[PATCH v4 4/6] coresight: tmc: Hook callback for panic kdump

From: Leo Yan
Date: Thu Mar 29 2018 - 23:17:00 EST


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@xxxxxxxxxx>
---
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)
+{
+ 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;
+
+ spin_lock_irqsave(&drvdata->spinlock, flags);
+
+ 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;
+
+ 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