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

From: Krishna Chaitanya Chundru
Date: Tue Oct 17 2023 - 05:09:43 EST



On 10/16/2023 8:43 PM, Steven Rostedt wrote:
On Fri, 13 Oct 2023 15:22:19 +0530
Krishna chaitanya chundru <quic_krichai@xxxxxxxxxxx> wrote:

+++ 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)
This is fine as __string() is four bytes in the event (2 bytes for offset
where the string exists, and 2 bytes for its length).

+ __field(u64, wp)
+ __field(__le64, tre_ptr)
Which makes the two 8 byte fields aligned. Good!

+ __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)
Here, I would switch the __field(__le64, ptr) with the __string().

__field(__le64, ptr)
__string(name, name)

otherwise you just created a 4 byte hole in the ring buffer, wasting
precious ring buffer space.

+ __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)
I would move __string(name, name) here (after the two 8 byte fields).

-- Steve

I will reoder as suggested in my next patch.

-- KC.

+ __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>