On 29/10/2020 07:19, Leo Yan wrote: > 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 <[email protected]>
Thanks for the change! Reviewed-by: Andre Przywara <[email protected]> Cheers, Andre > --- > .../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 */ >
