| Message ID | 20200915113621.10838-1-mike.leach@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | coresight: etm4x: Fix number of resources check for ETM 4.3 and above. | expand |
Hi Mike, On Tue, Sep 15, 2020 at 12:36:21PM +0100, Mike Leach wrote: > The initialisation code checks TRCIDR4 to determine the number of resource > selectors available on the system. Since ETM v 4.3, the value 0 has a > different meaning. This patch takes into account this change. > > Signed-off-by: Mike Leach <mike.leach@linaro.org> > --- > drivers/hwtracing/coresight/coresight-etm4x.c | 8 +++++++- > drivers/hwtracing/coresight/coresight-etm4x.h | 3 +++ > 2 files changed, 10 insertions(+), 1 deletion(-) > > diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c > index 00c9f0bb8b1a..be687276704c 100644 > --- a/drivers/hwtracing/coresight/coresight-etm4x.c > +++ b/drivers/hwtracing/coresight/coresight-etm4x.c > @@ -742,8 +742,14 @@ static void etm4_init_arch_data(void *info) > * The number of resource pairs conveyed by the HW starts at 0, i.e a > * value of 0x0 indicate 1 resource pair, 0x1 indicate two and so on. > * As such add 1 to the value of NUMRSPAIR for a better representation. > + * > + * For ETM v4.3 and later, 0x0 means 0, and no pairs are available - > + * the default TRUE and FALSE resource selectors are omitted. > + * Otherwise for values 0x1 and above the number is N + 1 as per v4.2. > */ That's a weird implementation... I had to double check the documentation to convince me that your comment was correct before applying the patch. Thanks, Mathieu > - drvdata->nr_resource = BMVAL(etmidr4, 16, 19) + 1; > + drvdata->nr_resource = BMVAL(etmidr4, 16, 19); > + if ((drvdata->arch < ETM4X_ARCH_4V3) || (drvdata->nr_resource > 0)) > + drvdata->nr_resource += 1; > /* > * NUMSSCC, bits[23:20] the number of single-shot > * comparator control for tracing. Read any status regs as these > diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h > index 5259f96fd28a..eefc7371c6c4 100644 > --- a/drivers/hwtracing/coresight/coresight-etm4x.h > +++ b/drivers/hwtracing/coresight/coresight-etm4x.h > @@ -200,6 +200,9 @@ > /* NS MON (EL3) mode never implemented */ > #define ETM_EXLEVEL_NS_VICTLR_MASK GENMASK(22, 20) > > +/* Interpretation of resource numbers change at ETM v4.3 architecture */ > +#define ETM4X_ARCH_4V3 0x43 > + > /** > * struct etmv4_config - configuration information related to an ETMv4 > * @mode: Controls various modes supported by this ETM. > -- > 2.17.1 >
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c index 00c9f0bb8b1a..be687276704c 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.c +++ b/drivers/hwtracing/coresight/coresight-etm4x.c @@ -742,8 +742,14 @@ static void etm4_init_arch_data(void *info) * The number of resource pairs conveyed by the HW starts at 0, i.e a * value of 0x0 indicate 1 resource pair, 0x1 indicate two and so on. * As such add 1 to the value of NUMRSPAIR for a better representation. + * + * For ETM v4.3 and later, 0x0 means 0, and no pairs are available - + * the default TRUE and FALSE resource selectors are omitted. + * Otherwise for values 0x1 and above the number is N + 1 as per v4.2. */ - drvdata->nr_resource = BMVAL(etmidr4, 16, 19) + 1; + drvdata->nr_resource = BMVAL(etmidr4, 16, 19); + if ((drvdata->arch < ETM4X_ARCH_4V3) || (drvdata->nr_resource > 0)) + drvdata->nr_resource += 1; /* * NUMSSCC, bits[23:20] the number of single-shot * comparator control for tracing. Read any status regs as these diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h index 5259f96fd28a..eefc7371c6c4 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.h +++ b/drivers/hwtracing/coresight/coresight-etm4x.h @@ -200,6 +200,9 @@ /* NS MON (EL3) mode never implemented */ #define ETM_EXLEVEL_NS_VICTLR_MASK GENMASK(22, 20) +/* Interpretation of resource numbers change at ETM v4.3 architecture */ +#define ETM4X_ARCH_4V3 0x43 + /** * struct etmv4_config - configuration information related to an ETMv4 * @mode: Controls various modes supported by this ETM.
The initialisation code checks TRCIDR4 to determine the number of resource selectors available on the system. Since ETM v 4.3, the value 0 has a different meaning. This patch takes into account this change. Signed-off-by: Mike Leach <mike.leach@linaro.org> --- drivers/hwtracing/coresight/coresight-etm4x.c | 8 +++++++- drivers/hwtracing/coresight/coresight-etm4x.h | 3 +++ 2 files changed, 10 insertions(+), 1 deletion(-)