Re: [PATCH 11/21] drm/i915/gtt: Introduce fill_page_dma()

From: Michel Thierry <michel.thierry@intel.com>
To: Mika Kuoppala <mika.kuoppala@linux.intel.com>,
	intel-gfx@lists.freedesktop.org
Subject: Re: [PATCH 11/21] drm/i915/gtt: Introduce fill_page_dma()
Date: Wed, 24 Jun 2015 16:05:23 +0100	[thread overview]
Message-ID: <558AC733.50905@intel.com> (raw)
In-Reply-To: <1434045022-22690-1-git-send-email-mika.kuoppala@intel.com>

On 6/11/2015 6:50 PM, Mika Kuoppala wrote:
> When we setup page directories and tables, we point the entries
> to a to the next level scratch structure. Make this generic
> by introducing a fill_page_dma which maps and flushes. We also
> need 32 bit variant for legacy gens.
>
> v2: Fix flushes and handle valleyview (Ville)
> v3: Now really fix flushes (Michel, Ville)

Daniel, I'll do some testing in bxt this week.

Having said that, before this patch the code was doing the flush in bxt, 
so it doesn't change the current behavior...

Reviewed-by: Michel Thierry <michel.thierry@intel.com>
>
> Signed-off-by: Mika Kuoppala <mika.kuoppala@intel.com>
> ---
>   drivers/gpu/drm/i915/i915_gem_gtt.c | 74 ++++++++++++++++++++-----------------
>   1 file changed, 40 insertions(+), 34 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
> index 698423b..60796b7 100644
> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
> @@ -330,6 +330,34 @@ static void cleanup_page_dma(struct drm_device *dev, struct i915_page_dma *p)
>   	memset(p, 0, sizeof(*p));
>   }
>
> +static void fill_page_dma(struct drm_device *dev, struct i915_page_dma *p,
> +			  const uint64_t val)
> +{
> +	int i;
> +	uint64_t * const vaddr = kmap_atomic(p->page);
> +
> +	for (i = 0; i < 512; i++)
> +		vaddr[i] = val;
> +
> +	/* There are only few exceptions for gen >=6. chv and bxt.
> +	 * And we are not sure about the latter so play safe for now.
> +	 */
> +	if (IS_CHERRYVIEW(dev) || IS_BROXTON(dev))
> +		drm_clflush_virt_range(vaddr, PAGE_SIZE);
> +
> +	kunmap_atomic(vaddr);
> +}
> +
> +static void fill_page_dma_32(struct drm_device *dev, struct i915_page_dma *p,
> +			     const uint32_t val32)
> +{
> +	uint64_t v = val32;
> +
> +	v = v << 32 | val32;
> +
> +	fill_page_dma(dev, p, v);
> +}
> +
>   static void free_pt(struct drm_device *dev, struct i915_page_table *pt)
>   {
>   	cleanup_page_dma(dev, &pt->base);
> @@ -340,19 +368,11 @@ static void free_pt(struct drm_device *dev, struct i915_page_table *pt)
>   static void gen8_initialize_pt(struct i915_address_space *vm,
>   			       struct i915_page_table *pt)
>   {
> -	gen8_pte_t *pt_vaddr, scratch_pte;
> -	int i;
> -
> -	pt_vaddr = kmap_atomic(pt->base.page);
> -	scratch_pte = gen8_pte_encode(vm->scratch.addr,
> -				      I915_CACHE_LLC, true);
> +	gen8_pte_t scratch_pte;
>
> -	for (i = 0; i < GEN8_PTES; i++)
> -		pt_vaddr[i] = scratch_pte;
> +	scratch_pte = gen8_pte_encode(vm->scratch.addr, I915_CACHE_LLC, true);
>
> -	if (!HAS_LLC(vm->dev))
> -		drm_clflush_virt_range(pt_vaddr, PAGE_SIZE);
> -	kunmap_atomic(pt_vaddr);
> +	fill_page_dma(vm->dev, &pt->base, scratch_pte);
>   }
>
>   static struct i915_page_table *alloc_pt(struct drm_device *dev)
> @@ -585,20 +605,13 @@ static void gen8_initialize_pd(struct i915_address_space *vm,
>   			       struct i915_page_directory *pd)
>   {
>   	struct i915_hw_ppgtt *ppgtt =
> -			container_of(vm, struct i915_hw_ppgtt, base);
> -	gen8_pde_t *page_directory;
> -	struct i915_page_table *pt;
> -	int i;
> +		container_of(vm, struct i915_hw_ppgtt, base);
> +	gen8_pde_t scratch_pde;
>
> -	page_directory = kmap_atomic(pd->base.page);
> -	pt = ppgtt->scratch_pt;
> -	for (i = 0; i < I915_PDES; i++)
> -		/* Map the PDE to the page table */
> -		__gen8_do_map_pt(page_directory + i, pt, vm->dev);
> +	scratch_pde = gen8_pde_encode(vm->dev, ppgtt->scratch_pt->base.daddr,
> +				      I915_CACHE_LLC);
>
> -	if (!HAS_LLC(vm->dev))
> -		drm_clflush_virt_range(page_directory, PAGE_SIZE);
> -	kunmap_atomic(page_directory);
> +	fill_page_dma(vm->dev, &pd->base, scratch_pde);
>   }
>
>   static void gen8_free_page_tables(struct i915_page_directory *pd, struct drm_device *dev)
> @@ -1250,22 +1263,15 @@ static void gen6_ppgtt_insert_entries(struct i915_address_space *vm,
>   }
>
>   static void gen6_initialize_pt(struct i915_address_space *vm,
> -		struct i915_page_table *pt)
> +			       struct i915_page_table *pt)
>   {
> -	gen6_pte_t *pt_vaddr, scratch_pte;
> -	int i;
> +	gen6_pte_t scratch_pte;
>
>   	WARN_ON(vm->scratch.addr == 0);
>
> -	scratch_pte = vm->pte_encode(vm->scratch.addr,
> -			I915_CACHE_LLC, true, 0);
> -
> -	pt_vaddr = kmap_atomic(pt->base.page);
> -
> -	for (i = 0; i < GEN6_PTES; i++)
> -		pt_vaddr[i] = scratch_pte;
> +	scratch_pte = vm->pte_encode(vm->scratch.addr, I915_CACHE_LLC, true, 0);
>
> -	kunmap_atomic(pt_vaddr);
> +	fill_page_dma_32(vm->dev, &pt->base, scratch_pte);
>   }
>
>   static int gen6_alloc_va_range(struct i915_address_space *vm,
>
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