[Intel-gfx] [PATCH v4] drm/i915/mtl: Add Wa_14019821291

[Matt Roper]

On Sat, Oct 28, 2023 at 01:20:52AM +0530, Dnyaneshwar Bhadane wrote:
> This workaround is primarily implemented by the BIOS.  However if the
> BIOS applies the workaround it will reserve a small piece of our DSM
> (which should be at the top, right below the WOPCM); we just need to
> keep that region reserved so that nothing else attempts to re-use it.
> 
> v2: Declare regs in intel_gt_regs.h (Matt Roper)
> 
> v3: Shift WA implementation before calculation of *base (Matt Roper)
> 
> v4:
> -  Change condition gscpmi base to be fall in DSM range.(Matt Roper)
> 
> Signed-off-by: Dnyaneshwar Bhadane <dnyaneshwar.bhadane at intel.com>

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

and applied to drm-intel-gt-next.  Thanks for the patch.


Matt

> ---
>  drivers/gpu/drm/i915/gem/i915_gem_stolen.c | 21 +++++++++++++++++++++
>  drivers/gpu/drm/i915/gt/intel_gt_regs.h    |  3 +++
>  2 files changed, 24 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
> index 1a766d8e7cce..8c88075eeab2 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
> @@ -386,6 +386,27 @@ static void icl_get_stolen_reserved(struct drm_i915_private *i915,
>  
>  	drm_dbg(&i915->drm, "GEN6_STOLEN_RESERVED = 0x%016llx\n", reg_val);
>  
> +	/* Wa_14019821291 */
> +	if (MEDIA_VER_FULL(i915) == IP_VER(13, 0)) {
> +		/*
> +		 * This workaround is primarily implemented by the BIOS.  We
> +		 * just need to figure out whether the BIOS has applied the
> +		 * workaround (meaning the programmed address falls within
> +		 * the DSM) and, if so, reserve that part of the DSM to
> +		 * prevent accidental reuse.  The DSM location should be just
> +		 * below the WOPCM.
> +		 */
> +		u64 gscpsmi_base = intel_uncore_read64_2x32(uncore,
> +							    MTL_GSCPSMI_BASEADDR_LSB,
> +							    MTL_GSCPSMI_BASEADDR_MSB);
> +		if (gscpsmi_base >= i915->dsm.stolen.start &&
> +		    gscpsmi_base < i915->dsm.stolen.end) {
> +			*base = gscpsmi_base;
> +			*size = i915->dsm.stolen.end - gscpsmi_base;
> +			return;
> +		}
> +	}
> +
>  	switch (reg_val & GEN8_STOLEN_RESERVED_SIZE_MASK) {
>  	case GEN8_STOLEN_RESERVED_1M:
>  		*size = 1024 * 1024;
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_regs.h b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> index eecd0a87a647..9de41703fae5 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gt_regs.h
> @@ -537,6 +537,9 @@
>  #define XEHP_SQCM				MCR_REG(0x8724)
>  #define   EN_32B_ACCESS				REG_BIT(30)
>  
> +#define MTL_GSCPSMI_BASEADDR_LSB		_MMIO(0x880c)
> +#define MTL_GSCPSMI_BASEADDR_MSB		_MMIO(0x8810)
> +
>  #define HSW_IDICR				_MMIO(0x9008)
>  #define   IDIHASHMSK(x)				(((x) & 0x3f) << 16)
>  
> -- 
> 2.34.1
> 

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