CoreSight September 2018

coresight@lists.linaro.org

25 participants
25 discussions

[PATCH 1/1] coresight: etm4x: Configure EL2 exception level when kernel is running in HYP

by Tomasz Nowicki

For non-VHE systems host kernel runs at EL1 and jumps to EL2 whenever hypervisor code should be executed. In this case ETM4x driver must restrict configuration to EL1 when it setups kernel tracing. However, there is no separate hypervisor privilege level when VHE is enabled, the host kernel runs at EL2. This patch fixes configuration of TRCACATRn register for VHE systems so that ETM_EXLEVEL_NS_HYP bit is used instead of ETM_EXLEVEL_NS_OS to on/off kernel tracing. At the same time, it moves common code to new helper. Signed-off-by: Tomasz Nowicki <tnowicki(a)caviumnetworks.com> --- drivers/hwtracing/coresight/coresight-etm4x.c | 39 ++++++++++--------- 1 file changed, 20 insertions(+), 19 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c index f79b0ea85d76..5f495c942f99 100644 --- a/drivers/hwtracing/coresight/coresight-etm4x.c +++ b/drivers/hwtracing/coresight/coresight-etm4x.c @@ -28,6 +28,7 @@ #include <linux/pm_runtime.h> #include <asm/sections.h> #include <asm/local.h> +#include <asm/virt.h> #include "coresight-etm4x.h" #include "coresight-etm-perf.h" @@ -606,7 +607,7 @@ static void etm4_set_default_config(struct etmv4_config *config) config->vinst_ctrl |= BIT(0); } -static u64 etm4_get_access_type(struct etmv4_config *config) +static u64 etm4_get_ns_access_type(struct etmv4_config *config) { u64 access_type = 0; @@ -617,17 +618,27 @@ static u64 etm4_get_access_type(struct etmv4_config *config) * Bit[13] Exception level 1 - OS * Bit[14] Exception level 2 - Hypervisor * Bit[15] Never implemented - * - * Always stay away from hypervisor mode. */ - access_type = ETM_EXLEVEL_NS_HYP; - if (config->mode & ETM_MODE_EXCL_KERN) - access_type |= ETM_EXLEVEL_NS_OS; + if (!is_kernel_in_hyp_mode()) { + /* Stay away from hypervisor mode for non-VHE */ + access_type = ETM_EXLEVEL_NS_HYP; + if (config->mode & ETM_MODE_EXCL_KERN) + access_type |= ETM_EXLEVEL_NS_OS; + } else if (config->mode & ETM_MODE_EXCL_KERN) { + access_type = ETM_EXLEVEL_NS_HYP; + } if (config->mode & ETM_MODE_EXCL_USER) access_type |= ETM_EXLEVEL_NS_APP; + return access_type; +} + +static u64 etm4_get_access_type(struct etmv4_config *config) +{ + u64 access_type = etm4_get_ns_access_type(config); + /* * EXLEVEL_S, bits[11:8], don't trace anything happening * in secure state. @@ -881,20 +892,10 @@ void etm4_config_trace_mode(struct etmv4_config *config) addr_acc = config->addr_acc[ETM_DEFAULT_ADDR_COMP]; /* clear default config */ - addr_acc &= ~(ETM_EXLEVEL_NS_APP | ETM_EXLEVEL_NS_OS); + addr_acc &= ~(ETM_EXLEVEL_NS_APP | ETM_EXLEVEL_NS_OS | + ETM_EXLEVEL_NS_HYP); - /* - * EXLEVEL_NS, bits[15:12] - * The Exception levels are: - * Bit[12] Exception level 0 - Application - * Bit[13] Exception level 1 - OS - * Bit[14] Exception level 2 - Hypervisor - * Bit[15] Never implemented - */ - if (mode & ETM_MODE_EXCL_KERN) - addr_acc |= ETM_EXLEVEL_NS_OS; - else - addr_acc |= ETM_EXLEVEL_NS_APP; + addr_acc |= etm4_get_ns_access_type(config); config->addr_acc[ETM_DEFAULT_ADDR_COMP] = addr_acc; config->addr_acc[ETM_DEFAULT_ADDR_COMP + 1] = addr_acc; -- 2.17.1

5 years, 8 months

[PATCH v2] perf: Support for Arm A32/T32 instruction sets in CoreSight trace

by Robert Walker

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(a)arm.com> --- v2: Minor fixes following review comments from Mathieu Rebased on v4.19-rc1 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; + (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..9351bd1 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; + u32 instr_count; 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..fcaa73f 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, ARRAY_SIZE(instrBytes), instrBytes); + /* 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. */ - 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

5 years, 8 months

Enabling Coresight in atomic context.

by Mike Bazov

Greetings, I'm trying to enable the Coresight ETMv4 trace from kernel mode. I saw there is no documentation on how to do this, except using the sysfs user mode interface and perf. To overcome this i looked a little bit in the coresight.h header file, and came to these APIs: > extern int coresight_enable(struct coresight_device *csdev); > > extern void coresight_disable(struct coresight_device *csdev); And the sysfs implementation uses these APIs when enabing/disabling the trace code, so i thought this could suit my needs. The next problem was actually getting the coresight devices data structures, which aren't exported and are actually provided internally to perf and sysfs. So i exported the coresight bus type: struct bus_type coresight_bustype = { > > .name = "coresight", > > }; > > EXPORT_SYMBOL(coresight_bustype); And enumerated the bus and just looked for the type CORESIGHT_DEV_TYPE_SOURCE, since the only source on my board is ETMv4, there isn't any conflicts so i should get only ETMv4s. This worked, and indeed i collected a coresight device for every CPU, and enabled the trace successfully while being in *non-atomic context*. The problem is, i must enable the trace in *atomic context synchronously *on the current thread's CPU(i can't issue a work-queue to enable the trace for me). So.. i got many BUG() errors because of non-atomic API usage, for example, the allocation of the TMC-ETR buffer: > dma_alloc_coherent(drvdata->dev, etr_buf->size, > &flat_buf->daddr, *GFP_KERNEL*); So my questions are: 1) Is there a more documented way of enabling coresight from kernel mode? i believe i achieved this using cheats. 2) I see there is no exported kernel API to config the coresight trace attributes(for example, filter EL0). I can only do so from sysfs.. am i missing something? 3) Are there any plans to make the Coresight infrastructure atomic-context friendly? If there are, is the development in progress? if not.. how would you suggest tackling the issues i've described in this message? Thank you!

5 years, 8 months

Coresight with Perf need ETR ?

by Christophe ROULLIER

Hi, I have followed procedure to integrate libopenCSD in perf tool in target ARM. (based on kernel 4.18rc1) I’ve seen in documentation that perf record need parameters cs_etm/(a)xxxxx.etr/u …<mailto:cs_etm/@xxxxx.etr/u%20…> I would like to know if ETR device is mandatory to use coresight trace with perf ? In my architecture, I’ve : 1 .funnel 1 .tpiu 2 .etm 1 .etf 1 .stm 1 replicator but no ETR ☹ If possible without ETR, do you have examples of perf record cmd usage ? I’ve configured my coresight register as followed : echo 1 > /sys/bus/coresight/devices/xxxx.stm/hwevent_select echo 2 > /sys/bus/coresight/devices/xxxx.stm/hwevent_extmux_select // Need to track IRQ up of UART echo 0x200000 > /sys/bus/coresight/devices/xxxx.stm/hwevent_enable echo 1 > /sys/bus/coresight/devices/yyyy.etf/enable_sink echo 1 > /sys/bus/coresight/devices/xxxx.stm/enable_source Which perf record cmd I must enter to catch my STM event ? Thanks for your help. Christophe.

5 years, 8 months

Failed for ETM decoding with db410c snapshot mode

by leo.yan＠linaro.org

Hi Mike, Mathieu, [ + CoreSight ML ] When I work on the CoreSight + perf tool and used crash extension program to extract the tracing data from perf aux buffer, finally I can get the trace data for about 1.6MB from ETF sink from DB410c board. To verify the extracted trace data, I used 'snapshot' mode under OpenCSD code base, you could see the tar file for this [1]. After you download this file, you could place it under OpenCSD folder: $ cp db410c_snapshot_kdump.tgz my_opencsd/decoder/tests/snapshots $ cd my_opencsd/decoder/tests/snapshots $ tar zxvf db410c_snapshot_kdump.tgz $ cd db410c_snapshot_kdump $ ../../bin/builddir/trc_pkt_lister $ ../../bin/builddir/trc_pkt_lister -decode If I use the command 'trc_pkt_lister' without any extra options, it can print out trace packets successfully; but if I add the extra option '-decode' it uses 'decode all' mode and it reports the errors as: 483710 Idx:53086; ID:10; [0xf8 ]; I_ATOM_F3 : Atom format 3.; NNN 483711 Idx:53086; ID:10; OCSD_GEN_TRC_ELEM_ADDR_NACC( 0xffff000008abc9f0 ) 483712 Idx:53088; ID:10; [0xdb ]; I_ATOM_F2 : Atom format 2.; EE 483713 Idx:53194; ID:10; [0x6b 0x8c 0x08 0xfa 0xdc 0x95 0x5c ]; I_COND_RES_F1 : Conditional Result, format 1. 483714 DCD_ETMV4_0016 : 0x0018 (OCSD_ERR_BAD_DECODE_PKT) [Reserved or unknown packet in decoder.]; Unsupported packet type.Trace Packet Lister : Data Path fatal error 483715 0x0018 (OCSD_ERR_BAD_DECODE_PKT) [Reserved or unknown packet in decoder.]; Unsupported packet type.Trace Packet Lister : Trace buffer done, processed 53216 bytes. You also could check detailed log trc_pkt_lister.ppl in the shared tar packet; After searched for the OpenCSD code and found this error is due it cannot support some types of packets [2]. So want to check what's the best for this issue; seems to me we need to fix this so it can support well to complete the decoding? Thanks in advance for suggestion. Leo Yan [1] http://people.linaro.org/~leo.yan/opencsd_db410c/db410c_snapshot_kdump.tgz [2] https://github.com/Linaro/OpenCSD/blob/master/decoder/source/etmv4/trc_pkt_…

5 years, 8 months

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CoreSight September 2018