From: Mathieu Poirier <mathieu.poirier@linaro.org>
To: Mao Jinlong <quic_jinlmao@quicinc.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
Mike Leach <mike.leach@linaro.org>, Leo Yan <leo.yan@linaro.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org,
Tingwei Zhang <quic_tingweiz@quicinc.com>,
Yuanfang Zhang <quic_yuanfang@quicinc.com>,
Tao Zhang <quic_taozha@quicinc.com>,
Trilok Soni <quic_tsoni@quicinc.com>,
linux-arm-msm@vger.kernel.org
Subject: Re: [PATCH v2 1/9] Use IDR to maintain all the enabled sources' paths.
Date: Tue, 14 Dec 2021 11:30:10 -0700 [thread overview]
Message-ID: <20211214183010.GA1549991@p14s> (raw)
In-Reply-To: <20211209141543.21314-2-quic_jinlmao@quicinc.com>
Hi Mao,
On Thu, Dec 09, 2021 at 10:15:35PM +0800, Mao Jinlong wrote:
> Use hash length of the source's device name to map to the pointer
> of the enabled path. Using IDR will be more efficient than using
> the list. And there could be other sources except STM and CPU etms
> in the new HWs. It is better to maintain all the paths together.
>
> Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com>
> ---
> drivers/hwtracing/coresight/coresight-core.c | 76 +++++++-------------
> 1 file changed, 26 insertions(+), 50 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-core.c b/drivers/hwtracing/coresight/coresight-core.c
> index 8a18c71df37a..cc6b6cabf85f 100644
> --- a/drivers/hwtracing/coresight/coresight-core.c
> +++ b/drivers/hwtracing/coresight/coresight-core.c
> @@ -7,6 +7,7 @@
> #include <linux/init.h>
> #include <linux/types.h>
> #include <linux/device.h>
> +#include <linux/idr.h>
> #include <linux/io.h>
> #include <linux/err.h>
> #include <linux/export.h>
> @@ -26,6 +27,12 @@
> static DEFINE_MUTEX(coresight_mutex);
> static DEFINE_PER_CPU(struct coresight_device *, csdev_sink);
>
> +/*
> + * Use IDR to map the hash length of the source's device name
> + * to the pointer of path for the source
> + */
> +static DEFINE_IDR(path_idr);
> +
> /**
> * struct coresight_node - elements of a path, from source to sink
> * @csdev: Address of an element.
> @@ -36,20 +43,6 @@ struct coresight_node {
> struct list_head link;
> };
>
> -/*
> - * When operating Coresight drivers from the sysFS interface, only a single
> - * path can exist from a tracer (associated to a CPU) to a sink.
> - */
> -static DEFINE_PER_CPU(struct list_head *, tracer_path);
> -
> -/*
> - * As of this writing only a single STM can be found in CS topologies. Since
> - * there is no way to know if we'll ever see more and what kind of
> - * configuration they will enact, for the time being only define a single path
> - * for STM.
> - */
> -static struct list_head *stm_path;
> -
> /*
> * When losing synchronisation a new barrier packet needs to be inserted at the
> * beginning of the data collected in a buffer. That way the decoder knows that
> @@ -1088,10 +1081,11 @@ static int coresight_validate_source(struct coresight_device *csdev,
>
> int coresight_enable(struct coresight_device *csdev)
> {
> - int cpu, ret = 0;
> + int ret = 0;
> struct coresight_device *sink;
> struct list_head *path;
> enum coresight_dev_subtype_source subtype;
> + u32 hash;
>
> subtype = csdev->subtype.source_subtype;
>
> @@ -1133,26 +1127,14 @@ int coresight_enable(struct coresight_device *csdev)
> if (ret)
> goto err_source;
>
> - switch (subtype) {
> - case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
> - /*
> - * When working from sysFS it is important to keep track
> - * of the paths that were created so that they can be
> - * undone in 'coresight_disable()'. Since there can only
> - * be a single session per tracer (when working from sysFS)
> - * a per-cpu variable will do just fine.
> - */
> - cpu = source_ops(csdev)->cpu_id(csdev);
> - per_cpu(tracer_path, cpu) = path;
> - break;
> - case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:
> - stm_path = path;
> - break;
> - default:
> - /* We can't be here */
> - break;
> - }
> -
> + /*
> + * Use the hash length of source's device name as ID
> + * and map the ID to the pointer of the path.
> + */
> + hash = hashlen_hash(hashlen_string(NULL, dev_name(&csdev->dev)));
> + ret = idr_alloc_u32(&path_idr, path, &hash, hash, GFP_KERNEL);
> + if (ret)
> + goto err_source;
> out:
> mutex_unlock(&coresight_mutex);
> return ret;
> @@ -1168,8 +1150,9 @@ EXPORT_SYMBOL_GPL(coresight_enable);
>
> void coresight_disable(struct coresight_device *csdev)
> {
> - int cpu, ret;
> + int ret;
> struct list_head *path = NULL;
> + u32 hash;
>
> mutex_lock(&coresight_mutex);
>
> @@ -1180,21 +1163,13 @@ void coresight_disable(struct coresight_device *csdev)
> if (!csdev->enable || !coresight_disable_source(csdev))
> goto out;
>
> - switch (csdev->subtype.source_subtype) {
> - case CORESIGHT_DEV_SUBTYPE_SOURCE_PROC:
> - cpu = source_ops(csdev)->cpu_id(csdev);
> - path = per_cpu(tracer_path, cpu);
> - per_cpu(tracer_path, cpu) = NULL;
> - break;
> - case CORESIGHT_DEV_SUBTYPE_SOURCE_SOFTWARE:
> - path = stm_path;
> - stm_path = NULL;
> - break;
> - default:
> - /* We can't be here */
> - break;
> - }
> + hash = hashlen_hash(hashlen_string(NULL, dev_name(&csdev->dev)));
> + /* Find the path by the hash length. */
> + path = idr_find(&path_idr, hash);
> + if (path == NULL)
> + return;
Please add a dev_err() here as this should really not be happening.
>
> + idr_remove(&path_idr, hash);
> coresight_disable_path(path);
> coresight_release_path(path);
>
> @@ -1779,6 +1754,7 @@ static int __init coresight_init(void)
>
> static void __exit coresight_exit(void)
> {
> + idr_destroy(&path_idr);
As far as I can tell this isn't needed.
> cscfg_exit();
> etm_perf_exit();
> bus_unregister(&coresight_bustype);
> --
> 2.17.1
>
next prev parent reply other threads:[~2021-12-14 18:30 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-09 14:15 [PATCH v2 0/9] Coresight: Add support for TPDM and TPDA Mao Jinlong
2021-12-09 14:15 ` [PATCH v2 1/9] Use IDR to maintain all the enabled sources' paths Mao Jinlong
2021-12-14 18:30 ` Mathieu Poirier [this message]
2021-12-15 15:40 ` Jinlong Mao
2021-12-09 14:15 ` [PATCH v2 2/9] Coresight: Add coresight TPDM source driver Mao Jinlong
2021-12-14 18:57 ` Mathieu Poirier
2021-12-15 16:10 ` Jinlong Mao
2021-12-16 17:45 ` Mike Leach
2021-12-16 19:02 ` Mathieu Poirier
2022-01-21 14:01 ` Jinlong Mao
2022-01-21 17:15 ` Mathieu Poirier
2022-01-26 7:07 ` Jinlong Mao
2022-01-26 15:34 ` Mathieu Poirier
2022-01-27 9:33 ` Jinlong Mao
2022-01-27 18:15 ` Mathieu Poirier
2021-12-09 14:15 ` [PATCH v2 3/9] dt-bindings: arm: Adds CoreSight TPDM hardware definitions Mao Jinlong
2021-12-09 14:15 ` [PATCH v2 4/9] coresight-tpdm: Add DSB dataset support Mao Jinlong
2021-12-09 14:15 ` [PATCH v2 5/9] coresight-tpdm: Add integration test support Mao Jinlong
2021-12-09 14:15 ` [PATCH v2 6/9] docs: sysfs: coresight: Add sysfs ABI documentation for TPDM Mao Jinlong
2021-12-09 14:25 ` Jinlong Mao
2021-12-09 18:34 ` Trilok Soni
2021-12-10 1:03 ` Jinlong Mao
2021-12-17 16:09 ` Greg Kroah-Hartman
2021-12-09 14:15 ` [PATCH v2 7/9] Coresight: Add TPDA link driver Mao Jinlong
2021-12-09 14:15 ` [PATCH v2 8/9] dt-bindings: arm: Adds CoreSight TPDA hardware definitions Mao Jinlong
2021-12-09 14:15 ` [PATCH v2 9/9] ARM: dts: msm: Add coresight components for SM8250 Mao Jinlong
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