On 31/05/2024 05:27, Linu Cherian wrote:
> * Introduce a new mode CS_MODE_READ_CRASHDATA for reading trace
> captured in previous crash/watchdog reset.
>
> * Add special device files for reading ETR/ETF crash data.
>
> * User can read the crash data as below
>
> For example, for reading crash data from tmc_etf sink
>
> #dd if=/dev/crash_tmc_etfXX of=~/cstrace.bin
>
> Signed-off-by: Anil Kumar Reddy <areddy3@xxxxxxxxxxx>
> Signed-off-by: Tanmay Jagdale <tanmay@xxxxxxxxxxx>
> Signed-off-by: Linu Cherian <lcherian@xxxxxxxxxxx>
> ---
> Changelog from v7:
> * Moved crash dev registration into new function,
> register_crash_dev_interface
> * Removed redundant variable trace_addr in
> tmc_etr_setup_crashdata_buf
>
> .../coresight/coresight-etm4x-core.c | 1 +
> .../hwtracing/coresight/coresight-tmc-core.c | 148 ++++++++++++++++-
> .../hwtracing/coresight/coresight-tmc-etf.c | 73 +++++++++
> .../hwtracing/coresight/coresight-tmc-etr.c | 152 +++++++++++++++++-
> drivers/hwtracing/coresight/coresight-tmc.h | 11 +-
> include/linux/coresight.h | 13 ++
> 6 files changed, 391 insertions(+), 7 deletions(-)
>
[...]
> +static void register_crash_dev_interface(struct tmc_drvdata * drvdata,
> + const char *name)
> +{
> + drvdata->crashdev.name =
> + devm_kasprintf(&drvdata->csdev->dev, GFP_KERNEL, "%s_%s", "crash", name);
> + drvdata->crashdev.minor = MISC_DYNAMIC_MINOR;
> + drvdata->crashdev.fops = &tmc_crashdata_fops;
> + if (misc_register(&drvdata->crashdev))
> + dev_dbg(&drvdata->csdev->dev,
> + "Failed to setup user interface for crashdata\n");
> +}
> +
> static int tmc_probe(struct amba_device *adev, const struct amba_id *id)
> {
> int ret = 0;
> @@ -619,6 +752,10 @@ static int tmc_probe(struct amba_device *adev, const struct amba_id *id)
> coresight_unregister(drvdata->csdev);
> else
> pm_runtime_put(&adev->dev);
> +
> + if (is_tmc_reserved_region_valid(dev))
> + register_crash_dev_interface(drvdata, desc.name);
> +
Now that you've added an extra step to the probe you need to add a "goto
out" when the previous step fails:
if (ret) {
coresight_unregister(drvdata->csdev);
+ goto out;
}
That seems to be the pattern in the rest of the function. Otherwise you
might register the interface on no device.
There's also a conflict here and in some other places. Since this has to
go through the coresight branch you should base it off of coresight-next.
> out:
> return ret;
> }
> @@ -630,7 +767,8 @@ static void tmc_shutdown(struct amba_device *adev)
>
> spin_lock_irqsave(&drvdata->spinlock, flags);
>
> - if (coresight_get_mode(drvdata->csdev) == CS_MODE_DISABLED)
> + if ((coresight_get_mode(drvdata->csdev) == CS_MODE_DISABLED) ||
> + (coresight_get_mode(drvdata->csdev) == CS_MODE_READ_CRASHDATA))
> goto out;
>
> if (drvdata->config_type == TMC_CONFIG_TYPE_ETR)
> diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c
> index f9569585e9f8..655c0c0ba54b 100644
> --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c
> +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c
> @@ -657,6 +657,56 @@ static int tmc_panic_sync_etf(struct coresight_device *csdev)
> return 0;
> }
>
[...]
> @@ -725,6 +789,7 @@ int tmc_read_prepare_etb(struct tmc_drvdata *drvdata)
> __tmc_etb_disable_hw(drvdata);
> }
>
> +mode_valid:
> drvdata->reading = true;
> out:
> spin_unlock_irqrestore(&drvdata->spinlock, flags);
> @@ -744,8 +809,16 @@ int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata)
> drvdata->config_type != TMC_CONFIG_TYPE_ETF))
> return -EINVAL;
>
> +
Whitespace change. There are a couple of other minor checkpatch style
warnings.
The rest looks good to me. All the tests are passing. I still think we
should all the kself test for this mode, but that can be done later.
