Re: [PATCH 4/7] cxl/pci: Hold memdev lock in cxl_event_trace_record()

[Dave Jiang]

On 3/10/26 8:57 AM, Li Ming wrote:
> This is a preparatory patch for the following changes.
> 
> To enable endpoint validity checks in cxl_dpa_to_region().
> cxl_dpa_to_region() has to require caller to hold CXL memdev lock to
> ensure the CXL memdev probing is completed.
> 
> So holding the given CXL memdev lock before invoking cxl_dpa_to_region()
> in cxl_event_trace_record().
> 
> Suggested-by: Dan Williams <dan.j.williams@xxxxxxxxx>
> Signed-off-by: Li Ming <ming.li@xxxxxxxxxxxx>

With what Dan said,
Reviewed-by: Dave Jiang <dave.jiang@xxxxxxxxx>

> ---
>  drivers/cxl/core/mbox.c | 5 +++--
>  drivers/cxl/cxlmem.h    | 2 +-
>  2 files changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/cxl/core/mbox.c b/drivers/cxl/core/mbox.c
> index e7a6452bf544..3f34bbabf4d3 100644
> --- a/drivers/cxl/core/mbox.c
> +++ b/drivers/cxl/core/mbox.c
> @@ -893,7 +893,7 @@ int cxl_enumerate_cmds(struct cxl_memdev_state *mds)
>  }
>  EXPORT_SYMBOL_NS_GPL(cxl_enumerate_cmds, "CXL");
>  
> -void cxl_event_trace_record(const struct cxl_memdev *cxlmd,
> +void cxl_event_trace_record(struct cxl_memdev *cxlmd,
>  			    enum cxl_event_log_type type,
>  			    enum cxl_event_type event_type,
>  			    const uuid_t *uuid, union cxl_event *evt)
> @@ -920,6 +920,7 @@ void cxl_event_trace_record(const struct cxl_memdev *cxlmd,
>  		 * translations. Take topology mutation locks and lookup
>  		 * { HPA, REGION } from { DPA, MEMDEV } in the event record.
>  		 */
> +		guard(device)(&cxlmd->dev);
>  		guard(rwsem_read)(&cxl_rwsem.region);
>  		guard(rwsem_read)(&cxl_rwsem.dpa);
>  
> @@ -968,7 +969,7 @@ void cxl_event_trace_record(const struct cxl_memdev *cxlmd,
>  }
>  EXPORT_SYMBOL_NS_GPL(cxl_event_trace_record, "CXL");
>  
> -static void __cxl_event_trace_record(const struct cxl_memdev *cxlmd,
> +static void __cxl_event_trace_record(struct cxl_memdev *cxlmd,
>  				     enum cxl_event_log_type type,
>  				     struct cxl_event_record_raw *record)
>  {
> diff --git a/drivers/cxl/cxlmem.h b/drivers/cxl/cxlmem.h
> index e21d744d639b..7a34a19c02c8 100644
> --- a/drivers/cxl/cxlmem.h
> +++ b/drivers/cxl/cxlmem.h
> @@ -864,7 +864,7 @@ void set_exclusive_cxl_commands(struct cxl_memdev_state *mds,
>  void clear_exclusive_cxl_commands(struct cxl_memdev_state *mds,
>  				  unsigned long *cmds);
>  void cxl_mem_get_event_records(struct cxl_memdev_state *mds, u32 status);
> -void cxl_event_trace_record(const struct cxl_memdev *cxlmd,
> +void cxl_event_trace_record(struct cxl_memdev *cxlmd,
>  			    enum cxl_event_log_type type,
>  			    enum cxl_event_type event_type,
>  			    const uuid_t *uuid, union cxl_event *evt);
>