[PATCH V2 1/6] cxl: Remove unused values in bare-metal environment.

[Frederic Barrat]

Le 14/03/2017 à 12:08, Christophe Lombard a écrit :
> The two fields pid and tid of the structure cxl_irq_info are only used
> in the guest environment. To avoid confusion, it's not necessary
> to fill the fields in the bare-metal environment.
> The PSL Process and Thread Identification Register is only used when
> attaching a dedicated process for PSL8 only.
>
> Signed-off-by: Christophe Lombard <clombard at linux.vnet.ibm.com>
> ---
>  drivers/misc/cxl/native.c | 5 -----
>  1 file changed, 5 deletions(-)
>
> diff --git a/drivers/misc/cxl/native.c b/drivers/misc/cxl/native.c
> index 7ae7105..7257e8b 100644
> --- a/drivers/misc/cxl/native.c
> +++ b/drivers/misc/cxl/native.c
> @@ -859,8 +859,6 @@ static int native_detach_process(struct cxl_context *ctx)
>
>  static int native_get_irq_info(struct cxl_afu *afu, struct cxl_irq_info *info)
>  {
> -	u64 pidtid;
> -
>  	/* If the adapter has gone away, we can't get any meaningful
>  	 * information.
>  	 */
> @@ -870,9 +868,6 @@ static int native_get_irq_info(struct cxl_afu *afu, struct cxl_irq_info *info)
>  	info->dsisr = cxl_p2n_read(afu, CXL_PSL_DSISR_An);
>  	info->dar = cxl_p2n_read(afu, CXL_PSL_DAR_An);
>  	info->dsr = cxl_p2n_read(afu, CXL_PSL_DSR_An);
> -	pidtid = cxl_p2n_read(afu, CXL_PSL_PID_TID_An);
> -	info->pid = pidtid >> 32;
> -	info->tid = pidtid & 0xffffffff;
>  	info->afu_err = cxl_p2n_read(afu, CXL_AFU_ERR_An);
>  	info->errstat = cxl_p2n_read(afu, CXL_PSL_ErrStat_An);
>  	info->proc_handle = 0;
>

Can we rename pid and tid to "reserved" in the struct cxl_irq_info?
By keeping them, they may be used in common code (bare-metal and guest), 
which will lead to undefined behavior on bare-metal.
Since the structure matches what is passed in a hcall, we can't get rid 
of them, but renaming would be safer.

   Fred