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