[Intel-gfx] [PATCH 06/11] drm/i915: Save all MMIO WAs and apply them at a later time

[Joonas Lahtinen]

On Wed, 2017-10-11 at 11:15 -0700, Oscar Mateo wrote:
> By doing this, we can dump these workarounds in debugfs for
> validation (which,
> at the moment, we are only able to do for the contexts WAs).
> 
> v2:
>   - Wrong macro used for MMIO set bit masked
>   - Improved naming
>   - Rebased
> 
> Signed-off-by: Oscar Mateo <oscar.mateo at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>

<SNIP>

> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1960,12 +1960,16 @@ struct i915_wa_reg {
>  	u32 mask;
>  };
>  
> -#define I915_MAX_WA_REGS 16
> +#define I915_MAX_CTX_WA_REGS 16
> +#define I915_MAX_MMIO_WA_REGS 32
>  
>  struct i915_workarounds {
> -	struct i915_wa_reg ctx_wa_reg[I915_MAX_WA_REGS];
> +	struct i915_wa_reg ctx_wa_reg[I915_MAX_CTX_WA_REGS];
>  	u32 ctx_wa_count;
>  
> +	struct i915_wa_reg mmio_wa_reg[I915_MAX_MMIO_WA_REGS];
> +	u32 mmio_wa_count;
> +
>  	u32 hw_whitelist_count[I915_NUM_ENGINES];
>  };

Could we instead consider a constant structure with platform bitmasks?
If that's not dynamic enough, then a bitmap which is initialized by the
platform bitmasks as a default. So instead of running code to add to
list, make it bit more declarative. Pseudo-code;


struct i915_workaround {
	u16 gen_mask;
	enum {
		I915_WA_CTX,
		I915_WA_MMIO,
		I915_WA_WHITELIST,
	} type;
	u32 reg;
}

... elsewhere in .c file

static const struct i915_workaround i915_workarounds[] = { {
	/* WaSomethingSomewhereUMDFoo:skl */
	.gen_mask = INTEL_GEN_MASK(X, Y),
	.type = I915_WA_CTX,
	.reg = ...
} };

Regards, Joonas
-- 
Joonas Lahtinen
Open Source Technology Center
Intel Corporation