[Intel-gfx] [PATCH v2 1/6] drm/i915: Handle all MCR ranges

[Mika Kuoppala]

Matt Roper <matthew.d.roper at intel.com> writes:

> The bspec documents multiple MCR ranges; make sure they're all captured
> by the driver.
>
> Bspec: 13991, 52079
> Fixes: 592a7c5e082e ("drm/i915: Extend non readable mcr range")

Yeah it seems that the ranges drip feed into documentation slowly.

> Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
> Signed-off-by: Matt Roper <matthew.d.roper at intel.com>

Reviewed-by: Mika Kuoppala <mika.kuoppala at linux.intel.com>

> ---
>  drivers/gpu/drm/i915/gt/intel_workarounds.c | 25 ++++++++++++++++++---
>  1 file changed, 22 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/gt/intel_workarounds.c b/drivers/gpu/drm/i915/gt/intel_workarounds.c
> index 391f39b1fb26..3e352e2a5b79 100644
> --- a/drivers/gpu/drm/i915/gt/intel_workarounds.c
> +++ b/drivers/gpu/drm/i915/gt/intel_workarounds.c
> @@ -1648,15 +1648,34 @@ create_scratch(struct i915_address_space *vm, int count)
>  	return ERR_PTR(err);
>  }
>  
> +static const struct {
> +	u32 start;
> +	u32 end;
> +} mcr_ranges_gen8[] = {
> +	{ .start = 0x5500, .end = 0x55ff },
> +	{ .start = 0x7000, .end = 0x7fff },
> +	{ .start = 0x9400, .end = 0x97ff },
> +	{ .start = 0xb000, .end = 0xb3ff },
> +	{ .start = 0xe000, .end = 0xe7ff },
> +	{},
> +};
> +
>  static bool mcr_range(struct drm_i915_private *i915, u32 offset)
>  {
> +	int i;
> +
> +	if (INTEL_GEN(i915) < 8)
> +		return false;
> +
>  	/*
> -	 * Registers in this range are affected by the MCR selector
> +	 * Registers in these ranges are affected by the MCR selector
>  	 * which only controls CPU initiated MMIO. Routing does not
>  	 * work for CS access so we cannot verify them on this path.
>  	 */
> -	if (INTEL_GEN(i915) >= 8 && (offset >= 0xb000 && offset <= 0xb4ff))
> -		return true;
> +	for (i = 0; mcr_ranges_gen8[i].start; i++)
> +		if (offset >= mcr_ranges_gen8[i].start &&
> +		    offset <= mcr_ranges_gen8[i].end)
> +			return true;
>  
>  	return false;
>  }
> -- 
> 2.24.1