On Fri, Mar 30, 2018 at 11:15:22AM +0800, Leo Yan wrote:
Since Coresight panic kdump functionality has been ready, this patch is to hook panic callback function for ETB/ETF driver. The driver data structure has allocated a buffer when the session started, so simply save tracing data into this buffer when panic happens and update buffer related info for kdump.
Signed-off-by: Leo Yan leo.yan@linaro.org
drivers/hwtracing/coresight/coresight-tmc-etf.c | 30 +++++++++++++++++++++++++ 1 file changed, 30 insertions(+)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c index e2513b7..d20d546 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c @@ -504,6 +504,35 @@ static void tmc_update_etf_buffer(struct coresight_device *csdev, CS_LOCK(drvdata->base); } +static void tmc_panic_cb(void *data)
I would call the function tmc_kdump_panic_cb()... That way there is absolutely no confusion as to what it does.
+{
- struct coresight_device *csdev = (struct coresight_device *)data;
- struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
- unsigned long flags;
- if (WARN_ON_ONCE(drvdata->config_type != TMC_CONFIG_TYPE_ETB &&
drvdata->config_type != TMC_CONFIG_TYPE_ETF))return;- if (drvdata->mode == CS_MODE_DISABLED)
return;
This is racy - between the check and acquiring the spinlock someone may beat you to it.
- spin_lock_irqsave(&drvdata->spinlock, flags);
if (drvdata->mode == CS_MODE_DISABLED) goto out;
drvdata->mode = CS_MODE_DISABLED
- CS_UNLOCK(drvdata->base);
- tmc_flush_and_stop(drvdata);
- tmc_etb_dump_hw(drvdata);
- CS_LOCK(drvdata->base);
- /* Update buffer info for panic dump */
- csdev->kdump_buf = drvdata->buf;
- csdev->kdump_buf_sz = drvdata->len;
out:
- spin_unlock_irqrestore(&drvdata->spinlock, flags);
+}
static const struct coresight_ops_sink tmc_etf_sink_ops = { .enable = tmc_enable_etf_sink, .disable = tmc_disable_etf_sink, @@ -512,6 +541,7 @@ static const struct coresight_ops_sink tmc_etf_sink_ops = { .set_buffer = tmc_set_etf_buffer, .reset_buffer = tmc_reset_etf_buffer, .update_buffer = tmc_update_etf_buffer,
- .panic_cb = tmc_panic_cb,
}; static const struct coresight_ops_link tmc_etf_link_ops = { -- 2.7.4