Refactor the tmc-etr enable operation to make it easier to handle errors in enabling the hardware. We need to make sure that the buffer is compatible with the ETR. This patch re-arranges to make the error handling easier, by deferring the hardware enablement until all the errors are checked. This also avoids turning the CATU on/off during a sysfs read session.
Cc: Mathieu Poirier mathieu.poirier@linaro.org Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com --- drivers/hwtracing/coresight/coresight-tmc-etr.c | 67 ++++++++++++++++--------- 1 file changed, 43 insertions(+), 24 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c index 56fea4f..c426935 100644 --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c @@ -918,21 +918,10 @@ static void tmc_sync_etr_buf(struct tmc_drvdata *drvdata) tmc_etr_buf_insert_barrier_packet(etr_buf, etr_buf->offset); }
-static void tmc_etr_enable_hw(struct tmc_drvdata *drvdata, - struct etr_buf *etr_buf) +static void __tmc_etr_enable_hw(struct tmc_drvdata *drvdata) { u32 axictl, sts; - - /* Callers should provide an appropriate buffer for use */ - if (WARN_ON(!etr_buf || drvdata->etr_buf)) - return; - drvdata->etr_buf = etr_buf; - - /* - * If this ETR is connected to a CATU, enable it before we turn - * this on - */ - tmc_etr_enable_catu(drvdata); + struct etr_buf *etr_buf = drvdata->etr_buf;
CS_UNLOCK(drvdata->base);
@@ -952,11 +941,8 @@ static void tmc_etr_enable_hw(struct tmc_drvdata *drvdata, axictl |= TMC_AXICTL_ARCACHE_OS; }
- if (etr_buf->mode == ETR_MODE_ETR_SG) { - if (WARN_ON(!tmc_etr_has_cap(drvdata, TMC_ETR_SG))) - return; + if (etr_buf->mode == ETR_MODE_ETR_SG) axictl |= TMC_AXICTL_SCT_GAT_MODE; - }
writel_relaxed(axictl, drvdata->base + TMC_AXICTL); tmc_write_dba(drvdata, etr_buf->hwaddr); @@ -982,6 +968,32 @@ static void tmc_etr_enable_hw(struct tmc_drvdata *drvdata, CS_LOCK(drvdata->base); }
+static int tmc_etr_enable_hw(struct tmc_drvdata *drvdata, + struct etr_buf *etr_buf) +{ + /* Callers should provide an appropriate buffer for use */ + if (WARN_ON(!etr_buf)) + return -EINVAL; + + if ((etr_buf->mode == ETR_MODE_ETR_SG) && + WARN_ON(!tmc_etr_has_cap(drvdata, TMC_ETR_SG))) + return -EINVAL; + + if (WARN_ON(drvdata->etr_buf)) + return -EBUSY; + + /* Set the buffer for the session */ + drvdata->etr_buf = etr_buf; + /* + * If this ETR is connected to a CATU, enable it before we turn + * this on. + */ + tmc_etr_enable_catu(drvdata); + + __tmc_etr_enable_hw(drvdata); + return 0; +} + /* * Return the available trace data in the buffer (starts at etr_buf->offset, * limited by etr_buf->len) from @pos, with a maximum limit of @len, @@ -1037,7 +1049,7 @@ static void tmc_etr_sync_sysfs_buf(struct tmc_drvdata *drvdata) } }
-static void tmc_etr_disable_hw(struct tmc_drvdata *drvdata) +static void __tmc_etr_disable_hw(struct tmc_drvdata *drvdata) { CS_UNLOCK(drvdata->base);
@@ -1053,6 +1065,11 @@ static void tmc_etr_disable_hw(struct tmc_drvdata *drvdata)
CS_LOCK(drvdata->base);
+} + +static void tmc_etr_disable_hw(struct tmc_drvdata *drvdata) +{ + __tmc_etr_disable_hw(drvdata); /* Disable CATU device if this ETR is connected to one */ tmc_etr_disable_catu(drvdata); /* Reset the ETR buf used by hardware */ @@ -1111,8 +1128,9 @@ static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev) drvdata->sysfs_buf = new_buf; }
- drvdata->mode = CS_MODE_SYSFS; - tmc_etr_enable_hw(drvdata, drvdata->sysfs_buf); + ret = tmc_etr_enable_hw(drvdata, drvdata->sysfs_buf); + if (!ret) + drvdata->mode = CS_MODE_SYSFS; out: spin_unlock_irqrestore(&drvdata->spinlock, flags);
@@ -1342,8 +1360,9 @@ static int tmc_enable_etr_sink_perf(struct coresight_device *csdev, void *data)
etr_perf->head = PERF_IDX2OFF(handle->head, etr_perf); drvdata->perf_data = etr_perf; - drvdata->mode = CS_MODE_PERF; - tmc_etr_enable_hw(drvdata, etr_perf->etr_buf); + rc = tmc_etr_enable_hw(drvdata, etr_perf->etr_buf); + if (!rc) + drvdata->mode = CS_MODE_PERF;
unlock_out: spin_unlock_irqrestore(&drvdata->spinlock, flags); @@ -1425,7 +1444,7 @@ int tmc_read_prepare_etr(struct tmc_drvdata *drvdata)
/* Disable the TMC if we are trying to read from a running session. */ if (drvdata->mode == CS_MODE_SYSFS) - tmc_etr_disable_hw(drvdata); + __tmc_etr_disable_hw(drvdata);
drvdata->reading = true; out: @@ -1452,7 +1471,7 @@ int tmc_read_unprepare_etr(struct tmc_drvdata *drvdata) * buffer. Since the tracer is still enabled drvdata::buf can't * be NULL. */ - tmc_etr_enable_hw(drvdata, drvdata->sysfs_buf); + __tmc_etr_enable_hw(drvdata); } else { /* * The ETR is not tracing and the buffer was just read.