drm/shmem-helper: Pass GEM shmem object in public interfaces

Change all GEM SHMEM object functions that receive a GEM object
of type struct drm_gem_object to expect an object of type
struct drm_gem_shmem_object instead.

This change reduces the number of upcasts from struct drm_gem_object
by moving them into callers. The C compiler can now verify that the
GEM SHMEM functions are called with the correct type.

For consistency, the patch also renames drm_gem_shmem_free_object to
drm_gem_shmem_free. It further updates documentation for a number of
functions.

v3:
	* fix docs for drm_gem_shmem_object_free()
v2:
	* mention _object_ callbacks in docs (Daniel)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20211108093149.7226-4-tzimmermann@suse.de

5 files changed, 13 insertions, 10 deletions

diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
index 82ad9a67f251..96bb5a465627 100644
--- a/drivers/gpu/drm/panfrost/panfrost_drv.c
+++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
@@ -427,7 +427,7 @@ static int panfrost_ioctl_madvise(struct drm_device *dev, void *data,
 		}
 	}
 
-	args->retained = drm_gem_shmem_madvise(gem_obj, args->madv);
+	args->retained = drm_gem_shmem_madvise(&bo->base, args->madv);
 
 	if (args->retained) {
 		if (args->madv == PANFROST_MADV_DONTNEED)
diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.c b/drivers/gpu/drm/panfrost/panfrost_gem.c
index be1cc6579a71..6d9bdb9180cb 100644
--- a/drivers/gpu/drm/panfrost/panfrost_gem.c
+++ b/drivers/gpu/drm/panfrost/panfrost_gem.c
@@ -49,7 +49,7 @@ static void panfrost_gem_free_object(struct drm_gem_object *obj)
 		kvfree(bo->sgts);
 	}
 
-	drm_gem_shmem_free_object(obj);
+	drm_gem_shmem_free(&bo->base);
 }
 
 struct panfrost_gem_mapping *
@@ -187,10 +187,12 @@ void panfrost_gem_close(struct drm_gem_object *obj, struct drm_file *file_priv)
 
 static int panfrost_gem_pin(struct drm_gem_object *obj)
 {
-	if (to_panfrost_bo(obj)->is_heap)
+	struct panfrost_gem_object *bo = to_panfrost_bo(obj);
+
+	if (bo->is_heap)
 		return -EINVAL;
 
-	return drm_gem_shmem_pin(obj);
+	return drm_gem_shmem_pin(&bo->base);
 }
 
 static const struct drm_gem_object_funcs panfrost_gem_funcs = {
diff --git a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c b/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
index 1b9f68d8e9aa..b0142341e223 100644
--- a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
+++ b/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
@@ -52,7 +52,7 @@ static bool panfrost_gem_purge(struct drm_gem_object *obj)
 		goto unlock_mappings;
 
 	panfrost_gem_teardown_mappings_locked(bo);
-	drm_gem_shmem_purge_locked(obj);
+	drm_gem_shmem_purge_locked(&bo->base);
 	ret = true;
 
 	mutex_unlock(&shmem->pages_lock);
diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
index f51d3f791a17..39562f2d11a4 100644
--- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
+++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
@@ -304,7 +304,8 @@ static int mmu_map_sg(struct panfrost_device *pfdev, struct panfrost_mmu *mmu,
 int panfrost_mmu_map(struct panfrost_gem_mapping *mapping)
 {
 	struct panfrost_gem_object *bo = mapping->obj;
-	struct drm_gem_object *obj = &bo->base.base;
+	struct drm_gem_shmem_object *shmem = &bo->base;
+	struct drm_gem_object *obj = &shmem->base;
 	struct panfrost_device *pfdev = to_panfrost_device(obj->dev);
 	struct sg_table *sgt;
 	int prot = IOMMU_READ | IOMMU_WRITE;
@@ -315,7 +316,7 @@ int panfrost_mmu_map(struct panfrost_gem_mapping *mapping)
 	if (bo->noexec)
 		prot |= IOMMU_NOEXEC;
 
-	sgt = drm_gem_shmem_get_pages_sgt(obj);
+	sgt = drm_gem_shmem_get_pages_sgt(shmem);
 	if (WARN_ON(IS_ERR(sgt)))
 		return PTR_ERR(sgt);
 
diff --git a/drivers/gpu/drm/panfrost/panfrost_perfcnt.c b/drivers/gpu/drm/panfrost/panfrost_perfcnt.c
index e116a4d9b8e5..1d36df5af98d 100644
--- a/drivers/gpu/drm/panfrost/panfrost_perfcnt.c
+++ b/drivers/gpu/drm/panfrost/panfrost_perfcnt.c
@@ -105,7 +105,7 @@ static int panfrost_perfcnt_enable_locked(struct panfrost_device *pfdev,
 		goto err_close_bo;
 	}
 
-	ret = drm_gem_shmem_vmap(&bo->base, &map);
+	ret = drm_gem_shmem_vmap(bo, &map);
 	if (ret)
 		goto err_put_mapping;
 	perfcnt->buf = map.vaddr;
@@ -164,7 +164,7 @@ static int panfrost_perfcnt_enable_locked(struct panfrost_device *pfdev,
 	return 0;
 
 err_vunmap:
-	drm_gem_shmem_vunmap(&bo->base, &map);
+	drm_gem_shmem_vunmap(bo, &map);
 err_put_mapping:
 	panfrost_gem_mapping_put(perfcnt->mapping);
 err_close_bo:
@@ -194,7 +194,7 @@ static int panfrost_perfcnt_disable_locked(struct panfrost_device *pfdev,
 		  GPU_PERFCNT_CFG_MODE(GPU_PERFCNT_CFG_MODE_OFF));
 
 	perfcnt->user = NULL;
-	drm_gem_shmem_vunmap(&perfcnt->mapping->obj->base.base, &map);
+	drm_gem_shmem_vunmap(&perfcnt->mapping->obj->base, &map);
 	perfcnt->buf = NULL;
 	panfrost_gem_close(&perfcnt->mapping->obj->base.base, file_priv);
 	panfrost_mmu_as_put(pfdev, perfcnt->mapping->mmu);