Messages in this thread | | | From | Mike Leach <> | Date | Wed, 1 Feb 2023 20:43:43 +0000 | Subject | Re: [PATCH v2] coresight: tmc: Don't enable TMC when it's not ready. |
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Hi,
On Fri, 27 Jan 2023 at 23:10, Yabin Cui <yabinc@google.com> wrote: > > If TMC ETR is enabled without being ready, in later use we may > see AXI bus errors caused by accessing invalid addresses. > > Signed-off-by: Yabin Cui <yabinc@google.com> > --- > V1 -> V2: Make change to all TMCs instead of just ETR > > .../hwtracing/coresight/coresight-tmc-core.c | 4 +- > .../hwtracing/coresight/coresight-tmc-etf.c | 43 +++++++++++++++---- > .../hwtracing/coresight/coresight-tmc-etr.c | 18 ++++++-- > drivers/hwtracing/coresight/coresight-tmc.h | 2 +- > 4 files changed, 53 insertions(+), 14 deletions(-) > > diff --git a/drivers/hwtracing/coresight/coresight-tmc-core.c b/drivers/hwtracing/coresight/coresight-tmc-core.c > index 07abf28ad725..c106d142e632 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc-core.c > +++ b/drivers/hwtracing/coresight/coresight-tmc-core.c > @@ -31,7 +31,7 @@ DEFINE_CORESIGHT_DEVLIST(etb_devs, "tmc_etb"); > DEFINE_CORESIGHT_DEVLIST(etf_devs, "tmc_etf"); > DEFINE_CORESIGHT_DEVLIST(etr_devs, "tmc_etr"); > > -void tmc_wait_for_tmcready(struct tmc_drvdata *drvdata) > +int tmc_wait_for_tmcready(struct tmc_drvdata *drvdata) > { > struct coresight_device *csdev = drvdata->csdev; > struct csdev_access *csa = &csdev->access; > @@ -40,7 +40,9 @@ void tmc_wait_for_tmcready(struct tmc_drvdata *drvdata) > if (coresight_timeout(csa, TMC_STS, TMC_STS_TMCREADY_BIT, 1)) { > dev_err(&csdev->dev, > "timeout while waiting for TMC to be Ready\n"); > + return -EBUSY; > } > + return 0; > } > > void tmc_flush_and_stop(struct tmc_drvdata *drvdata) > diff --git a/drivers/hwtracing/coresight/coresight-tmc-etf.c b/drivers/hwtracing/coresight/coresight-tmc-etf.c > index 4c4cbd1f7258..2840227e9135 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc-etf.c > +++ b/drivers/hwtracing/coresight/coresight-tmc-etf.c > @@ -16,12 +16,19 @@ > static int tmc_set_etf_buffer(struct coresight_device *csdev, > struct perf_output_handle *handle); > > -static void __tmc_etb_enable_hw(struct tmc_drvdata *drvdata) > +static int __tmc_etb_enable_hw(struct tmc_drvdata *drvdata) > { > + int rc = 0; > + > CS_UNLOCK(drvdata->base); > > /* Wait for TMCSReady bit to be set */ > - tmc_wait_for_tmcready(drvdata); > + rc = tmc_wait_for_tmcready(drvdata); > + if (rc) { > + dev_err(&drvdata->csdev->dev, "fails to enable not ready TMC\n"); > + CS_LOCK(drvdata->base); > + return rc; > + } > > writel_relaxed(TMC_MODE_CIRCULAR_BUFFER, drvdata->base + TMC_MODE); > writel_relaxed(TMC_FFCR_EN_FMT | TMC_FFCR_EN_TI | > @@ -33,6 +40,7 @@ static void __tmc_etb_enable_hw(struct tmc_drvdata *drvdata) > tmc_enable_hw(drvdata); > > CS_LOCK(drvdata->base); > + return rc; > } > > static int tmc_etb_enable_hw(struct tmc_drvdata *drvdata) > @@ -42,8 +50,10 @@ static int tmc_etb_enable_hw(struct tmc_drvdata *drvdata) > if (rc) > return rc; > > - __tmc_etb_enable_hw(drvdata); > - return 0; > + rc = __tmc_etb_enable_hw(drvdata); > + if (rc) > + coresight_disclaim_device(drvdata->csdev); > + return rc; > } > > static void tmc_etb_dump_hw(struct tmc_drvdata *drvdata) > @@ -91,12 +101,19 @@ static void tmc_etb_disable_hw(struct tmc_drvdata *drvdata) > coresight_disclaim_device(drvdata->csdev); > } > > -static void __tmc_etf_enable_hw(struct tmc_drvdata *drvdata) > +static int __tmc_etf_enable_hw(struct tmc_drvdata *drvdata) > { > + int rc = 0; > + > CS_UNLOCK(drvdata->base); > > /* Wait for TMCSReady bit to be set */ > - tmc_wait_for_tmcready(drvdata); > + rc = tmc_wait_for_tmcready(drvdata); > + if (rc) { > + dev_err(&drvdata->csdev->dev, "fails to enable not ready TMC\n"); > + CS_LOCK(drvdata->base); > + return rc; > + } > > writel_relaxed(TMC_MODE_HARDWARE_FIFO, drvdata->base + TMC_MODE); > writel_relaxed(TMC_FFCR_EN_FMT | TMC_FFCR_EN_TI, > @@ -105,6 +122,7 @@ static void __tmc_etf_enable_hw(struct tmc_drvdata *drvdata) > tmc_enable_hw(drvdata); > > CS_LOCK(drvdata->base); > + return rc; > } > > static int tmc_etf_enable_hw(struct tmc_drvdata *drvdata) > @@ -114,8 +132,10 @@ static int tmc_etf_enable_hw(struct tmc_drvdata *drvdata) > if (rc) > return rc; > > - __tmc_etf_enable_hw(drvdata); > - return 0; > + rc = __tmc_etf_enable_hw(drvdata); > + if (rc) > + coresight_disclaim_device(drvdata->csdev); > + return rc; > } > > static void tmc_etf_disable_hw(struct tmc_drvdata *drvdata) > @@ -639,6 +659,7 @@ int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata) > char *buf = NULL; > enum tmc_mode mode; > unsigned long flags; > + int rc = 0; > > /* config types are set a boot time and never change */ > if (WARN_ON_ONCE(drvdata->config_type != TMC_CONFIG_TYPE_ETB && > @@ -664,7 +685,11 @@ int tmc_read_unprepare_etb(struct tmc_drvdata *drvdata) > * can't be NULL. > */ > memset(drvdata->buf, 0, drvdata->size); > - __tmc_etb_enable_hw(drvdata); > + rc = __tmc_etb_enable_hw(drvdata); > + if (rc) { > + spin_unlock_irqrestore(&drvdata->spinlock, flags); > + return rc; > + }
There is a similar unprepare function in ETR - this should have similar updates.
> } else { > /* > * The ETB/ETF is not tracing and the buffer was just read. > diff --git a/drivers/hwtracing/coresight/coresight-tmc-etr.c b/drivers/hwtracing/coresight/coresight-tmc-etr.c > index 867ad8bb9b0c..0811cb44588b 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc-etr.c > +++ b/drivers/hwtracing/coresight/coresight-tmc-etr.c > @@ -983,15 +983,21 @@ static void tmc_sync_etr_buf(struct tmc_drvdata *drvdata) > etr_buf->ops->sync(etr_buf, rrp, rwp); > } > > -static void __tmc_etr_enable_hw(struct tmc_drvdata *drvdata) > +static int __tmc_etr_enable_hw(struct tmc_drvdata *drvdata) > { > u32 axictl, sts; > struct etr_buf *etr_buf = drvdata->etr_buf; > + int rc = 0; > > CS_UNLOCK(drvdata->base); > > /* Wait for TMCSReady bit to be set */ > - tmc_wait_for_tmcready(drvdata); > + rc = tmc_wait_for_tmcready(drvdata); > + if (rc) { > + dev_err(&drvdata->csdev->dev, "fails to enable not ready TMC\n"); > + CS_LOCK(drvdata->base); > + return rc; > + } > > writel_relaxed(etr_buf->size / 4, drvdata->base + TMC_RSZ); > writel_relaxed(TMC_MODE_CIRCULAR_BUFFER, drvdata->base + TMC_MODE); > @@ -1032,6 +1038,7 @@ static void __tmc_etr_enable_hw(struct tmc_drvdata *drvdata) > tmc_enable_hw(drvdata); > > CS_LOCK(drvdata->base); > + return rc; > } > > static int tmc_etr_enable_hw(struct tmc_drvdata *drvdata, > @@ -1060,7 +1067,12 @@ static int tmc_etr_enable_hw(struct tmc_drvdata *drvdata, > rc = coresight_claim_device(drvdata->csdev); > if (!rc) { > drvdata->etr_buf = etr_buf; > - __tmc_etr_enable_hw(drvdata); > + rc = __tmc_etr_enable_hw(drvdata); > + if (rc) { > + drvdata->etr_buf = NULL; > + coresight_disclaim_device(drvdata->csdev); > + tmc_etr_disable_catu(drvdata); > + } > } > > return rc; > diff --git a/drivers/hwtracing/coresight/coresight-tmc.h b/drivers/hwtracing/coresight/coresight-tmc.h > index 66959557cf39..01c0382a29c0 100644 > --- a/drivers/hwtracing/coresight/coresight-tmc.h > +++ b/drivers/hwtracing/coresight/coresight-tmc.h > @@ -255,7 +255,7 @@ struct tmc_sg_table { > }; > > /* Generic functions */ > -void tmc_wait_for_tmcready(struct tmc_drvdata *drvdata); > +int tmc_wait_for_tmcready(struct tmc_drvdata *drvdata); > void tmc_flush_and_stop(struct tmc_drvdata *drvdata); > void tmc_enable_hw(struct tmc_drvdata *drvdata); > void tmc_disable_hw(struct tmc_drvdata *drvdata); > -- > 2.39.1.456.gfc5497dd1b-goog >
The tmc_flush_and_stop() function also calls tmc_wait_for_tmcready().
The etb/etf_prepare_read operations disable the etb /etf before a read commences. For consistency if this fails due to TMC not being ready do we also need to fail the read prepare operations?
Regards
Mike
-- Mike Leach Principal Engineer, ARM Ltd. Manchester Design Centre. UK
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