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 <[email protected]>
---
.../util/arm-spe-decoder/arm-spe-pkt-decoder.c | 18 +++++++++---------
.../util/arm-spe-decoder/arm-spe-pkt-decoder.h | 3 +++
2 files changed, 12 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..4294c133a465 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 1 << SPE_HEADER_SZ(hdr);
}
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;
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..e9ea8e3ead5d 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
@@ -9,6 +9,7 @@
#include <stddef.h>
#include <stdint.h>
+#include <linux/bits.h>
#define ARM_SPE_PKT_DESC_MAX 256
@@ -36,6 +37,8 @@ struct arm_spe_pkt {
uint64_t payload;
};
+#define SPE_HEADER_SZ(val) ((val & GENMASK_ULL(5, 4)) >> 4)
+
#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
On 22/10/2020 15:57, Leo Yan wrote:
Hi Leo,
> 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 <[email protected]>
> ---
> .../util/arm-spe-decoder/arm-spe-pkt-decoder.c | 18 +++++++++---------
> .../util/arm-spe-decoder/arm-spe-pkt-decoder.h | 3 +++
> 2 files changed, 12 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..4294c133a465 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 1 << SPE_HEADER_SZ(hdr);
I know, I know, I asked for this, but now looking again at it - and
after having seen the whole series:
This is now really trivial, and there are just two users? And
SPE_HEADER_SZ() is only used in here?
So either you just stuff the "1U << .." into the callers of
arm_spe_payload_len(), or indeed put all of this into one macro (as you
had originally).
Apologies for this forth and back, but I didn't realise how this is
really used eventually, and I just saw the transition from function to
macro.
But please use 1U << .., signed shifts are treacherous.
> }
>
> 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;
> 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..e9ea8e3ead5d 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
> @@ -9,6 +9,7 @@
>
> #include <stddef.h>
> #include <stdint.h>
> +#include <linux/bits.h>
>
> #define ARM_SPE_PKT_DESC_MAX 256
>
> @@ -36,6 +37,8 @@ struct arm_spe_pkt {
> uint64_t payload;
> };
>
> +#define SPE_HEADER_SZ(val) ((val & GENMASK_ULL(5, 4)) >> 4)
If you should keep this, please put parentheses around "val".
Cheers,
Andre
> +
> #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)
>
Hi Andre,
On Fri, Oct 23, 2020 at 06:08:53PM +0100, Andr? Przywara wrote:
> On 22/10/2020 15:57, Leo Yan wrote:
>
> Hi Leo,
>
> > 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 <[email protected]>
> > ---
> > .../util/arm-spe-decoder/arm-spe-pkt-decoder.c | 18 +++++++++---------
> > .../util/arm-spe-decoder/arm-spe-pkt-decoder.h | 3 +++
> > 2 files changed, 12 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..4294c133a465 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 1 << SPE_HEADER_SZ(hdr);
>
> I know, I know, I asked for this, but now looking again at it - and
> after having seen the whole series:
> This is now really trivial, and there are just two users? And
> SPE_HEADER_SZ() is only used in here?
>
> So either you just stuff the "1U << .." into the callers of
> arm_spe_payload_len(), or indeed put all of this into one macro (as you
> had originally).
Okay, will stuff the "1U << .." into the function.
> Apologies for this forth and back, but I didn't realise how this is
> really used eventually, and I just saw the transition from function to
> macro.
Actually you considered more than me and I learned many details from the
reivewing process, so no worries :)
> But please use 1U << .., signed shifts are treacherous.
>
> > }
> >
> > 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;
> > 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..e9ea8e3ead5d 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
> > @@ -9,6 +9,7 @@
> >
> > #include <stddef.h>
> > #include <stdint.h>
> > +#include <linux/bits.h>
> >
> > #define ARM_SPE_PKT_DESC_MAX 256
> >
> > @@ -36,6 +37,8 @@ struct arm_spe_pkt {
> > uint64_t payload;
> > };
> >
> > +#define SPE_HEADER_SZ(val) ((val & GENMASK_ULL(5, 4)) >> 4)
>
> If you should keep this, please put parentheses around "val".
I went through your suggestions in this patch and other patches, looks
reasonable to me, will follow them and respin patch set.
Thanks a lot for timely reviewing!
Leo