[PATCH v2] perf arm-spe: Add raw decoding for SPEv1.2 previous branch address

From: Rob Herring
Date: Fri Feb 03 2023 - 11:24:25 EST


Arm SPEv1.2 adds a new optional address packet type: previous branch
target. The recorded address is the target virtual address of the most
recently taken branch in program order.

Add support for decoding the address packet in raw dumps.

Reviewed-by: Leo Yan <leo.yan@xxxxxxxxxx>
Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
---
v2:
- Use "PBT" instead of "LBR"
---
tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c | 4 +++-
tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.h | 1 +
2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c b/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
index 2f311189c6e8..fed4741f372e 100644
--- a/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
+++ b/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c
@@ -422,16 +422,18 @@ static int arm_spe_pkt_desc_addr(const struct arm_spe_pkt *packet,
int ch, pat;
u64 payload = packet->payload;
int err = 0;
+ static const char *idx_name[] = {"PC", "TGT", "VA", "PA", "PBT"};

switch (idx) {
case SPE_ADDR_PKT_HDR_INDEX_INS:
case SPE_ADDR_PKT_HDR_INDEX_BRANCH:
+ case SPE_ADDR_PKT_HDR_INDEX_PREV_BRANCH:
ns = !!SPE_ADDR_PKT_GET_NS(payload);
el = SPE_ADDR_PKT_GET_EL(payload);
payload = SPE_ADDR_PKT_ADDR_GET_BYTES_0_6(payload);
arm_spe_pkt_out_string(&err, &buf, &buf_len,
"%s 0x%llx el%d ns=%d",
- (idx == 1) ? "TGT" : "PC", payload, el, ns);
+ idx_name[idx], payload, el, ns);
break;
case SPE_ADDR_PKT_HDR_INDEX_DATA_VIRT:
arm_spe_pkt_out_string(&err, &buf, &buf_len,
diff --git a/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.h b/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.h
index 9b970e7bf1e2..f75ed3a8a050 100644
--- a/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.h
+++ b/tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.h
@@ -65,6 +65,7 @@ struct arm_spe_pkt {
#define SPE_ADDR_PKT_HDR_INDEX_BRANCH 0x1
#define SPE_ADDR_PKT_HDR_INDEX_DATA_VIRT 0x2
#define SPE_ADDR_PKT_HDR_INDEX_DATA_PHYS 0x3
+#define SPE_ADDR_PKT_HDR_INDEX_PREV_BRANCH 0x4

/* Address packet payload */
#define SPE_ADDR_PKT_ADDR_BYTE7_SHIFT 56
--
2.39.0