[PATCH RFC 2/4] drm/panfrost: Track BO resident size

[Boris Brezillon]

Heap BOs use an on-demand allocation scheme, meaning that the resident
size is different from the BO side. Track resident size so we can more
accurately per-FD expose memory usage.

Signed-off-by: Boris Brezillon <boris.brezillon at collabora.com>
---
 drivers/gpu/drm/panfrost/panfrost_gem.h          | 7 +++++++
 drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c | 1 +
 drivers/gpu/drm/panfrost/panfrost_mmu.c          | 2 ++
 3 files changed, 10 insertions(+)

diff --git a/drivers/gpu/drm/panfrost/panfrost_gem.h b/drivers/gpu/drm/panfrost/panfrost_gem.h
index 8088d5fd8480..58f5d091c983 100644
--- a/drivers/gpu/drm/panfrost/panfrost_gem.h
+++ b/drivers/gpu/drm/panfrost/panfrost_gem.h
@@ -36,6 +36,13 @@ struct panfrost_gem_object {
 	 */
 	atomic_t gpu_usecount;
 
+	/* Actual memory used by the BO. Should be zero before pages are
+	 * pinned, then the size of the BO, unless it's a heap BO. In
+	 * this case the resident size is updated when the fault handler
+	 * allocates memory.
+	 */
+	size_t resident_size;
+
 	bool noexec		:1;
 	bool is_heap		:1;
 };
diff --git a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c b/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
index bf0170782f25..efbc8dec4a9f 100644
--- a/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
+++ b/drivers/gpu/drm/panfrost/panfrost_gem_shrinker.c
@@ -54,6 +54,7 @@ static bool panfrost_gem_purge(struct drm_gem_object *obj)
 	panfrost_gem_teardown_mappings_locked(bo);
 	drm_gem_shmem_purge_locked(&bo->base);
 	ret = true;
+	bo->resident_size = 0;
 
 	mutex_unlock(&shmem->pages_lock);
 
diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
index 4e83a1891f3e..454799d5a0ef 100644
--- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
+++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
@@ -340,6 +340,7 @@ int panfrost_mmu_map(struct panfrost_gem_mapping *mapping)
 	mmu_map_sg(pfdev, mapping->mmu, mapping->mmnode.start << PAGE_SHIFT,
 		   prot, sgt);
 	mapping->active = true;
+	bo->resident_size = bo->base.base.size;
 
 	return 0;
 }
@@ -508,6 +509,7 @@ static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
 		}
 	}
 
+	bo->resident_size += SZ_2M;
 	mutex_unlock(&bo->base.pages_lock);
 
 	sgt = &bo->sgts[page_offset / (SZ_2M / PAGE_SIZE)];
-- 
2.38.1