc92fde 100644
--- a/drivers/bus/mhi/host/pm.c
+++ b/drivers/bus/mhi/host/pm.c
@@ -123,6 +123,7 @@ enum mhi_pm_state __must_check mhi_tryset_pm_state(struct mhi_controller *mhi_cn
 	if (unlikely(!(dev_state_transitions[index].to_states & state)))
 		return cur_state;
 
+	trace_mhi_tryset_pm_state(mhi_cntrl->mhi_dev->name, state);
 	mhi_cntrl->pm_state = state;
 	return mhi_cntrl->pm_state;
 }
@@ -753,7 +754,6 @@ void mhi_pm_st_worker(struct work_struct *work)
 	struct mhi_controller *mhi_cntrl = container_of(work,
 							struct mhi_controller,
 							st_worker);
-	struct device *dev = &mhi_cntrl->mhi_dev->dev;
 
 	spin_lock_irq(&mhi_cntrl->transition_lock);
 	list_splice_tail_init(&mhi_cntrl->transition_list, &head);
@@ -761,8 +761,8 @@ void mhi_pm_st_worker(struct work_struct *work)
 
 	list_for_each_entry_safe(itr, tmp, &head, node) {
 		list_del(&itr->node);
-		dev_dbg(dev, "Handling state transition: %s\n",
-			TO_DEV_STATE_TRANS_STR(itr->state));
+
+		trace_mhi_pm_st_transition(mhi_cntrl->mhi_dev->name, itr->state);
 
 		switch (itr->state) {
 		case DEV_ST_TRANSITION_PBL:
diff --git a/include/trace/events/mhi_host.h b/include/trace/events/mhi_host.h
new file mode 100644
index 000000000000..a496d99f8fad
--- /dev/null
+++ b/include/trace/events/mhi_host.h
@@ -0,0 +1,287 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved.
+ */
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM mhi_host
+
+#if !defined(_TRACE_EVENT_MHI_HOST_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_EVENT_MHI_HOST_H
+
+#include <linux/tracepoint.h>
+#define MHI_STATE						\
+	EM(MHI_STATE_RESET,	"RESET")			\
+	EM(MHI_STATE_READY,	"READY")			\
+	EM(MHI_STATE_M0,	"M0")				\
+	EM(MHI_STATE_M1,	"M1")				\
+	EM(MHI_STATE_M2,	"M2")				\
+	EM(MHI_STATE_M3,	"M3")				\
+	EM(MHI_STATE_M3_FAST,	"M3 FAST")			\
+	EM(MHI_STATE_BHI,	"BHI")				\
+	EMe(MHI_STATE_SYS_ERR,	"SYS ERROR")
+
+#define MHI_EE							\
+	EM(MHI_EE_PBL,		"PRIMARY BOOTLOADER")		\
+	EM(MHI_EE_SBL,		"SECONDARY BOOTLOADER")		\
+	EM(MHI_EE_AMSS,		"MISSION MODE")			\
+	EM(MHI_EE_RDDM,		"RAMDUMP DOWNLOAD MODE")	\
+	EM(MHI_EE_WFW,		"WLAN FIRMWARE")		\
+	EM(MHI_EE_PTHRU,	"PASS THROUGH")			\
+	EM(MHI_EE_EDL,		"EMERGENCY DOWNLOAD")		\
+	EM(MHI_EE_FP,		"FLASH PROGRAMMER")		\
+	EM(MHI_EE_DISABLE_TRANSITION,	"DISABLE")		\
+	EMe(MHI_EE_NOT_SUPPORTED,	"NOT SUPPORTED")
+
+#define MHI_PM_STATE							\
+	EM(MHI_PM_STATE_DISABLE,	"DISABLE")			\
+	EM(MHI_PM_STATE_POR,		"POWER ON RESET")		\
+	EM(MHI_PM_STATE_M0,		"M0")				\
+	EM(MHI_PM_STATE_M2,		"M2")				\
+	EM(MHI_PM_STATE_M3_ENTER,	"M?->M3")			\
+	EM(MHI_PM_STATE_M3,		"M3")				\
+	EM(MHI_PM_STATE_M3_EXIT,	"M3->M0")			\
+	EM(MHI_PM_STATE_FW_DL_ERR,	"Firmware Download Error")	\
+	EM(MHI_PM_STATE_SYS_ERR_DETECT,		"SYS ERROR Detect")	\
+	EM(MHI_PM_STATE_SYS_ERR_PROCESS,	"SYS ERROR Process")	\
+	EM(MHI_PM_STATE_SHUTDOWN_PROCESS,	"SHUTDOWN Process")	\
+	EMe(MHI_PM_STATE_LD_ERR_FATAL_DETECT,	"Linkdown or Error Fatal Detect")
+
+#define MHI_CH_STATE						\
+	EM(MHI_CH_STATE_TYPE_RESET, "RESET")			\
+	EM(MHI_CH_STATE_TYPE_STOP, "STOP")			\
+	EMe(MHI_CH_STATE_TYPE_START, "START")
+
+#define MHI_DEV_ST_TRANSITION						\
+	EM(DEV_ST_TRANSITION_PBL,	"PBL")				\
+	EM(DEV_ST_TRANSITION_READY,	"READY")			\
+	EM(DEV_ST_TRANSITION_SBL,	"SBL")				\
+	EM(DEV_ST_TRANSITION_MISSION_MODE,	"MISSION MODE")		\
+	EM(DEV_ST_TRANSITION_FP,		"FLASH PROGRAMMER")	\
+	EM(DEV_ST_TRANSITION_SYS_ERR,		"SYS ERROR")		\
+	EMe(DEV_ST_TRANSITION_DISABLE,		"DISABLE")
+
+/* Enums require being exported to userspace, for user tool parsing */
+#undef	EM
+#undef	EMe
+#define	EM(a, b)	TRACE_DEFINE_ENUM(a);
+#define	EMe(a, b)	TRACE_DEFINE_ENUM(a);
+
+MHI_STATE
+MHI_EE
+MHI_PM_STATE
+MHI_CH_STATE
+MHI_DEV_ST_TRANSITION
+
+/*
+ * Now redefine the EM() and EMe() macros to map the enums to the strings
+ * that will be printed in the output.
+ */
+#undef EM
+#undef EMe
+#define EM(a, b)	{a, b},
+#define EMe(a, b)	{a, b}
+
+TRACE_EVENT(mhi_gen_tre,
+
+	TP_PROTO(const char *name, int ch_num, u64 wp, __le64 tre_ptr,
+		 __le32 dword0, __le32 dword1),
+
+	TP_ARGS(name, ch_num, wp, tre_ptr, dword0, dword1),
+
+	TP_STRUCT__entry(
+		__string(name, name)
+		__field(int, ch_num)
+		__field(u64, wp)
+		__field(__le64, tre_ptr)
+		__field(__le32, dword0)
+		__field(__le32, dword1)
+	),
+
+	TP_fast_assign(
+		__assign_str(name, name);
+		__entry->ch_num = ch_num;
+		__entry->wp = wp;
+		__entry->tre_ptr = tre_ptr;
+		__entry->dword0 = dword0;
+		__entry->dword1 = dword1;
+	),
+
+	TP_printk("%s: Chan: %d WP: 0x%llx TRE: 0x%llx 0x%08x 0x%08x\n",
+		  __get_str(name), __entry->ch_num, __entry->wp, __entry->tre_ptr,
+		  __entry->dword0, __entry->dword1)
+);
+
+TRACE_EVENT(mhi_intvec_threaded_handler,
+
+	TP_PROTO(const char *name, int local_ee, int state, int dev_ee, int dev_state),
+
+	TP_ARGS(name, local_ee, state, dev_ee, dev_state),
+
+	TP_STRUCT__entry(
+		__string(name, name)
+		__field(int, local_ee)
+		__field(int, state)
+		__field(int, dev_ee)
+		__field(int, dev_state)
+	),
+
+	TP_fast_assign(
+		__assign_str(name, name);
+		__entry->local_ee = local_ee;
+		__entry->state = state;
+		__entry->dev_ee = dev_ee;
+		__entry->dev_state = dev_state;
+	),
+
+	TP_printk("%s: local ee: %s state: %s device ee: %s state: %s\n",
+		  __get_str(name),
+		  __print_symbolic(__entry->local_ee, MHI_EE),
+		  __print_symbolic(__entry->state, MHI_STATE),
+		  __print_symbolic(__entry->dev_ee, MHI_EE),
+		  __print_symbolic(__entry->dev_state, MHI_STATE))
+);
+
+TRACE_EVENT(mhi_tryset_pm_state,
+
+	TP_PROTO(const char *name, int pm_state),
+
+	TP_ARGS(name, pm_state),
+
+	TP_STRUCT__entry(
+		__string(name, name)
+		__field(int, pm_state)
+	),
+
+	TP_fast_assign(
+		__assign_str(name, name);
+		if (pm_state)
+			pm_state = __fls(pm_state);
+		__entry->pm_state = pm_state;
+	),
+
+	TP_printk("%s: PM state: %s\n", __get_str(name),
+		  __print_symbolic(__entry->pm_state, MHI_PM_STATE))
+);
+
+TRACE_EVENT(mhi_process_data_event_ring,
+
+	TP_PROTO(const char *name, __le64 ptr, __le32 dword0, __le32 dword1),
+
+	TP_ARGS(name, ptr, dword0, dword1),
+
+	TP_STRUCT__entry(
+		__string(name, name)
+		__field(__le64, ptr)
+		__field(__le32, dword0)
+		__field(__le32, dword1)
+	),
+
+	TP_fast_assign(
+		__assign_str(name, name);
+		__entry->ptr = ptr;
+		__entry->dword0 = dword0;
+		__entry->dword1 = dword1;
+	),
+
+	TP_printk("%s: Processing Event:0x%llx 0x%08x 0x%08x\n",
+		  __get_str(name), __entry->ptr, __entry->dword0, __entry->dword1)
+);
+
+TRACE_EVENT(mhi_process_ctrl_ev_ring,
+
+	TP_PROTO(const char *name, u64 rp, __le64 ptr, __le32 dword0, __le32 dword1, int state),
+
+	TP_ARGS(name, rp, ptr, dword0, dword1, state),
+
+	TP_STRUCT__entry(
+		__string(name, name)
+		__field(u64, rp)
+		__field(__le64, ptr)
+		__field(__le32, dword0)
+		__field(__le32, dword1)
+		__field(int, state)
+	),
+
+	TP_fast_assign(
+		__assign_str(name, name);
+		__entry->rp = rp;
+		__entry->ptr = ptr;
+		__entry->dword0 = dword0;
+		__entry->dword1 = dword1;
+		__entry->state = state;
+	),
+
+	TP_printk("%s: RP:0x%llx Processing Event:0x%llx 0x%08x 0x%08x state:%s\n",
+		  __get_str(name), __entry->rp, __entry->ptr, __entry->dword0,
+		  __entry->dword1, __print_symbolic(__entry->state, MHI_STATE))
+);
+
+TRACE_EVENT(mhi_update_channel_state_start,
+
+	TP_PROTO(const char *name, int ch_num, int state),
+
+	TP_ARGS(name, ch_num, state),
+
+	TP_STRUCT__entry(
+		__string(name, name)
+		__field(int, ch_num)
+		__field(int, state)
+	),
+
+	TP_fast_assign(
+		__assign_str(name, name);
+		__entry->ch_num = ch_num;
+		__entry->state = state;
+	),
+
+	TP_printk("%s: ch%d: Updating state to: %s\n",
+		  __get_str(name), __entry->ch_num,
+		  __print_symbolic(__entry->state, MHI_CH_STATE))
+);
+
+TRACE_EVENT(mhi_update_channel_state_end,
+
+	TP_PROTO(const char *name, int ch_num, int state),
+
+	TP_ARGS(name, ch_num, state),
+
+	TP_STRUCT__entry(
+		__string(name, name)
+		__field(int, ch_num)
+		__field(int, state)
+	),
+
+	TP_fast_assign(
+		__assign_str(name, name);
+		__entry->ch_num = ch_num;
+		__entry->state = state;
+	),
+
+	TP_printk("%s: ch%d: Updated state to: %s\n",
+		  __get_str(name), __entry->ch_num,
+		  __print_symbolic(__entry->state, MHI_CH_STATE))
+);
+
+TRACE_EVENT(mhi_pm_st_transition,
+
+	TP_PROTO(const char *name, int state),
+
+	TP_ARGS(name, state),
+
+	TP_STRUCT__entry(
+		__string(name, name)
+		__field(int, state)
+	),
+
+	TP_fast_assign(
+		__assign_str(name, name);
+		__entry->state = state;
+	),
+
+	TP_printk("%s: Handling state transition: %s\n", __get_str(name),
+		  __print_symbolic(__entry->state, MHI_DEV_ST_TRANSITION))
+);
+
+#endif
+#include <trace/define_trace.h>

---
base-commit: 3006adf3be79cde4d14b1800b963b82b6e5572e0
change-id: 20231005-ftrace_support-6869d4156139

Best regards,
-- 
Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx>