[PATCH v2] drm/i915/mtl: Skip MCR ops for ring fault register

[Matt Roper]

On Tue, Sep 26, 2023 at 11:58:02PM +0200, Nirmoy Das wrote:
> On MTL GEN12_RING_FAULT_REG is not replicated so don't
> do mcr based operation for this register.
> 
> v2: use MEDIA_VER() instead of GRAPHICS_VER()(Matt).
> 
> Signed-off-by: Nirmoy Das <nirmoy.das at intel.com>
> ---
>  drivers/gpu/drm/i915/gt/intel_gt.c      | 13 ++++++++++++-
>  drivers/gpu/drm/i915/gt/intel_gt_regs.h |  1 +
>  drivers/gpu/drm/i915/i915_gpu_error.c   | 10 +++++++++-
>  3 files changed, 22 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c
> index 93062c35e072..430738607f61 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt.c
> +++ b/drivers/gpu/drm/i915/gt/intel_gt.c
> @@ -262,10 +262,21 @@ intel_gt_clear_error_registers(struct intel_gt *gt,
>  				   I915_MASTER_ERROR_INTERRUPT);
>  	}
>  
> -	if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 50)) {
> +	/*
> +	 * for media tile this ring fault register is not replicated

Nitpicks:  s/tile/gt/ and either write it as "For the media GT..."
(singular) or "For media GTs..." (plural).  Same with the other copy of
this comment farther down.

> +	 * so skip doing mcr ops on it.
> +	 */
> +	if (MEDIA_VER(i915) == 13 && gt->type == GT_MEDIA) {

I guess for now we should probably make this (and the one farther down)
a ">=" instead of "==" under the assumption future media versions will
do the same in case we get some kind of refresh platform down the road
with a slightly higher version number.

Aside from those minor tweaks,

Reviewed-by: Matt Roper <matthew.d.roper at intel.com>

> +		intel_uncore_rmw(uncore, XELPMP_RING_FAULT_REG,
> +				 RING_FAULT_VALID, 0);
> +		intel_uncore_posting_read(uncore,
> +					  XELPMP_RING_FAULT_REG);
> +
> +	} else if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 50)) {
>  		intel_gt_mcr_multicast_rmw(gt, XEHP_RING_FAULT_REG,
>  					   RING_FAULT_VALID, 0);
>  		intel_gt_mcr_read_any(gt, XEHP_RING_FAULT_REG);
> +
>  	} else if (GRAPHICS_VER(i915) >= 12) {
>  		intel_uncore_rmw(uncore, GEN12_RING_FAULT_REG, RING_FAULT_VALID, 0);
>  		intel_uncore_posting_read(uncore, GEN12_RING_FAULT_REG);
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_regs.h b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> index cca4bac8f8b0..eecd0a87a647 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> @@ -1084,6 +1084,7 @@
>  
>  #define GEN12_RING_FAULT_REG			_MMIO(0xcec4)
>  #define XEHP_RING_FAULT_REG			MCR_REG(0xcec4)
> +#define XELPMP_RING_FAULT_REG			_MMIO(0xcec4)
>  #define   GEN8_RING_FAULT_ENGINE_ID(x)		(((x) >> 12) & 0x7)
>  #define   RING_FAULT_GTTSEL_MASK		(1 << 11)
>  #define   RING_FAULT_SRCID(x)			(((x) >> 3) & 0xff)
> diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
> index f4ebcfb70289..f0b691ea3a6e 100644
> --- a/drivers/gpu/drm/i915/i915_gpu_error.c
> +++ b/drivers/gpu/drm/i915/i915_gpu_error.c
> @@ -1234,7 +1234,15 @@ static void engine_record_registers(struct intel_engine_coredump *ee)
>  	if (GRAPHICS_VER(i915) >= 6) {
>  		ee->rc_psmi = ENGINE_READ(engine, RING_PSMI_CTL);
>  
> -		if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 50))
> +		/*
> +		 * for media tile this ring fault register is not replicated
> +		 * so skip doing mcr ops on it.
> +		 */
> +		if (MEDIA_VER(i915) == 13 && engine->gt->type == GT_MEDIA)
> +			ee->fault_reg = intel_uncore_read(engine->uncore,
> +							  XELPMP_RING_FAULT_REG);
> +
> +		else if (GRAPHICS_VER_FULL(i915) >= IP_VER(12, 50))
>  			ee->fault_reg = intel_gt_mcr_read_any(engine->gt,
>  							      XEHP_RING_FAULT_REG);
>  		else if (GRAPHICS_VER(i915) >= 12)
> -- 
> 2.41.0
> 

-- 
Matt Roper
Graphics Software Engineer
Linux GPU Platform Enablement
Intel Corporation