Messages in this thread Patch in this message | | | From | Rakesh Babu Saladi <> | Subject | [PATCH] arm64: smccc: Add trace events to SMC calls. | Date | Sat, 4 Mar 2023 18:28:50 +0530 |
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This patch adds start and end trace events to an SMC call sent from kernel to ATF. The start trace event prints the smc_id and the end trace event prints the smc_id and the time taken to process the SMC call.
Signed-off-by: Rakesh Babu Saladi <rsaladi2@marvell.com> --- drivers/firmware/smccc/Makefile | 3 +- drivers/firmware/smccc/smccc.c | 14 ++++++++++ drivers/firmware/smccc/smccc_trace.c | 7 +++++ drivers/firmware/smccc/smccc_trace.h | 41 ++++++++++++++++++++++++++++ include/linux/arm-smccc.h | 4 ++- kernel/time/timekeeping.c | 7 +++++ 6 files changed, 74 insertions(+), 2 deletions(-) create mode 100644 drivers/firmware/smccc/smccc_trace.c create mode 100644 drivers/firmware/smccc/smccc_trace.h
diff --git a/drivers/firmware/smccc/Makefile b/drivers/firmware/smccc/Makefile index 40d19144a860..e74c35191b49 100644 --- a/drivers/firmware/smccc/Makefile +++ b/drivers/firmware/smccc/Makefile @@ -1,4 +1,5 @@ # SPDX-License-Identifier: GPL-2.0 # -obj-$(CONFIG_HAVE_ARM_SMCCC_DISCOVERY) += smccc.o kvm_guest.o +ccflags-y += -I$(src) +obj-$(CONFIG_HAVE_ARM_SMCCC_DISCOVERY) += smccc_trace.o smccc.o kvm_guest.o obj-$(CONFIG_ARM_SMCCC_SOC_ID) += soc_id.o diff --git a/drivers/firmware/smccc/smccc.c b/drivers/firmware/smccc/smccc.c index 60ccf3e90d7d..7631a16479e9 100644 --- a/drivers/firmware/smccc/smccc.c +++ b/drivers/firmware/smccc/smccc.c @@ -11,6 +11,7 @@ #include <linux/kernel.h> #include <linux/platform_device.h> #include <asm/archrandom.h> +#include "smccc_trace.h" static u32 smccc_version = ARM_SMCCC_VERSION_1_0; static enum arm_smccc_conduit smccc_conduit = SMCCC_CONDUIT_NONE; @@ -59,3 +60,16 @@ static int __init smccc_devices_init(void) return 0; } device_initcall(smccc_devices_init); + +void arm_smccc_smc(unsigned long a0, unsigned long a1, unsigned long a2, unsigned long a3, + unsigned long a4, unsigned long a5, unsigned long a6, unsigned long a7, + struct arm_smccc_res *res) +{ + u64 start, elapsed; + + trace_arm_smccc_smc_start(a0); + start = ktime_get_ns(); + __arm_smccc_smc(a0, a1, a2, a3, a4, a5, a6, a7, res, NULL); + elapsed = ktime_get_ns() - start; + trace_arm_smccc_smc_end(a0, elapsed); +} diff --git a/drivers/firmware/smccc/smccc_trace.c b/drivers/firmware/smccc/smccc_trace.c new file mode 100644 index 000000000000..6b94d5d9c0f4 --- /dev/null +++ b/drivers/firmware/smccc/smccc_trace.c @@ -0,0 +1,7 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define CREATE_TRACE_POINTS +#include "smccc_trace.h" + +EXPORT_TRACEPOINT_SYMBOL(arm_smccc_smc_start); +EXPORT_TRACEPOINT_SYMBOL(arm_smccc_smc_end); diff --git a/drivers/firmware/smccc/smccc_trace.h b/drivers/firmware/smccc/smccc_trace.h new file mode 100644 index 000000000000..c0ef836bc093 --- /dev/null +++ b/drivers/firmware/smccc/smccc_trace.h @@ -0,0 +1,41 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#undef TRACE_SYSTEM +#define TRACE_SYSTEM smccc + +#if !defined(__SMCCC_TRACE_H) || defined(TRACE_HEADER_MULTI_READ) +#define __SMCCC_TRACE_H + +#include <linux/types.h> +#include <linux/tracepoint.h> + +TRACE_EVENT(arm_smccc_smc_start, + TP_PROTO(unsigned long smc_id), + TP_ARGS(smc_id), + TP_STRUCT__entry(__field(unsigned long, smc_id)), + TP_fast_assign(__entry->smc_id = smc_id;), + TP_printk("SMC ID: 0x%lx", __entry->smc_id) +); + +TRACE_EVENT(arm_smccc_smc_end, + TP_PROTO(unsigned long smc_id, u64 elapsed_time), + TP_ARGS(smc_id, elapsed_time), + TP_STRUCT__entry(__field(unsigned long, smc_id) + __field(u64, elapsed_time) + ), + TP_fast_assign(__entry->smc_id = smc_id; + __entry->elapsed_time = elapsed_time; + ), + TP_printk("SMC ID: 0x%lx time taken to process : %llu ns", + __entry->smc_id, __entry->elapsed_time) +); + +#endif /* __SMCCC_TRACE_H */ + +#undef TRACE_INCLUDE_PATH +#define TRACE_INCLUDE_PATH . + +#undef TRACE_INCLUDE_FILE +#define TRACE_INCLUDE_FILE smccc_trace + +#include <trace/define_trace.h> diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h index 220c8c60e021..39588c3db486 100644 --- a/include/linux/arm-smccc.h +++ b/include/linux/arm-smccc.h @@ -358,7 +358,9 @@ asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1, unsigned long a5, unsigned long a6, unsigned long a7, struct arm_smccc_res *res, struct arm_smccc_quirk *quirk); -#define arm_smccc_smc(...) __arm_smccc_smc(__VA_ARGS__, NULL) +void arm_smccc_smc(unsigned long a0, unsigned long a1, unsigned long a2, + unsigned long a3, unsigned long a4, unsigned long a5, + unsigned long a6, unsigned long a7, struct arm_smccc_res *res); #define arm_smccc_smc_quirk(...) __arm_smccc_smc(__VA_ARGS__) diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 5579ead449f2..3a3bf2d674a3 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -192,6 +192,13 @@ static inline u64 tk_clock_read(const struct tk_read_base *tkr) { struct clocksource *clock = READ_ONCE(tkr->clock); + /* At the time of kernel booting some SMC calls are called before the + * clock is initialized, in such cases it would lead to kernel crash. + * To prevent kernel crash in such cases this check is included. + */ + if (unlikely(!clock)) + return 0; + return clock->read(clock); } -- 2.17.1
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