Re: [PATCH 4/6] drm/xe/xe_migrate: Handle migration logic for xe2+ dgfx

["Jahagirdar, Akshata" <akshata.jahagirdar@intel.com>]

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On 7/12/2024 5:55 AM, Nirmoy Das wrote:
>
> Hi Akshata,
>
> On 7/12/2024 8:39 AM, Akshata Jahagirdar wrote:
>> From: "Jahagirdar, Akshata"<akshata.jahagirdar@intel.com>
>>
>> During eviction (vram->sysmem), we use the mapping from compressed -> uncompressed.
>> During restore (sysmem->vram), we need the mapping from uncompressed -> uncompressed.
>> Handle logic for selecting the compressed identity map for eviction,
>> and selecting uncompressed map for restore operations.
>>
>> Signed-off-by: Akshata Jahagirdar<akshata.jahagirdar@intel.com>
>> Reviewed-by: Matthew Auld<matthew.auld@intel.com>
>> Reviewed-by: Himal Prasad Ghimiray<himal.prasad.ghimiray@intel.com>
>> ---
>>   drivers/gpu/drm/xe/xe_migrate.c | 7 ++++---
>>   1 file changed, 4 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/xe/xe_migrate.c b/drivers/gpu/drm/xe/xe_migrate.c
>> index 3b8a334fe08f..1eee6be24423 100644
>> --- a/drivers/gpu/drm/xe/xe_migrate.c
>> +++ b/drivers/gpu/drm/xe/xe_migrate.c
>> @@ -715,7 +715,7 @@ static u32 xe_migrate_ccs_copy(struct xe_migrate *m,
>>   	struct xe_gt *gt = m->tile->primary_gt;
>>   	u32 flush_flags = 0;
>>   
>> -	if (xe_device_has_flat_ccs(gt_to_xe(gt)) && !copy_ccs && dst_is_indirect) {
>> +	if (xe_device_needs_ccs_emit(gt_to_xe(gt)) && !copy_ccs && dst_is_indirect) {
>
>
> Do we need to call xe_migrate_ccs_copy() when 
> xe_device_needs_ccs_emit() is true ? If not then move the check for 
> xe_device_needs_ccs_emit() to xe_migrate_copy()
>
> to ensure that xe_migrate_ccs_copy() is not even called on such platforms.
>
> Regards,
> Nirmoy

xe_device_needs_ccs_emit() is true for any non-BMG platform that has 
flat-ccs enabled.
In such cases, we do need to call xe_migrate_ccs_copy() while clearing 
any ccs metadata in vram.

BR,
Akshata

>>   		/*
>>   		 * If the src is already in vram, then it should already
>>   		 * have been cleared by us, or has been populated by the
>> @@ -791,6 +791,7 @@ struct dma_fence *xe_migrate_copy(struct xe_migrate *m,
>>   	bool copy_ccs = xe_device_has_flat_ccs(xe) &&
>>   		xe_bo_needs_ccs_pages(src_bo) && xe_bo_needs_ccs_pages(dst_bo);
>>   	bool copy_system_ccs = copy_ccs && (!src_is_vram || !dst_is_vram);
>> +	bool use_comp_pat = GRAPHICS_VER(xe) >= 20 && IS_DGFX(xe) && src_is_vram && !dst_is_vram;
>>   
>>   	/* Copying CCS between two different BOs is not supported yet. */
>>   	if (XE_WARN_ON(copy_ccs && src_bo != dst_bo))
>> @@ -833,7 +834,7 @@ struct dma_fence *xe_migrate_copy(struct xe_migrate *m,
>>   
>>   		src_L0 = min(src_L0, dst_L0);
>>   
>> -		batch_size += pte_update_size(m, src_is_vram, false, src, &src_it, &src_L0,
>> +		batch_size += pte_update_size(m, src_is_vram, use_comp_pat, src, &src_it, &src_L0,
>>   					      &src_L0_ofs, &src_L0_pt, 0, 0,
>>   					      avail_pts);
>>   
>> @@ -852,7 +853,7 @@ struct dma_fence *xe_migrate_copy(struct xe_migrate *m,
>>   
>>   		/* Add copy commands size here */
>>   		batch_size += ((copy_only_ccs) ? 0 : EMIT_COPY_DW) +
>> -			((xe_device_has_flat_ccs(xe) ? EMIT_COPY_CCS_DW : 0));
>> +			((xe_device_needs_ccs_emit(xe) ? EMIT_COPY_CCS_DW : 0));
>>   
>>   		bb = xe_bb_new(gt, batch_size, usm);
>>   		if (IS_ERR(bb)) {

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