[Intel-gfx] [PATCH] drm/i915/gtt: Fix rounding for 36b

[Abdiel Janulgue]

On 19/07/2019 16.07, Chris Wilson wrote:
> The top-level page directory for 36b is a single entry, not multiple
> like 32b. Fix up the rounding on the calculation of the size of the top
> level so that we populate the 4th level correctly for 36b.
> 

Reviewed-by: Abdiel Janulgue <abdiel.janulgue at linux.intel.com>

> Reported-by: Jose Souza <jose.souza at intel.com>
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Fixes: 1eda701eace2 ("drm/i915/gtt: Recursive cleanup for gen8")
> Cc: Abdiel Janulgue <abdiel.janulgue at linux.intel.com>
> Cc: Jose Souza <jose.souza at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_gem_gtt.c | 17 ++++++++++-------
>  1 file changed, 10 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
> index 220aba5a94d2..7dd08ff6c0eb 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> @@ -905,6 +905,12 @@ static inline unsigned int gen8_pt_count(u64 start, u64 end)
>  		return end - start;
>  }
>  
> +static inline unsigned int gen8_pd_top_count(const struct i915_address_space *vm)
> +{
> +	unsigned int shift = __gen8_pte_shift(vm->top);
> +	return (vm->total + (1ull << shift) - 1) >> shift;
> +}
> +
>  static void __gen8_ppgtt_cleanup(struct i915_address_space *vm,
>  				 struct i915_page_directory *pd,
>  				 int count, int lvl)
> @@ -930,9 +936,7 @@ static void gen8_ppgtt_cleanup(struct i915_address_space *vm)
>  	if (intel_vgpu_active(vm->i915))
>  		gen8_ppgtt_notify_vgt(ppgtt, false);
>  
> -	__gen8_ppgtt_cleanup(vm, ppgtt->pd,
> -			     vm->total >> __gen8_pte_shift(vm->top),
> -			     vm->top);
> +	__gen8_ppgtt_cleanup(vm, ppgtt->pd, gen8_pd_top_count(vm), vm->top);
>  	free_scratch(vm);
>  }
>  
> @@ -1391,7 +1395,7 @@ static int gen8_preallocate_top_level_pdp(struct i915_ppgtt *ppgtt)
>  	unsigned int idx;
>  
>  	GEM_BUG_ON(vm->top != 2);
> -	GEM_BUG_ON((vm->total >> __gen8_pte_shift(2)) != GEN8_3LVL_PDPES);
> +	GEM_BUG_ON(gen8_pd_top_count(vm) != GEN8_3LVL_PDPES);
>  
>  	for (idx = 0; idx < GEN8_3LVL_PDPES; idx++) {
>  		struct i915_page_directory *pde;
> @@ -1428,7 +1432,7 @@ static void ppgtt_init(struct i915_ppgtt *ppgtt, struct intel_gt *gt)
>  static struct i915_page_directory *
>  gen8_alloc_top_pd(struct i915_address_space *vm)
>  {
> -	const unsigned int count = vm->total >> __gen8_pte_shift(vm->top);
> +	const unsigned int count = gen8_pd_top_count(vm);
>  	struct i915_page_directory *pd;
>  
>  	GEM_BUG_ON(count > ARRAY_SIZE(pd->entry));
> @@ -1514,8 +1518,7 @@ static struct i915_ppgtt *gen8_ppgtt_create(struct drm_i915_private *i915)
>  
>  err_free_pd:
>  	__gen8_ppgtt_cleanup(&ppgtt->vm, ppgtt->pd,
> -			     ppgtt->vm.total >> __gen8_pte_shift(ppgtt->vm.top),
> -			     ppgtt->vm.top);
> +			     gen8_pd_top_count(&ppgtt->vm), ppgtt->vm.top);
>  err_free_scratch:
>  	free_scratch(&ppgtt->vm);
>  err_free:
>