[Intel-xe] [PATCH 2/2] drm/xe: Drop coalescing of GGTT invalidations

[Matthew Brost]

On Wed, Apr 05, 2023 at 08:42:36PM -0700, Niranjana Vishwanathapura wrote:
> On Wed, Apr 05, 2023 at 04:34:03PM -0700, Matthew Brost wrote:
> > Causing a bunch of hangs driver load and in user space. Benefit is
> > rather small too, so just drop this for to stablize the stack.
> > 
> 
> Looks like this should instead be revert of following patches?
> 
> drm/xe: Coalesce GGTT invalidations
> drm/xe: Pad GGTT mapping with an extra page pointing to scratch
> 

git revert conflicts...

Matt

> Niranjana
> 
> > Signed-off-by: Matthew Brost <matthew.brost at intel.com>
> > ---
> > drivers/gpu/drm/xe/xe_bo.c         |  1 -
> > drivers/gpu/drm/xe/xe_bo_types.h   |  2 --
> > drivers/gpu/drm/xe/xe_ggtt.c       | 25 +------------------------
> > drivers/gpu/drm/xe/xe_ggtt_types.h |  2 --
> > 4 files changed, 1 insertion(+), 29 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
> > index 5460e6fe3c1f..c7f175a149be 100644
> > --- a/drivers/gpu/drm/xe/xe_bo.c
> > +++ b/drivers/gpu/drm/xe/xe_bo.c
> > @@ -975,7 +975,6 @@ struct xe_bo *__xe_bo_create_locked(struct xe_device *xe, struct xe_bo *bo,
> > 			return bo;
> > 	}
> > 
> > -	bo->requested_size = size;
> > 	if (flags & (XE_BO_CREATE_VRAM_MASK | XE_BO_CREATE_STOLEN_BIT) &&
> > 	    !(flags & XE_BO_CREATE_IGNORE_MIN_PAGE_SIZE_BIT) &&
> > 	    xe->info.vram_flags & XE_VRAM_FLAGS_NEED64K) {
> > diff --git a/drivers/gpu/drm/xe/xe_bo_types.h b/drivers/gpu/drm/xe/xe_bo_types.h
> > index db217500a970..6071611a2b29 100644
> > --- a/drivers/gpu/drm/xe/xe_bo_types.h
> > +++ b/drivers/gpu/drm/xe/xe_bo_types.h
> > @@ -23,8 +23,6 @@ struct xe_vm;
> > struct xe_bo {
> > 	/** @ttm: TTM base buffer object */
> > 	struct ttm_buffer_object ttm;
> > -	/** @requested_size: Requested size of this buffer object */
> > -	size_t requested_size;
> > 	/** @size: Size of this buffer object after alignment adjusting */
> > 	size_t size;
> > 	/** @flags: flags for this buffer object */
> > diff --git a/drivers/gpu/drm/xe/xe_ggtt.c b/drivers/gpu/drm/xe/xe_ggtt.c
> > index a430d1568890..93f78aba2c8e 100644
> > --- a/drivers/gpu/drm/xe/xe_ggtt.c
> > +++ b/drivers/gpu/drm/xe/xe_ggtt.c
> > @@ -273,15 +273,7 @@ void xe_ggtt_map_bo(struct xe_ggtt *ggtt, struct xe_bo *bo)
> > 		xe_ggtt_set_pte(ggtt, start + offset, pte);
> > 	}
> > 
> > -	if (bo->size == bo->requested_size) {
> > -		pte = xe_ggtt_pte_encode(ggtt->scratch ?: bo, 0);
> > -		xe_ggtt_set_pte(ggtt, start + bo->size, pte);
> > -	}
> > -
> > -	if (ggtt->invalidate) {
> > -		xe_ggtt_invalidate(ggtt->gt);
> > -		ggtt->invalidate = false;
> > -	}
> > +	xe_ggtt_invalidate(ggtt->gt);
> > }
> > 
> > static int __xe_ggtt_insert_bo_at(struct xe_ggtt *ggtt, struct xe_bo *bo,
> > @@ -302,19 +294,6 @@ static int __xe_ggtt_insert_bo_at(struct xe_ggtt *ggtt, struct xe_bo *bo,
> > 	if (err)
> > 		return err;
> > 
> > -	/*
> > -	 * We add an extra page when mapping a BO in the GGTT so we can coalesce
> > -	 * GGTT invalidations. Without this extra page GGTT prefetches can leave
> > -	 * entries in the TLB pointing to an invalidation GGTT entry when in
> > -	 * fact we have programmed this GGTT entry to a valid entry. BO aligned
> > -	 * to 64k already have padding so no need to add an extra page.
> > -	 */
> > -	if (bo->size == bo->requested_size) {
> > -		size += SZ_4K;
> > -		if (end != U64_MAX)
> > -			end += SZ_4K;
> > -	}
> > -
> > 	mutex_lock(&ggtt->lock);
> > 	err = drm_mm_insert_node_in_range(&ggtt->mm, &bo->ggtt_node, size,
> > 					  alignment, 0, start, end, 0);
> > @@ -344,8 +323,6 @@ void xe_ggtt_remove_node(struct xe_ggtt *ggtt, struct drm_mm_node *node)
> > 	drm_mm_remove_node(node);
> > 	node->size = 0;
> > 
> > -	ggtt->invalidate = true;
> > -
> > 	mutex_unlock(&ggtt->lock);
> > }
> > 
> > diff --git a/drivers/gpu/drm/xe/xe_ggtt_types.h b/drivers/gpu/drm/xe/xe_ggtt_types.h
> > index 8198aa784654..ea70aaef4b31 100644
> > --- a/drivers/gpu/drm/xe/xe_ggtt_types.h
> > +++ b/drivers/gpu/drm/xe/xe_ggtt_types.h
> > @@ -26,8 +26,6 @@ struct xe_ggtt {
> > 	u64 __iomem *gsm;
> > 
> > 	struct drm_mm mm;
> > -
> > -	bool invalidate;
> > };
> > 
> > #endif
> > -- 
> > 2.34.1
> >