[PATCH 3/3] drm/i915: Use selective tlb invalidations where supported

[Cavitt, Jonathan]

-----Original Message-----
From: Das, Nirmoy <nirmoy.das at intel.com> 
Sent: Friday, November 17, 2023 6:50 AM
To: intel-gfx-trybot at lists.freedesktop.org
Cc: Cavitt, Jonathan <jonathan.cavitt at intel.com>; Prathap Kumar Valsan <prathap.kumar.valsan at intel.com>; Vishwanathapura, Niranjana <niranjana.vishwanathapura at intel.com>; Yang, Fei <fei.yang at intel.com>; Mauro Carvalho Chehab <mchehab at kernel.org>
Subject: [PATCH 3/3] drm/i915: Use selective tlb invalidations where supported
> 
> From: Jonathan Cavitt <jonathan.cavitt at intel.com>
> 
> For platforms supporting selective tlb invalidations, we don't need to
> do a full tlb invalidation. Rather do a range based tlb invalidation for
> every unbind of purged vma belongs to an active vm.
> 
> Signed-off-by: Prathap Kumar Valsan <prathap.kumar.valsan at intel.com>
> Cc: Niranjana Vishwanathapura <niranjana.vishwanathapura at intel.com>
> Cc: Fei Yang <fei.yang at intel.com>
> Signed-off-by: Mauro Carvalho Chehab <mchehab at kernel.org>
> Signed-off-by: Jonathan Cavitt <jonathan.cavitt at intel.com>
> ---
>  drivers/gpu/drm/i915/gt/intel_ppgtt.c |  2 +-
>  drivers/gpu/drm/i915/i915_vma.c       | 14 +++++++++-----
>  drivers/gpu/drm/i915/i915_vma.h       |  3 ++-
>  3 files changed, 12 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gt/intel_ppgtt.c b/drivers/gpu/drm/i915/gt/intel_ppgtt.c
> index d07a4f97b943..b43dae3cbd59 100644
> --- a/drivers/gpu/drm/i915/gt/intel_ppgtt.c
> +++ b/drivers/gpu/drm/i915/gt/intel_ppgtt.c
> @@ -211,7 +211,7 @@ void ppgtt_unbind_vma(struct i915_address_space *vm,
>  		return;
>  
>  	vm->clear_range(vm, vma_res->start, vma_res->vma_size);
> -	vma_invalidate_tlb(vm, vma_res->tlb);
> +	vma_invalidate_tlb(vm, vma_res->tlb, vma_res->start, vma_res->vma_size);
>  }
>  
>  static unsigned long pd_count(u64 size, int shift)
> diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
> index d09aad34ba37..cb05d794f0d0 100644
> --- a/drivers/gpu/drm/i915/i915_vma.c
> +++ b/drivers/gpu/drm/i915/i915_vma.c
> @@ -1339,7 +1339,8 @@ I915_SELFTEST_EXPORT int i915_vma_get_pages(struct i915_vma *vma)
>  	return err;
>  }
>  
> -void vma_invalidate_tlb(struct i915_address_space *vm, u32 *tlb)
> +void vma_invalidate_tlb(struct i915_address_space *vm, u32 *tlb


There's a missing comma here, after "u32 *tlb", which is causing (or will cause)
the kernel to not compile.
This was an issue with the original RFC I sent that suggested this change, so I
apologize that this was ever a problem to begin with.
-Jonathan Cavitt


> +			u64 start, u64 size)
>  {
>  	struct intel_gt *gt;
>  	int id;
> @@ -1355,9 +1356,11 @@ void vma_invalidate_tlb(struct i915_address_space *vm, u32 *tlb)
>  	 * the most recent TLB invalidation seqno, and if we have not yet
>  	 * flushed the TLBs upon release, perform a full invalidation.
>  	 */
> -	for_each_gt(gt, vm->i915, id)
> -		WRITE_ONCE(tlb[id],
> -			   intel_gt_next_invalidate_tlb_full(gt));
> +	for_each_gt(gt, vm->i915, id) {
> +		if (!intel_gt_invalidate_tlb_range(gt, start, size))
> +			WRITE_ONCE(tlb[id],
> +				   intel_gt_next_invalidate_tlb_full(gt));
> +	}
>  }
>  
>  static void __vma_put_pages(struct i915_vma *vma, unsigned int count)
> @@ -2041,7 +2044,8 @@ struct dma_fence *__i915_vma_evict(struct i915_vma *vma, bool async)
>  			dma_fence_put(unbind_fence);
>  			unbind_fence = NULL;
>  		}
> -		vma_invalidate_tlb(vma->vm, vma->obj->mm.tlb);
> +		vma_invalidate_tlb(vma->vm, vma->obj->mm.tlb,
> +				   vma->node.start, vma->size);
>  	}
>  
>  	/*
> diff --git a/drivers/gpu/drm/i915/i915_vma.h b/drivers/gpu/drm/i915/i915_vma.h
> index e356dfb883d3..5a604aad55df 100644
> --- a/drivers/gpu/drm/i915/i915_vma.h
> +++ b/drivers/gpu/drm/i915/i915_vma.h
> @@ -260,7 +260,8 @@ bool i915_vma_misplaced(const struct i915_vma *vma,
>  			u64 size, u64 alignment, u64 flags);
>  void __i915_vma_set_map_and_fenceable(struct i915_vma *vma);
>  void i915_vma_revoke_mmap(struct i915_vma *vma);
> -void vma_invalidate_tlb(struct i915_address_space *vm, u32 *tlb);
> +void vma_invalidate_tlb(struct i915_address_space *vm, u32 *tlb,
> +			u64 start, u64 size);
>  struct dma_fence *__i915_vma_evict(struct i915_vma *vma, bool async);
>  int __i915_vma_unbind(struct i915_vma *vma);
>  int __must_check i915_vma_unbind(struct i915_vma *vma);
> -- 
> 2.42.0
> 
>