[PATCH 2/3] drm/xe: Restore system memory GGTT mappings

[Matthew Brost]

On Tue, Oct 29, 2024 at 09:44:32AM +0000, Matthew Auld wrote:
> On 29/10/2024 00:32, Matthew Brost wrote:
> > GGTT mappings reside on the device and this state is lost during suspend
> > / d3cold thus this state must be restored resume regardless if the BO is
> > in system memory or VRAM.
> > 
> > Signed-off-by: Matthew Brost <matthew.brost at intel.com>
> 
> I think this needs fixes?
> 

I don't think we have a user of SYSTEM pinned BOs upstream on DGFX
platforms yet. But let me double check... If we do, then yea fixes tags
would be good.

> > ---
> >   drivers/gpu/drm/xe/xe_bo.c       | 14 +++++++++++---
> >   drivers/gpu/drm/xe/xe_bo_evict.c |  1 -
> >   2 files changed, 11 insertions(+), 4 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
> > index bd747e53eb9b..6c8fd5ced2a2 100644
> > --- a/drivers/gpu/drm/xe/xe_bo.c
> > +++ b/drivers/gpu/drm/xe/xe_bo.c
> > @@ -890,8 +890,8 @@ int xe_bo_evict_pinned(struct xe_bo *bo)
> >   	if (WARN_ON(!xe_bo_is_pinned(bo)))
> >   		return -EINVAL;
> > -	if (WARN_ON(!xe_bo_is_vram(bo)))
> > -		return -EINVAL;
> > +	if (!xe_bo_is_vram(bo))
> > +		return 0;
> 
> In the suspend flow in xe_bo_evict_all() there is:
> 
> 	if (!IS_DGFX(xe))
> 		return 0;
> 
> But seems like we now need this flow for igpu, so need to also drop that
> check?
> 

I don't think so. AFIAK GGTT mappings are not blown away on iGPU
platforms so this isn't needed.

Matt

> >   	if (bo->flags & XE_BO_FLAG_PINNED_WONTNEED) {
> >   		ttm_bo_move_null(&bo->ttm, NULL);
> > @@ -946,6 +946,7 @@ int xe_bo_restore_pinned(struct xe_bo *bo)
> >   		.interruptible = false,
> >   	};
> >   	struct ttm_resource *new_mem;
> > +	struct ttm_place *place = &(bo->placements[0]);
> >   	int ret;
> >   	xe_bo_assert_held(bo);
> > @@ -961,6 +962,9 @@ int xe_bo_restore_pinned(struct xe_bo *bo)
> >   			return -EINVAL;
> >   	}
> > +	if (!mem_type_is_vram(place->mem_type))
> > +		return 0;
> > +
> >   	ret = ttm_bo_mem_space(&bo->ttm, &bo->placement, &new_mem, &ctx);
> >   	if (ret)
> >   		return ret;
> > @@ -1814,7 +1818,10 @@ int xe_bo_pin(struct xe_bo *bo)
> >   			place->fpfn = (xe_bo_addr(bo, 0, PAGE_SIZE) -
> >   				       vram_region_gpu_offset(bo->ttm.resource)) >> PAGE_SHIFT;
> >   			place->lpfn = place->fpfn + (bo->size >> PAGE_SHIFT);
> > +		}
> > +		if (mem_type_is_vram(place->mem_type) ||
> > +		    bo->flags & XE_BO_FLAG_GGTT) {
> >   			spin_lock(&xe->pinned.lock);
> >   			list_add_tail(&bo->pinned_link, &xe->pinned.kernel_bo_present);
> >   			spin_unlock(&xe->pinned.lock);
> > @@ -1875,7 +1882,8 @@ void xe_bo_unpin(struct xe_bo *bo)
> >   	    bo->flags & XE_BO_FLAG_INTERNAL_TEST)) {
> >   		struct ttm_place *place = &(bo->placements[0]);
> > -		if (mem_type_is_vram(place->mem_type)) {
> > +		if (mem_type_is_vram(place->mem_type) ||
> > +		    bo->flags & XE_BO_FLAG_GGTT) {
> >   			spin_lock(&xe->pinned.lock);
> >   			xe_assert(xe, !list_empty(&bo->pinned_link));
> >   			list_del_init(&bo->pinned_link);
> > diff --git a/drivers/gpu/drm/xe/xe_bo_evict.c b/drivers/gpu/drm/xe/xe_bo_evict.c
> > index 541b49007d73..32043e1e5a86 100644
> > --- a/drivers/gpu/drm/xe/xe_bo_evict.c
> > +++ b/drivers/gpu/drm/xe/xe_bo_evict.c
> > @@ -159,7 +159,6 @@ int xe_bo_restore_kernel(struct xe_device *xe)
> >   		 * should setup the iosys map.
> >   		 */
> >   		xe_assert(xe, !iosys_map_is_null(&bo->vmap));
> > -		xe_assert(xe, xe_bo_is_vram(bo));
> >   		xe_bo_put(bo);