[PATCH v7 00/22] perf arm-spe: Refactor decoding & dumping flow

[PATCH v7 00/22] perf arm-spe: Refactor decoding & dumping flow

[Leo Yan]

This is patch set v7 for refactoring Arm SPE trace decoding and dumping.
It follows Dave's comment to consolidate the return value for
arm_spe_pkt_desc().

This patch set is cleanly applied on the top of perf/core branch
with commit 7b3bcedf5ee5 ("perf scripting python: Avoid declaring
function pointers with a visibility attribute").

Have tested this patch set on Hisilicon D06 platform with commands
"perf report -D" and "perf script", compared the decoding results
between with this patch set and without this patch set, didn't find
issue with "diff" tool.

Changes from v6:
- Removed the redundant comma from the string in the patch 21/22 "perf
  arm_spe: Decode memory tagging properties" (Dave);
- Refined the return value for arm_spe_pkt_desc(): returns 0 for
  success, otherwise returns non zero for failures; handle error code at
  the end of function arm_spe_pkt_desc(); this is accomplished in the
  new patch 07/22 "perf arm-spe: Consolidate arm_spe_pkt_desc()'s
  return value" (Dave).

Changes from v5:
- Directly bail out arm_spe_pkt_snprintf() if any error occurred
  (Andre).

Changes from v4:
- Implemented a cumulative error for arm_spe_pkt_snprintf() and changed
  to condense code for printing strings (Dave);
- Changed to check payload bits [55:52] for parse kernel address
  (Andre).

Changes from v3:
- Refined arm_spe_payload_len() and removed macro SPE_HEADER_SZ()
  (Andre);
- Refined packet header index macros (Andre);
- Added patch "perf arm_spe: Fixup top byte for data virtual address" to
  fixup the data virtual address for 64KB pages and refined comments for
  the fixup (Andre);
- Added Andre's review tag (using "b4 am" command);
- Changed the macros to SPE_PKT_IS_XXX() format to check operation types
  (Andre).


Andre Przywara (1):
  perf arm_spe: Decode memory tagging properties

Leo Yan (20):
  perf arm-spe: Include bitops.h for BIT() macro
  perf arm-spe: Fix a typo in comment
  perf arm-spe: Refactor payload size calculation
  perf arm-spe: Refactor arm_spe_get_events()
  perf arm-spe: Fix packet length handling
  perf arm-spe: Refactor printing string to buffer
  perf arm-spe: Consolidate arm_spe_pkt_desc()'s return value
  perf arm-spe: Refactor packet header parsing
  perf arm-spe: Add new function arm_spe_pkt_desc_addr()
  perf arm-spe: Refactor address packet handling
  perf arm_spe: Fixup top byte for data virtual address
  perf arm-spe: Refactor context packet handling
  perf arm-spe: Add new function arm_spe_pkt_desc_counter()
  perf arm-spe: Refactor counter packet handling
  perf arm-spe: Add new function arm_spe_pkt_desc_event()
  perf arm-spe: Refactor event type handling
  perf arm-spe: Remove size condition checking for events
  perf arm-spe: Add new function arm_spe_pkt_desc_op_type()
  perf arm-spe: Refactor operation packet handling
  perf arm-spe: Add more sub classes for operation packet

Wei Li (1):
  perf arm-spe: Add support for ARMv8.3-SPE

 .../util/arm-spe-decoder/arm-spe-decoder.c    |  59 +-
 .../util/arm-spe-decoder/arm-spe-decoder.h    |  17 -
 .../arm-spe-decoder/arm-spe-pkt-decoder.c     | 601 ++++++++++--------
 .../arm-spe-decoder/arm-spe-pkt-decoder.h     | 122 +++-
 tools/perf/util/arm-spe.c                     |   2 +-
 5 files changed, 479 insertions(+), 322 deletions(-)

-- 
2.17.1

[PATCH v7 01/22] perf arm-spe: Include bitops.h for BIT() macro

[Leo Yan]

Include header linux/bitops.h, directly use its BIT() macro and remove
the self defined macros.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
---
 tools/perf/util/arm-spe-decoder/arm-spe-decoder.c     | 5 +----
 tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c | 3 +--
 2 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c b/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c
index 93e063f22be5..cc18a1e8c212 100644
--- a/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c
+++ b/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c
@@ -12,6 +12,7 @@
 #include <string.h>
 #include <stdint.h>
 #include <stdlib.h>
+#include <linux/bitops.h>
 #include <linux/compiler.h>
 #include <linux/zalloc.h>
 
@@ -21,10 +22,6 @@
 
 #include "arm-spe-decoder.h"
 
-#ifndef BIT
-#define BIT(n)		(1UL << (n))
-#endif
-
 static u64 arm_spe_calc_ip(int index, u64 payload)
 {
 	u8 *addr = (u8 *)&payload;
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 b94001b756c7..46ddb53a6457 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
@@ -8,11 +8,10 @@
 #include <string.h>
 #include <endian.h>
 #include <byteswap.h>
+#include <linux/bitops.h>
 
 #include "arm-spe-pkt-decoder.h"
 
-#define BIT(n)		(1ULL << (n))
-
 #define NS_FLAG		BIT(63)
 #define EL_FLAG		(BIT(62) | BIT(61))
 
-- 
2.17.1

[PATCH v7 02/22] perf arm-spe: Fix a typo in comment

[Leo Yan]

Fix a typo: s/iff/if.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
---
 tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c | 2 +-
 1 file changed, 1 insertion(+), 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 46ddb53a6457..7c7b5eb09fba 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
@@ -142,7 +142,7 @@ static int arm_spe_get_events(const unsigned char *buf, size_t len,
 
 	/* we use index to identify Events with a less number of
 	 * comparisons in arm_spe_pkt_desc(): E.g., the LLC-ACCESS,
-	 * LLC-REFILL, and REMOTE-ACCESS events are identified iff
+	 * LLC-REFILL, and REMOTE-ACCESS events are identified if
 	 * index > 1.
 	 */
 	packet->index = ret - 1;
-- 
2.17.1

[PATCH v7 03/22] perf arm-spe: Refactor payload size calculation

[Leo Yan]

This patch defines macro to extract "sz" field from header, and renames
the function payloadlen() to arm_spe_payload_len().

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
---
 .../util/arm-spe-decoder/arm-spe-pkt-decoder.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

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 7c7b5eb09fba..06b3eec4494e 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
@@ -69,22 +69,22 @@ const char *arm_spe_pkt_name(enum arm_spe_pkt_type type)
 	return arm_spe_packet_name[type];
 }
 
-/* return ARM SPE payload size from its encoding,
- * which is in bits 5:4 of the byte.
- * 00 : byte
- * 01 : halfword (2)
- * 10 : word (4)
- * 11 : doubleword (8)
+/*
+ * Extracts the field "sz" from header bits and converts to bytes:
+ *   00 : byte (1)
+ *   01 : halfword (2)
+ *   10 : word (4)
+ *   11 : doubleword (8)
  */
-static int payloadlen(unsigned char byte)
+static unsigned int arm_spe_payload_len(unsigned char hdr)
 {
-	return 1 << ((byte & 0x30) >> 4);
+	return 1U << ((hdr & GENMASK_ULL(5, 4)) >> 4);
 }
 
 static int arm_spe_get_payload(const unsigned char *buf, size_t len,
 			       struct arm_spe_pkt *packet)
 {
-	size_t payload_len = payloadlen(buf[0]);
+	size_t payload_len = arm_spe_payload_len(buf[0]);
 
 	if (len < 1 + payload_len)
 		return ARM_SPE_NEED_MORE_BYTES;
-- 
2.17.1

[PATCH v7 04/22] perf arm-spe: Refactor arm_spe_get_events()

[Leo Yan]

In function arm_spe_get_events(), the event packet's 'index' is assigned
as payload length, but the flow is not directive: it firstly gets the
packet length from the return value of arm_spe_get_payload(), the value
includes header length (1) and payload length:

  int ret = arm_spe_get_payload(buf, len, packet);

and then reduces header length from packet length, so finally get the
payload length:

  packet->index = ret - 1;

To simplify the code, this patch directly assigns payload length to
event packet's index; and at the end it calls arm_spe_get_payload() to
return the payload value.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
---
 tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

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 06b3eec4494e..f1b4cb008837 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
@@ -136,8 +136,6 @@ static int arm_spe_get_timestamp(const unsigned char *buf, size_t len,
 static int arm_spe_get_events(const unsigned char *buf, size_t len,
 			      struct arm_spe_pkt *packet)
 {
-	int ret = arm_spe_get_payload(buf, len, packet);
-
 	packet->type = ARM_SPE_EVENTS;
 
 	/* we use index to identify Events with a less number of
@@ -145,9 +143,9 @@ static int arm_spe_get_events(const unsigned char *buf, size_t len,
 	 * LLC-REFILL, and REMOTE-ACCESS events are identified if
 	 * index > 1.
 	 */
-	packet->index = ret - 1;
+	packet->index = arm_spe_payload_len(buf[0]);
 
-	return ret;
+	return arm_spe_get_payload(buf, len, packet);
 }
 
 static int arm_spe_get_data_source(const unsigned char *buf, size_t len,
-- 
2.17.1

[PATCH v7 05/22] perf arm-spe: Fix packet length handling

[Leo Yan]

When processing address packet and counter packet, if the packet
contains extended header, it misses to account the extra one byte for
header length calculation, thus returns the wrong packet length.

To correct the packet length calculation, one possible fixing is simply
to plus extra 1 for extended header, but will spread some duplicate code
in the flows for processing address packet and counter packet.
Alternatively, we can refine the function arm_spe_get_payload() to not
only support short header and allow it to support extended header, and
rely on it for the packet length calculation.

So this patch refactors function arm_spe_get_payload() with a new
argument 'ext_hdr' for support extended header; the packet processing
flows can invoke this function to unify the packet length calculation.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
---
 .../arm-spe-decoder/arm-spe-pkt-decoder.c     | 34 +++++++------------
 1 file changed, 12 insertions(+), 22 deletions(-)

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 f1b4cb008837..04fd7fd7c15f 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
@@ -82,14 +82,15 @@ static unsigned int arm_spe_payload_len(unsigned char hdr)
 }
 
 static int arm_spe_get_payload(const unsigned char *buf, size_t len,
+			       unsigned char ext_hdr,
 			       struct arm_spe_pkt *packet)
 {
-	size_t payload_len = arm_spe_payload_len(buf[0]);
+	size_t payload_len = arm_spe_payload_len(buf[ext_hdr]);
 
-	if (len < 1 + payload_len)
+	if (len < 1 + ext_hdr + payload_len)
 		return ARM_SPE_NEED_MORE_BYTES;
 
-	buf++;
+	buf += 1 + ext_hdr;
 
 	switch (payload_len) {
 	case 1: packet->payload = *(uint8_t *)buf; break;
@@ -99,7 +100,7 @@ static int arm_spe_get_payload(const unsigned char *buf, size_t len,
 	default: return ARM_SPE_BAD_PACKET;
 	}
 
-	return 1 + payload_len;
+	return 1 + ext_hdr + payload_len;
 }
 
 static int arm_spe_get_pad(struct arm_spe_pkt *packet)
@@ -130,7 +131,7 @@ static int arm_spe_get_timestamp(const unsigned char *buf, size_t len,
 				 struct arm_spe_pkt *packet)
 {
 	packet->type = ARM_SPE_TIMESTAMP;
-	return arm_spe_get_payload(buf, len, packet);
+	return arm_spe_get_payload(buf, len, 0, packet);
 }
 
 static int arm_spe_get_events(const unsigned char *buf, size_t len,
@@ -145,14 +146,14 @@ static int arm_spe_get_events(const unsigned char *buf, size_t len,
 	 */
 	packet->index = arm_spe_payload_len(buf[0]);
 
-	return arm_spe_get_payload(buf, len, packet);
+	return arm_spe_get_payload(buf, len, 0, packet);
 }
 
 static int arm_spe_get_data_source(const unsigned char *buf, size_t len,
 				   struct arm_spe_pkt *packet)
 {
 	packet->type = ARM_SPE_DATA_SOURCE;
-	return arm_spe_get_payload(buf, len, packet);
+	return arm_spe_get_payload(buf, len, 0, packet);
 }
 
 static int arm_spe_get_context(const unsigned char *buf, size_t len,
@@ -160,8 +161,7 @@ static int arm_spe_get_context(const unsigned char *buf, size_t len,
 {
 	packet->type = ARM_SPE_CONTEXT;
 	packet->index = buf[0] & 0x3;
-
-	return arm_spe_get_payload(buf, len, packet);
+	return arm_spe_get_payload(buf, len, 0, packet);
 }
 
 static int arm_spe_get_op_type(const unsigned char *buf, size_t len,
@@ -169,41 +169,31 @@ static int arm_spe_get_op_type(const unsigned char *buf, size_t len,
 {
 	packet->type = ARM_SPE_OP_TYPE;
 	packet->index = buf[0] & 0x3;
-	return arm_spe_get_payload(buf, len, packet);
+	return arm_spe_get_payload(buf, len, 0, packet);
 }
 
 static int arm_spe_get_counter(const unsigned char *buf, size_t len,
 			       const unsigned char ext_hdr, struct arm_spe_pkt *packet)
 {
-	if (len < 2)
-		return ARM_SPE_NEED_MORE_BYTES;
-
 	packet->type = ARM_SPE_COUNTER;
 	if (ext_hdr)
 		packet->index = ((buf[0] & 0x3) << 3) | (buf[1] & 0x7);
 	else
 		packet->index = buf[0] & 0x7;
 
-	packet->payload = le16_to_cpu(*(uint16_t *)(buf + 1));
-
-	return 1 + ext_hdr + 2;
+	return arm_spe_get_payload(buf, len, ext_hdr, packet);
 }
 
 static int arm_spe_get_addr(const unsigned char *buf, size_t len,
 			    const unsigned char ext_hdr, struct arm_spe_pkt *packet)
 {
-	if (len < 8)
-		return ARM_SPE_NEED_MORE_BYTES;
-
 	packet->type = ARM_SPE_ADDRESS;
 	if (ext_hdr)
 		packet->index = ((buf[0] & 0x3) << 3) | (buf[1] & 0x7);
 	else
 		packet->index = buf[0] & 0x7;
 
-	memcpy_le64(&packet->payload, buf + 1, 8);
-
-	return 1 + ext_hdr + 8;
+	return arm_spe_get_payload(buf, len, ext_hdr, packet);
 }
 
 static int arm_spe_do_get_packet(const unsigned char *buf, size_t len,
-- 
2.17.1

[PATCH v7 06/22] perf arm-spe: Refactor printing string to buffer

[Leo Yan]

When outputs strings to the decoding buffer with function snprintf(),
SPE decoder needs to detects if any error returns from snprintf() and if
so needs to directly bail out.  If snprintf() returns success, it needs
to update buffer pointer and reduce the buffer length so can continue to
output the next string into the consequent memory space.

This complex logics are spreading in the function arm_spe_pkt_desc() so
there has many duplicate codes for handling error detecting, increment
buffer pointer and decrement buffer size.

To avoid the duplicate code, this patch introduces a new helper function
arm_spe_pkt_snprintf() which is used to wrap up the complex logics, and
it's used by the caller arm_spe_pkt_desc().

This patch also moves the variable 'blen' as the function's local
variable, this allows to remove the unnecessary braces and improve the
readability.

Suggested-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
---
 .../arm-spe-decoder/arm-spe-pkt-decoder.c     | 260 +++++++++---------
 1 file changed, 126 insertions(+), 134 deletions(-)

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 04fd7fd7c15f..1970686f7020 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
@@ -9,6 +9,7 @@
 #include <endian.h>
 #include <byteswap.h>
 #include <linux/bitops.h>
+#include <stdarg.h>
 
 #include "arm-spe-pkt-decoder.h"
 
@@ -258,192 +259,183 @@ int arm_spe_get_packet(const unsigned char *buf, size_t len,
 	return ret;
 }
 
+static int arm_spe_pkt_snprintf(int *err, char **buf_p, size_t *blen,
+				const char *fmt, ...)
+{
+	va_list ap;
+	int ret;
+
+	/* Bail out if any error occurred */
+	if (err && *err)
+		return *err;
+
+	va_start(ap, fmt);
+	ret = vsnprintf(*buf_p, *blen, fmt, ap);
+	va_end(ap);
+
+	if (ret < 0) {
+		if (err && !*err)
+			*err = ret;
+
+	/*
+	 * A return value of (*blen - 1) or more means that the
+	 * output was truncated and the buffer is overrun.
+	 */
+	} else if (ret >= ((int)*blen - 1)) {
+		(*buf_p)[*blen - 1] = '\0';
+
+		/*
+		 * Set *err to 'ret' to avoid overflow if tries to
+		 * fill this buffer sequentially.
+		 */
+		if (err && !*err)
+			*err = ret;
+	} else {
+		*buf_p += ret;
+		*blen -= ret;
+	}
+
+	return ret;
+}
+
 int arm_spe_pkt_desc(const struct arm_spe_pkt *packet, char *buf,
 		     size_t buf_len)
 {
 	int ret, ns, el, idx = packet->index;
 	unsigned long long payload = packet->payload;
 	const char *name = arm_spe_pkt_name(packet->type);
+	size_t blen = buf_len;
+	int err = 0;
 
 	switch (packet->type) {
 	case ARM_SPE_BAD:
 	case ARM_SPE_PAD:
 	case ARM_SPE_END:
-		return snprintf(buf, buf_len, "%s", name);
-	case ARM_SPE_EVENTS: {
-		size_t blen = buf_len;
-
-		ret = 0;
-		ret = snprintf(buf, buf_len, "EV");
-		buf += ret;
-		blen -= ret;
-		if (payload & 0x1) {
-			ret = snprintf(buf, buf_len, " EXCEPTION-GEN");
-			buf += ret;
-			blen -= ret;
-		}
-		if (payload & 0x2) {
-			ret = snprintf(buf, buf_len, " RETIRED");
-			buf += ret;
-			blen -= ret;
-		}
-		if (payload & 0x4) {
-			ret = snprintf(buf, buf_len, " L1D-ACCESS");
-			buf += ret;
-			blen -= ret;
-		}
-		if (payload & 0x8) {
-			ret = snprintf(buf, buf_len, " L1D-REFILL");
-			buf += ret;
-			blen -= ret;
-		}
-		if (payload & 0x10) {
-			ret = snprintf(buf, buf_len, " TLB-ACCESS");
-			buf += ret;
-			blen -= ret;
-		}
-		if (payload & 0x20) {
-			ret = snprintf(buf, buf_len, " TLB-REFILL");
-			buf += ret;
-			blen -= ret;
-		}
-		if (payload & 0x40) {
-			ret = snprintf(buf, buf_len, " NOT-TAKEN");
-			buf += ret;
-			blen -= ret;
-		}
-		if (payload & 0x80) {
-			ret = snprintf(buf, buf_len, " MISPRED");
-			buf += ret;
-			blen -= ret;
-		}
+		return arm_spe_pkt_snprintf(&err, &buf, &blen, "%s", name);
+	case ARM_SPE_EVENTS:
+		ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "EV");
+
+		if (payload & 0x1)
+			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " EXCEPTION-GEN");
+		if (payload & 0x2)
+			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " RETIRED");
+		if (payload & 0x4)
+			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " L1D-ACCESS");
+		if (payload & 0x8)
+			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " L1D-REFILL");
+		if (payload & 0x10)
+			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " TLB-ACCESS");
+		if (payload & 0x20)
+			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " TLB-REFILL");
+		if (payload & 0x40)
+			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " NOT-TAKEN");
+		if (payload & 0x80)
+			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " MISPRED");
 		if (idx > 1) {
-			if (payload & 0x100) {
-				ret = snprintf(buf, buf_len, " LLC-ACCESS");
-				buf += ret;
-				blen -= ret;
-			}
-			if (payload & 0x200) {
-				ret = snprintf(buf, buf_len, " LLC-REFILL");
-				buf += ret;
-				blen -= ret;
-			}
-			if (payload & 0x400) {
-				ret = snprintf(buf, buf_len, " REMOTE-ACCESS");
-				buf += ret;
-				blen -= ret;
-			}
+			if (payload & 0x100)
+				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " LLC-ACCESS");
+			if (payload & 0x200)
+				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " LLC-REFILL");
+			if (payload & 0x400)
+				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " REMOTE-ACCESS");
 		}
 		if (ret < 0)
 			return ret;
 		blen -= ret;
 		return buf_len - blen;
-	}
 	case ARM_SPE_OP_TYPE:
 		switch (idx) {
-		case 0:	return snprintf(buf, buf_len, "%s", payload & 0x1 ?
-					"COND-SELECT" : "INSN-OTHER");
-		case 1:	{
-			size_t blen = buf_len;
+		case 0:
+			return arm_spe_pkt_snprintf(&err, &buf, &blen,
+					payload & 0x1 ? "COND-SELECT" : "INSN-OTHER");
+		case 1:
+			ret = arm_spe_pkt_snprintf(&err, &buf, &blen,
+						   payload & 0x1 ? "ST" : "LD");
 
-			if (payload & 0x1)
-				ret = snprintf(buf, buf_len, "ST");
-			else
-				ret = snprintf(buf, buf_len, "LD");
-			buf += ret;
-			blen -= ret;
 			if (payload & 0x2) {
-				if (payload & 0x4) {
-					ret = snprintf(buf, buf_len, " AT");
-					buf += ret;
-					blen -= ret;
-				}
-				if (payload & 0x8) {
-					ret = snprintf(buf, buf_len, " EXCL");
-					buf += ret;
-					blen -= ret;
-				}
-				if (payload & 0x10) {
-					ret = snprintf(buf, buf_len, " AR");
-					buf += ret;
-					blen -= ret;
-				}
+				if (payload & 0x4)
+					ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " AT");
+				if (payload & 0x8)
+					ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " EXCL");
+				if (payload & 0x10)
+					ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " AR");
 			} else if (payload & 0x4) {
-				ret = snprintf(buf, buf_len, " SIMD-FP");
-				buf += ret;
-				blen -= ret;
+				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " SIMD-FP");
 			}
+
 			if (ret < 0)
 				return ret;
 			blen -= ret;
 			return buf_len - blen;
-		}
-		case 2:	{
-			size_t blen = buf_len;
 
-			ret = snprintf(buf, buf_len, "B");
-			buf += ret;
-			blen -= ret;
-			if (payload & 0x1) {
-				ret = snprintf(buf, buf_len, " COND");
-				buf += ret;
-				blen -= ret;
-			}
-			if (payload & 0x2) {
-				ret = snprintf(buf, buf_len, " IND");
-				buf += ret;
-				blen -= ret;
-			}
+		case 2:
+			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "B");
+
+			if (payload & 0x1)
+				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " COND");
+			if (payload & 0x2)
+				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " IND");
+
 			if (ret < 0)
 				return ret;
 			blen -= ret;
 			return buf_len - blen;
-			}
-		default: return 0;
+
+		default:
+			return 0;
 		}
 	case ARM_SPE_DATA_SOURCE:
 	case ARM_SPE_TIMESTAMP:
-		return snprintf(buf, buf_len, "%s %lld", name, payload);
+		return arm_spe_pkt_snprintf(&err, &buf, &blen, "%s %lld", name, payload);
 	case ARM_SPE_ADDRESS:
 		switch (idx) {
 		case 0:
-		case 1: ns = !!(packet->payload & NS_FLAG);
+		case 1:
+			ns = !!(packet->payload & NS_FLAG);
 			el = (packet->payload & EL_FLAG) >> 61;
 			payload &= ~(0xffULL << 56);
-			return snprintf(buf, buf_len, "%s 0x%llx el%d ns=%d",
+			return arm_spe_pkt_snprintf(&err, &buf, &blen,
+					"%s 0x%llx el%d ns=%d",
 				        (idx == 1) ? "TGT" : "PC", payload, el, ns);
-		case 2:	return snprintf(buf, buf_len, "VA 0x%llx", payload);
-		case 3:	ns = !!(packet->payload & NS_FLAG);
+		case 2:
+			return arm_spe_pkt_snprintf(&err, &buf, &blen,
+						    "VA 0x%llx", payload);
+		case 3:
+			ns = !!(packet->payload & NS_FLAG);
 			payload &= ~(0xffULL << 56);
-			return snprintf(buf, buf_len, "PA 0x%llx ns=%d",
-					payload, ns);
-		default: return 0;
+			return arm_spe_pkt_snprintf(&err, &buf, &blen,
+						    "PA 0x%llx ns=%d", payload, ns);
+		default:
+			return 0;
 		}
 	case ARM_SPE_CONTEXT:
-		return snprintf(buf, buf_len, "%s 0x%lx el%d", name,
-				(unsigned long)payload, idx + 1);
-	case ARM_SPE_COUNTER: {
-		size_t blen = buf_len;
-
-		ret = snprintf(buf, buf_len, "%s %d ", name,
-			       (unsigned short)payload);
-		buf += ret;
-		blen -= ret;
+		return arm_spe_pkt_snprintf(&err, &buf, &blen, "%s 0x%lx el%d",
+					    name, (unsigned long)payload, idx + 1);
+	case ARM_SPE_COUNTER:
+		ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "%s %d ", name,
+					   (unsigned short)payload);
 		switch (idx) {
-		case 0:	ret = snprintf(buf, buf_len, "TOT"); break;
-		case 1:	ret = snprintf(buf, buf_len, "ISSUE"); break;
-		case 2:	ret = snprintf(buf, buf_len, "XLAT"); break;
-		default: ret = 0;
+		case 0:
+			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "TOT");
+			break;
+		case 1:
+			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "ISSUE");
+			break;
+		case 2:
+			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "XLAT");
+			break;
+		default:
+			ret = 0;
+			break;
 		}
 		if (ret < 0)
 			return ret;
 		blen -= ret;
 		return buf_len - blen;
-	}
 	default:
 		break;
 	}
 
-	return snprintf(buf, buf_len, "%s 0x%llx (%d)",
-			name, payload, packet->index);
+	return arm_spe_pkt_snprintf(&err, &buf, &blen, "%s 0x%llx (%d)",
+				    name, payload, packet->index);
 }
-- 
2.17.1

[PATCH v7 07/22] perf arm-spe: Consolidate arm_spe_pkt_desc()'s return value

[Leo Yan]

arm_spe_pkt_desc() returns the length of consumed the buffer for
the success case; otherwise, it delivers the return value from
arm_spe_pkt_snprintf(), and returns the last return value if there have
multiple calling arm_spe_pkt_snprintf().

Since arm_spe_pkt_snprintf() has the same semantics with vsnprintf() for
the return value, and vsnprintf() might return value equals to or bigger
than the parameter 'size' to indicate the truncation.  Because the
return value is >= 0 when the string is truncated, this condition will
be returned up the stack as "success".

This patch simplifies the return value for arm_spe_pkt_desc(): '0' means
success and other values mean an error has occurred.  To realize this,
it relies on arm_spe_pkt_snprintf()'s parameter 'err', the 'err' is a
cumulative value, returns its final value if printing buffer is called
for one time or multiple times.

To unify the error value generation, this patch handles error in a
central place, rather than directly bailing out in switch-cases,
it returns error at the end of arm_spe_pkt_desc().

This patch changes the caller arm_spe_dump() to respect the updated
return value semantics of arm_spe_pkt_desc().

Suggested-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
---
 .../arm-spe-decoder/arm-spe-pkt-decoder.c     | 128 +++++++++---------
 tools/perf/util/arm-spe.c                     |   2 +-
 2 files changed, 68 insertions(+), 62 deletions(-)

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 1970686f7020..33baef0c2c0b 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
@@ -301,9 +301,10 @@ static int arm_spe_pkt_snprintf(int *err, char **buf_p, size_t *blen,
 int arm_spe_pkt_desc(const struct arm_spe_pkt *packet, char *buf,
 		     size_t buf_len)
 {
-	int ret, ns, el, idx = packet->index;
+	int ns, el, idx = packet->index;
 	unsigned long long payload = packet->payload;
 	const char *name = arm_spe_pkt_name(packet->type);
+	char *buf_orig = buf;
 	size_t blen = buf_len;
 	int err = 0;
 
@@ -311,82 +312,76 @@ int arm_spe_pkt_desc(const struct arm_spe_pkt *packet, char *buf,
 	case ARM_SPE_BAD:
 	case ARM_SPE_PAD:
 	case ARM_SPE_END:
-		return arm_spe_pkt_snprintf(&err, &buf, &blen, "%s", name);
+		arm_spe_pkt_snprintf(&err, &buf, &blen, "%s", name);
+		break;
 	case ARM_SPE_EVENTS:
-		ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "EV");
+		arm_spe_pkt_snprintf(&err, &buf, &blen, "EV");
 
 		if (payload & 0x1)
-			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " EXCEPTION-GEN");
+			arm_spe_pkt_snprintf(&err, &buf, &blen, " EXCEPTION-GEN");
 		if (payload & 0x2)
-			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " RETIRED");
+			arm_spe_pkt_snprintf(&err, &buf, &blen, " RETIRED");
 		if (payload & 0x4)
-			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " L1D-ACCESS");
+			arm_spe_pkt_snprintf(&err, &buf, &blen, " L1D-ACCESS");
 		if (payload & 0x8)
-			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " L1D-REFILL");
+			arm_spe_pkt_snprintf(&err, &buf, &blen, " L1D-REFILL");
 		if (payload & 0x10)
-			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " TLB-ACCESS");
+			arm_spe_pkt_snprintf(&err, &buf, &blen, " TLB-ACCESS");
 		if (payload & 0x20)
-			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " TLB-REFILL");
+			arm_spe_pkt_snprintf(&err, &buf, &blen, " TLB-REFILL");
 		if (payload & 0x40)
-			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " NOT-TAKEN");
+			arm_spe_pkt_snprintf(&err, &buf, &blen, " NOT-TAKEN");
 		if (payload & 0x80)
-			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " MISPRED");
+			arm_spe_pkt_snprintf(&err, &buf, &blen, " MISPRED");
 		if (idx > 1) {
 			if (payload & 0x100)
-				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " LLC-ACCESS");
+				arm_spe_pkt_snprintf(&err, &buf, &blen, " LLC-ACCESS");
 			if (payload & 0x200)
-				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " LLC-REFILL");
+				arm_spe_pkt_snprintf(&err, &buf, &blen, " LLC-REFILL");
 			if (payload & 0x400)
-				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " REMOTE-ACCESS");
+				arm_spe_pkt_snprintf(&err, &buf, &blen, " REMOTE-ACCESS");
 		}
-		if (ret < 0)
-			return ret;
-		blen -= ret;
-		return buf_len - blen;
+		break;
 	case ARM_SPE_OP_TYPE:
 		switch (idx) {
 		case 0:
-			return arm_spe_pkt_snprintf(&err, &buf, &blen,
+			arm_spe_pkt_snprintf(&err, &buf, &blen,
 					payload & 0x1 ? "COND-SELECT" : "INSN-OTHER");
+			break;
 		case 1:
-			ret = arm_spe_pkt_snprintf(&err, &buf, &blen,
-						   payload & 0x1 ? "ST" : "LD");
+			arm_spe_pkt_snprintf(&err, &buf, &blen,
+					     payload & 0x1 ? "ST" : "LD");
 
 			if (payload & 0x2) {
 				if (payload & 0x4)
-					ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " AT");
+					arm_spe_pkt_snprintf(&err, &buf, &blen, " AT");
 				if (payload & 0x8)
-					ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " EXCL");
+					arm_spe_pkt_snprintf(&err, &buf, &blen, " EXCL");
 				if (payload & 0x10)
-					ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " AR");
+					arm_spe_pkt_snprintf(&err, &buf, &blen, " AR");
 			} else if (payload & 0x4) {
-				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " SIMD-FP");
+				arm_spe_pkt_snprintf(&err, &buf, &blen, " SIMD-FP");
 			}
-
-			if (ret < 0)
-				return ret;
-			blen -= ret;
-			return buf_len - blen;
-
+			break;
 		case 2:
-			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "B");
+			arm_spe_pkt_snprintf(&err, &buf, &blen, "B");
 
 			if (payload & 0x1)
-				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " COND");
+				arm_spe_pkt_snprintf(&err, &buf, &blen, " COND");
 			if (payload & 0x2)
-				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " IND");
-
-			if (ret < 0)
-				return ret;
-			blen -= ret;
-			return buf_len - blen;
+				arm_spe_pkt_snprintf(&err, &buf, &blen, " IND");
 
+			break;
 		default:
-			return 0;
+			/* Unknown index */
+			err = -1;
+			break;
 		}
+		break;
 	case ARM_SPE_DATA_SOURCE:
 	case ARM_SPE_TIMESTAMP:
-		return arm_spe_pkt_snprintf(&err, &buf, &blen, "%s %lld", name, payload);
+		arm_spe_pkt_snprintf(&err, &buf, &blen, "%s %lld", name, payload);
+		break;
 	case ARM_SPE_ADDRESS:
 		switch (idx) {
 		case 0:
@@ -394,48 +389,59 @@ int arm_spe_pkt_desc(const struct arm_spe_pkt *packet, char *buf,
 			ns = !!(packet->payload & NS_FLAG);
 			el = (packet->payload & EL_FLAG) >> 61;
 			payload &= ~(0xffULL << 56);
-			return arm_spe_pkt_snprintf(&err, &buf, &blen,
+			arm_spe_pkt_snprintf(&err, &buf, &blen,
 					"%s 0x%llx el%d ns=%d",
 				        (idx == 1) ? "TGT" : "PC", payload, el, ns);
+			break;
 		case 2:
-			return arm_spe_pkt_snprintf(&err, &buf, &blen,
-						    "VA 0x%llx", payload);
+			arm_spe_pkt_snprintf(&err, &buf, &blen,
+					     "VA 0x%llx", payload);
+			break;
 		case 3:
 			ns = !!(packet->payload & NS_FLAG);
 			payload &= ~(0xffULL << 56);
-			return arm_spe_pkt_snprintf(&err, &buf, &blen,
-						    "PA 0x%llx ns=%d", payload, ns);
+			arm_spe_pkt_snprintf(&err, &buf, &blen,
+					     "PA 0x%llx ns=%d", payload, ns);
+			break;
 		default:
-			return 0;
+			/* Unknown index */
+			err = -1;
+			break;
 		}
+		break;
 	case ARM_SPE_CONTEXT:
-		return arm_spe_pkt_snprintf(&err, &buf, &blen, "%s 0x%lx el%d",
-					    name, (unsigned long)payload, idx + 1);
+		arm_spe_pkt_snprintf(&err, &buf, &blen, "%s 0x%lx el%d",
+				     name, (unsigned long)payload, idx + 1);
+		break;
 	case ARM_SPE_COUNTER:
-		ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "%s %d ", name,
-					   (unsigned short)payload);
+		arm_spe_pkt_snprintf(&err, &buf, &blen, "%s %d ", name,
+				     (unsigned short)payload);
 		switch (idx) {
 		case 0:
-			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "TOT");
+			arm_spe_pkt_snprintf(&err, &buf, &blen, "TOT");
 			break;
 		case 1:
-			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "ISSUE");
+			arm_spe_pkt_snprintf(&err, &buf, &blen, "ISSUE");
 			break;
 		case 2:
-			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "XLAT");
+			arm_spe_pkt_snprintf(&err, &buf, &blen, "XLAT");
 			break;
 		default:
-			ret = 0;
 			break;
 		}
-		if (ret < 0)
-			return ret;
-		blen -= ret;
-		return buf_len - blen;
+		break;
 	default:
+		/* Unknown index */
+		err = -1;
 		break;
 	}
 
-	return arm_spe_pkt_snprintf(&err, &buf, &blen, "%s 0x%llx (%d)",
-				    name, payload, packet->index);
+	/* Output raw data if detect any error */
+	if (err) {
+		err = 0;
+		arm_spe_pkt_snprintf(&err, &buf_orig, &blen, "%s 0x%llx (%d)",
+				     name, payload, packet->index);
+	}
+
+	return err;
 }
diff --git a/tools/perf/util/arm-spe.c b/tools/perf/util/arm-spe.c
index 3882a5360ada..8901a1656a41 100644
--- a/tools/perf/util/arm-spe.c
+++ b/tools/perf/util/arm-spe.c
@@ -113,7 +113,7 @@ static void arm_spe_dump(struct arm_spe *spe __maybe_unused,
 		if (ret > 0) {
 			ret = arm_spe_pkt_desc(&packet, desc,
 					       ARM_SPE_PKT_DESC_MAX);
-			if (ret > 0)
+			if (!ret)
 				color_fprintf(stdout, color, " %s\n", desc);
 		} else {
 			color_fprintf(stdout, color, " Bad packet!\n");
-- 
2.17.1

[PATCH v7 08/22] perf arm-spe: Refactor packet header parsing

[Leo Yan]

The packet header parsing uses the hard coded values and it uses nested
if-else statements.

To improve the readability, this patch refactors the macros for packet
header format so it removes the hard coded values.  Furthermore, based
on the new mask macros it reduces the nested if-else statements and
changes to use the flat conditions checking, this is directive and can
easily map to the descriptions in ARMv8-a architecture reference manual
(ARM DDI 0487E.a), chapter 'D10.1.5 Statistical Profiling Extension
protocol packet headers'.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
---
 .../arm-spe-decoder/arm-spe-pkt-decoder.c     | 92 +++++++++----------
 .../arm-spe-decoder/arm-spe-pkt-decoder.h     | 20 ++++
 2 files changed, 61 insertions(+), 51 deletions(-)

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 33baef0c2c0b..6608a73a7cbe 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
@@ -16,28 +16,6 @@
 #define NS_FLAG		BIT(63)
 #define EL_FLAG		(BIT(62) | BIT(61))
 
-#define SPE_HEADER0_PAD			0x0
-#define SPE_HEADER0_END			0x1
-#define SPE_HEADER0_ADDRESS		0x30 /* address packet (short) */
-#define SPE_HEADER0_ADDRESS_MASK	0x38
-#define SPE_HEADER0_COUNTER		0x18 /* counter packet (short) */
-#define SPE_HEADER0_COUNTER_MASK	0x38
-#define SPE_HEADER0_TIMESTAMP		0x71
-#define SPE_HEADER0_TIMESTAMP		0x71
-#define SPE_HEADER0_EVENTS		0x2
-#define SPE_HEADER0_EVENTS_MASK		0xf
-#define SPE_HEADER0_SOURCE		0x3
-#define SPE_HEADER0_SOURCE_MASK		0xf
-#define SPE_HEADER0_CONTEXT		0x24
-#define SPE_HEADER0_CONTEXT_MASK	0x3c
-#define SPE_HEADER0_OP_TYPE		0x8
-#define SPE_HEADER0_OP_TYPE_MASK	0x3c
-#define SPE_HEADER1_ALIGNMENT		0x0
-#define SPE_HEADER1_ADDRESS		0xb0 /* address packet (extended) */
-#define SPE_HEADER1_ADDRESS_MASK	0xf8
-#define SPE_HEADER1_COUNTER		0x98 /* counter packet (extended) */
-#define SPE_HEADER1_COUNTER_MASK	0xf8
-
 #if __BYTE_ORDER == __BIG_ENDIAN
 #define le16_to_cpu bswap_16
 #define le32_to_cpu bswap_32
@@ -200,46 +178,58 @@ static int arm_spe_get_addr(const unsigned char *buf, size_t len,
 static int arm_spe_do_get_packet(const unsigned char *buf, size_t len,
 				 struct arm_spe_pkt *packet)
 {
-	unsigned int byte;
+	unsigned int hdr;
+	unsigned char ext_hdr = 0;
 
 	memset(packet, 0, sizeof(struct arm_spe_pkt));
 
 	if (!len)
 		return ARM_SPE_NEED_MORE_BYTES;
 
-	byte = buf[0];
-	if (byte == SPE_HEADER0_PAD)
+	hdr = buf[0];
+
+	if (hdr == SPE_HEADER0_PAD)
 		return arm_spe_get_pad(packet);
-	else if (byte == SPE_HEADER0_END) /* no timestamp at end of record */
+
+	if (hdr == SPE_HEADER0_END) /* no timestamp at end of record */
 		return arm_spe_get_end(packet);
-	else if (byte & 0xc0 /* 0y11xxxxxx */) {
-		if (byte & 0x80) {
-			if ((byte & SPE_HEADER0_ADDRESS_MASK) == SPE_HEADER0_ADDRESS)
-				return arm_spe_get_addr(buf, len, 0, packet);
-			if ((byte & SPE_HEADER0_COUNTER_MASK) == SPE_HEADER0_COUNTER)
-				return arm_spe_get_counter(buf, len, 0, packet);
-		} else
-			if (byte == SPE_HEADER0_TIMESTAMP)
-				return arm_spe_get_timestamp(buf, len, packet);
-			else if ((byte & SPE_HEADER0_EVENTS_MASK) == SPE_HEADER0_EVENTS)
-				return arm_spe_get_events(buf, len, packet);
-			else if ((byte & SPE_HEADER0_SOURCE_MASK) == SPE_HEADER0_SOURCE)
-				return arm_spe_get_data_source(buf, len, packet);
-			else if ((byte & SPE_HEADER0_CONTEXT_MASK) == SPE_HEADER0_CONTEXT)
-				return arm_spe_get_context(buf, len, packet);
-			else if ((byte & SPE_HEADER0_OP_TYPE_MASK) == SPE_HEADER0_OP_TYPE)
-				return arm_spe_get_op_type(buf, len, packet);
-	} else if ((byte & 0xe0) == 0x20 /* 0y001xxxxx */) {
-		/* 16-bit header */
-		byte = buf[1];
-		if (byte == SPE_HEADER1_ALIGNMENT)
+
+	if (hdr == SPE_HEADER0_TIMESTAMP)
+		return arm_spe_get_timestamp(buf, len, packet);
+
+	if ((hdr & SPE_HEADER0_MASK1) == SPE_HEADER0_EVENTS)
+		return arm_spe_get_events(buf, len, packet);
+
+	if ((hdr & SPE_HEADER0_MASK1) == SPE_HEADER0_SOURCE)
+		return arm_spe_get_data_source(buf, len, packet);
+
+	if ((hdr & SPE_HEADER0_MASK2) == SPE_HEADER0_CONTEXT)
+		return arm_spe_get_context(buf, len, packet);
+
+	if ((hdr & SPE_HEADER0_MASK2) == SPE_HEADER0_OP_TYPE)
+		return arm_spe_get_op_type(buf, len, packet);
+
+	if ((hdr & SPE_HEADER0_MASK2) == SPE_HEADER0_EXTENDED) {
+		/* 16-bit extended format header */
+		ext_hdr = 1;
+
+		hdr = buf[1];
+		if (hdr == SPE_HEADER1_ALIGNMENT)
 			return arm_spe_get_alignment(buf, len, packet);
-		else if ((byte & SPE_HEADER1_ADDRESS_MASK) == SPE_HEADER1_ADDRESS)
-			return arm_spe_get_addr(buf, len, 1, packet);
-		else if ((byte & SPE_HEADER1_COUNTER_MASK) == SPE_HEADER1_COUNTER)
-			return arm_spe_get_counter(buf, len, 1, packet);
 	}
 
+	/*
+	 * The short format header's byte 0 or the extended format header's
+	 * byte 1 has been assigned to 'hdr', which uses the same encoding for
+	 * address packet and counter packet, so don't need to distinguish if
+	 * it's short format or extended format and handle in once.
+	 */
+	if ((hdr & SPE_HEADER0_MASK3) == SPE_HEADER0_ADDRESS)
+		return arm_spe_get_addr(buf, len, ext_hdr, packet);
+
+	if ((hdr & SPE_HEADER0_MASK3) == SPE_HEADER0_COUNTER)
+		return arm_spe_get_counter(buf, len, ext_hdr, packet);
+
 	return ARM_SPE_BAD_PACKET;
 }
 
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 4c870521b8eb..129f43405eb1 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
@@ -36,6 +36,26 @@ struct arm_spe_pkt {
 	uint64_t		payload;
 };
 
+/* Short header (HEADER0) and extended header (HEADER1) */
+#define SPE_HEADER0_PAD				0x0
+#define SPE_HEADER0_END				0x1
+#define SPE_HEADER0_TIMESTAMP			0x71
+/* Mask for event & data source */
+#define SPE_HEADER0_MASK1			(GENMASK_ULL(7, 6) | GENMASK_ULL(3, 0))
+#define SPE_HEADER0_EVENTS			0x42
+#define SPE_HEADER0_SOURCE			0x43
+/* Mask for context & operation */
+#define SPE_HEADER0_MASK2			GENMASK_ULL(7, 2)
+#define SPE_HEADER0_CONTEXT			0x64
+#define SPE_HEADER0_OP_TYPE			0x48
+/* Mask for extended format */
+#define SPE_HEADER0_EXTENDED			0x20
+/* Mask for address & counter */
+#define SPE_HEADER0_MASK3			GENMASK_ULL(7, 3)
+#define SPE_HEADER0_ADDRESS			0xb0
+#define SPE_HEADER0_COUNTER			0x98
+#define SPE_HEADER1_ALIGNMENT			0x0
+
 #define SPE_ADDR_PKT_HDR_INDEX_INS		(0x0)
 #define SPE_ADDR_PKT_HDR_INDEX_BRANCH		(0x1)
 #define SPE_ADDR_PKT_HDR_INDEX_DATA_VIRT	(0x2)
-- 
2.17.1

[PATCH v7 09/22] perf arm-spe: Add new function arm_spe_pkt_desc_addr()

[Leo Yan]

This patch moves out the address parsing code from arm_spe_pkt_desc()
and uses the new introduced function arm_spe_pkt_desc_addr() to process
address packet.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
---
 .../arm-spe-decoder/arm-spe-pkt-decoder.c     | 64 +++++++++++--------
 1 file changed, 38 insertions(+), 26 deletions(-)

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 6608a73a7cbe..81f19966643d 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
@@ -288,10 +288,46 @@ static int arm_spe_pkt_snprintf(int *err, char **buf_p, size_t *blen,
 	return ret;
 }
 
+static int arm_spe_pkt_desc_addr(const struct arm_spe_pkt *packet,
+				 char *buf, size_t buf_len)
+{
+	int ns, el, idx = packet->index;
+	u64 payload = packet->payload;
+	int err = 0;
+
+	switch (idx) {
+	case 0:
+	case 1:
+		ns = !!(packet->payload & NS_FLAG);
+		el = (packet->payload & EL_FLAG) >> 61;
+		payload &= ~(0xffULL << 56);
+		arm_spe_pkt_snprintf(&err, &buf, &buf_len,
+				"%s 0x%llx el%d ns=%d",
+				(idx == 1) ? "TGT" : "PC", payload, el, ns);
+		break;
+	case 2:
+		arm_spe_pkt_snprintf(&err, &buf, &buf_len,
+				     "VA 0x%llx", payload);
+		break;
+	case 3:
+		ns = !!(packet->payload & NS_FLAG);
+		payload &= ~(0xffULL << 56);
+		arm_spe_pkt_snprintf(&err, &buf, &buf_len,
+				     "PA 0x%llx ns=%d", payload, ns);
+		break;
+	default:
+		/* Unknown index */
+		err = -1;
+		break;
+	}
+
+	return err;
+}
+
 int arm_spe_pkt_desc(const struct arm_spe_pkt *packet, char *buf,
 		     size_t buf_len)
 {
-	int ns, el, idx = packet->index;
+	int idx = packet->index;
 	unsigned long long payload = packet->payload;
 	const char *name = arm_spe_pkt_name(packet->type);
 	char *buf_orig = buf;
@@ -373,31 +409,7 @@ int arm_spe_pkt_desc(const struct arm_spe_pkt *packet, char *buf,
 		arm_spe_pkt_snprintf(&err, &buf, &blen, "%s %lld", name, payload);
 		break;
 	case ARM_SPE_ADDRESS:
-		switch (idx) {
-		case 0:
-		case 1:
-			ns = !!(packet->payload & NS_FLAG);
-			el = (packet->payload & EL_FLAG) >> 61;
-			payload &= ~(0xffULL << 56);
-			arm_spe_pkt_snprintf(&err, &buf, &blen,
-					"%s 0x%llx el%d ns=%d",
-				        (idx == 1) ? "TGT" : "PC", payload, el, ns);
-			break;
-		case 2:
-			arm_spe_pkt_snprintf(&err, &buf, &blen,
-					     "VA 0x%llx", payload);
-			break;
-		case 3:
-			ns = !!(packet->payload & NS_FLAG);
-			payload &= ~(0xffULL << 56);
-			arm_spe_pkt_snprintf(&err, &buf, &blen,
-					     "PA 0x%llx ns=%d", payload, ns);
-			break;
-		default:
-			/* Unknown index */
-			err = -1;
-			break;
-		}
+		err = arm_spe_pkt_desc_addr(packet, buf, buf_len);
 		break;
 	case ARM_SPE_CONTEXT:
 		arm_spe_pkt_snprintf(&err, &buf, &blen, "%s 0x%lx el%d",
-- 
2.17.1

[PATCH v7 10/22] perf arm-spe: Refactor address packet handling

[Leo Yan]

This patch is to refactor address packet handling, it defines macros for
address packet's header and payload, these macros are used by decoder
and the dump flow.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
---
 .../util/arm-spe-decoder/arm-spe-decoder.c    | 29 ++++++++-------
 .../arm-spe-decoder/arm-spe-pkt-decoder.c     | 26 +++++++-------
 .../arm-spe-decoder/arm-spe-pkt-decoder.h     | 35 ++++++++++++-------
 3 files changed, 48 insertions(+), 42 deletions(-)

diff --git a/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c b/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c
index cc18a1e8c212..776b3e6628bb 100644
--- a/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c
+++ b/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c
@@ -24,36 +24,35 @@
 
 static u64 arm_spe_calc_ip(int index, u64 payload)
 {
-	u8 *addr = (u8 *)&payload;
-	int ns, el;
+	u64 ns, el;
 
 	/* Instruction virtual address or Branch target address */
 	if (index == SPE_ADDR_PKT_HDR_INDEX_INS ||
 	    index == SPE_ADDR_PKT_HDR_INDEX_BRANCH) {
-		ns = addr[7] & SPE_ADDR_PKT_NS;
-		el = (addr[7] & SPE_ADDR_PKT_EL_MASK) >> SPE_ADDR_PKT_EL_OFFSET;
+		ns = SPE_ADDR_PKT_GET_NS(payload);
+		el = SPE_ADDR_PKT_GET_EL(payload);
+
+		/* Clean highest byte */
+		payload = SPE_ADDR_PKT_ADDR_GET_BYTES_0_6(payload);
 
 		/* Fill highest byte for EL1 or EL2 (VHE) mode */
 		if (ns && (el == SPE_ADDR_PKT_EL1 || el == SPE_ADDR_PKT_EL2))
-			addr[7] = 0xff;
-		/* Clean highest byte for other cases */
-		else
-			addr[7] = 0x0;
+			payload |= 0xffULL << SPE_ADDR_PKT_ADDR_BYTE7_SHIFT;
 
 	/* Data access virtual address */
 	} else if (index == SPE_ADDR_PKT_HDR_INDEX_DATA_VIRT) {
 
+		/* Clean tags */
+		payload = SPE_ADDR_PKT_ADDR_GET_BYTES_0_6(payload);
+
 		/* Fill highest byte if bits [48..55] is 0xff */
-		if (addr[6] == 0xff)
-			addr[7] = 0xff;
-		/* Otherwise, cleanup tags */
-		else
-			addr[7] = 0x0;
+		if (SPE_ADDR_PKT_ADDR_GET_BYTE_6(payload) == 0xffULL)
+			payload |= 0xffULL << SPE_ADDR_PKT_ADDR_BYTE7_SHIFT;
 
 	/* Data access physical address */
 	} else if (index == SPE_ADDR_PKT_HDR_INDEX_DATA_PHYS) {
-		/* Cleanup byte 7 */
-		addr[7] = 0x0;
+		/* Clean highest byte */
+		payload = SPE_ADDR_PKT_ADDR_GET_BYTES_0_6(payload);
 	} else {
 		pr_err("unsupported address packet index: 0x%x\n", index);
 	}
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 81f19966643d..ab02fc424938 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
@@ -13,9 +13,6 @@
 
 #include "arm-spe-pkt-decoder.h"
 
-#define NS_FLAG		BIT(63)
-#define EL_FLAG		(BIT(62) | BIT(61))
-
 #if __BYTE_ORDER == __BIG_ENDIAN
 #define le16_to_cpu bswap_16
 #define le32_to_cpu bswap_32
@@ -167,10 +164,11 @@ static int arm_spe_get_addr(const unsigned char *buf, size_t len,
 			    const unsigned char ext_hdr, struct arm_spe_pkt *packet)
 {
 	packet->type = ARM_SPE_ADDRESS;
+
 	if (ext_hdr)
-		packet->index = ((buf[0] & 0x3) << 3) | (buf[1] & 0x7);
+		packet->index = SPE_HDR_EXTENDED_INDEX(buf[0], buf[1]);
 	else
-		packet->index = buf[0] & 0x7;
+		packet->index = SPE_HDR_SHORT_INDEX(buf[0]);
 
 	return arm_spe_get_payload(buf, len, ext_hdr, packet);
 }
@@ -296,22 +294,22 @@ static int arm_spe_pkt_desc_addr(const struct arm_spe_pkt *packet,
 	int err = 0;
 
 	switch (idx) {
-	case 0:
-	case 1:
-		ns = !!(packet->payload & NS_FLAG);
-		el = (packet->payload & EL_FLAG) >> 61;
-		payload &= ~(0xffULL << 56);
+	case SPE_ADDR_PKT_HDR_INDEX_INS:
+	case SPE_ADDR_PKT_HDR_INDEX_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_snprintf(&err, &buf, &buf_len,
 				"%s 0x%llx el%d ns=%d",
 				(idx == 1) ? "TGT" : "PC", payload, el, ns);
 		break;
-	case 2:
+	case SPE_ADDR_PKT_HDR_INDEX_DATA_VIRT:
 		arm_spe_pkt_snprintf(&err, &buf, &buf_len,
 				     "VA 0x%llx", payload);
 		break;
-	case 3:
-		ns = !!(packet->payload & NS_FLAG);
-		payload &= ~(0xffULL << 56);
+	case SPE_ADDR_PKT_HDR_INDEX_DATA_PHYS:
+		ns = !!SPE_ADDR_PKT_GET_NS(payload);
+		payload = SPE_ADDR_PKT_ADDR_GET_BYTES_0_6(payload);
 		arm_spe_pkt_snprintf(&err, &buf, &buf_len,
 				     "PA 0x%llx ns=%d", payload, ns);
 		break;
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 129f43405eb1..f97d6840be3a 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
@@ -56,19 +56,28 @@ struct arm_spe_pkt {
 #define SPE_HEADER0_COUNTER			0x98
 #define SPE_HEADER1_ALIGNMENT			0x0
 
-#define SPE_ADDR_PKT_HDR_INDEX_INS		(0x0)
-#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_NS				BIT(7)
-#define SPE_ADDR_PKT_CH				BIT(6)
-#define SPE_ADDR_PKT_EL_OFFSET			(5)
-#define SPE_ADDR_PKT_EL_MASK			(0x3 << SPE_ADDR_PKT_EL_OFFSET)
-#define SPE_ADDR_PKT_EL0			(0)
-#define SPE_ADDR_PKT_EL1			(1)
-#define SPE_ADDR_PKT_EL2			(2)
-#define SPE_ADDR_PKT_EL3			(3)
+#define SPE_HDR_SHORT_INDEX(h)			((h) & GENMASK_ULL(2, 0))
+#define SPE_HDR_EXTENDED_INDEX(h0, h1)		(((h0) & GENMASK_ULL(1, 0)) << 3 | \
+						 SPE_HDR_SHORT_INDEX(h1))
+
+/* Address packet header */
+#define SPE_ADDR_PKT_HDR_INDEX_INS		0x0
+#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
+
+/* Address packet payload */
+#define SPE_ADDR_PKT_ADDR_BYTE7_SHIFT		56
+#define SPE_ADDR_PKT_ADDR_GET_BYTES_0_6(v)	((v) & GENMASK_ULL(55, 0))
+#define SPE_ADDR_PKT_ADDR_GET_BYTE_6(v)		(((v) & GENMASK_ULL(55, 48)) >> 48)
+
+#define SPE_ADDR_PKT_GET_NS(v)			(((v) & BIT_ULL(63)) >> 63)
+#define SPE_ADDR_PKT_GET_EL(v)			(((v) & GENMASK_ULL(62, 61)) >> 61)
+
+#define SPE_ADDR_PKT_EL0			0
+#define SPE_ADDR_PKT_EL1			1
+#define SPE_ADDR_PKT_EL2			2
+#define SPE_ADDR_PKT_EL3			3
 
 const char *arm_spe_pkt_name(enum arm_spe_pkt_type);
 
-- 
2.17.1

[PATCH v7 11/22] perf arm_spe: Fixup top byte for data virtual address

[Leo Yan]

To establish a valid address from the address packet payload and finally
the address value can be used for parsing data symbol in DSO, current
code uses 0xff to replace the tag in the top byte of data virtual
address.

So far the code only fixups top byte for the memory layouts with 4KB
pages, it misses to support memory layouts with 64KB pages.

This patch adds the conditions for checking bits [55:52] are 0xf, if
detects the pattern it will fill 0xff into the top byte of the address,
also adds comment to explain the fixing up.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
---
 .../util/arm-spe-decoder/arm-spe-decoder.c    | 20 ++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c b/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c
index 776b3e6628bb..cac2ef79c025 100644
--- a/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c
+++ b/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c
@@ -24,7 +24,7 @@
 
 static u64 arm_spe_calc_ip(int index, u64 payload)
 {
-	u64 ns, el;
+	u64 ns, el, val;
 
 	/* Instruction virtual address or Branch target address */
 	if (index == SPE_ADDR_PKT_HDR_INDEX_INS ||
@@ -45,8 +45,22 @@ static u64 arm_spe_calc_ip(int index, u64 payload)
 		/* Clean tags */
 		payload = SPE_ADDR_PKT_ADDR_GET_BYTES_0_6(payload);
 
-		/* Fill highest byte if bits [48..55] is 0xff */
-		if (SPE_ADDR_PKT_ADDR_GET_BYTE_6(payload) == 0xffULL)
+		/*
+		 * Armv8 ARM (ARM DDI 0487F.c), chapter "D10.2.1 Address packet"
+		 * defines the data virtual address payload format, the top byte
+		 * (bits [63:56]) is assigned as top-byte tag; so we only can
+		 * retrieve address value from bits [55:0].
+		 *
+		 * According to Documentation/arm64/memory.rst, if detects the
+		 * specific pattern in bits [55:52] of payload which falls in
+		 * the kernel space, should fixup the top byte and this allows
+		 * perf tool to parse DSO symbol for data address correctly.
+		 *
+		 * For this reason, if detects the bits [55:52] is 0xf, will
+		 * fill 0xff into the top byte.
+		 */
+		val = SPE_ADDR_PKT_ADDR_GET_BYTE_6(payload);
+		if ((val & 0xf0ULL) == 0xf0ULL)
 			payload |= 0xffULL << SPE_ADDR_PKT_ADDR_BYTE7_SHIFT;
 
 	/* Data access physical address */
-- 
2.17.1

[PATCH v7 12/22] perf arm-spe: Refactor context packet handling

[Leo Yan]

Minor refactoring to use macro for index mask.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
---
 tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c | 2 +-
 tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.h | 3 +++
 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 ab02fc424938..74be3a0d8556 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
@@ -136,7 +136,7 @@ static int arm_spe_get_context(const unsigned char *buf, size_t len,
 			       struct arm_spe_pkt *packet)
 {
 	packet->type = ARM_SPE_CONTEXT;
-	packet->index = buf[0] & 0x3;
+	packet->index = SPE_CTX_PKT_HDR_INDEX(buf[0]);
 	return arm_spe_get_payload(buf, len, 0, packet);
 }
 
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 f97d6840be3a..9bc876bffd35 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
@@ -79,6 +79,9 @@ struct arm_spe_pkt {
 #define SPE_ADDR_PKT_EL2			2
 #define SPE_ADDR_PKT_EL3			3
 
+/* Context packet header */
+#define SPE_CTX_PKT_HDR_INDEX(h)		((h) & GENMASK_ULL(1, 0))
+
 const char *arm_spe_pkt_name(enum arm_spe_pkt_type);
 
 int arm_spe_get_packet(const unsigned char *buf, size_t len,
-- 
2.17.1

[PATCH v7 13/22] perf arm-spe: Add new function arm_spe_pkt_desc_counter()

[Leo Yan]

This patch moves out the counter packet parsing code from
arm_spe_pkt_desc() to the new function arm_spe_pkt_desc_counter().

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
---
 .../arm-spe-decoder/arm-spe-pkt-decoder.c     | 43 ++++++++++++-------
 1 file changed, 28 insertions(+), 15 deletions(-)

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 74be3a0d8556..ea769e555bf5 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
@@ -322,6 +322,33 @@ static int arm_spe_pkt_desc_addr(const struct arm_spe_pkt *packet,
 	return err;
 }
 
+static int arm_spe_pkt_desc_counter(const struct arm_spe_pkt *packet,
+				    char *buf, size_t buf_len)
+{
+	u64 payload = packet->payload;
+	const char *name = arm_spe_pkt_name(packet->type);
+	int err = 0;
+
+	arm_spe_pkt_snprintf(&err, &buf, &buf_len, "%s %d ", name,
+			     (unsigned short)payload);
+
+	switch (packet->index) {
+	case 0:
+		arm_spe_pkt_snprintf(&err, &buf, &buf_len, "TOT");
+		break;
+	case 1:
+		arm_spe_pkt_snprintf(&err, &buf, &buf_len, "ISSUE");
+		break;
+	case 2:
+		arm_spe_pkt_snprintf(&err, &buf, &buf_len, "XLAT");
+		break;
+	default:
+		break;
+	}
+
+	return err;
+}
+
 int arm_spe_pkt_desc(const struct arm_spe_pkt *packet, char *buf,
 		     size_t buf_len)
 {
@@ -414,21 +441,7 @@ int arm_spe_pkt_desc(const struct arm_spe_pkt *packet, char *buf,
 				     name, (unsigned long)payload, idx + 1);
 		break;
 	case ARM_SPE_COUNTER:
-		arm_spe_pkt_snprintf(&err, &buf, &blen, "%s %d ", name,
-				     (unsigned short)payload);
-		switch (idx) {
-		case 0:
-			arm_spe_pkt_snprintf(&err, &buf, &blen, "TOT");
-			break;
-		case 1:
-			arm_spe_pkt_snprintf(&err, &buf, &blen, "ISSUE");
-			break;
-		case 2:
-			arm_spe_pkt_snprintf(&err, &buf, &blen, "XLAT");
-			break;
-		default:
-			break;
-		}
+		err = arm_spe_pkt_desc_counter(packet, buf, buf_len);
 		break;
 	default:
 		/* Unknown index */
-- 
2.17.1

[PATCH v7 14/22] perf arm-spe: Refactor counter packet handling

[Leo Yan]

This patch defines macros for counter packet header, and uses macros to
replace hard code values in functions arm_spe_get_counter() and
arm_spe_pkt_desc().

In the function arm_spe_get_counter(), adds a new line for more
readable.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
---
 tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c | 11 ++++++-----
 tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.h |  5 +++++
 2 files changed, 11 insertions(+), 5 deletions(-)

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 ea769e555bf5..4b58aa6a2877 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
@@ -152,10 +152,11 @@ static int arm_spe_get_counter(const unsigned char *buf, size_t len,
 			       const unsigned char ext_hdr, struct arm_spe_pkt *packet)
 {
 	packet->type = ARM_SPE_COUNTER;
+
 	if (ext_hdr)
-		packet->index = ((buf[0] & 0x3) << 3) | (buf[1] & 0x7);
+		packet->index = SPE_HDR_EXTENDED_INDEX(buf[0], buf[1]);
 	else
-		packet->index = buf[0] & 0x7;
+		packet->index = SPE_HDR_SHORT_INDEX(buf[0]);
 
 	return arm_spe_get_payload(buf, len, ext_hdr, packet);
 }
@@ -333,13 +334,13 @@ static int arm_spe_pkt_desc_counter(const struct arm_spe_pkt *packet,
 			     (unsigned short)payload);
 
 	switch (packet->index) {
-	case 0:
+	case SPE_CNT_PKT_HDR_INDEX_TOTAL_LAT:
 		arm_spe_pkt_snprintf(&err, &buf, &buf_len, "TOT");
 		break;
-	case 1:
+	case SPE_CNT_PKT_HDR_INDEX_ISSUE_LAT:
 		arm_spe_pkt_snprintf(&err, &buf, &buf_len, "ISSUE");
 		break;
-	case 2:
+	case SPE_CNT_PKT_HDR_INDEX_TRANS_LAT:
 		arm_spe_pkt_snprintf(&err, &buf, &buf_len, "XLAT");
 		break;
 	default:
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 9bc876bffd35..7d8e34e35f05 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
@@ -82,6 +82,11 @@ struct arm_spe_pkt {
 /* Context packet header */
 #define SPE_CTX_PKT_HDR_INDEX(h)		((h) & GENMASK_ULL(1, 0))
 
+/* Counter packet header */
+#define SPE_CNT_PKT_HDR_INDEX_TOTAL_LAT		0x0
+#define SPE_CNT_PKT_HDR_INDEX_ISSUE_LAT		0x1
+#define SPE_CNT_PKT_HDR_INDEX_TRANS_LAT		0x2
+
 const char *arm_spe_pkt_name(enum arm_spe_pkt_type);
 
 int arm_spe_get_packet(const unsigned char *buf, size_t len,
-- 
2.17.1

[PATCH v7 15/22] perf arm-spe: Add new function arm_spe_pkt_desc_event()

[Leo Yan]

This patch moves out the event packet parsing from arm_spe_pkt_desc()
to the new function arm_spe_pkt_desc_event().

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
---
 .../arm-spe-decoder/arm-spe-pkt-decoder.c     | 63 +++++++++++--------
 1 file changed, 37 insertions(+), 26 deletions(-)

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 4b58aa6a2877..a1fd7d58bf83 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
@@ -287,6 +287,42 @@ static int arm_spe_pkt_snprintf(int *err, char **buf_p, size_t *blen,
 	return ret;
 }
 
+static int arm_spe_pkt_desc_event(const struct arm_spe_pkt *packet,
+				  char *buf, size_t buf_len)
+{
+	u64 payload = packet->payload;
+	int err = 0;
+
+	arm_spe_pkt_snprintf(&err, &buf, &buf_len, "EV");
+
+	if (payload & 0x1)
+		arm_spe_pkt_snprintf(&err, &buf, &buf_len, " EXCEPTION-GEN");
+	if (payload & 0x2)
+		arm_spe_pkt_snprintf(&err, &buf, &buf_len, " RETIRED");
+	if (payload & 0x4)
+		arm_spe_pkt_snprintf(&err, &buf, &buf_len, " L1D-ACCESS");
+	if (payload & 0x8)
+		arm_spe_pkt_snprintf(&err, &buf, &buf_len, " L1D-REFILL");
+	if (payload & 0x10)
+		arm_spe_pkt_snprintf(&err, &buf, &buf_len, " TLB-ACCESS");
+	if (payload & 0x20)
+		arm_spe_pkt_snprintf(&err, &buf, &buf_len, " TLB-REFILL");
+	if (payload & 0x40)
+		arm_spe_pkt_snprintf(&err, &buf, &buf_len, " NOT-TAKEN");
+	if (payload & 0x80)
+		arm_spe_pkt_snprintf(&err, &buf, &buf_len, " MISPRED");
+	if (packet->index > 1) {
+		if (payload & 0x100)
+			arm_spe_pkt_snprintf(&err, &buf, &buf_len, " LLC-ACCESS");
+		if (payload & 0x200)
+			arm_spe_pkt_snprintf(&err, &buf, &buf_len, " LLC-REFILL");
+		if (payload & 0x400)
+			arm_spe_pkt_snprintf(&err, &buf, &buf_len, " REMOTE-ACCESS");
+	}
+
+	return err;
+}
+
 static int arm_spe_pkt_desc_addr(const struct arm_spe_pkt *packet,
 				 char *buf, size_t buf_len)
 {
@@ -367,32 +403,7 @@ int arm_spe_pkt_desc(const struct arm_spe_pkt *packet, char *buf,
 		arm_spe_pkt_snprintf(&err, &buf, &blen, "%s", name);
 		break;
 	case ARM_SPE_EVENTS:
-		arm_spe_pkt_snprintf(&err, &buf, &blen, "EV");
-
-		if (payload & 0x1)
-			arm_spe_pkt_snprintf(&err, &buf, &blen, " EXCEPTION-GEN");
-		if (payload & 0x2)
-			arm_spe_pkt_snprintf(&err, &buf, &blen, " RETIRED");
-		if (payload & 0x4)
-			arm_spe_pkt_snprintf(&err, &buf, &blen, " L1D-ACCESS");
-		if (payload & 0x8)
-			arm_spe_pkt_snprintf(&err, &buf, &blen, " L1D-REFILL");
-		if (payload & 0x10)
-			arm_spe_pkt_snprintf(&err, &buf, &blen, " TLB-ACCESS");
-		if (payload & 0x20)
-			arm_spe_pkt_snprintf(&err, &buf, &blen, " TLB-REFILL");
-		if (payload & 0x40)
-			arm_spe_pkt_snprintf(&err, &buf, &blen, " NOT-TAKEN");
-		if (payload & 0x80)
-			arm_spe_pkt_snprintf(&err, &buf, &blen, " MISPRED");
-		if (idx > 1) {
-			if (payload & 0x100)
-				arm_spe_pkt_snprintf(&err, &buf, &blen, " LLC-ACCESS");
-			if (payload & 0x200)
-				arm_spe_pkt_snprintf(&err, &buf, &blen, " LLC-REFILL");
-			if (payload & 0x400)
-				arm_spe_pkt_snprintf(&err, &buf, &blen, " REMOTE-ACCESS");
-		}
+		err = arm_spe_pkt_desc_event(packet, buf, buf_len);
 		break;
 	case ARM_SPE_OP_TYPE:
 		switch (idx) {
-- 
2.17.1

[PATCH v7 16/22] perf arm-spe: Refactor event type handling

[Leo Yan]

Move the enums of event types to arm-spe-pkt-decoder.h, thus function
arm_spe_pkt_desc() can them for bitmasks.

Suggested-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
---
 .../util/arm-spe-decoder/arm-spe-decoder.h    | 17 --------------
 .../arm-spe-decoder/arm-spe-pkt-decoder.c     | 22 +++++++++----------
 .../arm-spe-decoder/arm-spe-pkt-decoder.h     | 18 +++++++++++++++
 3 files changed, 29 insertions(+), 28 deletions(-)

diff --git a/tools/perf/util/arm-spe-decoder/arm-spe-decoder.h b/tools/perf/util/arm-spe-decoder/arm-spe-decoder.h
index a5111a8d4360..24727b8ca7ff 100644
--- a/tools/perf/util/arm-spe-decoder/arm-spe-decoder.h
+++ b/tools/perf/util/arm-spe-decoder/arm-spe-decoder.h
@@ -13,23 +13,6 @@
 
 #include "arm-spe-pkt-decoder.h"
 
-enum arm_spe_events {
-	EV_EXCEPTION_GEN	= 0,
-	EV_RETIRED		= 1,
-	EV_L1D_ACCESS		= 2,
-	EV_L1D_REFILL		= 3,
-	EV_TLB_ACCESS		= 4,
-	EV_TLB_WALK		= 5,
-	EV_NOT_TAKEN		= 6,
-	EV_MISPRED		= 7,
-	EV_LLC_ACCESS		= 8,
-	EV_LLC_MISS		= 9,
-	EV_REMOTE_ACCESS	= 10,
-	EV_ALIGNMENT		= 11,
-	EV_PARTIAL_PREDICATE	= 17,
-	EV_EMPTY_PREDICATE	= 18,
-};
-
 enum arm_spe_sample_type {
 	ARM_SPE_L1D_ACCESS	= 1 << 0,
 	ARM_SPE_L1D_MISS	= 1 << 1,
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 a1fd7d58bf83..6df3f18d1a5f 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
@@ -295,28 +295,28 @@ static int arm_spe_pkt_desc_event(const struct arm_spe_pkt *packet,
 
 	arm_spe_pkt_snprintf(&err, &buf, &buf_len, "EV");
 
-	if (payload & 0x1)
+	if (payload & BIT(EV_EXCEPTION_GEN))
 		arm_spe_pkt_snprintf(&err, &buf, &buf_len, " EXCEPTION-GEN");
-	if (payload & 0x2)
+	if (payload & BIT(EV_RETIRED))
 		arm_spe_pkt_snprintf(&err, &buf, &buf_len, " RETIRED");
-	if (payload & 0x4)
+	if (payload & BIT(EV_L1D_ACCESS))
 		arm_spe_pkt_snprintf(&err, &buf, &buf_len, " L1D-ACCESS");
-	if (payload & 0x8)
+	if (payload & BIT(EV_L1D_REFILL))
 		arm_spe_pkt_snprintf(&err, &buf, &buf_len, " L1D-REFILL");
-	if (payload & 0x10)
+	if (payload & BIT(EV_TLB_ACCESS))
 		arm_spe_pkt_snprintf(&err, &buf, &buf_len, " TLB-ACCESS");
-	if (payload & 0x20)
+	if (payload & BIT(EV_TLB_WALK))
 		arm_spe_pkt_snprintf(&err, &buf, &buf_len, " TLB-REFILL");
-	if (payload & 0x40)
+	if (payload & BIT(EV_NOT_TAKEN))
 		arm_spe_pkt_snprintf(&err, &buf, &buf_len, " NOT-TAKEN");
-	if (payload & 0x80)
+	if (payload & BIT(EV_MISPRED))
 		arm_spe_pkt_snprintf(&err, &buf, &buf_len, " MISPRED");
 	if (packet->index > 1) {
-		if (payload & 0x100)
+		if (payload & BIT(EV_LLC_ACCESS))
 			arm_spe_pkt_snprintf(&err, &buf, &buf_len, " LLC-ACCESS");
-		if (payload & 0x200)
+		if (payload & BIT(EV_LLC_MISS))
 			arm_spe_pkt_snprintf(&err, &buf, &buf_len, " LLC-REFILL");
-		if (payload & 0x400)
+		if (payload & BIT(EV_REMOTE_ACCESS))
 			arm_spe_pkt_snprintf(&err, &buf, &buf_len, " REMOTE-ACCESS");
 	}
 
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 7d8e34e35f05..42ed4e61ede2 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
@@ -87,6 +87,24 @@ struct arm_spe_pkt {
 #define SPE_CNT_PKT_HDR_INDEX_ISSUE_LAT		0x1
 #define SPE_CNT_PKT_HDR_INDEX_TRANS_LAT		0x2
 
+/* Event packet payload */
+enum arm_spe_events {
+	EV_EXCEPTION_GEN	= 0,
+	EV_RETIRED		= 1,
+	EV_L1D_ACCESS		= 2,
+	EV_L1D_REFILL		= 3,
+	EV_TLB_ACCESS		= 4,
+	EV_TLB_WALK		= 5,
+	EV_NOT_TAKEN		= 6,
+	EV_MISPRED		= 7,
+	EV_LLC_ACCESS		= 8,
+	EV_LLC_MISS		= 9,
+	EV_REMOTE_ACCESS	= 10,
+	EV_ALIGNMENT		= 11,
+	EV_PARTIAL_PREDICATE	= 17,
+	EV_EMPTY_PREDICATE	= 18,
+};
+
 const char *arm_spe_pkt_name(enum arm_spe_pkt_type);
 
 int arm_spe_get_packet(const unsigned char *buf, size_t len,
-- 
2.17.1

[PATCH v7 17/22] perf arm-spe: Remove size condition checking for events

[Leo Yan]

In the Armv8 ARM (ARM DDI 0487F.c), chapter "D10.2.6 Events packet", it
describes the event bit is valid with specific payload requirement.  For
example, the Last Level cache access event, the bit is defined as:

  E[8], byte 1 bit [0], when SZ == 0b01 , when SZ == 0b10 ,
  		     or when SZ == 0b11

It requires the payload size is at least 2 bytes, when byte 1 (start
counting from 0) is valid, E[8] (bit 0 in byte 1) can be used for LLC
access event type.  For safety, the code checks the condition for
payload size firstly, if meet the requirement for payload size, then
continue to parse event type.

If review function arm_spe_get_payload(), it has used cast, so any bytes
beyond the valid size have been set to zeros.

For this reason, we don't need to check payload size anymore afterwards
when parse events, thus this patch removes payload size conditions.

Suggested-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
---
 tools/perf/util/arm-spe-decoder/arm-spe-decoder.c  |  9 +++------
 .../util/arm-spe-decoder/arm-spe-pkt-decoder.c     | 14 ++++++--------
 2 files changed, 9 insertions(+), 14 deletions(-)

diff --git a/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c b/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c
index cac2ef79c025..90d575cee1b9 100644
--- a/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c
+++ b/tools/perf/util/arm-spe-decoder/arm-spe-decoder.c
@@ -192,16 +192,13 @@ static int arm_spe_read_record(struct arm_spe_decoder *decoder)
 			if (payload & BIT(EV_TLB_ACCESS))
 				decoder->record.type |= ARM_SPE_TLB_ACCESS;
 
-			if ((idx == 2 || idx == 4 || idx == 8) &&
-			    (payload & BIT(EV_LLC_MISS)))
+			if (payload & BIT(EV_LLC_MISS))
 				decoder->record.type |= ARM_SPE_LLC_MISS;
 
-			if ((idx == 2 || idx == 4 || idx == 8) &&
-			    (payload & BIT(EV_LLC_ACCESS)))
+			if (payload & BIT(EV_LLC_ACCESS))
 				decoder->record.type |= ARM_SPE_LLC_ACCESS;
 
-			if ((idx == 2 || idx == 4 || idx == 8) &&
-			    (payload & BIT(EV_REMOTE_ACCESS)))
+			if (payload & BIT(EV_REMOTE_ACCESS))
 				decoder->record.type |= ARM_SPE_REMOTE_ACCESS;
 
 			if (payload & BIT(EV_MISPRED))
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 6df3f18d1a5f..87ef8866221e 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
@@ -311,14 +311,12 @@ static int arm_spe_pkt_desc_event(const struct arm_spe_pkt *packet,
 		arm_spe_pkt_snprintf(&err, &buf, &buf_len, " NOT-TAKEN");
 	if (payload & BIT(EV_MISPRED))
 		arm_spe_pkt_snprintf(&err, &buf, &buf_len, " MISPRED");
-	if (packet->index > 1) {
-		if (payload & BIT(EV_LLC_ACCESS))
-			arm_spe_pkt_snprintf(&err, &buf, &buf_len, " LLC-ACCESS");
-		if (payload & BIT(EV_LLC_MISS))
-			arm_spe_pkt_snprintf(&err, &buf, &buf_len, " LLC-REFILL");
-		if (payload & BIT(EV_REMOTE_ACCESS))
-			arm_spe_pkt_snprintf(&err, &buf, &buf_len, " REMOTE-ACCESS");
-	}
+	if (payload & BIT(EV_LLC_ACCESS))
+		arm_spe_pkt_snprintf(&err, &buf, &buf_len, " LLC-ACCESS");
+	if (payload & BIT(EV_LLC_MISS))
+		arm_spe_pkt_snprintf(&err, &buf, &buf_len, " LLC-REFILL");
+	if (payload & BIT(EV_REMOTE_ACCESS))
+		arm_spe_pkt_snprintf(&err, &buf, &buf_len, " REMOTE-ACCESS");
 
 	return err;
 }
-- 
2.17.1

[PATCH v7 18/22] perf arm-spe: Add new function arm_spe_pkt_desc_op_type()

[Leo Yan]

The operation type packet is complex and contains subclass; the parsing
flow causes deep indentation; for more readable, this patch introduces
a new function arm_spe_pkt_desc_op_type() which is used for operation
type parsing.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
---
 .../arm-spe-decoder/arm-spe-pkt-decoder.c     | 79 +++++++++++--------
 1 file changed, 45 insertions(+), 34 deletions(-)

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 87ef8866221e..a8027819018a 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
@@ -321,6 +321,50 @@ static int arm_spe_pkt_desc_event(const struct arm_spe_pkt *packet,
 	return err;
 }
 
+static int arm_spe_pkt_desc_op_type(const struct arm_spe_pkt *packet,
+				    char *buf, size_t buf_len)
+{
+	u64 payload = packet->payload;
+	int err = 0;
+
+	switch (packet->index) {
+	case 0:
+		arm_spe_pkt_snprintf(&err, &buf, &buf_len,
+				payload & 0x1 ? "COND-SELECT" : "INSN-OTHER");
+		break;
+	case 1:
+		arm_spe_pkt_snprintf(&err, &buf, &buf_len,
+				     payload & 0x1 ? "ST" : "LD");
+
+		if (payload & 0x2) {
+			if (payload & 0x4)
+				arm_spe_pkt_snprintf(&err, &buf, &buf_len, " AT");
+			if (payload & 0x8)
+				arm_spe_pkt_snprintf(&err, &buf, &buf_len, " EXCL");
+			if (payload & 0x10)
+				arm_spe_pkt_snprintf(&err, &buf, &buf_len, " AR");
+		} else if (payload & 0x4) {
+			arm_spe_pkt_snprintf(&err, &buf, &buf_len, " SIMD-FP");
+		}
+		break;
+	case 2:
+		arm_spe_pkt_snprintf(&err, &buf, &buf_len, "B");
+
+		if (payload & 0x1)
+			arm_spe_pkt_snprintf(&err, &buf, &buf_len, " COND");
+		if (payload & 0x2)
+			arm_spe_pkt_snprintf(&err, &buf, &buf_len, " IND");
+
+		break;
+	default:
+		/* Unknown index */
+		err = -1;
+		break;
+	}
+
+	return err;
+}
+
 static int arm_spe_pkt_desc_addr(const struct arm_spe_pkt *packet,
 				 char *buf, size_t buf_len)
 {
@@ -404,40 +448,7 @@ int arm_spe_pkt_desc(const struct arm_spe_pkt *packet, char *buf,
 		err = arm_spe_pkt_desc_event(packet, buf, buf_len);
 		break;
 	case ARM_SPE_OP_TYPE:
-		switch (idx) {
-		case 0:
-			arm_spe_pkt_snprintf(&err, &buf, &blen,
-					payload & 0x1 ? "COND-SELECT" : "INSN-OTHER");
-			break;
-		case 1:
-			arm_spe_pkt_snprintf(&err, &buf, &blen,
-					     payload & 0x1 ? "ST" : "LD");
-
-			if (payload & 0x2) {
-				if (payload & 0x4)
-					arm_spe_pkt_snprintf(&err, &buf, &blen, " AT");
-				if (payload & 0x8)
-					arm_spe_pkt_snprintf(&err, &buf, &blen, " EXCL");
-				if (payload & 0x10)
-					arm_spe_pkt_snprintf(&err, &buf, &blen, " AR");
-			} else if (payload & 0x4) {
-				arm_spe_pkt_snprintf(&err, &buf, &blen, " SIMD-FP");
-			}
-			break;
-		case 2:
-			arm_spe_pkt_snprintf(&err, &buf, &blen, "B");
-
-			if (payload & 0x1)
-				arm_spe_pkt_snprintf(&err, &buf, &blen, " COND");
-			if (payload & 0x2)
-				arm_spe_pkt_snprintf(&err, &buf, &blen, " IND");
-
-			break;
-		default:
-			/* Unknown index */
-			err = -1;
-			break;
-		}
+		err = arm_spe_pkt_desc_op_type(packet, buf, buf_len);
 		break;
 	case ARM_SPE_DATA_SOURCE:
 	case ARM_SPE_TIMESTAMP:
-- 
2.17.1

[PATCH v7 19/22] perf arm-spe: Refactor operation packet handling

[Leo Yan]

Defines macros for operation packet header and formats (support sub
classes for 'other', 'branch', 'load and store', etc).  Uses these
macros for operation packet decoding and dumping.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
---
 .../arm-spe-decoder/arm-spe-pkt-decoder.c     | 26 ++++++++++---------
 .../arm-spe-decoder/arm-spe-pkt-decoder.h     | 23 ++++++++++++++++
 2 files changed, 37 insertions(+), 12 deletions(-)

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 a8027819018a..ea0bbf7c5aa1 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
@@ -144,7 +144,7 @@ static int arm_spe_get_op_type(const unsigned char *buf, size_t len,
 			       struct arm_spe_pkt *packet)
 {
 	packet->type = ARM_SPE_OP_TYPE;
-	packet->index = buf[0] & 0x3;
+	packet->index = SPE_OP_PKT_HDR_CLASS(buf[0]);
 	return arm_spe_get_payload(buf, len, 0, packet);
 }
 
@@ -328,31 +328,33 @@ static int arm_spe_pkt_desc_op_type(const struct arm_spe_pkt *packet,
 	int err = 0;
 
 	switch (packet->index) {
-	case 0:
+	case SPE_OP_PKT_HDR_CLASS_OTHER:
 		arm_spe_pkt_snprintf(&err, &buf, &buf_len,
-				payload & 0x1 ? "COND-SELECT" : "INSN-OTHER");
+			payload & SPE_OP_PKT_COND ? "COND-SELECT" : "INSN-OTHER");
 		break;
-	case 1:
+	case SPE_OP_PKT_HDR_CLASS_LD_ST_ATOMIC:
 		arm_spe_pkt_snprintf(&err, &buf, &buf_len,
 				     payload & 0x1 ? "ST" : "LD");
 
-		if (payload & 0x2) {
-			if (payload & 0x4)
+		if (SPE_OP_PKT_IS_LDST_ATOMIC(payload)) {
+			if (payload & SPE_OP_PKT_AT)
 				arm_spe_pkt_snprintf(&err, &buf, &buf_len, " AT");
-			if (payload & 0x8)
+			if (payload & SPE_OP_PKT_EXCL)
 				arm_spe_pkt_snprintf(&err, &buf, &buf_len, " EXCL");
-			if (payload & 0x10)
+			if (payload & SPE_OP_PKT_AR)
 				arm_spe_pkt_snprintf(&err, &buf, &buf_len, " AR");
-		} else if (payload & 0x4) {
+		} else if (SPE_OP_PKT_LDST_SUBCLASS_GET(payload) ==
+					SPE_OP_PKT_LDST_SUBCLASS_SIMD_FP) {
 			arm_spe_pkt_snprintf(&err, &buf, &buf_len, " SIMD-FP");
 		}
 		break;
-	case 2:
+	case SPE_OP_PKT_HDR_CLASS_BR_ERET:
 		arm_spe_pkt_snprintf(&err, &buf, &buf_len, "B");
 
-		if (payload & 0x1)
+		if (payload & SPE_OP_PKT_COND)
 			arm_spe_pkt_snprintf(&err, &buf, &buf_len, " COND");
-		if (payload & 0x2)
+
+		if (SPE_OP_PKT_IS_INDIRECT_BRANCH(payload))
 			arm_spe_pkt_snprintf(&err, &buf, &buf_len, " IND");
 
 		break;
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 42ed4e61ede2..7032fc141ad4 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
@@ -105,6 +105,29 @@ enum arm_spe_events {
 	EV_EMPTY_PREDICATE	= 18,
 };
 
+/* Operation packet header */
+#define SPE_OP_PKT_HDR_CLASS(h)			((h) & GENMASK_ULL(1, 0))
+#define SPE_OP_PKT_HDR_CLASS_OTHER		0x0
+#define SPE_OP_PKT_HDR_CLASS_LD_ST_ATOMIC	0x1
+#define SPE_OP_PKT_HDR_CLASS_BR_ERET		0x2
+
+#define SPE_OP_PKT_COND				BIT(0)
+
+#define SPE_OP_PKT_LDST_SUBCLASS_GET(v)		((v) & GENMASK_ULL(7, 1))
+#define SPE_OP_PKT_LDST_SUBCLASS_GP_REG		0x0
+#define SPE_OP_PKT_LDST_SUBCLASS_SIMD_FP	0x4
+#define SPE_OP_PKT_LDST_SUBCLASS_UNSPEC_REG	0x10
+#define SPE_OP_PKT_LDST_SUBCLASS_NV_SYSREG	0x30
+
+#define SPE_OP_PKT_IS_LDST_ATOMIC(v)		(((v) & (GENMASK_ULL(7, 5) | BIT(1))) == 0x2)
+
+#define SPE_OP_PKT_AR				BIT(4)
+#define SPE_OP_PKT_EXCL				BIT(3)
+#define SPE_OP_PKT_AT				BIT(2)
+#define SPE_OP_PKT_ST				BIT(0)
+
+#define SPE_OP_PKT_IS_INDIRECT_BRANCH(v)	(((v) & GENMASK_ULL(7, 1)) == 0x2)
+
 const char *arm_spe_pkt_name(enum arm_spe_pkt_type);
 
 int arm_spe_get_packet(const unsigned char *buf, size_t len,
-- 
2.17.1

[PATCH v7 20/22] perf arm-spe: Add more sub classes for operation packet

[Leo Yan]

For the operation type packet payload with load/store class, it misses
to support these sub classes:

  - A load/store targeting the general-purpose registers;
  - A load/store targeting unspecified registers;
  - The ARMv8.4 nested virtualisation extension can redirect system
    register accesses to a memory page controlled by the hypervisor.
    The SPE profiling feature in newer implementations can tag those
    memory accesses accordingly.

Add the bit pattern describing load/store sub classes, so that the perf
tool can decode it properly.

Inspired by Andre Przywara, refined the commit log and code for more
clear description.

Co-developed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
---
 .../util/arm-spe-decoder/arm-spe-pkt-decoder.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

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 ea0bbf7c5aa1..ec962a9bff78 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
@@ -343,9 +343,23 @@ static int arm_spe_pkt_desc_op_type(const struct arm_spe_pkt *packet,
 				arm_spe_pkt_snprintf(&err, &buf, &buf_len, " EXCL");
 			if (payload & SPE_OP_PKT_AR)
 				arm_spe_pkt_snprintf(&err, &buf, &buf_len, " AR");
-		} else if (SPE_OP_PKT_LDST_SUBCLASS_GET(payload) ==
-					SPE_OP_PKT_LDST_SUBCLASS_SIMD_FP) {
+		}
+
+		switch (SPE_OP_PKT_LDST_SUBCLASS_GET(payload)) {
+		case SPE_OP_PKT_LDST_SUBCLASS_SIMD_FP:
 			arm_spe_pkt_snprintf(&err, &buf, &buf_len, " SIMD-FP");
+			break;
+		case SPE_OP_PKT_LDST_SUBCLASS_GP_REG:
+			arm_spe_pkt_snprintf(&err, &buf, &buf_len, " GP-REG");
+			break;
+		case SPE_OP_PKT_LDST_SUBCLASS_UNSPEC_REG:
+			arm_spe_pkt_snprintf(&err, &buf, &buf_len, " UNSPEC-REG");
+			break;
+		case SPE_OP_PKT_LDST_SUBCLASS_NV_SYSREG:
+			arm_spe_pkt_snprintf(&err, &buf, &buf_len, " NV-SYSREG");
+			break;
+		default:
+			break;
 		}
 		break;
 	case SPE_OP_PKT_HDR_CLASS_BR_ERET:
-- 
2.17.1

[PATCH v7 21/22] perf arm_spe: Decode memory tagging properties

[Leo Yan]

From: Andre Przywara <andre.przywara@arm.com>

When SPE records a physical address, it can additionally tag the event
with information from the Memory Tagging architecture extension.

Decode the two additional fields in the SPE event payload.

[leoy: Refined patch to use predefined macros]

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
---
 tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.c | 6 +++++-
 tools/perf/util/arm-spe-decoder/arm-spe-pkt-decoder.h | 2 ++
 2 files changed, 7 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 ec962a9bff78..4744048478ca 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
@@ -385,6 +385,7 @@ static int arm_spe_pkt_desc_addr(const struct arm_spe_pkt *packet,
 				 char *buf, size_t buf_len)
 {
 	int ns, el, idx = packet->index;
+	int ch, pat;
 	u64 payload = packet->payload;
 	int err = 0;
 
@@ -404,9 +405,12 @@ static int arm_spe_pkt_desc_addr(const struct arm_spe_pkt *packet,
 		break;
 	case SPE_ADDR_PKT_HDR_INDEX_DATA_PHYS:
 		ns = !!SPE_ADDR_PKT_GET_NS(payload);
+		ch = !!SPE_ADDR_PKT_GET_CH(payload);
+		pat = SPE_ADDR_PKT_GET_PAT(payload);
 		payload = SPE_ADDR_PKT_ADDR_GET_BYTES_0_6(payload);
 		arm_spe_pkt_snprintf(&err, &buf, &buf_len,
-				     "PA 0x%llx ns=%d", payload, ns);
+				     "PA 0x%llx ns=%d ch=%d pat=%x",
+				     payload, ns, ch, pat);
 		break;
 	default:
 		/* Unknown index */
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 7032fc141ad4..1ad14885c2a1 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
@@ -73,6 +73,8 @@ struct arm_spe_pkt {
 
 #define SPE_ADDR_PKT_GET_NS(v)			(((v) & BIT_ULL(63)) >> 63)
 #define SPE_ADDR_PKT_GET_EL(v)			(((v) & GENMASK_ULL(62, 61)) >> 61)
+#define SPE_ADDR_PKT_GET_CH(v)			(((v) & BIT_ULL(62)) >> 62)
+#define SPE_ADDR_PKT_GET_PAT(v)			(((v) & GENMASK_ULL(59, 56)) >> 56)
 
 #define SPE_ADDR_PKT_EL0			0
 #define SPE_ADDR_PKT_EL1			1
-- 
2.17.1

[PATCH v7 22/22] perf arm-spe: Add support for ARMv8.3-SPE

[Leo Yan]

From: Wei Li <liwei391@huawei.com>

This patch is to support Armv8.3 extension for SPE, it adds alignment
field in the Events packet and it supports the Scalable Vector Extension
(SVE) for Operation packet and Events packet with two additions:

  - The vector length for SVE operations in the Operation Type packet;
  - The incomplete predicate and empty predicate fields in the Events
    packet.

Signed-off-by: Wei Li <liwei391@huawei.com>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
---
 .../arm-spe-decoder/arm-spe-pkt-decoder.c     | 36 +++++++++++++++++--
 .../arm-spe-decoder/arm-spe-pkt-decoder.h     | 16 +++++++++
 2 files changed, 50 insertions(+), 2 deletions(-)

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 4744048478ca..7b77b9bc1f08 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
@@ -317,6 +317,12 @@ static int arm_spe_pkt_desc_event(const struct arm_spe_pkt *packet,
 		arm_spe_pkt_snprintf(&err, &buf, &buf_len, " LLC-REFILL");
 	if (payload & BIT(EV_REMOTE_ACCESS))
 		arm_spe_pkt_snprintf(&err, &buf, &buf_len, " REMOTE-ACCESS");
+	if (payload & BIT(EV_ALIGNMENT))
+		arm_spe_pkt_snprintf(&err, &buf, &buf_len, " ALIGNMENT");
+	if (payload & BIT(EV_PARTIAL_PREDICATE))
+		arm_spe_pkt_snprintf(&err, &buf, &buf_len, " SVE-PARTIAL-PRED");
+	if (payload & BIT(EV_EMPTY_PREDICATE))
+		arm_spe_pkt_snprintf(&err, &buf, &buf_len, " SVE-EMPTY-PRED");
 
 	return err;
 }
@@ -329,8 +335,23 @@ static int arm_spe_pkt_desc_op_type(const struct arm_spe_pkt *packet,
 
 	switch (packet->index) {
 	case SPE_OP_PKT_HDR_CLASS_OTHER:
-		arm_spe_pkt_snprintf(&err, &buf, &buf_len,
-			payload & SPE_OP_PKT_COND ? "COND-SELECT" : "INSN-OTHER");
+		if (SPE_OP_PKT_IS_OTHER_SVE_OP(payload)) {
+			arm_spe_pkt_snprintf(&err, &buf, &buf_len, "SVE-OTHER");
+
+			/* SVE effective vector length */
+			arm_spe_pkt_snprintf(&err, &buf, &buf_len, " EVLEN %d",
+					     SPE_OP_PKG_SVE_EVL(payload));
+
+			if (payload & SPE_OP_PKT_SVE_FP)
+				arm_spe_pkt_snprintf(&err, &buf, &buf_len, " FP");
+			if (payload & SPE_OP_PKT_SVE_PRED)
+				arm_spe_pkt_snprintf(&err, &buf, &buf_len, " PRED");
+		} else {
+			arm_spe_pkt_snprintf(&err, &buf, &buf_len, "OTHER");
+			arm_spe_pkt_snprintf(&err, &buf, &buf_len, " %s",
+					     payload & SPE_OP_PKT_COND ?
+					     "COND-SELECT" : "INSN-OTHER");
+		}
 		break;
 	case SPE_OP_PKT_HDR_CLASS_LD_ST_ATOMIC:
 		arm_spe_pkt_snprintf(&err, &buf, &buf_len,
@@ -361,6 +382,17 @@ static int arm_spe_pkt_desc_op_type(const struct arm_spe_pkt *packet,
 		default:
 			break;
 		}
+
+		if (SPE_OP_PKT_IS_LDST_SVE(payload)) {
+			/* SVE effective vector length */
+			arm_spe_pkt_snprintf(&err, &buf, &buf_len, " EVLEN %d",
+					     SPE_OP_PKG_SVE_EVL(payload));
+
+			if (payload & SPE_OP_PKT_SVE_PRED)
+				arm_spe_pkt_snprintf(&err, &buf, &buf_len, " PRED");
+			if (payload & SPE_OP_PKT_SVE_SG)
+				arm_spe_pkt_snprintf(&err, &buf, &buf_len, " SG");
+		}
 		break;
 	case SPE_OP_PKT_HDR_CLASS_BR_ERET:
 		arm_spe_pkt_snprintf(&err, &buf, &buf_len, "B");
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 1ad14885c2a1..9b970e7bf1e2 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
@@ -113,6 +113,8 @@ enum arm_spe_events {
 #define SPE_OP_PKT_HDR_CLASS_LD_ST_ATOMIC	0x1
 #define SPE_OP_PKT_HDR_CLASS_BR_ERET		0x2
 
+#define SPE_OP_PKT_IS_OTHER_SVE_OP(v)		(((v) & (BIT(7) | BIT(3) | BIT(0))) == 0x8)
+
 #define SPE_OP_PKT_COND				BIT(0)
 
 #define SPE_OP_PKT_LDST_SUBCLASS_GET(v)		((v) & GENMASK_ULL(7, 1))
@@ -128,6 +130,20 @@ enum arm_spe_events {
 #define SPE_OP_PKT_AT				BIT(2)
 #define SPE_OP_PKT_ST				BIT(0)
 
+#define SPE_OP_PKT_IS_LDST_SVE(v)		(((v) & (BIT(3) | BIT(1))) == 0x8)
+
+#define SPE_OP_PKT_SVE_SG			BIT(7)
+/*
+ * SVE effective vector length (EVL) is stored in byte 0 bits [6:4];
+ * the length is rounded up to a power of two and use 32 as one step,
+ * so EVL calculation is:
+ *
+ *   32 * (2 ^ bits [6:4]) = 32 << (bits [6:4])
+ */
+#define SPE_OP_PKG_SVE_EVL(v)			(32 << (((v) & GENMASK_ULL(6, 4)) >> 4))
+#define SPE_OP_PKT_SVE_PRED			BIT(2)
+#define SPE_OP_PKT_SVE_FP			BIT(1)
+
 #define SPE_OP_PKT_IS_INDIRECT_BRANCH(v)	(((v) & GENMASK_ULL(7, 1)) == 0x2)
 
 const char *arm_spe_pkt_name(enum arm_spe_pkt_type);
-- 
2.17.1

Re: [PATCH v7 06/22] perf arm-spe: Refactor printing string to buffer

[André Przywara]

On 06/11/2020 01:41, Leo Yan wrote:
> When outputs strings to the decoding buffer with function snprintf(),
> SPE decoder needs to detects if any error returns from snprintf() and if
> so needs to directly bail out.  If snprintf() returns success, it needs
> to update buffer pointer and reduce the buffer length so can continue to
> output the next string into the consequent memory space.
> 
> This complex logics are spreading in the function arm_spe_pkt_desc() so
> there has many duplicate codes for handling error detecting, increment
> buffer pointer and decrement buffer size.
> 
> To avoid the duplicate code, this patch introduces a new helper function
> arm_spe_pkt_snprintf() which is used to wrap up the complex logics, and
> it's used by the caller arm_spe_pkt_desc().
> 
> This patch also moves the variable 'blen' as the function's local
> variable, this allows to remove the unnecessary braces and improve the
> readability.
> 
> Suggested-by: Dave Martin <Dave.Martin@arm.com>
> Signed-off-by: Leo Yan <leo.yan@linaro.org>

Well, I am not sure this is particularly easier to review ;-), but here
we go:

Checked - vs. + in an editor to verify the transformation.

I also put the new printf routine into some very simple test program,
and it seems to work as advertised: buffer overflows are detected, and
the string never gets bigger or loses the terminating 0.

So that looks alright to me:

Reviewed-by: Andre Przywara <andre.przywara@arm.com>

Cheers,
Andre

> ---
>  .../arm-spe-decoder/arm-spe-pkt-decoder.c     | 260 +++++++++---------
>  1 file changed, 126 insertions(+), 134 deletions(-)
> 
> 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 04fd7fd7c15f..1970686f7020 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
> @@ -9,6 +9,7 @@
>  #include <endian.h>
>  #include <byteswap.h>
>  #include <linux/bitops.h>
> +#include <stdarg.h>
>  
>  #include "arm-spe-pkt-decoder.h"
>  
> @@ -258,192 +259,183 @@ int arm_spe_get_packet(const unsigned char *buf, size_t len,
>  	return ret;
>  }
>  
> +static int arm_spe_pkt_snprintf(int *err, char **buf_p, size_t *blen,
> +				const char *fmt, ...)
> +{
> +	va_list ap;
> +	int ret;
> +
> +	/* Bail out if any error occurred */
> +	if (err && *err)
> +		return *err;
> +
> +	va_start(ap, fmt);
> +	ret = vsnprintf(*buf_p, *blen, fmt, ap);
> +	va_end(ap);
> +
> +	if (ret < 0) {
> +		if (err && !*err)
> +			*err = ret;
> +
> +	/*
> +	 * A return value of (*blen - 1) or more means that the
> +	 * output was truncated and the buffer is overrun.
> +	 */
> +	} else if (ret >= ((int)*blen - 1)) {
> +		(*buf_p)[*blen - 1] = '\0';
> +
> +		/*
> +		 * Set *err to 'ret' to avoid overflow if tries to
> +		 * fill this buffer sequentially.
> +		 */
> +		if (err && !*err)
> +			*err = ret;
> +	} else {
> +		*buf_p += ret;
> +		*blen -= ret;
> +	}
> +
> +	return ret;
> +}
> +
>  int arm_spe_pkt_desc(const struct arm_spe_pkt *packet, char *buf,
>  		     size_t buf_len)
>  {
>  	int ret, ns, el, idx = packet->index;
>  	unsigned long long payload = packet->payload;
>  	const char *name = arm_spe_pkt_name(packet->type);
> +	size_t blen = buf_len;
> +	int err = 0;
>  
>  	switch (packet->type) {
>  	case ARM_SPE_BAD:
>  	case ARM_SPE_PAD:
>  	case ARM_SPE_END:
> -		return snprintf(buf, buf_len, "%s", name);
> -	case ARM_SPE_EVENTS: {
> -		size_t blen = buf_len;
> -
> -		ret = 0;
> -		ret = snprintf(buf, buf_len, "EV");
> -		buf += ret;
> -		blen -= ret;
> -		if (payload & 0x1) {
> -			ret = snprintf(buf, buf_len, " EXCEPTION-GEN");
> -			buf += ret;
> -			blen -= ret;
> -		}
> -		if (payload & 0x2) {
> -			ret = snprintf(buf, buf_len, " RETIRED");
> -			buf += ret;
> -			blen -= ret;
> -		}
> -		if (payload & 0x4) {
> -			ret = snprintf(buf, buf_len, " L1D-ACCESS");
> -			buf += ret;
> -			blen -= ret;
> -		}
> -		if (payload & 0x8) {
> -			ret = snprintf(buf, buf_len, " L1D-REFILL");
> -			buf += ret;
> -			blen -= ret;
> -		}
> -		if (payload & 0x10) {
> -			ret = snprintf(buf, buf_len, " TLB-ACCESS");
> -			buf += ret;
> -			blen -= ret;
> -		}
> -		if (payload & 0x20) {
> -			ret = snprintf(buf, buf_len, " TLB-REFILL");
> -			buf += ret;
> -			blen -= ret;
> -		}
> -		if (payload & 0x40) {
> -			ret = snprintf(buf, buf_len, " NOT-TAKEN");
> -			buf += ret;
> -			blen -= ret;
> -		}
> -		if (payload & 0x80) {
> -			ret = snprintf(buf, buf_len, " MISPRED");
> -			buf += ret;
> -			blen -= ret;
> -		}
> +		return arm_spe_pkt_snprintf(&err, &buf, &blen, "%s", name);
> +	case ARM_SPE_EVENTS:
> +		ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "EV");
> +
> +		if (payload & 0x1)
> +			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " EXCEPTION-GEN");
> +		if (payload & 0x2)
> +			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " RETIRED");
> +		if (payload & 0x4)
> +			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " L1D-ACCESS");
> +		if (payload & 0x8)
> +			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " L1D-REFILL");
> +		if (payload & 0x10)
> +			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " TLB-ACCESS");
> +		if (payload & 0x20)
> +			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " TLB-REFILL");
> +		if (payload & 0x40)
> +			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " NOT-TAKEN");
> +		if (payload & 0x80)
> +			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " MISPRED");
>  		if (idx > 1) {
> -			if (payload & 0x100) {
> -				ret = snprintf(buf, buf_len, " LLC-ACCESS");
> -				buf += ret;
> -				blen -= ret;
> -			}
> -			if (payload & 0x200) {
> -				ret = snprintf(buf, buf_len, " LLC-REFILL");
> -				buf += ret;
> -				blen -= ret;
> -			}
> -			if (payload & 0x400) {
> -				ret = snprintf(buf, buf_len, " REMOTE-ACCESS");
> -				buf += ret;
> -				blen -= ret;
> -			}
> +			if (payload & 0x100)
> +				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " LLC-ACCESS");
> +			if (payload & 0x200)
> +				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " LLC-REFILL");
> +			if (payload & 0x400)
> +				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " REMOTE-ACCESS");
>  		}
>  		if (ret < 0)
>  			return ret;
>  		blen -= ret;
>  		return buf_len - blen;
> -	}
>  	case ARM_SPE_OP_TYPE:
>  		switch (idx) {
> -		case 0:	return snprintf(buf, buf_len, "%s", payload & 0x1 ?
> -					"COND-SELECT" : "INSN-OTHER");
> -		case 1:	{
> -			size_t blen = buf_len;
> +		case 0:
> +			return arm_spe_pkt_snprintf(&err, &buf, &blen,
> +					payload & 0x1 ? "COND-SELECT" : "INSN-OTHER");
> +		case 1:
> +			ret = arm_spe_pkt_snprintf(&err, &buf, &blen,
> +						   payload & 0x1 ? "ST" : "LD");
>  
> -			if (payload & 0x1)
> -				ret = snprintf(buf, buf_len, "ST");
> -			else
> -				ret = snprintf(buf, buf_len, "LD");
> -			buf += ret;
> -			blen -= ret;
>  			if (payload & 0x2) {
> -				if (payload & 0x4) {
> -					ret = snprintf(buf, buf_len, " AT");
> -					buf += ret;
> -					blen -= ret;
> -				}
> -				if (payload & 0x8) {
> -					ret = snprintf(buf, buf_len, " EXCL");
> -					buf += ret;
> -					blen -= ret;
> -				}
> -				if (payload & 0x10) {
> -					ret = snprintf(buf, buf_len, " AR");
> -					buf += ret;
> -					blen -= ret;
> -				}
> +				if (payload & 0x4)
> +					ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " AT");
> +				if (payload & 0x8)
> +					ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " EXCL");
> +				if (payload & 0x10)
> +					ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " AR");
>  			} else if (payload & 0x4) {
> -				ret = snprintf(buf, buf_len, " SIMD-FP");
> -				buf += ret;
> -				blen -= ret;
> +				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " SIMD-FP");
>  			}
> +
>  			if (ret < 0)
>  				return ret;
>  			blen -= ret;
>  			return buf_len - blen;
> -		}
> -		case 2:	{
> -			size_t blen = buf_len;
>  
> -			ret = snprintf(buf, buf_len, "B");
> -			buf += ret;
> -			blen -= ret;
> -			if (payload & 0x1) {
> -				ret = snprintf(buf, buf_len, " COND");
> -				buf += ret;
> -				blen -= ret;
> -			}
> -			if (payload & 0x2) {
> -				ret = snprintf(buf, buf_len, " IND");
> -				buf += ret;
> -				blen -= ret;
> -			}
> +		case 2:
> +			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "B");
> +
> +			if (payload & 0x1)
> +				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " COND");
> +			if (payload & 0x2)
> +				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " IND");
> +
>  			if (ret < 0)
>  				return ret;
>  			blen -= ret;
>  			return buf_len - blen;
> -			}
> -		default: return 0;
> +
> +		default:
> +			return 0;
>  		}
>  	case ARM_SPE_DATA_SOURCE:
>  	case ARM_SPE_TIMESTAMP:
> -		return snprintf(buf, buf_len, "%s %lld", name, payload);
> +		return arm_spe_pkt_snprintf(&err, &buf, &blen, "%s %lld", name, payload);
>  	case ARM_SPE_ADDRESS:
>  		switch (idx) {
>  		case 0:
> -		case 1: ns = !!(packet->payload & NS_FLAG);
> +		case 1:
> +			ns = !!(packet->payload & NS_FLAG);
>  			el = (packet->payload & EL_FLAG) >> 61;
>  			payload &= ~(0xffULL << 56);
> -			return snprintf(buf, buf_len, "%s 0x%llx el%d ns=%d",
> +			return arm_spe_pkt_snprintf(&err, &buf, &blen,
> +					"%s 0x%llx el%d ns=%d",
>  				        (idx == 1) ? "TGT" : "PC", payload, el, ns);
> -		case 2:	return snprintf(buf, buf_len, "VA 0x%llx", payload);
> -		case 3:	ns = !!(packet->payload & NS_FLAG);
> +		case 2:
> +			return arm_spe_pkt_snprintf(&err, &buf, &blen,
> +						    "VA 0x%llx", payload);
> +		case 3:
> +			ns = !!(packet->payload & NS_FLAG);
>  			payload &= ~(0xffULL << 56);
> -			return snprintf(buf, buf_len, "PA 0x%llx ns=%d",
> -					payload, ns);
> -		default: return 0;
> +			return arm_spe_pkt_snprintf(&err, &buf, &blen,
> +						    "PA 0x%llx ns=%d", payload, ns);
> +		default:
> +			return 0;
>  		}
>  	case ARM_SPE_CONTEXT:
> -		return snprintf(buf, buf_len, "%s 0x%lx el%d", name,
> -				(unsigned long)payload, idx + 1);
> -	case ARM_SPE_COUNTER: {
> -		size_t blen = buf_len;
> -
> -		ret = snprintf(buf, buf_len, "%s %d ", name,
> -			       (unsigned short)payload);
> -		buf += ret;
> -		blen -= ret;
> +		return arm_spe_pkt_snprintf(&err, &buf, &blen, "%s 0x%lx el%d",
> +					    name, (unsigned long)payload, idx + 1);
> +	case ARM_SPE_COUNTER:
> +		ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "%s %d ", name,
> +					   (unsigned short)payload);
>  		switch (idx) {
> -		case 0:	ret = snprintf(buf, buf_len, "TOT"); break;
> -		case 1:	ret = snprintf(buf, buf_len, "ISSUE"); break;
> -		case 2:	ret = snprintf(buf, buf_len, "XLAT"); break;
> -		default: ret = 0;
> +		case 0:
> +			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "TOT");
> +			break;
> +		case 1:
> +			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "ISSUE");
> +			break;
> +		case 2:
> +			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "XLAT");
> +			break;
> +		default:
> +			ret = 0;
> +			break;
>  		}
>  		if (ret < 0)
>  			return ret;
>  		blen -= ret;
>  		return buf_len - blen;
> -	}
>  	default:
>  		break;
>  	}
>  
> -	return snprintf(buf, buf_len, "%s 0x%llx (%d)",
> -			name, payload, packet->index);
> +	return arm_spe_pkt_snprintf(&err, &buf, &blen, "%s 0x%llx (%d)",
> +				    name, payload, packet->index);
>  }
> 

Re: [PATCH v7 07/22] perf arm-spe: Consolidate arm_spe_pkt_desc()'s return value

[André Przywara]

On 06/11/2020 01:41, Leo Yan wrote:
> arm_spe_pkt_desc() returns the length of consumed the buffer for
> the success case; otherwise, it delivers the return value from
> arm_spe_pkt_snprintf(), and returns the last return value if there have
> multiple calling arm_spe_pkt_snprintf().
> 
> Since arm_spe_pkt_snprintf() has the same semantics with vsnprintf() for
> the return value, and vsnprintf() might return value equals to or bigger
> than the parameter 'size' to indicate the truncation.  Because the
> return value is >= 0 when the string is truncated, this condition will
> be returned up the stack as "success".
> 
> This patch simplifies the return value for arm_spe_pkt_desc(): '0' means
> success and other values mean an error has occurred.  To realize this,
> it relies on arm_spe_pkt_snprintf()'s parameter 'err', the 'err' is a
> cumulative value, returns its final value if printing buffer is called
> for one time or multiple times.
> 
> To unify the error value generation, this patch handles error in a
> central place, rather than directly bailing out in switch-cases,
> it returns error at the end of arm_spe_pkt_desc().

And the but-last hunk means it will basically always return 0?
Just checking, it's probably fine (and I don't want to review a v8 ;-)

> This patch changes the caller arm_spe_dump() to respect the updated
> return value semantics of arm_spe_pkt_desc().
> 
> Suggested-by: Dave Martin <Dave.Martin@arm.com>
> Signed-off-by: Leo Yan <leo.yan@linaro.org>

One tiny thing below ...

> ---
>  .../arm-spe-decoder/arm-spe-pkt-decoder.c     | 128 +++++++++---------
>  tools/perf/util/arm-spe.c                     |   2 +-
>  2 files changed, 68 insertions(+), 62 deletions(-)
> 
> 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 1970686f7020..33baef0c2c0b 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
> @@ -301,9 +301,10 @@ static int arm_spe_pkt_snprintf(int *err, char **buf_p, size_t *blen,
>  int arm_spe_pkt_desc(const struct arm_spe_pkt *packet, char *buf,
>  		     size_t buf_len)
>  {
> -	int ret, ns, el, idx = packet->index;
> +	int ns, el, idx = packet->index;
>  	unsigned long long payload = packet->payload;
>  	const char *name = arm_spe_pkt_name(packet->type);
> +	char *buf_orig = buf;
>  	size_t blen = buf_len;
>  	int err = 0;
>  
> @@ -311,82 +312,76 @@ int arm_spe_pkt_desc(const struct arm_spe_pkt *packet, char *buf,
>  	case ARM_SPE_BAD:
>  	case ARM_SPE_PAD:
>  	case ARM_SPE_END:
> -		return arm_spe_pkt_snprintf(&err, &buf, &blen, "%s", name);
> +		arm_spe_pkt_snprintf(&err, &buf, &blen, "%s", name);
> +		break;
>  	case ARM_SPE_EVENTS:
> -		ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "EV");
> +		arm_spe_pkt_snprintf(&err, &buf, &blen, "EV");
>  
>  		if (payload & 0x1)
> -			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " EXCEPTION-GEN");
> +			arm_spe_pkt_snprintf(&err, &buf, &blen, " EXCEPTION-GEN");
>  		if (payload & 0x2)
> -			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " RETIRED");
> +			arm_spe_pkt_snprintf(&err, &buf, &blen, " RETIRED");
>  		if (payload & 0x4)
> -			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " L1D-ACCESS");
> +			arm_spe_pkt_snprintf(&err, &buf, &blen, " L1D-ACCESS");
>  		if (payload & 0x8)
> -			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " L1D-REFILL");
> +			arm_spe_pkt_snprintf(&err, &buf, &blen, " L1D-REFILL");
>  		if (payload & 0x10)
> -			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " TLB-ACCESS");
> +			arm_spe_pkt_snprintf(&err, &buf, &blen, " TLB-ACCESS");
>  		if (payload & 0x20)
> -			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " TLB-REFILL");
> +			arm_spe_pkt_snprintf(&err, &buf, &blen, " TLB-REFILL");
>  		if (payload & 0x40)
> -			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " NOT-TAKEN");
> +			arm_spe_pkt_snprintf(&err, &buf, &blen, " NOT-TAKEN");
>  		if (payload & 0x80)
> -			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " MISPRED");
> +			arm_spe_pkt_snprintf(&err, &buf, &blen, " MISPRED");
>  		if (idx > 1) {
>  			if (payload & 0x100)
> -				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " LLC-ACCESS");
> +				arm_spe_pkt_snprintf(&err, &buf, &blen, " LLC-ACCESS");
>  			if (payload & 0x200)
> -				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " LLC-REFILL");
> +				arm_spe_pkt_snprintf(&err, &buf, &blen, " LLC-REFILL");
>  			if (payload & 0x400)
> -				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " REMOTE-ACCESS");
> +				arm_spe_pkt_snprintf(&err, &buf, &blen, " REMOTE-ACCESS");
>  		}
> -		if (ret < 0)
> -			return ret;
> -		blen -= ret;
> -		return buf_len - blen;
> +		break;
>  	case ARM_SPE_OP_TYPE:
>  		switch (idx) {
>  		case 0:
> -			return arm_spe_pkt_snprintf(&err, &buf, &blen,
> +			arm_spe_pkt_snprintf(&err, &buf, &blen,
>  					payload & 0x1 ? "COND-SELECT" : "INSN-OTHER");
> +			break;
>  		case 1:
> -			ret = arm_spe_pkt_snprintf(&err, &buf, &blen,
> -						   payload & 0x1 ? "ST" : "LD");
> +			arm_spe_pkt_snprintf(&err, &buf, &blen,
> +					     payload & 0x1 ? "ST" : "LD");
>  
>  			if (payload & 0x2) {
>  				if (payload & 0x4)
> -					ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " AT");
> +					arm_spe_pkt_snprintf(&err, &buf, &blen, " AT");
>  				if (payload & 0x8)
> -					ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " EXCL");
> +					arm_spe_pkt_snprintf(&err, &buf, &blen, " EXCL");
>  				if (payload & 0x10)
> -					ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " AR");
> +					arm_spe_pkt_snprintf(&err, &buf, &blen, " AR");
>  			} else if (payload & 0x4) {
> -				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " SIMD-FP");
> +				arm_spe_pkt_snprintf(&err, &buf, &blen, " SIMD-FP");
>  			}
> -
> -			if (ret < 0)
> -				return ret;
> -			blen -= ret;
> -			return buf_len - blen;
> -
> +			break;
>  		case 2:
> -			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "B");
> +			arm_spe_pkt_snprintf(&err, &buf, &blen, "B");
>  
>  			if (payload & 0x1)
> -				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " COND");
> +				arm_spe_pkt_snprintf(&err, &buf, &blen, " COND");
>  			if (payload & 0x2)
> -				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " IND");
> -
> -			if (ret < 0)
> -				return ret;
> -			blen -= ret;
> -			return buf_len - blen;
> +				arm_spe_pkt_snprintf(&err, &buf, &blen, " IND");
>  
> +			break;
>  		default:
> -			return 0;
> +			/* Unknown index */
> +			err = -1;
> +			break;
>  		}
> +		break;
>  	case ARM_SPE_DATA_SOURCE:
>  	case ARM_SPE_TIMESTAMP:
> -		return arm_spe_pkt_snprintf(&err, &buf, &blen, "%s %lld", name, payload);
> +		arm_spe_pkt_snprintf(&err, &buf, &blen, "%s %lld", name, payload);
> +		break;
>  	case ARM_SPE_ADDRESS:
>  		switch (idx) {
>  		case 0:
> @@ -394,48 +389,59 @@ int arm_spe_pkt_desc(const struct arm_spe_pkt *packet, char *buf,
>  			ns = !!(packet->payload & NS_FLAG);
>  			el = (packet->payload & EL_FLAG) >> 61;
>  			payload &= ~(0xffULL << 56);
> -			return arm_spe_pkt_snprintf(&err, &buf, &blen,
> +			arm_spe_pkt_snprintf(&err, &buf, &blen,
>  					"%s 0x%llx el%d ns=%d",
>  				        (idx == 1) ? "TGT" : "PC", payload, el, ns);
> +			break;
>  		case 2:
> -			return arm_spe_pkt_snprintf(&err, &buf, &blen,
> -						    "VA 0x%llx", payload);
> +			arm_spe_pkt_snprintf(&err, &buf, &blen,
> +					     "VA 0x%llx", payload);
> +			break;
>  		case 3:
>  			ns = !!(packet->payload & NS_FLAG);
>  			payload &= ~(0xffULL << 56);
> -			return arm_spe_pkt_snprintf(&err, &buf, &blen,
> -						    "PA 0x%llx ns=%d", payload, ns);
> +			arm_spe_pkt_snprintf(&err, &buf, &blen,
> +					     "PA 0x%llx ns=%d", payload, ns);
> +			break;
>  		default:
> -			return 0;
> +			/* Unknown index */
> +			err = -1;
> +			break;
>  		}
> +		break;
>  	case ARM_SPE_CONTEXT:
> -		return arm_spe_pkt_snprintf(&err, &buf, &blen, "%s 0x%lx el%d",
> -					    name, (unsigned long)payload, idx + 1);
> +		arm_spe_pkt_snprintf(&err, &buf, &blen, "%s 0x%lx el%d",
> +				     name, (unsigned long)payload, idx + 1);
> +		break;
>  	case ARM_SPE_COUNTER:
> -		ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "%s %d ", name,
> -					   (unsigned short)payload);
> +		arm_spe_pkt_snprintf(&err, &buf, &blen, "%s %d ", name,
> +				     (unsigned short)payload);
>  		switch (idx) {
>  		case 0:
> -			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "TOT");
> +			arm_spe_pkt_snprintf(&err, &buf, &blen, "TOT");
>  			break;
>  		case 1:
> -			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "ISSUE");
> +			arm_spe_pkt_snprintf(&err, &buf, &blen, "ISSUE");
>  			break;
>  		case 2:
> -			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "XLAT");
> +			arm_spe_pkt_snprintf(&err, &buf, &blen, "XLAT");
>  			break;
>  		default:
> -			ret = 0;
>  			break;
>  		}
> -		if (ret < 0)
> -			return ret;
> -		blen -= ret;
> -		return buf_len - blen;
> +		break;
>  	default:
> +		/* Unknown index */
> +		err = -1;
>  		break;
>  	}
>  
> -	return arm_spe_pkt_snprintf(&err, &buf, &blen, "%s 0x%llx (%d)",
> -				    name, payload, packet->index);
> +	/* Output raw data if detect any error */
> +	if (err) {
> +		err = 0;
> +		arm_spe_pkt_snprintf(&err, &buf_orig, &blen, "%s 0x%llx (%d)",

That needs to be &buf_len here, doesn't it?

With that fixed:

Reviewed-by: Andre Przywara <andre.przywara@arm.com>

Cheers,
Andre

> +				     name, payload, packet->index);
> +	}
> +
> +	return err;
>  }
> diff --git a/tools/perf/util/arm-spe.c b/tools/perf/util/arm-spe.c
> index 3882a5360ada..8901a1656a41 100644
> --- a/tools/perf/util/arm-spe.c
> +++ b/tools/perf/util/arm-spe.c
> @@ -113,7 +113,7 @@ static void arm_spe_dump(struct arm_spe *spe __maybe_unused,
>  		if (ret > 0) {
>  			ret = arm_spe_pkt_desc(&packet, desc,
>  					       ARM_SPE_PKT_DESC_MAX);
> -			if (ret > 0)
> +			if (!ret)
>  				color_fprintf(stdout, color, " %s\n", desc);
>  		} else {
>  			color_fprintf(stdout, color, " Bad packet!\n");
> 

Re: [PATCH v7 07/22] perf arm-spe: Consolidate arm_spe_pkt_desc()'s return value

[Leo Yan]

On Mon, Nov 09, 2020 at 04:52:35PM +0000, André Przywara wrote:
> On 06/11/2020 01:41, Leo Yan wrote:
> > arm_spe_pkt_desc() returns the length of consumed the buffer for
> > the success case; otherwise, it delivers the return value from
> > arm_spe_pkt_snprintf(), and returns the last return value if there have
> > multiple calling arm_spe_pkt_snprintf().
> > 
> > Since arm_spe_pkt_snprintf() has the same semantics with vsnprintf() for
> > the return value, and vsnprintf() might return value equals to or bigger
> > than the parameter 'size' to indicate the truncation.  Because the
> > return value is >= 0 when the string is truncated, this condition will
> > be returned up the stack as "success".
> > 
> > This patch simplifies the return value for arm_spe_pkt_desc(): '0' means
> > success and other values mean an error has occurred.  To realize this,
> > it relies on arm_spe_pkt_snprintf()'s parameter 'err', the 'err' is a
> > cumulative value, returns its final value if printing buffer is called
> > for one time or multiple times.
> > 
> > To unify the error value generation, this patch handles error in a
> > central place, rather than directly bailing out in switch-cases,
> > it returns error at the end of arm_spe_pkt_desc().
> 
> And the but-last hunk means it will basically always return 0?

Yes, if the buffer is overflow, the last chunk code tries to rollback
to dump the packet name, payload's raw data nd packet index.  So in
theory, it should always return 0.

> Just checking, it's probably fine (and I don't want to review a v8 ;-)

> > This patch changes the caller arm_spe_dump() to respect the updated
> > return value semantics of arm_spe_pkt_desc().
> > 
> > Suggested-by: Dave Martin <Dave.Martin@arm.com>
> > Signed-off-by: Leo Yan <leo.yan@linaro.org>
> 
> One tiny thing below ...
> 
> > ---
> >  .../arm-spe-decoder/arm-spe-pkt-decoder.c     | 128 +++++++++---------
> >  tools/perf/util/arm-spe.c                     |   2 +-
> >  2 files changed, 68 insertions(+), 62 deletions(-)
> > 
> > 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 1970686f7020..33baef0c2c0b 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
> > @@ -301,9 +301,10 @@ static int arm_spe_pkt_snprintf(int *err, char **buf_p, size_t *blen,
> >  int arm_spe_pkt_desc(const struct arm_spe_pkt *packet, char *buf,
> >  		     size_t buf_len)
> >  {
> > -	int ret, ns, el, idx = packet->index;
> > +	int ns, el, idx = packet->index;
> >  	unsigned long long payload = packet->payload;
> >  	const char *name = arm_spe_pkt_name(packet->type);
> > +	char *buf_orig = buf;
> >  	size_t blen = buf_len;
> >  	int err = 0;
> >  
> > @@ -311,82 +312,76 @@ int arm_spe_pkt_desc(const struct arm_spe_pkt *packet, char *buf,
> >  	case ARM_SPE_BAD:
> >  	case ARM_SPE_PAD:
> >  	case ARM_SPE_END:
> > -		return arm_spe_pkt_snprintf(&err, &buf, &blen, "%s", name);
> > +		arm_spe_pkt_snprintf(&err, &buf, &blen, "%s", name);
> > +		break;
> >  	case ARM_SPE_EVENTS:
> > -		ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "EV");
> > +		arm_spe_pkt_snprintf(&err, &buf, &blen, "EV");
> >  
> >  		if (payload & 0x1)
> > -			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " EXCEPTION-GEN");
> > +			arm_spe_pkt_snprintf(&err, &buf, &blen, " EXCEPTION-GEN");
> >  		if (payload & 0x2)
> > -			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " RETIRED");
> > +			arm_spe_pkt_snprintf(&err, &buf, &blen, " RETIRED");
> >  		if (payload & 0x4)
> > -			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " L1D-ACCESS");
> > +			arm_spe_pkt_snprintf(&err, &buf, &blen, " L1D-ACCESS");
> >  		if (payload & 0x8)
> > -			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " L1D-REFILL");
> > +			arm_spe_pkt_snprintf(&err, &buf, &blen, " L1D-REFILL");
> >  		if (payload & 0x10)
> > -			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " TLB-ACCESS");
> > +			arm_spe_pkt_snprintf(&err, &buf, &blen, " TLB-ACCESS");
> >  		if (payload & 0x20)
> > -			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " TLB-REFILL");
> > +			arm_spe_pkt_snprintf(&err, &buf, &blen, " TLB-REFILL");
> >  		if (payload & 0x40)
> > -			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " NOT-TAKEN");
> > +			arm_spe_pkt_snprintf(&err, &buf, &blen, " NOT-TAKEN");
> >  		if (payload & 0x80)
> > -			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " MISPRED");
> > +			arm_spe_pkt_snprintf(&err, &buf, &blen, " MISPRED");
> >  		if (idx > 1) {
> >  			if (payload & 0x100)
> > -				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " LLC-ACCESS");
> > +				arm_spe_pkt_snprintf(&err, &buf, &blen, " LLC-ACCESS");
> >  			if (payload & 0x200)
> > -				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " LLC-REFILL");
> > +				arm_spe_pkt_snprintf(&err, &buf, &blen, " LLC-REFILL");
> >  			if (payload & 0x400)
> > -				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " REMOTE-ACCESS");
> > +				arm_spe_pkt_snprintf(&err, &buf, &blen, " REMOTE-ACCESS");
> >  		}
> > -		if (ret < 0)
> > -			return ret;
> > -		blen -= ret;
> > -		return buf_len - blen;
> > +		break;
> >  	case ARM_SPE_OP_TYPE:
> >  		switch (idx) {
> >  		case 0:
> > -			return arm_spe_pkt_snprintf(&err, &buf, &blen,
> > +			arm_spe_pkt_snprintf(&err, &buf, &blen,
> >  					payload & 0x1 ? "COND-SELECT" : "INSN-OTHER");
> > +			break;
> >  		case 1:
> > -			ret = arm_spe_pkt_snprintf(&err, &buf, &blen,
> > -						   payload & 0x1 ? "ST" : "LD");
> > +			arm_spe_pkt_snprintf(&err, &buf, &blen,
> > +					     payload & 0x1 ? "ST" : "LD");
> >  
> >  			if (payload & 0x2) {
> >  				if (payload & 0x4)
> > -					ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " AT");
> > +					arm_spe_pkt_snprintf(&err, &buf, &blen, " AT");
> >  				if (payload & 0x8)
> > -					ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " EXCL");
> > +					arm_spe_pkt_snprintf(&err, &buf, &blen, " EXCL");
> >  				if (payload & 0x10)
> > -					ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " AR");
> > +					arm_spe_pkt_snprintf(&err, &buf, &blen, " AR");
> >  			} else if (payload & 0x4) {
> > -				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " SIMD-FP");
> > +				arm_spe_pkt_snprintf(&err, &buf, &blen, " SIMD-FP");
> >  			}
> > -
> > -			if (ret < 0)
> > -				return ret;
> > -			blen -= ret;
> > -			return buf_len - blen;
> > -
> > +			break;
> >  		case 2:
> > -			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "B");
> > +			arm_spe_pkt_snprintf(&err, &buf, &blen, "B");
> >  
> >  			if (payload & 0x1)
> > -				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " COND");
> > +				arm_spe_pkt_snprintf(&err, &buf, &blen, " COND");
> >  			if (payload & 0x2)
> > -				ret = arm_spe_pkt_snprintf(&err, &buf, &blen, " IND");
> > -
> > -			if (ret < 0)
> > -				return ret;
> > -			blen -= ret;
> > -			return buf_len - blen;
> > +				arm_spe_pkt_snprintf(&err, &buf, &blen, " IND");
> >  
> > +			break;
> >  		default:
> > -			return 0;
> > +			/* Unknown index */
> > +			err = -1;
> > +			break;
> >  		}
> > +		break;
> >  	case ARM_SPE_DATA_SOURCE:
> >  	case ARM_SPE_TIMESTAMP:
> > -		return arm_spe_pkt_snprintf(&err, &buf, &blen, "%s %lld", name, payload);
> > +		arm_spe_pkt_snprintf(&err, &buf, &blen, "%s %lld", name, payload);
> > +		break;
> >  	case ARM_SPE_ADDRESS:
> >  		switch (idx) {
> >  		case 0:
> > @@ -394,48 +389,59 @@ int arm_spe_pkt_desc(const struct arm_spe_pkt *packet, char *buf,
> >  			ns = !!(packet->payload & NS_FLAG);
> >  			el = (packet->payload & EL_FLAG) >> 61;
> >  			payload &= ~(0xffULL << 56);
> > -			return arm_spe_pkt_snprintf(&err, &buf, &blen,
> > +			arm_spe_pkt_snprintf(&err, &buf, &blen,
> >  					"%s 0x%llx el%d ns=%d",
> >  				        (idx == 1) ? "TGT" : "PC", payload, el, ns);
> > +			break;
> >  		case 2:
> > -			return arm_spe_pkt_snprintf(&err, &buf, &blen,
> > -						    "VA 0x%llx", payload);
> > +			arm_spe_pkt_snprintf(&err, &buf, &blen,
> > +					     "VA 0x%llx", payload);
> > +			break;
> >  		case 3:
> >  			ns = !!(packet->payload & NS_FLAG);
> >  			payload &= ~(0xffULL << 56);
> > -			return arm_spe_pkt_snprintf(&err, &buf, &blen,
> > -						    "PA 0x%llx ns=%d", payload, ns);
> > +			arm_spe_pkt_snprintf(&err, &buf, &blen,
> > +					     "PA 0x%llx ns=%d", payload, ns);
> > +			break;
> >  		default:
> > -			return 0;
> > +			/* Unknown index */
> > +			err = -1;
> > +			break;
> >  		}
> > +		break;
> >  	case ARM_SPE_CONTEXT:
> > -		return arm_spe_pkt_snprintf(&err, &buf, &blen, "%s 0x%lx el%d",
> > -					    name, (unsigned long)payload, idx + 1);
> > +		arm_spe_pkt_snprintf(&err, &buf, &blen, "%s 0x%lx el%d",
> > +				     name, (unsigned long)payload, idx + 1);
> > +		break;
> >  	case ARM_SPE_COUNTER:
> > -		ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "%s %d ", name,
> > -					   (unsigned short)payload);
> > +		arm_spe_pkt_snprintf(&err, &buf, &blen, "%s %d ", name,
> > +				     (unsigned short)payload);
> >  		switch (idx) {
> >  		case 0:
> > -			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "TOT");
> > +			arm_spe_pkt_snprintf(&err, &buf, &blen, "TOT");
> >  			break;
> >  		case 1:
> > -			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "ISSUE");
> > +			arm_spe_pkt_snprintf(&err, &buf, &blen, "ISSUE");
> >  			break;
> >  		case 2:
> > -			ret = arm_spe_pkt_snprintf(&err, &buf, &blen, "XLAT");
> > +			arm_spe_pkt_snprintf(&err, &buf, &blen, "XLAT");
> >  			break;
> >  		default:
> > -			ret = 0;
> >  			break;
> >  		}
> > -		if (ret < 0)
> > -			return ret;
> > -		blen -= ret;
> > -		return buf_len - blen;
> > +		break;
> >  	default:
> > +		/* Unknown index */
> > +		err = -1;
> >  		break;
> >  	}
> >  
> > -	return arm_spe_pkt_snprintf(&err, &buf, &blen, "%s 0x%llx (%d)",
> > -				    name, payload, packet->index);
> > +	/* Output raw data if detect any error */
> > +	if (err) {
> > +		err = 0;
> > +		arm_spe_pkt_snprintf(&err, &buf_orig, &blen, "%s 0x%llx (%d)",
> 
> That needs to be &buf_len here, doesn't it?

Oops :)  Good catching; will fix.

> With that fixed:
> 
> Reviewed-by: Andre Przywara <andre.przywara@arm.com>

Thanks for the review and very detailed testing in the patch 06/22.

Leo

> Cheers,
> Andre
> 
> > +				     name, payload, packet->index);
> > +	}
> > +
> > +	return err;
> >  }
> > diff --git a/tools/perf/util/arm-spe.c b/tools/perf/util/arm-spe.c
> > index 3882a5360ada..8901a1656a41 100644
> > --- a/tools/perf/util/arm-spe.c
> > +++ b/tools/perf/util/arm-spe.c
> > @@ -113,7 +113,7 @@ static void arm_spe_dump(struct arm_spe *spe __maybe_unused,
> >  		if (ret > 0) {
> >  			ret = arm_spe_pkt_desc(&packet, desc,
> >  					       ARM_SPE_PKT_DESC_MAX);
> > -			if (ret > 0)
> > +			if (!ret)
> >  				color_fprintf(stdout, color, " %s\n", desc);
> >  		} else {
> >  			color_fprintf(stdout, color, " Bad packet!\n");
> > 
>