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authorSuzuki K Poulose <suzuki.poulose@arm.com>2021-10-19 17:31:43 +0100
committerMathieu Poirier <mathieu.poirier@linaro.org>2021-10-27 11:45:46 -0600
commit41c0e5b7a35392c90a467a9a085178642a131324 (patch)
tree3d60c911130d9689dc3ec1d7ea8e9bc6f5eac5b9 /drivers/hwtracing
parenta08025b3fe56185290a1ea476581f03ca733f967 (diff)
downloadlinux-41c0e5b7a35392c90a467a9a085178642a131324.tar.bz2
coresight: trbe: Add a helper to calculate the trace generated
We collect the trace from the TRBE on FILL event from IRQ context and via update_buffer(), when the event is stopped. Let us consolidate how we calculate the trace generated into a helper. Cc: Mathieu Poirier <mathieu.poirier@linaro.org> 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/20211019163153.3692640-6-suzuki.poulose@arm.com Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Diffstat (limited to 'drivers/hwtracing')
-rw-r--r--drivers/hwtracing/coresight/coresight-trbe.c47
1 files changed, 29 insertions, 18 deletions
diff --git a/drivers/hwtracing/coresight/coresight-trbe.c b/drivers/hwtracing/coresight/coresight-trbe.c
index 5d77baba8b0f..54f5d61ee9fb 100644
--- a/drivers/hwtracing/coresight/coresight-trbe.c
+++ b/drivers/hwtracing/coresight/coresight-trbe.c
@@ -499,6 +499,29 @@ static enum trbe_fault_action trbe_get_fault_act(u64 trbsr)
return TRBE_FAULT_ACT_SPURIOUS;
}
+static unsigned long trbe_get_trace_size(struct perf_output_handle *handle,
+ struct trbe_buf *buf, bool wrap)
+{
+ u64 write;
+ u64 start_off, end_off;
+
+ /*
+ * If the TRBE has wrapped around the write pointer has
+ * wrapped and should be treated as limit.
+ */
+ if (wrap)
+ write = get_trbe_limit_pointer();
+ else
+ write = get_trbe_write_pointer();
+
+ end_off = write - get_trbe_base_pointer();
+ start_off = PERF_IDX2OFF(handle->head, buf);
+
+ if (WARN_ON_ONCE(end_off < start_off))
+ return 0;
+ return (end_off - start_off);
+}
+
static void *arm_trbe_alloc_buffer(struct coresight_device *csdev,
struct perf_event *event, void **pages,
int nr_pages, bool snapshot)
@@ -560,9 +583,9 @@ static unsigned long arm_trbe_update_buffer(struct coresight_device *csdev,
struct trbe_cpudata *cpudata = dev_get_drvdata(&csdev->dev);
struct trbe_buf *buf = config;
enum trbe_fault_action act;
- unsigned long size, offset;
- unsigned long write, base, status;
+ unsigned long size, status;
unsigned long flags;
+ bool wrap = false;
WARN_ON(buf->cpudata != cpudata);
WARN_ON(cpudata->cpu != smp_processor_id());
@@ -602,8 +625,6 @@ static unsigned long arm_trbe_update_buffer(struct coresight_device *csdev,
* handle gets freed in etm_event_stop().
*/
trbe_drain_and_disable_local();
- write = get_trbe_write_pointer();
- base = get_trbe_base_pointer();
/* Check if there is a pending interrupt and handle it here */
status = read_sysreg_s(SYS_TRBSR_EL1);
@@ -627,20 +648,11 @@ static unsigned long arm_trbe_update_buffer(struct coresight_device *csdev,
goto done;
}
- /*
- * Otherwise, the buffer is full and the write pointer
- * has reached base. Adjust this back to the Limit pointer
- * for correct size. Also, mark the buffer truncated.
- */
- write = get_trbe_limit_pointer();
trbe_report_wrap_event(handle);
+ wrap = true;
}
- offset = write - base;
- if (WARN_ON_ONCE(offset < PERF_IDX2OFF(handle->head, buf)))
- size = 0;
- else
- size = offset - PERF_IDX2OFF(handle->head, buf);
+ size = trbe_get_trace_size(handle, buf, wrap);
done:
local_irq_restore(flags);
@@ -721,11 +733,10 @@ static int trbe_handle_overflow(struct perf_output_handle *handle)
{
struct perf_event *event = handle->event;
struct trbe_buf *buf = etm_perf_sink_config(handle);
- unsigned long offset, size;
+ unsigned long size;
struct etm_event_data *event_data;
- offset = get_trbe_limit_pointer() - get_trbe_base_pointer();
- size = offset - PERF_IDX2OFF(handle->head, buf);
+ size = trbe_get_trace_size(handle, buf, true);
if (buf->snapshot)
handle->head += size;