Re: [PATCH 03/12] drm/i915: make PDE|PTE platform specific

[Jesse Barnes <jbarnes@virtuousgeek.org>]

On Tue, 23 Apr 2013 23:15:31 -0700
Ben Widawsky <ben@bwidawsk.net> wrote:

> Accomplish this be removing the PDE count define which is (and has
> always been) part of the PPGTT structure anyway. With the addition of
> the gen specific init function, we can nicely tuck away the magic number
> in there.
> 
> In this vain, make the PTE define less of a magic number.

vein

> 
> The remaining code in the global gtt setup is a bit messy, but an
> upcoming patch will clean that one up.
> 
> Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
> ---
>  drivers/gpu/drm/i915/i915_drv.h     |  2 --
>  drivers/gpu/drm/i915/i915_gem_gtt.c | 10 +++++-----
>  2 files changed, 5 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index d5dcf7f..0a9c7cd 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -431,8 +431,6 @@ struct i915_gtt {
>  };
>  #define gtt_total_entries(gtt) ((gtt).total >> PAGE_SHIFT)
>  
> -#define I915_PPGTT_PD_ENTRIES 512
> -#define I915_PPGTT_PT_ENTRIES 1024
>  struct i915_hw_ppgtt {
>  	struct drm_device *dev;
>  	unsigned num_pd_entries;
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
> index 0503f09..11a50cf 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> @@ -29,6 +29,7 @@
>  #include "intel_drv.h"
>  
>  typedef uint32_t gen6_gtt_pte_t;
> +#define I915_PPGTT_PT_ENTRIES (PAGE_SIZE / sizeof(gen6_gtt_pte_t))
>  
>  /* PPGTT stuff */
>  #define GEN6_GTT_ADDR_ENCODE(addr)	((addr) | (((addr) >> 28) & 0xff0))
> @@ -235,10 +236,9 @@ static int gen6_ppgtt_init(struct i915_hw_ppgtt *ppgtt)
>  	/* ppgtt PDEs reside in the global gtt pagetable, which has 512*1024
>  	 * entries. For aliasing ppgtt support we just steal them at the end for
>  	 * now. */
> -	first_pd_entry_in_global_pt =
> -		gtt_total_entries(dev_priv->gtt) - I915_PPGTT_PD_ENTRIES;
> +	first_pd_entry_in_global_pt = gtt_total_entries(dev_priv->gtt) - 512;
>  
> -	ppgtt->num_pd_entries = I915_PPGTT_PD_ENTRIES;
> +	ppgtt->num_pd_entries = 512;
>  	ppgtt->enable = gen6_ppgtt_enable;
>  	ppgtt->clear_range = gen6_ppgtt_clear_range;
>  	ppgtt->insert_entries = gen6_ppgtt_insert_entries;
> @@ -646,7 +646,7 @@ void i915_gem_init_global_gtt(struct drm_device *dev)
>  		if (INTEL_INFO(dev)->gen <= 7) {
>  			/* PPGTT pdes are stolen from global gtt ptes, so shrink the
>  			 * aperture accordingly when using aliasing ppgtt. */
> -			gtt_size -= I915_PPGTT_PD_ENTRIES*PAGE_SIZE;
> +			gtt_size -= 512 * PAGE_SIZE;
>  		}
>  
>  		i915_gem_setup_global_gtt(dev, 0, mappable_size, gtt_size);
> @@ -657,7 +657,7 @@ void i915_gem_init_global_gtt(struct drm_device *dev)
>  
>  		DRM_ERROR("Aliased PPGTT setup failed %d\n", ret);
>  		drm_mm_takedown(&dev_priv->mm.gtt_space);
> -		gtt_size += I915_PPGTT_PD_ENTRIES*PAGE_SIZE;
> +		gtt_size += 512 * PAGE_SIZE;
>  	}
>  	i915_gem_setup_global_gtt(dev, 0, mappable_size, gtt_size);
>  }

I thought we could have 1024 PDEs?  Either way, this just drops the
macro, which is fine, unless we want to increase our PDE count.

Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>

-- 
Jesse Barnes, Intel Open Source Technology Center