The TRBE hardware mandates a minimum alignment for the TRBPTR_EL1, advertised via the TRBIDR_EL1. This is used by the driver to align the buffer write head. This patch allows the driver to choose a different alignment from that of the hardware, by decoupling the alignment tracking. This will be useful for working around errata.
Cc: Mathieu Poirier mathieu.poirier@linaro.org Cc: Anshuman Khandual anshuman.khandual@arm.com Cc: Mike Leach mike.leach@linaro.org Cc: Leo Yan leo.yan@linaro.org Reviewed-by: Anshuman Khandual anshuman.khandual@arm.com Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com --- drivers/hwtracing/coresight/coresight-trbe.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c index 27616eac24ba..f569010c672b 100644 --- a/drivers/hwtracing/coresight/coresight-trbe.c +++ b/drivers/hwtracing/coresight/coresight-trbe.c @@ -92,7 +92,8 @@ static unsigned long trbe_errata_cpucaps[TRBE_ERRATA_MAX] = { /* * struct trbe_cpudata: TRBE instance specific data * @trbe_flag - TRBE dirty/access flag support - * @tbre_align - Actual TRBE alignment required for TRBPTR_EL1. + * @trbe_hw_align - Actual TRBE alignment required for TRBPTR_EL1. + * @trbe_align - Software alignment used for the TRBPTR_EL1, * @cpu - CPU this TRBE belongs to. * @mode - Mode of current operation. (perf/disabled) * @drvdata - TRBE specific drvdata @@ -100,6 +101,7 @@ static unsigned long trbe_errata_cpucaps[TRBE_ERRATA_MAX] = { */ struct trbe_cpudata { bool trbe_flag; + u64 trbe_hw_align; u64 trbe_align; int cpu; enum cs_mode mode; @@ -903,7 +905,7 @@ static ssize_t align_show(struct device *dev, struct device_attribute *attr, cha { struct trbe_cpudata *cpudata = dev_get_drvdata(dev);
- return sprintf(buf, "%llx\n", cpudata->trbe_align); + return sprintf(buf, "%llx\n", cpudata->trbe_hw_align); } static DEVICE_ATTR_RO(align);
@@ -991,13 +993,14 @@ static void arm_trbe_probe_cpu(void *info) goto cpu_clear; }
- cpudata->trbe_align = 1ULL << get_trbe_address_align(trbidr); - if (cpudata->trbe_align > SZ_2K) { + cpudata->trbe_hw_align = 1ULL << get_trbe_address_align(trbidr); + if (cpudata->trbe_hw_align > SZ_2K) { pr_err("Unsupported alignment on cpu %d\n", cpu); goto cpu_clear; }
trbe_check_errata(cpudata); + cpudata->trbe_align = cpudata->trbe_hw_align; cpudata->trbe_flag = get_trbe_flag_update(trbidr); cpudata->cpu = cpu; cpudata->drvdata = drvdata;