Hi Robert,

Your patch landed in the middle of the merge window and will have to be sent again rebased on 4.19-rc1 and long with minor fix found below.

Regards, Mathieu

On Wed, Aug 22, 2018 at 05:03:57PM +0100, Robert Walker wrote:

This patch adds support for generating instruction samples from trace of AArch32 programs using the A32 and T32 instruction sets.

T32 has variable 2 or 4 byte instruction size, so the conversion between addresses and instruction counts requires extra information from the trace decoder, requiring version 0.9.1 of OpenCSD. A check for the new struct member has been added to the feature check for OpenCSD.

Signed-off-by: Robert Walker robert.walker@arm.com

tools/build/feature/test-libopencsd.c | 7 +++ tools/perf/util/cs-etm-decoder/cs-etm-decoder.c | 27 ++++++++++ tools/perf/util/cs-etm-decoder/cs-etm-decoder.h | 10 ++++ tools/perf/util/cs-etm.c | 71 +++++++++++-------------- 4 files changed, 75 insertions(+), 40 deletions(-)

diff --git a/tools/build/feature/test-libopencsd.c b/tools/build/feature/test-libopencsd.c index 5ff1246..d96b2df 100644 --- a/tools/build/feature/test-libopencsd.c +++ b/tools/build/feature/test-libopencsd.c @@ -3,6 +3,13 @@ int main(void) {

• /*

• * Requires ocsd_generic_trace_elem.num_instr_range introduced in
  

• * OpenCSD 0.9
  

• */
  

• ocsd_generic_trace_elem elem;
• (void)elem.num_instr_range;

I really like this - simple and efficient.

(void)ocsd_get_version(); return 0; } diff --git a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c index 938def6..73d8384 100644 --- a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c +++ b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.c @@ -263,9 +263,12 @@ static void cs_etm_decoder__clear_buffer(struct cs_etm_decoder *decoder) decoder->tail = 0; decoder->packet_count = 0; for (i = 0; i < MAX_BUFFER; i++) {

• decoder->packet_buffer[i].isa = CS_ETM_ISA_UNKNOWN;
  

  decoder->packet_buffer[i].start_addr = CS_ETM_INVAL_ADDR; decoder->packet_buffer[i].end_addr = CS_ETM_INVAL_ADDR;

• decoder->packet_buffer[i].instr_count = 0;
  

  decoder->packet_buffer[i].last_instr_taken_branch = false;

• decoder->packet_buffer[i].last_instr_size = 0;
  

  decoder->packet_buffer[i].exc = false; decoder->packet_buffer[i].exc_ret = false; decoder->packet_buffer[i].cpu = INT_MIN;

@@ -294,11 +297,13 @@ cs_etm_decoder__buffer_packet(struct cs_etm_decoder *decoder, decoder->packet_count++; decoder->packet_buffer[et].sample_type = sample_type;

• decoder->packet_buffer[et].isa = CS_ETM_ISA_UNKNOWN; decoder->packet_buffer[et].exc = false; decoder->packet_buffer[et].exc_ret = false; decoder->packet_buffer[et].cpu = *((int *)inode->priv); decoder->packet_buffer[et].start_addr = CS_ETM_INVAL_ADDR; decoder->packet_buffer[et].end_addr = CS_ETM_INVAL_ADDR;
• decoder->packet_buffer[et].instr_count = 0;

if (decoder->packet_count == MAX_BUFFER - 1) return OCSD_RESP_WAIT; @@ -321,8 +326,28 @@ cs_etm_decoder__buffer_range(struct cs_etm_decoder *decoder, packet = &decoder->packet_buffer[decoder->tail];

• switch (elem->isa) {
• case ocsd_isa_aarch64:

• packet->isa = CS_ETM_ISA_A64;
  

• break;
  

• case ocsd_isa_arm:

• packet->isa = CS_ETM_ISA_A32;
  

• break;
  

• case ocsd_isa_thumb2:

• packet->isa = CS_ETM_ISA_T32;
  

• break;
  

• case ocsd_isa_tee:
• case ocsd_isa_jazelle:
• case ocsd_isa_custom:
• case ocsd_isa_unknown:
• default:

• packet->isa = CS_ETM_ISA_UNKNOWN;
  

• }
• packet->start_addr = elem->st_addr; packet->end_addr = elem->en_addr;
• packet->instr_count = elem->num_instr_range;
• switch (elem->last_i_type) { case OCSD_INSTR_BR: case OCSD_INSTR_BR_INDIRECT:

@@ -336,6 +361,8 @@ cs_etm_decoder__buffer_range(struct cs_etm_decoder *decoder, break; }

• packet->last_instr_size = elem->last_instr_sz;
• return ret;

} diff --git a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.h b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.h index 612b575..9a10eda 100644 --- a/tools/perf/util/cs-etm-decoder/cs-etm-decoder.h +++ b/tools/perf/util/cs-etm-decoder/cs-etm-decoder.h @@ -28,11 +28,21 @@ enum cs_etm_sample_type { CS_ETM_TRACE_ON = 1 << 1, }; +enum cs_etm_isa {

• CS_ETM_ISA_UNKNOWN,
• CS_ETM_ISA_A64,
• CS_ETM_ISA_A32,
• CS_ETM_ISA_T32,

+};

struct cs_etm_packet { enum cs_etm_sample_type sample_type;

• enum cs_etm_isa isa; u64 start_addr; u64 end_addr;
• u64 instr_count;

Shouldn't this be a u32 since ocsd_generic_trace_elem::num_instr_range is a uint32_t in the openCSD library?

u8 last_instr_taken_branch;

• u8 last_instr_size; u8 exc; u8 exc_ret; int cpu;

diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c index 2ae6402..579f52a 100644 --- a/tools/perf/util/cs-etm.c +++ b/tools/perf/util/cs-etm.c @@ -31,14 +31,6 @@ #define MAX_TIMESTAMP (~0ULL) -/*

• • A64 instructions are always 4 bytes
• • Only A64 is supported, so can use this constant for converting between
• • addresses and instruction counts, calculting offsets etc
• */

-#define A64_INSTR_SIZE 4

struct cs_etm_auxtrace { struct auxtrace auxtrace; struct auxtrace_queues queues; @@ -492,21 +484,16 @@ static inline void cs_etm__reset_last_branch_rb(struct cs_etm_queue *etmq) etmq->last_branch_rb->nr = 0; } -static inline u64 cs_etm__last_executed_instr(struct cs_etm_packet *packet) -{

• /* Returns 0 for the CS_ETM_TRACE_ON packet */
• if (packet->sample_type == CS_ETM_TRACE_ON)

• return 0;
  

+static inline int cs_etm__t32_instr_size(struct cs_etm_queue *etmq,

• 			 u64 addr) {
  

• u8 instrBytes[2];

• /*

• * The packet records the execution range with an exclusive end address
  

• *
  

• * A64 instructions are constant size, so the last executed
  

• * instruction is A64_INSTR_SIZE before the end address
  

• * Will need to do instruction level decode for T32 instructions as
  

• * they can be variable size (not yet supported).
  

• cs_etm__mem_access(etmq, addr, 2, instrBytes);

Please use ARRAY_SIZE(), although trivial here it is just a matter of time before someone else submits a patch for it.

• /* T32 instruction size is indicated by bits[15:11] of the first

• * 16-bit word of the instruction: 0b11101, 0b11110 and 0b11111
  

• * denote a 32-bit instruction.
  

  */

Thanks for the documentation.

• return packet->end_addr - A64_INSTR_SIZE;

• return ((instrBytes[1] & 0xF8) >= 0xE8) ? 4 : 2;

} static inline u64 cs_etm__first_executed_instr(struct cs_etm_packet *packet) @@ -518,27 +505,32 @@ static inline u64 cs_etm__first_executed_instr(struct cs_etm_packet *packet) return packet->start_addr; } -static inline u64 cs_etm__instr_count(const struct cs_etm_packet *packet) +static inline +u64 cs_etm__last_executed_instr(const struct cs_etm_packet *packet) {

• /*

• * Only A64 instructions are currently supported, so can get
  

• * instruction count by dividing.
  

• * Will need to do instruction level decode for T32 instructions as
  

• * they can be variable size (not yet supported).
  

• */
  

• return (packet->end_addr - packet->start_addr) / A64_INSTR_SIZE;

• /* Returns 0 for the CS_ETM_TRACE_ON packet */
• if (packet->sample_type == CS_ETM_TRACE_ON)

• return 0;
  

• return packet->end_addr - packet->last_instr_size;

} -static inline u64 cs_etm__instr_addr(const struct cs_etm_packet *packet, +static inline u64 cs_etm__instr_addr(struct cs_etm_queue *etmq,

• 		     const struct cs_etm_packet *packet,
  	     u64 offset)
  

{

• /*

• * Only A64 instructions are currently supported, so can get
  

• * instruction address by muliplying.
  

• * Will need to do instruction level decode for T32 instructions as
  

• * they can be variable size (not yet supported).
  

• */
  

• return packet->start_addr + offset * A64_INSTR_SIZE;

• if (packet->isa == CS_ETM_ISA_T32) {

• u64 addr = packet->start_addr;
  

• while (offset > 0) {
  

• 	addr += cs_etm__t32_instr_size(etmq, addr);
  

• 	offset--;
  

• }
  

• return addr;
  

• }
• /* Assume a 4 byte instruction size (A32/A64) */
• return packet->start_addr + offset * 4;

} static void cs_etm__update_last_branch_rb(struct cs_etm_queue *etmq) @@ -867,9 +859,8 @@ static int cs_etm__sample(struct cs_etm_queue *etmq) struct cs_etm_auxtrace *etm = etmq->etm; struct cs_etm_packet *tmp; int ret;

• u64 instrs_executed;

• u64 instrs_executed = etmq->packet->instr_count;

• instrs_executed = cs_etm__instr_count(etmq->packet); etmq->period_instructions += instrs_executed;

/* @@ -899,7 +890,7 @@ static int cs_etm__sample(struct cs_etm_queue *etmq) * executed, but PC has not advanced to next instruction) */ u64 offset = (instrs_executed - instrs_over - 1);

• u64 addr = cs_etm__instr_addr(etmq->packet, offset);
  

• u64 addr = cs_etm__instr_addr(etmq, etmq->packet, offset);
  

ret = cs_etm__synth_instruction_sample( etmq, addr, etm->instructions_sample_period); -- 2.7.4