From: Mathieu Poirier <mathieu.poirier@linaro.org>
To: Mike Leach <mike.leach@linaro.org>
Cc: coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org,
suzuki.poulose@arm.com
Subject: Re: [PATCH] coresight: etmv4: Update default filter and initialisation.
Date: Mon, 20 Apr 2020 12:16:11 -0600 [thread overview]
Message-ID: <20200420181611.GB25885@xps15> (raw)
In-Reply-To: <20200415201030.15617-1-mike.leach@linaro.org>
On Wed, Apr 15, 2020 at 09:10:30PM +0100, Mike Leach wrote:
> Differing default states set on driver init / perf init and as a result
> of a sysfs reset.
>
> The ETMv4 can be programmed to trace the entire instruction address range
> without the need to use address comparator filter resources.
> (Described in the ETMv4.x technical reference manual)
>
> sysfs reset was using this method, perf and default driver init were setup
> with an address range comparator for the entire address range.
>
> The perf / driver init has been altered to use the method without needing
> any comparator address hardware.
>
> Minor adjustment to the vinst_ctrl register initialisation to ensure
> correct zero initialisation.
>
> Applies to Linux 5.7-rc1, tested on Juno-r1 and DB410c platforms.
>
> Signed-off-by: Mike Leach <mike.leach@linaro.org>
Applied - thanks,
Mathieu
> ---
> .../coresight/coresight-etm4x-sysfs.c | 2 +-
> drivers/hwtracing/coresight/coresight-etm4x.c | 23 +++++--------------
> 2 files changed, 7 insertions(+), 18 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> index ce41482431f9..b673e738bc9a 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x-sysfs.c
> @@ -205,7 +205,7 @@ static ssize_t reset_store(struct device *dev,
> * started state. ARM recommends start-stop logic is set before
> * each trace run.
> */
> - config->vinst_ctrl |= BIT(0);
> + config->vinst_ctrl = BIT(0);
> if (drvdata->nr_addr_cmp == true) {
> config->mode |= ETM_MODE_VIEWINST_STARTSTOP;
> /* SSSTATUS, bit[9] */
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x.c b/drivers/hwtracing/coresight/coresight-etm4x.c
> index a90d757f7043..58ae5498ecf1 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x.c
> @@ -791,7 +791,7 @@ static void etm4_set_default_config(struct etmv4_config *config)
> config->ts_ctrl = 0x0;
>
> /* TRCVICTLR::EVENT = 0x01, select the always on logic */
> - config->vinst_ctrl |= BIT(0);
> + config->vinst_ctrl = BIT(0);
> }
>
> static u64 etm4_get_ns_access_type(struct etmv4_config *config)
> @@ -894,17 +894,8 @@ static void etm4_set_start_stop_filter(struct etmv4_config *config,
>
> static void etm4_set_default_filter(struct etmv4_config *config)
> {
> - u64 start, stop;
> -
> - /*
> - * Configure address range comparator '0' to encompass all
> - * possible addresses.
> - */
> - start = 0x0;
> - stop = ~0x0;
> -
> - etm4_set_comparator_filter(config, start, stop,
> - ETM_DEFAULT_ADDR_COMP);
> + /* Trace everything 'default' filter achieved by no filtering */
> + config->viiectlr = 0x0;
>
> /*
> * TRCVICTLR::SSSTATUS == 1, the start-stop logic is
> @@ -925,11 +916,9 @@ static void etm4_set_default(struct etmv4_config *config)
> /*
> * Make default initialisation trace everything
> *
> - * Select the "always true" resource selector on the
> - * "Enablign Event" line and configure address range comparator
> - * '0' to trace all the possible address range. From there
> - * configure the "include/exclude" engine to include address
> - * range comparator '0'.
> + * This is done by a minimum default config sufficient to enable
> + * full instruction trace - with a default filter for trace all
> + * achieved by having no filtering.
> */
> etm4_set_default_config(config);
> etm4_set_default_filter(config);
> --
> 2.17.1
>
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prev parent reply other threads:[~2020-04-20 18:16 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-15 20:10 [PATCH] coresight: etmv4: Update default filter and initialisation Mike Leach
2020-04-20 18:16 ` Mathieu Poirier [this message]
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