On 26/08/2019 23:33, Rob Herring wrote:
> There's no need to serialize io-pgtable calls and the as_lock is
> sufficient to serialize flush operations, so we can remove the per
> page table lock.
>
> Fixes: 7282f7645d06 ("drm/panfrost: Implement per FD address spaces")
> Suggested-by: Robin Murphy <robin.mur...@arm.com>
> Cc: Tomeu Vizoso <tomeu.viz...@collabora.com>
> Cc: Steven Price <steven.pr...@arm.com>
> Cc: Alyssa Rosenzweig <alyssa.rosenzw...@collabora.com>
> Cc: David Airlie <airl...@linux.ie>
> Cc: Daniel Vetter <dan...@ffwll.ch>
> Signed-off-by: Rob Herring <r...@kernel.org>
Reviewed-by: Steven Price <steven.pr...@arm.com>
Steve
> ---
> v3:
> - new patch
>
> drivers/gpu/drm/panfrost/panfrost_device.h | 1 -
> drivers/gpu/drm/panfrost/panfrost_mmu.c | 9 ---------
> 2 files changed, 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/panfrost/panfrost_device.h
> b/drivers/gpu/drm/panfrost/panfrost_device.h
> index f503c566e99f..b7fa08ed3a23 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_device.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_device.h
> @@ -104,7 +104,6 @@ struct panfrost_device {
> struct panfrost_mmu {
> struct io_pgtable_cfg pgtbl_cfg;
> struct io_pgtable_ops *pgtbl_ops;
> - struct mutex lock;
> int as;
> atomic_t as_count;
> struct list_head list;
> diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c
> b/drivers/gpu/drm/panfrost/panfrost_mmu.c
> index 842bdd7cf6be..3a8bcfa7e7b6 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
> @@ -228,8 +228,6 @@ static int mmu_map_sg(struct panfrost_device *pfdev,
> struct panfrost_mmu *mmu,
> struct io_pgtable_ops *ops = mmu->pgtbl_ops;
> u64 start_iova = iova;
>
> - mutex_lock(&mmu->lock);
> -
> for_each_sg(sgt->sgl, sgl, sgt->nents, count) {
> unsigned long paddr = sg_dma_address(sgl);
> size_t len = sg_dma_len(sgl);
> @@ -249,8 +247,6 @@ 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);
>
> - mutex_unlock(&mmu->lock);
> -
> return 0;
> }
>
> @@ -304,8 +300,6 @@ void panfrost_mmu_unmap(struct panfrost_gem_object *bo)
> if (ret < 0)
> return;
>
> - mutex_lock(&bo->mmu->lock);
> -
> while (unmapped_len < len) {
> size_t unmapped_page;
> size_t pgsize = get_pgsize(iova, len - unmapped_len);
> @@ -321,8 +315,6 @@ void panfrost_mmu_unmap(struct panfrost_gem_object *bo)
> mmu_hw_do_operation(pfdev, bo->mmu, bo->node.start << PAGE_SHIFT,
> bo->node.size << PAGE_SHIFT, AS_COMMAND_FLUSH_PT);
>
> - mutex_unlock(&bo->mmu->lock);
> -
> pm_runtime_mark_last_busy(pfdev->dev);
> pm_runtime_put_autosuspend(pfdev->dev);
> bo->is_mapped = false;
> @@ -356,7 +348,6 @@ int panfrost_mmu_pgtable_alloc(struct panfrost_file_priv
> *priv)
> struct panfrost_mmu *mmu = &priv->mmu;
> struct panfrost_device *pfdev = priv->pfdev;
>
> - mutex_init(&mmu->lock);
> INIT_LIST_HEAD(&mmu->list);
> mmu->as = -1;
>
> --
> 2.20.1
> _______________________________________________
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> dri-devel@lists.freedesktop.org
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>
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