Re: [PATCH 3/3] perf cs-etm: Update deduction of TRCCONFIGR register for branch broadcast
From: Leo Yan <hidden>
Date: 2021-12-10 02:41:47
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linux-perf-users, lkml
On Wed, Dec 08, 2021 at 04:09:07PM +0000, James Clark wrote:
quoted hunk ↗ jump to hunk
Now that a config flag for branch broadcast has been added, take it into account when trying to deduce what the driver would have programmed the TRCCONFIGR register to. Signed-off-by: James Clark <redacted> --- tools/include/linux/coresight-pmu.h | 2 ++ tools/perf/arch/arm/util/cs-etm.c | 3 +++ 2 files changed, 5 insertions(+)diff --git a/tools/include/linux/coresight-pmu.h b/tools/include/linux/coresight-pmu.h index 4ac5c081af93..6c2fd6cc5a98 100644 --- a/tools/include/linux/coresight-pmu.h +++ b/tools/include/linux/coresight-pmu.h@@ -18,6 +18,7 @@ * ETMv3.5/PTM doesn't define ETMCR config bits with prefix "ETM3_" and * directly use below macros as config bits. */ +#define ETM_OPT_BRANCH_BROADCAST 8
I checked ETMv3 architecture spec (ARM IHI 0014Q), its bit 8 is "branch output" for all branch address outputting. I am not sure if it is the same thing between ETMv3's "branch output" and ETMv4's "branch broadcasting", but it makes sense for me to use bit 8 as an unified config bit to control these two options for ETMv3 and ETMv4 respectively. Just note, I understand this patch set is to enable branch broadcasting for entire memory region rather than using any comparators (see TRCBBCTLR) to limit branch broadcasting ranges. This is fine for me and we could enable ranges later. Reviewed-by: Leo Yan <redacted>
quoted hunk ↗ jump to hunk
#define ETM_OPT_CYCACC 12 #define ETM_OPT_CTXTID 14 #define ETM_OPT_CTXTID2 15@@ -25,6 +26,7 @@ #define ETM_OPT_RETSTK 29 /* ETMv4 CONFIGR programming bits for the ETM OPTs */ +#define ETM4_CFG_BIT_BB 3 #define ETM4_CFG_BIT_CYCACC 4 #define ETM4_CFG_BIT_CTXTID 6 #define ETM4_CFG_BIT_VMID 7diff --git a/tools/perf/arch/arm/util/cs-etm.c b/tools/perf/arch/arm/util/cs-etm.c index 293a23bf8be3..c7ef4e9b4a3a 100644 --- a/tools/perf/arch/arm/util/cs-etm.c +++ b/tools/perf/arch/arm/util/cs-etm.c@@ -527,6 +527,9 @@ static u64 cs_etmv4_get_config(struct auxtrace_record *itr) if (config_opts & BIT(ETM_OPT_CTXTID2)) config |= BIT(ETM4_CFG_BIT_VMID) | BIT(ETM4_CFG_BIT_VMID_OPT); + if (config_opts & BIT(ETM_OPT_BRANCH_BROADCAST)) + config |= BIT(ETM4_CFG_BIT_BB); + return config; }-- 2.28.0
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