On Tue, Feb 02, 2021 at 11:19:22PM +0000, Suzuki Kuruppassery Poulose wrote:
On 2/2/21 4:38 PM, Leo Yan wrote:
This patch adds helper function cs_etm__get_pid_fmt(), by passing parameter "traceID", it returns the PID format.
Signed-off-by: Leo Yan leo.yan@linaro.org
tools/perf/util/cs-etm.c | 43 ++++++++++++++++++++++++++++++++++++++++ tools/perf/util/cs-etm.h | 1 + 2 files changed, 44 insertions(+)
diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c index a2a369e2fbb6..8194ddbd01e5 100644 --- a/tools/perf/util/cs-etm.c +++ b/tools/perf/util/cs-etm.c @@ -7,6 +7,7 @@ */ #include <linux/bitops.h> +#include <linux/coresight-pmu.h> #include <linux/err.h> #include <linux/kernel.h> #include <linux/log2.h> @@ -156,6 +157,48 @@ int cs_etm__get_cpu(u8 trace_chan_id, int *cpu) return 0; } +/*
- The returned PID format is presented by two bits:
- Bit ETM_OPT_CTXTID: CONTEXTIDR or CONTEXTIDR_EL1 is traced;
- Bit ETM_OPT_CTXTID2: CONTEXTIDR_EL2 is traced.
- It's possible that these two bits are set together, this means the tracing
- contains PIDs for both CONTEXTIDR_EL1 and CONTEXTIDR_EL2.
This is a bit confusing. If both the bits are set, the session was run on an EL2 kernel. Thus, the PID is always in CONTEXTIDR_EL2.
Sorry for confusion. I'd like to rephrase as:
It's possible that the two bits ETM_OPT_CTXTID and ETM_OPT_CTXTID2 are enabled at the same time when the session runs on an EL2 kernel. This means the CONTEXTIDR_EL1 and CONTEXTIDR_EL2 both will be recorded in the trace data, the tool will selectively use CONTEXTIDR_EL2 as PID.
- */
+int cs_etm__get_pid_fmt(u8 trace_chan_id, u64 *pid_fmt) +{
- struct int_node *inode;
- u64 *metadata, val;
- inode = intlist__find(traceid_list, trace_chan_id);
- if (!inode)
return -EINVAL;- metadata = inode->priv;
- if (metadata[CS_ETM_MAGIC] == __perf_cs_etmv3_magic) {
val = metadata[CS_ETM_ETMCR];/* CONTEXTIDR is traced */if (val & BIT(ETM_OPT_CTXTID))*pid_fmt = BIT(ETM_OPT_CTXTID);- } else {
val = metadata[CS_ETMV4_TRCCONFIGR];*pid_fmt = 0;/* CONTEXTIDR_EL2 is traced */if (val & (BIT(ETM4_CFG_BIT_VMID) | BIT(ETM4_CFG_BIT_VMID_OPT)))*pid_fmt = BIT(ETM_OPT_CTXTID2);/* CONTEXTIDR_EL1 is traced */if (val & BIT(ETM4_CFG_BIT_CTXTID))I haven't looked at how this gets used. But, Shouldn't this be :
else if (val & BIT(ETM4_CFG_BIT_CTXTID)) ?
Actually it's deliberately to set both bits ETM_OPT_CTXTID2 and ETM_OPT_CTXTID if user has enable configs "contextid1" and "contextid2". So this is exactly the reversed flow in the function cs_etmv4_get_config().
Thanks, Leo