Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit ec7eba47 authored by Rob Herring's avatar Rob Herring
Browse files

drm/panfrost: Rework page table flushing and runtime PM interaction 



There is no point in resuming the h/w just to do flush operations and
doing so takes several locks which cause lockdep issues with the shrinker.
Rework the flush operations to only happen when the h/w is already awake.
This avoids taking any locks associated with resuming which trigger
lockdep warnings.

Fixes: 013b6510 ("drm/panfrost: Add madvise and shrinker support")
Cc: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: default avatarRob Herring <robh@kernel.org>
Acked-by: default avatarAlyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Reviewed-by: default avatarRobin Murphy <robin.murphy@arm.com>
Reviewed-by: default avatarSteven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190826223317.28509-5-robh@kernel.org
parent e316f08f

drivers/gpu/drm/panfrost/panfrost_mmu.c

+18 −20
Original line number Diff line number Diff line
@@ -220,6 +220,22 @@ static size_t get_pgsize(u64 addr, size_t size) 
	return SZ_2M;

}



void panfrost_mmu_flush_range(struct panfrost_device *pfdev,

			      struct panfrost_mmu *mmu,

			      u64 iova, size_t size)

{

	if (mmu->as < 0)

		return;



	pm_runtime_get_noresume(pfdev->dev);



	/* Flush the PTs only if we're already awake */

	if (pm_runtime_active(pfdev->dev))

		mmu_hw_do_operation(pfdev, mmu, iova, size, AS_COMMAND_FLUSH_PT);



	pm_runtime_put_sync_autosuspend(pfdev->dev);

}



static int mmu_map_sg(struct panfrost_device *pfdev, struct panfrost_mmu *mmu,

		      u64 iova, int prot, struct sg_table *sgt)

{
@@ -244,8 +260,7 @@ static int mmu_map_sg(struct panfrost_device *pfdev, struct panfrost_mmu *mmu, 
		}

	}



	mmu_hw_do_operation(pfdev, mmu, start_iova, iova - start_iova,

			    AS_COMMAND_FLUSH_PT);

	panfrost_mmu_flush_range(pfdev, mmu, start_iova, iova - start_iova);



	return 0;

}
@@ -255,7 +270,6 @@ int panfrost_mmu_map(struct panfrost_gem_object *bo) 
	struct drm_gem_object *obj = &bo->base.base;

	struct panfrost_device *pfdev = to_panfrost_device(obj->dev);

	struct sg_table *sgt;

	int ret;

	int prot = IOMMU_READ | IOMMU_WRITE;



	if (WARN_ON(bo->is_mapped))
@@ -268,14 +282,7 @@ int panfrost_mmu_map(struct panfrost_gem_object *bo) 
	if (WARN_ON(IS_ERR(sgt)))

		return PTR_ERR(sgt);



	ret = pm_runtime_get_sync(pfdev->dev);

	if (ret < 0)

		return ret;



	mmu_map_sg(pfdev, bo->mmu, bo->node.start << PAGE_SHIFT, prot, sgt);



	pm_runtime_mark_last_busy(pfdev->dev);

	pm_runtime_put_autosuspend(pfdev->dev);

	bo->is_mapped = true;



	return 0;
@@ -289,17 +296,12 @@ void panfrost_mmu_unmap(struct panfrost_gem_object *bo) 
	u64 iova = bo->node.start << PAGE_SHIFT;

	size_t len = bo->node.size << PAGE_SHIFT;

	size_t unmapped_len = 0;

	int ret;



	if (WARN_ON(!bo->is_mapped))

		return;



	dev_dbg(pfdev->dev, "unmap: as=%d, iova=%llx, len=%zx", bo->mmu->as, iova, len);



	ret = pm_runtime_get_sync(pfdev->dev);

	if (ret < 0)

		return;



	while (unmapped_len < len) {

		size_t unmapped_page;

		size_t pgsize = get_pgsize(iova, len - unmapped_len);
@@ -312,11 +314,7 @@ void panfrost_mmu_unmap(struct panfrost_gem_object *bo) 
		unmapped_len += pgsize;

	}



	mmu_hw_do_operation(pfdev, bo->mmu, bo->node.start << PAGE_SHIFT,

			    bo->node.size << PAGE_SHIFT, AS_COMMAND_FLUSH_PT);



	pm_runtime_mark_last_busy(pfdev->dev);

	pm_runtime_put_autosuspend(pfdev->dev);

	panfrost_mmu_flush_range(pfdev, bo->mmu, bo->node.start << PAGE_SHIFT, len);

	bo->is_mapped = false;

}