[PATCH] coresight: stm: support marked packet
Mathieu Poirier
mathieu.poirier at linaro.org
Tue Jul 21 13:12:18 EDT 2020
Hi Tingwei,
On Sun, Jul 19, 2020 at 02:27:12PM +0800, Tingwei Zhang wrote:
> STP_PACKET_MARKED is not supported by STM currently.
> Add STM_FLAG_MARKED to support marked packet in STM.
>
> Signed-off-by: Tingwei Zhang <tingwei at codeaurora.org>
> ---
> drivers/hwtracing/coresight/coresight-stm.c | 11 +++++++----
> include/uapi/linux/coresight-stm.h | 1 +
> 2 files changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/hwtracing/coresight/coresight-stm.c
> index b908ca104645..36fb1838b1d1 100644
> --- a/drivers/hwtracing/coresight/coresight-stm.c
> +++ b/drivers/hwtracing/coresight/coresight-stm.c
> @@ -412,6 +412,7 @@ static ssize_t notrace stm_generic_packet(struct stm_data *stm_data,
> void __iomem *ch_addr;
> struct stm_drvdata *drvdata = container_of(stm_data,
> struct stm_drvdata, stm);
> + unsigned int stm_flags;
>
> if (!(drvdata && local_read(&drvdata->mode)))
> return -EACCES;
> @@ -421,8 +422,10 @@ static ssize_t notrace stm_generic_packet(struct stm_data *stm_data,
>
> ch_addr = stm_channel_addr(drvdata, channel);
>
> - flags = (flags == STP_PACKET_TIMESTAMPED) ? STM_FLAG_TIMESTAMPED : 0;
> - flags |= test_bit(channel, drvdata->chs.guaranteed) ?
> + stm_flags = (flags & STP_PACKET_TIMESTAMPED) ?
> + STM_FLAG_TIMESTAMPED : 0;
> + stm_flags |= (flags & STP_PACKET_MARKED) ? STM_FLAG_MARKED : 0;
Looking at the STM programmer's manual there is a marked area for data packets
only. Clearing the marked bit for non-data access ends up in a reserved area
and yet here it is set invariably.
Out of curiosity, what kind of use case are you using this for?
Thanks,
Mathieu
> + stm_flags |= test_bit(channel, drvdata->chs.guaranteed) ?
> STM_FLAG_GUARANTEED : 0;
>
> if (size > drvdata->write_bytes)
> @@ -432,7 +435,7 @@ static ssize_t notrace stm_generic_packet(struct stm_data *stm_data,
>
> switch (packet) {
> case STP_PACKET_FLAG:
> - ch_addr += stm_channel_off(STM_PKT_TYPE_FLAG, flags);
> + ch_addr += stm_channel_off(STM_PKT_TYPE_FLAG, stm_flags);
>
> /*
> * The generic STM core sets a size of '0' on flag packets.
> @@ -444,7 +447,7 @@ static ssize_t notrace stm_generic_packet(struct stm_data *stm_data,
> break;
>
> case STP_PACKET_DATA:
> - ch_addr += stm_channel_off(STM_PKT_TYPE_DATA, flags);
> + ch_addr += stm_channel_off(STM_PKT_TYPE_DATA, stm_flags);
> stm_send(ch_addr, payload, size,
> drvdata->write_bytes);
> break;
> diff --git a/include/uapi/linux/coresight-stm.h b/include/uapi/linux/coresight-stm.h
> index 8847dbf24151..7ff3709c01b8 100644
> --- a/include/uapi/linux/coresight-stm.h
> +++ b/include/uapi/linux/coresight-stm.h
> @@ -5,6 +5,7 @@
> #include <linux/const.h>
>
> #define STM_FLAG_TIMESTAMPED _BITUL(3)
> +#define STM_FLAG_MARKED _BITUL(4)
> #define STM_FLAG_GUARANTEED _BITUL(7)
>
> /*
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>
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