Re: [RFC PATCH 4/4] ultrasoc: Add System Memory Buffer driver

["liuqi (BA)" <liuqi115@huawei.com>]

Hi Suzuki,
On 2021/6/25 6:47, Suzuki K Poulose wrote:
> Hi Qi
> 
> On 15/06/2021 10:34, Qi Liu wrote:
>> This patch adds driver for System Memory Buffer. It includes
>> a platform driver for the SMB device.
>>
>> Signed-off-by: Jonathan Zhou <jonathan.zhouwen@huawei.com>
>> Signed-off-by: Qi Liu <liuqi115@huawei.com>
>> ---
>>   drivers/hwtracing/ultrasoc/Kconfig        |   9 +
>>   drivers/hwtracing/ultrasoc/Makefile       |   3 +
>>   drivers/hwtracing/ultrasoc/ultrasoc-smb.c | 663 
>> ++++++++++++++++++++++++++++++
>>   drivers/hwtracing/ultrasoc/ultrasoc-smb.h | 182 ++++++++
>>   4 files changed, 857 insertions(+)
>>   create mode 100644 drivers/hwtracing/ultrasoc/ultrasoc-smb.c
>>   create mode 100644 drivers/hwtracing/ultrasoc/ultrasoc-smb.h
>>
> 
>> +/*
>> + * Coresight doesn't export the following
>> + * structures(cs_mode,cs_buffers,etm_event_data),
>> + * so we redefine a copy here.
>> + */
> 
> Please do not duplicate them. This indicates, either :
> 
>   - You need to place your driver under coresight
> 
>   OR
> 
>   - Export the required definitions.
> 

got it, I'll move this driver to coresight/ultrasoc, thanks.

Qi
>> +enum cs_mode {
>> +    CS_MODE_DISABLED,
>> +    CS_MODE_SYSFS,
>> +    CS_MODE_PERF,
>> +};
>> +
> 
>> +struct cs_buffers {
>> +    unsigned int        cur;
>> +    unsigned int        nr_pages;
>> +    unsigned long        offset;
>> +    local_t            data_size;
>> +    bool            snapshot;
>> +    void            **data_pages;
>> +};
>> +
> 
> Why does this need to be replicated ?
> 
>> +struct etm_event_data {
>> +    struct work_struct work;
>> +    cpumask_t mask;
>> +    void *snk_config;
>> +    struct list_head * __percpu *path;
>> +};
>> +
>> +#if IS_ENABLED(CONFIG_CORESIGHT)
>> +int etm_perf_symlink(struct coresight_device *csdev, bool link);
>> +int etm_perf_add_symlink_sink(struct coresight_device *csdev);
>> +void etm_perf_del_symlink_sink(struct coresight_device *csdev);
>> +static inline void *etm_perf_sink_config(struct perf_output_handle 
>> *handle)
>> +{
>> +    struct etm_event_data *data = perf_get_aux(handle);
>> +
>> +    if (data)
>> +        return data->snk_config;
>> +    return NULL;
>> +}
>> +#else
>> +static inline int etm_perf_symlink(struct coresight_device *csdev, 
>> bool link)
>> +{ return -EINVAL; }
>> +int etm_perf_add_symlink_sink(struct coresight_device *csdev)
>> +{ return -EINVAL; }
>> +void etm_perf_del_symlink_sink(struct coresight_device *csdev) {}
>> +static inline void *etm_perf_sink_config(struct perf_output_handle 
>> *handle)
>> +{
>> +    return NULL;
>> +}
>> +
>> +#endif /* CONFIG_CORESIGHT */
>> +
>> +#endif
>>
> 
> Suzuki
> .