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Message-ID: <CAJ9a7Vi8yE9mEbP3pPoE4xXxgomiqz6N_vz35PmFEH2tYcv=xw@mail.gmail.com>
Date: Thu, 18 Jul 2024 16:57:26 +0100
From: Mike Leach <mike.leach@...aro.org>
To: Mao Jinlong <quic_jinlmao@...cinc.com>
Cc: Suzuki K Poulose <suzuki.poulose@....com>, James Clark <james.clark@....com>,
Rob Herring <robh@...nel.org>, Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley <conor+dt@...nel.org>,
Alexander Shishkin <alexander.shishkin@...ux.intel.com>, coresight@...ts.linaro.org,
linux-arm-kernel@...ts.infradead.org, devicetree@...r.kernel.org,
linux-kernel@...r.kernel.org, linux-arm-msm@...r.kernel.org,
Tingwei Zhang <quic_tingweiz@...cinc.com>, Yuanfang Zhang <quic_yuanfang@...cinc.com>,
Tao Zhang <quic_taozha@...cinc.com>, songchai <quic_songchai@...cinc.com>
Subject: Re: [PATCH v3 2/3] coresight: Add support to get preferred id for
system trace sources
Hi,
On Wed, 26 Jun 2024 at 07:07, Mao Jinlong <quic_jinlmao@...cinc.com> wrote:
>
> Dynamic trace id was introduced in coresight subsystem, so trace id is
> allocated dynamically. However, some hardware ATB source has static trace
> id and it cannot be changed via software programming. For such source,
> it can call coresight_get_source_traceid to get the fixed trace id from
> device node and pass id to coresight_trace_id_get_system_id to reserve
> the id.
>
> Signed-off-by: Mao Jinlong <quic_jinlmao@...cinc.com>
> ---
> .../hwtracing/coresight/coresight-platform.c | 25 +++++++++++++
> drivers/hwtracing/coresight/coresight-stm.c | 2 +-
> drivers/hwtracing/coresight/coresight-tpda.c | 2 +-
> .../hwtracing/coresight/coresight-trace-id.c | 35 ++++++++++++-------
> .../hwtracing/coresight/coresight-trace-id.h | 11 +++++-
> include/linux/coresight.h | 1 +
> 6 files changed, 61 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/drivers/hwtracing/coresight/coresight-platform.c
> index 9d550f5697fa..df169f3f367e 100644
> --- a/drivers/hwtracing/coresight/coresight-platform.c
> +++ b/drivers/hwtracing/coresight/coresight-platform.c
> @@ -183,6 +183,17 @@ static int of_coresight_get_cpu(struct device *dev)
> return cpu;
> }
>
> +/*
> + * of_coresight_get_trace_id: Get the atid of a source device.
> + *
> + * Returns 0 on success.
> + */
> +static int of_coresight_get_trace_id(struct device *dev, u32 *id)
name this "of_coresight_get_static_trace_id"
> +{
> +
> + return of_property_read_u32(dev->of_node, "arm,trace-id", id);
should be "arm,static-trace-id" for consistency.
> +}
> +
> /*
> * of_coresight_parse_endpoint : Parse the given output endpoint @ep
> * and fill the connection information in @pdata->out_conns
> @@ -315,6 +326,11 @@ static inline int of_coresight_get_cpu(struct device *dev)
> {
> return -ENODEV;
> }
> +
> +static inline int of_coresight_get_trace_id(struct device *dev, u32 *id)
> +{
> + return -ENODEV;
> +}
> #endif
>
> #ifdef CONFIG_ACPI
> @@ -794,6 +810,15 @@ int coresight_get_cpu(struct device *dev)
> }
> EXPORT_SYMBOL_GPL(coresight_get_cpu);
>
> +int coresight_get_source_traceid(struct device *dev, u32 *id)
This should be coresight_get_static_traceid.
> +{
> + if (!is_of_node(dev->fwnode))
> + return -EINVAL;
> +
> + return of_coresight_get_trace_id(dev, id);
> +}
> +EXPORT_SYMBOL_GPL(coresight_get_source_traceid);
> +
> struct coresight_platform_data *
> coresight_get_platform_data(struct device *dev)
> {
> diff --git a/drivers/hwtracing/coresight/coresight-stm.c b/drivers/hwtracing/coresight/coresight-stm.c
> index e1c62820dfda..34fab2ce9a76 100644
> --- a/drivers/hwtracing/coresight/coresight-stm.c
> +++ b/drivers/hwtracing/coresight/coresight-stm.c
> @@ -901,7 +901,7 @@ static int __stm_probe(struct device *dev, struct resource *res)
> goto stm_unregister;
> }
>
> - trace_id = coresight_trace_id_get_system_id();
> + trace_id = coresight_trace_id_get_system_id(TRACE_ID_ANY);
implement a coresight_trace_id_get_static_system_id() function and
drop this change
> if (trace_id < 0) {
> ret = trace_id;
> goto cs_unregister;
> diff --git a/drivers/hwtracing/coresight/coresight-tpda.c b/drivers/hwtracing/coresight/coresight-tpda.c
> index 7739bc7adc44..46161cadb9e5 100644
> --- a/drivers/hwtracing/coresight/coresight-tpda.c
> +++ b/drivers/hwtracing/coresight/coresight-tpda.c
> @@ -251,7 +251,7 @@ static int tpda_init_default_data(struct tpda_drvdata *drvdata)
> * same trace-id. When TPDA does packetization, different
> * port will have unique channel number for decoding.
> */
> - atid = coresight_trace_id_get_system_id();
> + atid = coresight_trace_id_get_system_id(TRACE_ID_ANY);
and here
> if (atid < 0)
> return atid;
>
> diff --git a/drivers/hwtracing/coresight/coresight-trace-id.c b/drivers/hwtracing/coresight/coresight-trace-id.c
> index af5b4ef59cea..59194f60362c 100644
> --- a/drivers/hwtracing/coresight/coresight-trace-id.c
> +++ b/drivers/hwtracing/coresight/coresight-trace-id.c
> @@ -75,21 +75,26 @@ static int coresight_trace_id_find_odd_id(struct coresight_trace_id_map *id_map)
> * Allocate new ID and set in use
> *
> * if @preferred_id is a valid id then try to use that value if available.
> - * if @preferred_id is not valid and @prefer_odd_id is true, try for odd id.
> + * if TRACE_ID_WANT_PREFERRED is set, @preferred_id must be free, otherwise return
> + * error -EINVAL.
> + * if @preferred_id is not valid and TRACE_ID_WANT_ODD is true, try for odd id.
> *
> * Otherwise allocate next available ID.
> */
> static int coresight_trace_id_alloc_new_id(struct coresight_trace_id_map *id_map,
> - int preferred_id, bool prefer_odd_id)
> + int preferred_id, unsigned int flags)
> {
> int id = 0;
>
> /* for backwards compatibility, cpu IDs may use preferred value */
> - if (IS_VALID_CS_TRACE_ID(preferred_id) &&
> - !test_bit(preferred_id, id_map->used_ids)) {
> - id = preferred_id;
> - goto trace_id_allocated;
> - } else if (prefer_odd_id) {
> + if (IS_VALID_CS_TRACE_ID(preferred_id)) {
> + if (!test_bit(preferred_id, id_map->used_ids)) {
> + id = preferred_id;
> + goto trace_id_allocated;
> + } else if (WARN((flags & TRACE_ID_WANT_PREFERRED), "Trace ID %d is used.\n",
> + preferred_id))
> + return -EINVAL;
> + } else if (flags & TRACE_ID_WANT_ODD) {
> /* may use odd ids to avoid preferred legacy cpu IDs */
> id = coresight_trace_id_find_odd_id(id_map);
> if (id)
> @@ -175,7 +180,7 @@ static int coresight_trace_id_map_get_cpu_id(int cpu, struct coresight_trace_id_
> */
> id = coresight_trace_id_alloc_new_id(id_map,
> CORESIGHT_LEGACY_CPU_TRACE_ID(cpu),
> - false);
> + TRACE_ID_ANY);
> if (!IS_VALID_CS_TRACE_ID(id))
> goto get_cpu_id_out_unlock;
>
> @@ -222,14 +227,20 @@ static void coresight_trace_id_map_put_cpu_id(int cpu, struct coresight_trace_id
> DUMP_ID_MAP(id_map);
> }
>
> -static int coresight_trace_id_map_get_system_id(struct coresight_trace_id_map *id_map)
> +static int coresight_trace_id_map_get_system_id(struct coresight_trace_id_map *id_map,
> + int preferred_id)
Add a trace_id flags parameter here and call in with flags already set
> {
> unsigned long flags;
> int id;
> + unsigned int traceid_flags = 0;
>
> spin_lock_irqsave(&id_map_lock, flags);
> +
> /* prefer odd IDs for system components to avoid legacy CPU IDS */
> - id = coresight_trace_id_alloc_new_id(id_map, 0, true);
> + traceid_flags = TRACE_ID_WANT_ODD;
> + traceid_flags |= preferred_id > 0 ? TRACE_ID_WANT_PREFERRED : 0;
> +
move the flags calculations to the calling functions
> + id = coresight_trace_id_alloc_new_id(id_map, preferred_id, traceid_flags);
> spin_unlock_irqrestore(&id_map_lock, flags);
>
> DUMP_ID(id);
> @@ -269,9 +280,9 @@ int coresight_trace_id_read_cpu_id(int cpu)
> }
> EXPORT_SYMBOL_GPL(coresight_trace_id_read_cpu_id);
>
> -int coresight_trace_id_get_system_id(void)
> +int coresight_trace_id_get_system_id(int id)
> {
> - return coresight_trace_id_map_get_system_id(&id_map_default);
drop the change to this function header and the call becomes
trace_id_map_get_system_id(&id_map_default, 0, TRACE_ID_PREFER_ODD)
> + return coresight_trace_id_map_get_system_id(&id_map_default, id);
> }
> EXPORT_SYMBOL_GPL(coresight_trace_id_get_system_id);
>
Add in a coresight_trace_id_get_system_static_id(int trace_id) API
function and call
trace_id_map_get_system_id(&id_map_default, trace_id, TRACE_ID_REQ_STATIC)
> diff --git a/drivers/hwtracing/coresight/coresight-trace-id.h b/drivers/hwtracing/coresight/coresight-trace-id.h
> index 3797777d367e..a236cf87c169 100644
> --- a/drivers/hwtracing/coresight/coresight-trace-id.h
> +++ b/drivers/hwtracing/coresight/coresight-trace-id.h
> @@ -61,6 +61,12 @@ struct coresight_trace_id_map {
> DECLARE_BITMAP(pend_rel_ids, CORESIGHT_TRACE_IDS_MAX);
> };
>
> +enum trace_id_flags {
> + TRACE_ID_ANY = 0x0,
> + TRACE_ID_WANT_ODD = 0x1,
TRACE_ID_PREFER_ODD
> + TRACE_ID_WANT_PREFERRED = 0x2,
TRACE_ID_REQ_STATIC
> +};
These flags can move to the coresight-trace-id.c file.
> /* Allocate and release IDs for a single default trace ID map */
>
> /**
> @@ -118,9 +124,12 @@ int coresight_trace_id_read_cpu_id(int cpu);
> *
> * Used to allocate IDs for system trace sources such as STM.
> *
> + * @id: Preferred id value. If id is TRACE_ID_ANY, get a free id from id map.
> + * If id is greater than TRACE_ID_ANY, get a preferred id.
> + *
> * return: Trace ID or -EINVAL if allocation is impossible.
> */
> -int coresight_trace_id_get_system_id(void);
> +int coresight_trace_id_get_system_id(int id);
>
> /**
> * Release an allocated system trace ID.
> diff --git a/include/linux/coresight.h b/include/linux/coresight.h
> index f09ace92176e..0599303be326 100644
> --- a/include/linux/coresight.h
> +++ b/include/linux/coresight.h
> @@ -643,6 +643,7 @@ void coresight_relaxed_write64(struct coresight_device *csdev,
> void coresight_write64(struct coresight_device *csdev, u64 val, u32 offset);
>
> extern int coresight_get_cpu(struct device *dev);
> +extern int coresight_get_source_traceid(struct device *dev, u32 *id);
>
> struct coresight_platform_data *coresight_get_platform_data(struct device *dev);
> struct coresight_connection *
> --
> 2.41.0
>
Regards
Mike
--
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK
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