From ec7eba47da867e1dd0ff7d442a8717d70c064658 Mon Sep 17 00:00:00 2001 From: Rob Herring Date: Mon, 26 Aug 2019 17:33:13 -0500 Subject: [PATCH] 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: 013b65101315 ("drm/panfrost: Add madvise and shrinker support") Cc: Tomeu Vizoso Cc: David Airlie Cc: Daniel Vetter Signed-off-by: Rob Herring Acked-by: Alyssa Rosenzweig Reviewed-by: Robin Murphy Reviewed-by: Steven Price Link: https://patchwork.freedesktop.org/patch/msgid/20190826223317.28509-5-robh@kernel.org --- drivers/gpu/drm/panfrost/panfrost_mmu.c | 38 ++++++++++++++++----------------- 1 file changed, 18 insertions(+), 20 deletions(-) diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c index 3a8bcfa..2204e60 100644 --- a/drivers/gpu/drm/panfrost/panfrost_mmu.c +++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c @@ -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; } -- 2.7.4