[Intel-gfx] [PATCH v2 1/4] drm/i915/uc: Add ops to intel_uc

[Chris Wilson]

Quoting Michal Wajdeczko (2020-01-10 16:29:27)
> Instead of spreading multiple conditionals across the uC code
> to find out current mode of uC operation, start using predefined
> set of function pointers that reflect that mode.
> 
> Begin with pair of init_hw/fini_hw functions that are responsible
> for uC hardware initialization and cleanup.
> 
> v2: drop ops_none, use macro to generate ops helpers
> 
> Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
> ---
>  drivers/gpu/drm/i915/gt/uc/intel_uc.c | 45 ++++++++++++++++++++++-----
>  drivers/gpu/drm/i915/gt/uc/intel_uc.h | 21 +++++++++++--
>  2 files changed, 57 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_uc.c b/drivers/gpu/drm/i915/gt/uc/intel_uc.c
> index 3ffc6267f96e..da401e97bba3 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_uc.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_uc.c
> @@ -12,6 +12,19 @@
>  
>  #include "i915_drv.h"
>  
> +static int __uc_check_hw(struct intel_uc *uc);
> +static int __uc_init_hw(struct intel_uc *uc);
> +static void __uc_fini_hw(struct intel_uc *uc);
> +
> +static const struct intel_uc_ops uc_ops_off = {
> +       .init_hw = __uc_check_hw,
> +};
> +
> +static const struct intel_uc_ops uc_ops_on = {
> +       .init_hw = __uc_init_hw,
> +       .fini_hw = __uc_fini_hw,
> +};
> +
>  /* Reset GuC providing us with fresh state for both GuC and HuC.
>   */
>  static int __intel_uc_reset_hw(struct intel_uc *uc)
> @@ -89,6 +102,11 @@ void intel_uc_init_early(struct intel_uc *uc)
>         intel_huc_init_early(&uc->huc);
>  
>         __confirm_options(uc);
> +
> +       if (intel_uc_uses_guc(uc))
> +               uc->ops = &uc_ops_on;
> +       else
> +               uc->ops = &uc_ops_off;
>  }
>  
>  void intel_uc_driver_late_release(struct intel_uc *uc)
> @@ -380,24 +398,37 @@ static bool uc_is_wopcm_locked(struct intel_uc *uc)
>                (intel_uncore_read(uncore, DMA_GUC_WOPCM_OFFSET) & GUC_WOPCM_OFFSET_VALID);
>  }
>  
> -int intel_uc_init_hw(struct intel_uc *uc)
> +static int __uc_check_hw(struct intel_uc *uc)
> +{
> +       if (!intel_uc_supports_guc(uc))
> +               return 0;
> +
> +       /*
> +        * We can silently continue without GuC only if it was never enabled
> +        * before on this system after reboot, otherwise we risk GPU hangs.
> +        * To check if GuC was loaded before we look at WOPCM registers.
> +        */
> +       if (uc_is_wopcm_locked(uc))
> +               return -EIO;
> +
> +       return 0;
> +}
> +
> +static int __uc_init_hw(struct intel_uc *uc)
>  {
>         struct drm_i915_private *i915 = uc_to_gt(uc)->i915;
>         struct intel_guc *guc = &uc->guc;
>         struct intel_huc *huc = &uc->huc;
>         int ret, attempts;
>  
> -       if (!intel_uc_supports_guc(uc))
> -               return 0;
> +       GEM_BUG_ON(!intel_uc_supports_guc(uc));
> +       GEM_BUG_ON(!intel_uc_uses_guc(uc));
>  
>         /*
>          * We can silently continue without GuC only if it was never enabled
>          * before on this system after reboot, otherwise we risk GPU hangs.
>          * To check if GuC was loaded before we look at WOPCM registers.
>          */

This comment still required?
Shouldn't there be a call here to __uc_check_hw() instead?

> -       if (!intel_uc_uses_guc(uc) && !uc_is_wopcm_locked(uc))
> -               return 0;
> -
>         if (!intel_uc_fw_is_available(&guc->fw)) {
>                 ret = uc_is_wopcm_locked(uc) ||
>                       intel_uc_fw_is_overridden(&guc->fw) ||
> @@ -495,7 +526,7 @@ int intel_uc_init_hw(struct intel_uc *uc)
>         return -EIO;
>  }