[PATCH 12/13] powerpc/tracing: tracepoints for RTAS entry and exit
Nicholas Piggin
npiggin at gmail.com
Mon Nov 28 13:54:19 AEDT 2022
On Sat Nov 19, 2022 at 1:07 AM AEST, Nathan Lynch wrote:
> Add two sets of tracepoints to be used around RTAS entry:
>
> * rtas_input/rtas_output, which emit the function name, its inputs,
> the returned status, and any other outputs. These produce an API-level
> record of OS<->RTAS activity.
>
> * rtas_ll_entry/rtas_ll_exit, which are lower-level and emit the
> entire contents of the parameter block (aka rtas_args) on entry and
> exit. Likely useful only for debugging.
>
> With uses of these tracepoints in do_enter_rtas() to be added in the
> following patch, examples of get-time-of-day and event-scan functions
> as rendered by trace-cmd (with some multi-line formatting manually
> imposed on the rtas_ll_* entries to avoid extremely long lines in the
> commit message):
>
> cat-36800 [059] 4978.518303: rtas_input: get-time-of-day arguments:
> cat-36800 [059] 4978.518306: rtas_ll_entry: token=3 nargs=0 nret=8
> params: [0]=0x00000000 [1]=0x00000000 [2]=0x00000000 [3]=0x00000000
> [4]=0x00000000 [5]=0x00000000 [6]=0x00000000 [7]=0x00000000
> [8]=0x00000000 [9]=0x00000000 [10]=0x00000000 [11]=0x00000000
> [12]=0x00000000 [13]=0x00000000 [14]=0x00000000 [15]=0x00000000
> cat-36800 [059] 4978.518366: rtas_ll_exit: token=3 nargs=0 nret=8
> params: [0]=0x00000000 [1]=0x000007e6 [2]=0x0000000b [3]=0x00000001
> [4]=0x00000000 [5]=0x0000000e [6]=0x00000008 [7]=0x2e0dac40
> [8]=0x00000000 [9]=0x00000000 [10]=0x00000000 [11]=0x00000000
> [12]=0x00000000 [13]=0x00000000 [14]=0x00000000 [15]=0x00000000
> cat-36800 [059] 4978.518366: rtas_output: get-time-of-day status: 0, other outputs: 2022 11 1 0 14 8 772648000
>
> kworker/39:1-336 [039] 4982.731623: rtas_input: event-scan arguments: 4294967295 0 80484920 2048
> kworker/39:1-336 [039] 4982.731626: rtas_ll_entry: token=6 nargs=4 nret=1
> params: [0]=0xffffffff [1]=0x00000000 [2]=0x04cc1a38 [3]=0x00000800
> [4]=0x00000000 [5]=0x0000000e [6]=0x00000008 [7]=0x2e0dac40
> [8]=0x00000000 [9]=0x00000000 [10]=0x00000000 [11]=0x00000000
> [12]=0x00000000 [13]=0x00000000 [14]=0x00000000 [15]=0x00000000
> kworker/39:1-336 [039] 4982.731676: rtas_ll_exit: token=6 nargs=4 nret=1
> params: [0]=0xffffffff [1]=0x00000000 [2]=0x04cc1a38 [3]=0x00000800
> [4]=0x00000001 [5]=0x0000000e [6]=0x00000008 [7]=0x2e0dac40
> [8]=0x00000000 [9]=0x00000000 [10]=0x00000000 [11]=0x00000000
> [12]=0x00000000 [13]=0x00000000 [14]=0x00000000 [15]=0x00000000
> kworker/39:1-336 [039] 4982.731677: rtas_output: event-scan status: 1, other outputs:
>
> Signed-off-by: Nathan Lynch <nathanl at linux.ibm.com>
> ---
> arch/powerpc/include/asm/trace.h | 116 +++++++++++++++++++++++++++++++
> 1 file changed, 116 insertions(+)
>
> diff --git a/arch/powerpc/include/asm/trace.h b/arch/powerpc/include/asm/trace.h
> index 08cd60cd70b7..e7a301c9eb95 100644
> --- a/arch/powerpc/include/asm/trace.h
> +++ b/arch/powerpc/include/asm/trace.h
> @@ -119,6 +119,122 @@ TRACE_EVENT_FN_COND(hcall_exit,
> );
> #endif
>
> +#ifdef CONFIG_PPC_RTAS
> +
> +#include <asm/rtas-types.h>
> +
> +/*
> + * Since stop-self is how CPUs go offline on RTAS platforms,
> + * these tracepoints are conditional.
> + */
> +
> +TRACE_EVENT_CONDITION(rtas_input,
> +
> + TP_PROTO(struct rtas_args *rtas_args, const char *name),
> +
> + TP_ARGS(rtas_args, name),
> +
> + TP_CONDITION(cpu_online(raw_smp_processor_id())),
> +
> + TP_STRUCT__entry(
> + __field(__u32, nargs)
> + __string(name, name)
> + __dynamic_array(__u32, inputs, be32_to_cpu(rtas_args->nargs))
> + ),
> +
> + TP_fast_assign(
> + __entry->nargs = be32_to_cpu(rtas_args->nargs);
> + __assign_str(name, name);
> + be32_to_cpu_array(__get_dynamic_array(inputs), rtas_args->args, __entry->nargs);
> + ),
> +
> + TP_printk("%s arguments: %s", __get_str(name),
> + __print_array(__get_dynamic_array(inputs), __entry->nargs, 4)
> + )
> +);
> +
> +TRACE_EVENT_CONDITION(rtas_output,
> +
> + TP_PROTO(struct rtas_args *rtas_args, const char *name),
> +
> + TP_ARGS(rtas_args, name),
> +
> + TP_CONDITION(cpu_online(raw_smp_processor_id())),
> +
> + TP_STRUCT__entry(
> + __field(__u32, nr_other)
> + __field(__s32, status)
> + __string(name, name)
> + __dynamic_array(__u32, other_outputs, be32_to_cpu(rtas_args->nret) - 1)
> + ),
> +
> + TP_fast_assign(
> + __entry->nr_other = be32_to_cpu(rtas_args->nret) - 1;
> + __entry->status = be32_to_cpu(rtas_args->rets[0]);
> + __assign_str(name, name);
> + be32_to_cpu_array(__get_dynamic_array(other_outputs),
> + &rtas_args->rets[1], __entry->nr_other);
> + ),
> +
> + TP_printk("%s status: %d, other outputs: %s", __get_str(name), __entry->status,
> + __print_array(__get_dynamic_array(other_outputs),
> + __entry->nr_other, 4)
> + )
> +);
> +
> +DECLARE_EVENT_CLASS(rtas_parameter_block,
> +
> + TP_PROTO(struct rtas_args *rtas_args),
> +
> + TP_ARGS(rtas_args),
> +
> + TP_STRUCT__entry(
> + __field(u32, token)
> + __field(u32, nargs)
> + __field(u32, nret)
> + __array(__u32, params, 16)
> + ),
> +
> + TP_fast_assign(
> + __entry->token = be32_to_cpu(rtas_args->token);
> + __entry->nargs = be32_to_cpu(rtas_args->nargs);
> + __entry->nret = be32_to_cpu(rtas_args->nret);
> + be32_to_cpu_array(__entry->params, rtas_args->args, ARRAY_SIZE(rtas_args->args));
> + ),
> +
> + TP_printk("token=%u nargs=%u nret=%u params:"
> + " [0]=0x%08x [1]=0x%08x [2]=0x%08x [3]=0x%08x"
> + " [4]=0x%08x [5]=0x%08x [6]=0x%08x [7]=0x%08x"
> + " [8]=0x%08x [9]=0x%08x [10]=0x%08x [11]=0x%08x"
> + " [12]=0x%08x [13]=0x%08x [14]=0x%08x [15]=0x%08x",
You could justify these since you went to the trouble to format them
nicely. Not a big deal though.
Reviewed-by: Nicholas Piggin <npiggin at gmail.com>
> + __entry->token, __entry->nargs, __entry->nret,
> + __entry->params[0], __entry->params[1], __entry->params[2], __entry->params[3],
> + __entry->params[4], __entry->params[5], __entry->params[6], __entry->params[7],
> + __entry->params[8], __entry->params[9], __entry->params[10], __entry->params[11],
> + __entry->params[12], __entry->params[13], __entry->params[14], __entry->params[15]
> + )
> +);
> +
> +DEFINE_EVENT_CONDITION(rtas_parameter_block, rtas_ll_entry,
> +
> + TP_PROTO(struct rtas_args *rtas_args),
> +
> + TP_ARGS(rtas_args),
> +
> + TP_CONDITION(cpu_online(raw_smp_processor_id()))
> +);
> +
> +DEFINE_EVENT_CONDITION(rtas_parameter_block, rtas_ll_exit,
> +
> + TP_PROTO(struct rtas_args *rtas_args),
> +
> + TP_ARGS(rtas_args),
> +
> + TP_CONDITION(cpu_online(raw_smp_processor_id()))
> +);
> +
> +#endif /* CONFIG_PPC_RTAS */
> +
> #ifdef CONFIG_PPC_POWERNV
> extern int opal_tracepoint_regfunc(void);
> extern void opal_tracepoint_unregfunc(void);
> --
> 2.37.1
More information about the Linuxppc-dev
mailing list