[PATCH v4 RESEND 2/3] coresight: Add support to get static id for system trace sources
Jinlong Mao
quic_jinlmao at quicinc.com
Thu Oct 10 02:37:30 PDT 2024
On 2024/10/10 17:19, Suzuki K Poulose wrote:
> On 09/10/2024 11:37, Jinlong Mao wrote:
>>
>>
>> On 2024/10/9 17:50, Suzuki K Poulose wrote:
>>> On 10/09/2024 11:01, Mao Jinlong 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_static_trace_id to get the fixed trace id
>>>> from
>>>> device node and pass id to coresight_trace_id_get_static_system_id to
>>>> reserve the id.
>>>>
>>>> Signed-off-by: Mao Jinlong <quic_jinlmao at quicinc.com>
>>>
>>> This patch is technically doing two different things :
>>>
>>> 1. Support for reading the static traceid from the firmware. (users
>>> of which comes later in Dummy)
>>>
>>> 2. Support for allocating a "specific" traceid for system sources.
>>>
>>>
>>> Both the names are a bit similar and could be confusing.
>>>
>>> For (1), I don't think we need to add a helper like that. See my
>>> comments below, and drop all of that from here this patch.
>>
>> Hi Suzuki,
>>
>> This helper will be common for other new drivers in future.
>> Some other driver will use it, not only for dummy driver.
>
> Ok, fair enough. But couldn't we still use the fwnode_xx directly from
> the "helper" rather than defining of_xxx. That way it should work for
> ACPI based systems too.
>
Sure. I will use the fwnode_xx.
>>
>> Thanks
>> Jinlong Mao
>>
>>>
>>>
>>>> ---
>>>> .../hwtracing/coresight/coresight-platform.c | 26 +++++++++++++
>>>> .../hwtracing/coresight/coresight-trace-id.c | 38 +++++++++++++
>>>> +-----
>>>> .../hwtracing/coresight/coresight-trace-id.h | 9 +++++
>>>> include/linux/coresight.h | 1 +
>>>> 4 files changed, 64 insertions(+), 10 deletions(-)
>>>>
>>>> diff --git a/drivers/hwtracing/coresight/coresight-platform.c b/
>>>> drivers/hwtracing/coresight/coresight-platform.c
>>>> index 64e171eaad82..703abf0fa3f9 100644
>>>> --- a/drivers/hwtracing/coresight/coresight-platform.c
>>>> +++ b/drivers/hwtracing/coresight/coresight-platform.c
>>>> @@ -183,6 +183,18 @@ 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_static_trace_id(struct device *dev, u32
>>>> *id)
>>>> +{
>>>> +
>>>> + return of_property_read_u32(dev->of_node, "arm,static-trace-
>>>> id", id);
>>>> +}
>>>> +
>>>> +
>
> Drop these ^^
>
>
>>>> /*
>>>> * of_coresight_parse_endpoint : Parse the given output endpoint @ep
>>>> * and fill the connection information in @pdata->out_conns
>>>> @@ -317,6 +329,11 @@ static inline int of_coresight_get_cpu(struct
>>>> device *dev)
>>>> {
>>>> return -ENODEV;
>>>> }
>>>> +
>>>> +static inline int of_coresight_get_static_trace_id(struct device
>>>> *dev, u32 *id)
>>>> +{
>>>> + return -ENODEV;
>>>> +}
>>>> #endif
>>>
>>>
>>>> #ifdef CONFIG_ACPI
>>>> @@ -796,6 +813,15 @@ int coresight_get_cpu(struct device *dev)
>>>> }
>>>> EXPORT_SYMBOL_GPL(coresight_get_cpu);
>>>> +int coresight_get_static_trace_id(struct device *dev, u32 *id)
>>>> +{
>>>> + if (!is_of_node(dev->fwnode))
>>>> + return -EINVAL;
>>>> +
>>>> + return of_coresight_get_static_trace_id(dev, id);
>>>
>>> Please could we not directly use :
>>>
>>> fwnode_property_read_u32(dev_fwnode(dev), "arm,static-trace-id",
>>> &traceid) in the dummy driver ?
>
> return fwnode_property_read_u32(dev_fwnode(dev), "arm,static-trace-
> id", id);
>
>
> Suzuki
>
>
>>>
>>> The rest looks fine to me.
>>>
>>> Suzuki
>>>
>>>
>>>> +}
>>>> +EXPORT_SYMBOL_GPL(coresight_get_static_trace_id);
>>>> +
>>>> struct coresight_platform_data *
>>>> coresight_get_platform_data(struct device *dev)
>>>> {
>>>> diff --git a/drivers/hwtracing/coresight/coresight-trace-id.c b/
>>>> drivers/hwtracing/coresight/coresight-trace-id.c
>>>> index af5b4ef59cea..ca3c3de4683e 100644
>>>> --- a/drivers/hwtracing/coresight/coresight-trace-id.c
>>>> +++ b/drivers/hwtracing/coresight/coresight-trace-id.c
>>>> @@ -11,6 +11,12 @@
>>>> #include "coresight-trace-id.h"
>>>> +enum trace_id_flags {
>>>> + TRACE_ID_ANY = 0x0,
>>>> + TRACE_ID_PREFER_ODD = 0x1,
>>>> + TRACE_ID_REQ_STATIC = 0x2,
>>>> +};
>>>> +
>>>> /* Default trace ID map. Used on systems that don't require per
>>>> sink mappings */
>>>> static struct coresight_trace_id_map id_map_default;
>>>> @@ -80,16 +86,19 @@ static int coresight_trace_id_find_odd_id(struct
>>>> coresight_trace_id_map *id_map)
>>>> * 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_REQ_STATIC), "Trace ID %d
>>>> is used.\n",
>>>> + preferred_id))
>>>> + return -EINVAL;
>>>> + } else if (flags & TRACE_ID_PREFER_ODD) {
>>>> /* may use odd ids to avoid preferred legacy cpu IDs */
>>>> id = coresight_trace_id_find_odd_id(id_map);
>>>> if (id)
>>>> @@ -175,7 +184,7 @@ 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 +231,15 @@ 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, unsigned int traceid_flags)
>>>> {
>>>> unsigned long flags;
>>>> int id;
>>>> 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);
>>>> + id = coresight_trace_id_alloc_new_id(id_map, preferred_id,
>>>> traceid_flags);
>>>> spin_unlock_irqrestore(&id_map_lock, flags);
>>>> DUMP_ID(id);
>>>> @@ -271,10 +281,18 @@
>>>> EXPORT_SYMBOL_GPL(coresight_trace_id_read_cpu_id);
>>>> int coresight_trace_id_get_system_id(void)
>>>> {
>>>> - return coresight_trace_id_map_get_system_id(&id_map_default);
>>>> + return coresight_trace_id_map_get_system_id(&id_map_default, 0,
>>>> + TRACE_ID_PREFER_ODD);
>>>> }
>>>> EXPORT_SYMBOL_GPL(coresight_trace_id_get_system_id);
>>>> +int coresight_trace_id_get_static_system_id(int trace_id)
>>>> +{
>>>> + return coresight_trace_id_map_get_system_id(&id_map_default,
>>>> + trace_id, TRACE_ID_REQ_STATIC);
>>>> +}
>>>> +EXPORT_SYMBOL_GPL(coresight_trace_id_get_static_system_id);
>>>> +
>>>> void coresight_trace_id_put_system_id(int id)
>>>> {
>>>> coresight_trace_id_map_put_system_id(&id_map_default, id);
>>>> diff --git a/drivers/hwtracing/coresight/coresight-trace-id.h b/
>>>> drivers/hwtracing/coresight/coresight-trace-id.h
>>>> index 3797777d367e..ca2fdf31c835 100644
>>>> --- a/drivers/hwtracing/coresight/coresight-trace-id.h
>>>> +++ b/drivers/hwtracing/coresight/coresight-trace-id.h
>>>> @@ -122,6 +122,15 @@ int coresight_trace_id_read_cpu_id(int cpu);
>>>> */
>>>> int coresight_trace_id_get_system_id(void);
>>>> +/**
>>>> + * Allocate a CoreSight static trace ID for a system component.
>>>> + *
>>>> + * Used to allocate static IDs for system trace sources such as
>>>> dummy source.
>>>> + *
>>>> + * return: Trace ID or -EINVAL if allocation is impossible.
>>>> + */
>>>> +int coresight_trace_id_get_static_system_id(int id);
>>>> +
>>>> /**
>>>> * Release an allocated system trace ID.
>>>> *
>>>> diff --git a/include/linux/coresight.h b/include/linux/coresight.h
>>>> index f09ace92176e..2cdc0b1cd536 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_static_trace_id(struct device *dev, u32 *id);
>>>> struct coresight_platform_data *coresight_get_platform_data(struct
>>>> device *dev);
>>>> struct coresight_connection *
>>>
>>
>
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