[PATCH v6 08/15] coresight: trbe: Allow driver to choose a different alignment
From: Suzuki K Poulose <suzuki.poulose@arm.com>
Date: 2021-10-19 16:33:40
Also in:
lkml
Subsystem:
arm/coresight framework and drivers, hardware tracing facilities, the rest · Maintainers:
Suzuki K Poulose, Alexander Shishkin, Linus Torvalds
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 <redacted> Cc: Mike Leach <redacted> Cc: Leo Yan <redacted> Reviewed-by: Anshuman Khandual <redacted> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> --- drivers/hwtracing/coresight/coresight-trbe.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c
index ae0bde9630f6..cdbb134892f6 100644
--- a/drivers/hwtracing/coresight/coresight-trbe.c
+++ b/drivers/hwtracing/coresight/coresight-trbe.c@@ -67,8 +67,18 @@ struct trbe_buf { struct trbe_cpudata *cpudata; }; +/* + * struct trbe_cpudata: TRBE instance specific data + * @trbe_flag - TRBE dirty/access flag support + * @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 + */ struct trbe_cpudata { bool trbe_flag; + u64 trbe_hw_align; u64 trbe_align; int cpu; enum cs_mode mode;
@@ -875,7 +885,7 @@ 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);
@@ -967,11 +977,13 @@ 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; } + + cpudata->trbe_align = cpudata->trbe_hw_align; cpudata->trbe_flag = get_trbe_flag_update(trbidr); cpudata->cpu = cpu; cpudata->drvdata = drvdata;
--
2.25.4
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