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authorSuzuki K Poulose <suzuki.poulose@arm.com>2021-10-19 18:31:46 +0200
committerMathieu Poirier <mathieu.poirier@linaro.org>2021-10-27 19:45:52 +0200
commite4bc8829a748c61ab07617b41da5d071b060126e (patch)
treee662c24a60cb962d8ef8bd84eb049bfee7ef674a
parentcoresight: trbe: Decouple buffer base from the hardware base (diff)
downloadlinux-e4bc8829a748c61ab07617b41da5d071b060126e.tar.xz
linux-e4bc8829a748c61ab07617b41da5d071b060126e.zip
coresight: trbe: Allow driver to choose a different alignment
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> Link: https://lore.kernel.org/r/20211019163153.3692640-9-suzuki.poulose@arm.com Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
-rw-r--r--drivers/hwtracing/coresight/coresight-trbe.c18
1 files 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;