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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: 013b651013 ("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: Rob Herring <robh@kernel.org>
Acked-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190826223317.28509-5-robh@kernel.org
This commit is contained in:
Rob Herring 2019-08-26 17:33:13 -05:00
parent e316f08f1a
commit ec7eba47da
1 changed files with 18 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
drivers/gpu/drm/panfrost/panfrost_mmu.c
View File

@ -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;
}