Re: [RFC PATCH 03/11] soc: mediatek: dram-ecc: add tracepoints

[Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>]

> diff --git a/drivers/soc/mediatek/dram-ecc/core/trace.c b/drivers/soc/mediatek/dram-ecc/core/trace.c
> new file mode 100644
> index 000000000000..9a8b20e48069
> --- /dev/null
> +++ b/drivers/soc/mediatek/dram-ecc/core/trace.c
> @@ -0,0 +1,6 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2026 MediaTek Inc.
> + */
> +#define CREATE_TRACE_POINTS
> +#include "trace.h"
> diff --git a/drivers/soc/mediatek/dram-ecc/core/trace.h b/drivers/soc/mediatek/dram-ecc/core/trace.h
> new file mode 100644
> index 000000000000..d603fc38f0a7
> --- /dev/null
> +++ b/drivers/soc/mediatek/dram-ecc/core/trace.h
> @@ -0,0 +1,119 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2026 MediaTek Inc.
> + */
> +#undef TRACE_SYSTEM
> +#define TRACE_SYSTEM mtk_dram_ecc
> +
> +#if !defined(_TRACE_MTK_DRAM_ECC_H) || defined(TRACE_HEADER_MULTI_READ)
> +#define _TRACE_MTK_DRAM_ECC_H
> +
> +#include <linux/tracepoint.h>
> +
> +/* driver lifecycle - state: 0=init, 1=exit */
> +
> +TRACE_EVENT(mtk_dram_ecc_lifecycle,
> +	TP_PROTO(int state),
> +	TP_ARGS(state),
> +	TP_STRUCT__entry(
> +		__field(int, state)
> +	),
> +	TP_fast_assign(
> +		__entry->state = state;
> +	),
> +	TP_printk("%s", __entry->state ? "driver removed" : "driver initialized")
> +);
> +
> +/*
> + * ECC events - spa/channel/subchannel/rank/bank/row/column decoded from the
> + * ECCERR_INFO0/1 entry that determined severity (see ghes_notifier.c),
> + * mirroring ATF dram_ecc/mt8992/fiq.c's decode. No agent/master ID: ATF's
> + * GHES vendor section doesn't compute them (see mtk_dram_ecc_event.h).
> + */
> +
> +TRACE_EVENT(mtk_dram_ecc_ce,

Why push these through a custom tracepoint?  This look very similar to what
is in the Memory Error Section 2 CPER.

> +	TP_PROTO(u64 spa, u8 channel, u8 subch, u16 rank, u16 bank, u32 row,
> +		 u16 column),
> +	TP_ARGS(spa, channel, subch, rank, bank, row, column),
> +	TP_STRUCT__entry(
> +		__field(u64, spa)
> +		__field(u8, channel)
> +		__field(u8, subch)
> +		__field(u16, rank)
> +		__field(u16, bank)
> +		__field(u32, row)
> +		__field(u16, column)
> +	),
> +	TP_fast_assign(
> +		__entry->spa     = spa;
> +		__entry->channel = channel;
> +		__entry->subch   = subch;
> +		__entry->rank    = rank;
> +		__entry->bank    = bank;
> +		__entry->row     = row;
> +		__entry->column  = column;
> +	),
> +	TP_printk("spa=0x%016llx ch=%u subch=%u rank=%u bank=%u row=%u column=%u",
> +		  __entry->spa, __entry->channel, __entry->subch,
> +		  __entry->rank, __entry->bank, __entry->row,
> +		  __entry->column)
> +);
> +
> +TRACE_EVENT(mtk_dram_ecc_uce,
> +	TP_PROTO(u64 spa, u8 channel, u8 subch, u16 rank, u16 bank, u32 row,
> +		 u16 column),
> +	TP_ARGS(spa, channel, subch, rank, bank, row, column),
> +	TP_STRUCT__entry(
> +		__field(u64, spa)
> +		__field(u8, channel)
> +		__field(u8, subch)
> +		__field(u16, rank)
> +		__field(u16, bank)
> +		__field(u32, row)
> +		__field(u16, column)
> +	),
> +	TP_fast_assign(
> +		__entry->spa     = spa;
> +		__entry->channel = channel;
> +		__entry->subch   = subch;
> +		__entry->rank    = rank;
> +		__entry->bank    = bank;
> +		__entry->row     = row;
> +		__entry->column  = column;
> +	),
> +	TP_printk("spa=0x%016llx ch=%u subch=%u rank=%u bank=%u row=%u column=%u",
> +		  __entry->spa, __entry->channel, __entry->subch,
> +		  __entry->rank, __entry->bank, __entry->row,
> +		  __entry->column)
> +);