perf arm-spe: Refactor packet header parsing

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>
Acked-by: Will Deacon <will@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Al Grant <Al.Grant@arm.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Dave Martin <Dave.Martin@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wei Li <liwei391@huawei.com>
Link: https://lore.kernel.org/r/20201119152441.6972-3-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

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 fbededc..a769fe5 100644 (file)
--- 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_ULL(63)
 #define EL_FLAG                (BIT_ULL(62) | BIT_ULL(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 4c87052..129f434 100644 (file)
--- 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)