[Intel-xe] [PATCH v6 2/2] drm/xe/display: Add writing of remapped dpt

[Juha-Pekka Heikkila]

On 16.10.2023 17.59, Ruhl, Michael J wrote:
>> -----Original Message-----
>> From: Juha-Pekka Heikkila <juhapekka.heikkila at gmail.com>
>> Sent: Monday, October 16, 2023 10:54 AM
>> To: Ruhl, Michael J <michael.j.ruhl at intel.com>
>> Subject: Fwd: [PATCH v6 2/2] drm/xe/display: Add writing of remapped dpt
>>
>> Xe need to use remapped display page table for tiled framebuffers
>> on anywhere else than DG2. Here add function to write such dpt and
>> enable usage of remapped display page tables where needed.
>>
>> Signed-off-by: Juha-Pekka Heikkila <juhapekka.heikkila at gmail.com>
>> ---
>>   drivers/gpu/drm/xe/display/xe_fb_pin.c | 52 +++++++++++++++++++++++--
>> -
>>   1 file changed, 46 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/xe/display/xe_fb_pin.c
>> b/drivers/gpu/drm/xe/display/xe_fb_pin.c
>> index 89cf65c58191..ffd35a59f405 100644
>> --- a/drivers/gpu/drm/xe/display/xe_fb_pin.c
>> +++ b/drivers/gpu/drm/xe/display/xe_fb_pin.c
>> @@ -45,6 +45,37 @@ write_dpt_rotated(struct xe_bo *bo, struct iosys_map
>> *map, u32 *dpt_ofs, u32 bo_
>>   	*dpt_ofs = ALIGN(*dpt_ofs, 4096);
>>   }
>>   +static void
>> +write_dpt_remapped(struct xe_bo *bo, struct iosys_map *map, u32
>> *dpt_ofs,
>> +		   u32 bo_ofs, u32 width, u32 height, u32 src_stride,
>> +		   u32 dst_stride)
>> +{
>> +	struct xe_device *xe = xe_bo_device(bo);
>> +	struct xe_ggtt *ggtt = xe_device_get_root_tile(xe)->mem.ggtt;
>> +	u64 (*pte_encode_bo)(struct xe_bo *bo, u64 bo_offset, u16
>> pat_index)
>> +		= ggtt->pt_ops->pte_encode_bo;
>> +	u32 column, row;
>> +
>> +	for (row = 0; row < height; row++) {
>> +		u32 src_idx = src_stride * row + bo_ofs;
>> +
>> +		for (column = 0; column < width; column++) {
>> +			iosys_map_wr(map, *dpt_ofs, u64,
>> +				     pte_encode_bo(bo, src_idx * XE_PAGE_SIZE,
>> +				     xe->pat.idx[XE_CACHE_WB]));
>> +
>> +			*dpt_ofs += 8;
>> +			src_idx++;
>> +		}
>> +
>> +		/* The DE ignores the PTEs for the padding tiles */
>> +		*dpt_ofs += (dst_stride - width) * 8;
>> +	}
>> +
>> +	/* Align to next page */
>> +	*dpt_ofs = ALIGN(*dpt_ofs, 4096);
> 
> The use of 4096 here is unclear.
> 
> Should this value be XE_PAGE_SIZE?

I earlier was not certain about this so I checked with Maarten and he 
confirmed this is not about XE_PAGE_SIZE but gtt mapping size so each 
entry is 4k. Agreed there are lot of these magic numbers which at some 
point will likely be defined but it's not in the scope of this patch.

/Juha-Pekka

> 
> If not, or updated with this value,
> 
> Reviewed-by: Michael J. Ruhl <michael.j.ruhl at intel.com>
> 
> 
>> +}
>> +
>>   static int __xe_pin_fb_vma_dpt(struct intel_framebuffer *fb,
>>   			       const struct i915_gtt_view *view,
>>   			       struct i915_vma *vma)
>> @@ -57,6 +88,9 @@ static int __xe_pin_fb_vma_dpt(struct
>> intel_framebuffer *fb,
>>    	if (view->type == I915_GTT_VIEW_NORMAL)
>>   		dpt_size = ALIGN(size / XE_PAGE_SIZE * 8, XE_PAGE_SIZE);
>> +	else if (view->type == I915_GTT_VIEW_REMAPPED)
>> +		dpt_size =
>> ALIGN(intel_remapped_info_size(&fb->remapped_view.gtt.remapped) * 8,
>> +				 XE_PAGE_SIZE);
>>   	else
>>   		/* display uses 4K tiles instead of bytes here, convert to
>> entries.. */
>>   		dpt_size = ALIGN(intel_rotation_info_size(&view->rotated) * 8,
>> @@ -89,6 +123,18 @@ static int __xe_pin_fb_vma_dpt(struct
>> intel_framebuffer *fb,
>>    			iosys_map_wr(&dpt->vmap, x * 8, u64, pte);
>>   		}
>> +	} else if (view->type == I915_GTT_VIEW_REMAPPED) {
>> +		const struct intel_remapped_info *remap_info = &view-
>>> remapped;
>> +		u32 i, dpt_ofs = 0;
>> +
>> +		for (i = 0; i < ARRAY_SIZE(remap_info->plane); i++)
>> +			write_dpt_remapped(bo, &dpt->vmap, &dpt_ofs,
>> +					   remap_info->plane[i].offset,
>> +					   remap_info->plane[i].width,
>> +					   remap_info->plane[i].height,
>> +					   remap_info->plane[i].src_stride,
>> +					   remap_info->plane[i].dst_stride);
>> +
>>   	} else {
>>   		const struct intel_rotation_info *rot_info = &view->rotated;
>>   		u32 i, dpt_ofs = 0;
>> @@ -212,12 +258,6 @@ static struct i915_vma *__xe_pin_fb_vma(struct
>> intel_framebuffer *fb,
>>   	if (!vma)
>>   		return ERR_PTR(-ENODEV);
>>   -	/* Remapped view is only required on ADL-P, which xe doesn't support.
>> */
>> -	if (XE_WARN_ON(view->type == I915_GTT_VIEW_REMAPPED)) {
>> -		ret = -ENODEV;
>> -		goto err;
>> -	}
>> -
>>   	if (IS_DGFX(to_xe_device(bo->ttm.base.dev)) &&
>>   	    intel_fb_rc_ccs_cc_plane(&fb->base) >= 0 &&
>>   	    !(bo->flags & XE_BO_NEEDS_CPU_ACCESS)) {
>> --
>> 2.25.1
>