[PATCH v3 5/5] drm/i915/mtl: Hold forcewake and MCR lock over PPAT setup

[Matt Roper]

On Thu, Dec 01, 2022 at 02:56:30PM +0530, Balasubramani Vivekanandan wrote:
> On 30.11.2022 07:58, Matt Roper wrote:
> > PPAT setup involves a series of multicast writes.  This can be optimized
> > slightly be acquiring forcewake and the steering lock just once for the
> > entire sequence.
> > 
> > v2:
> >  - We should use FW_REG_WRITE instead of FW_REG_READ.  (Bala)
> > 
> > Suggested-by: Balasubramani Vivekanandan <balasubramani.vivekanandan at intel.com>
> > Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
> 
> Reviewed-by: Balasubramani Vivekanandan <balasubramani.vivekanandan at intel.com>

Thanks.  Since this patch is independent of patch #4 (the only one that
hasn't been reviewed yet), I went ahead and pushed this one to
drm-intel-gt-next.  BTW, I noticed I wrote "mtl" in the patch title
where I actually meant to have "mcr" (this isn't a MTL-specific change),
so I corrected that typo while pushing as well.


Matt

> 
> Regards,
> Bala
> 
> > ---
> >  drivers/gpu/drm/i915/gt/intel_gtt.c | 27 +++++++++++++++++++--------
> >  1 file changed, 19 insertions(+), 8 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.c b/drivers/gpu/drm/i915/gt/intel_gtt.c
> > index 2ba3983984b9..e37164a60d37 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_gtt.c
> > +++ b/drivers/gpu/drm/i915/gt/intel_gtt.c
> > @@ -482,14 +482,25 @@ static void tgl_setup_private_ppat(struct intel_uncore *uncore)
> >  
> >  static void xehp_setup_private_ppat(struct intel_gt *gt)
> >  {
> > -	intel_gt_mcr_multicast_write(gt, XEHP_PAT_INDEX(0), GEN8_PPAT_WB);
> > -	intel_gt_mcr_multicast_write(gt, XEHP_PAT_INDEX(1), GEN8_PPAT_WC);
> > -	intel_gt_mcr_multicast_write(gt, XEHP_PAT_INDEX(2), GEN8_PPAT_WT);
> > -	intel_gt_mcr_multicast_write(gt, XEHP_PAT_INDEX(3), GEN8_PPAT_UC);
> > -	intel_gt_mcr_multicast_write(gt, XEHP_PAT_INDEX(4), GEN8_PPAT_WB);
> > -	intel_gt_mcr_multicast_write(gt, XEHP_PAT_INDEX(5), GEN8_PPAT_WB);
> > -	intel_gt_mcr_multicast_write(gt, XEHP_PAT_INDEX(6), GEN8_PPAT_WB);
> > -	intel_gt_mcr_multicast_write(gt, XEHP_PAT_INDEX(7), GEN8_PPAT_WB);
> > +	enum forcewake_domains fw;
> > +	unsigned long flags;
> > +
> > +	fw = intel_uncore_forcewake_for_reg(gt->uncore, _MMIO(XEHP_PAT_INDEX(0).reg),
> > +					    FW_REG_WRITE);
> > +	intel_uncore_forcewake_get(gt->uncore, fw);
> > +
> > +	intel_gt_mcr_lock(gt, &flags);
> > +	intel_gt_mcr_multicast_write_fw(gt, XEHP_PAT_INDEX(0), GEN8_PPAT_WB);
> > +	intel_gt_mcr_multicast_write_fw(gt, XEHP_PAT_INDEX(1), GEN8_PPAT_WC);
> > +	intel_gt_mcr_multicast_write_fw(gt, XEHP_PAT_INDEX(2), GEN8_PPAT_WT);
> > +	intel_gt_mcr_multicast_write_fw(gt, XEHP_PAT_INDEX(3), GEN8_PPAT_UC);
> > +	intel_gt_mcr_multicast_write_fw(gt, XEHP_PAT_INDEX(4), GEN8_PPAT_WB);
> > +	intel_gt_mcr_multicast_write_fw(gt, XEHP_PAT_INDEX(5), GEN8_PPAT_WB);
> > +	intel_gt_mcr_multicast_write_fw(gt, XEHP_PAT_INDEX(6), GEN8_PPAT_WB);
> > +	intel_gt_mcr_multicast_write_fw(gt, XEHP_PAT_INDEX(7), GEN8_PPAT_WB);
> > +	intel_gt_mcr_unlock(gt, flags);
> > +
> > +	intel_uncore_forcewake_put(gt->uncore, fw);
> >  }
> >  
> >  static void icl_setup_private_ppat(struct intel_uncore *uncore)
> > -- 
> > 2.38.1
> > 

-- 
Matt Roper
Graphics Software Engineer
VTT-OSGC Platform Enablement
Intel Corporation