[PATCH RFC 3/4] drm/panfrost: Add a helper to retrieve MMU context stats

[Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>]

For now we only gather a few memory usage stats that we'll expose
through fdinfo, but this can be extended if needed.

Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxx>
---
 drivers/gpu/drm/panfrost/panfrost_mmu.c | 25 +++++++++++++++++++++++++
 drivers/gpu/drm/panfrost/panfrost_mmu.h | 10 ++++++++++
 2 files changed, 35 insertions(+)

diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.c b/drivers/gpu/drm/panfrost/panfrost_mmu.c
index 454799d5a0ef..80c6e0e17195 100644
--- a/drivers/gpu/drm/panfrost/panfrost_mmu.c
+++ b/drivers/gpu/drm/panfrost/panfrost_mmu.c
@@ -435,6 +435,31 @@ addr_to_mapping(struct panfrost_device *pfdev, int as, u64 addr)
 	return mapping;
 }
 
+void panfrost_mmu_get_stats(struct panfrost_mmu *mmu,
+			    struct panfrost_mmu_stats *stats)
+{
+	struct drm_mm_node *node;
+
+	memset(stats, 0, sizeof(*stats));
+
+	spin_lock(&mmu->mm_lock);
+	drm_mm_for_each_node(node, &mmu->mm) {
+		struct panfrost_gem_mapping *mapping;
+		struct panfrost_gem_object *bo;
+
+		mapping = container_of(node, struct panfrost_gem_mapping, mmnode);
+		bo = mapping->obj;
+
+		stats->all += bo->base.base.size;
+		stats->resident += bo->resident_size;
+		if (bo->base.madv > 0)
+			stats->purgeable += bo->resident_size;
+		if (bo->base.base.dma_buf)
+			stats->shared += bo->base.base.size;
+	}
+	spin_unlock(&mmu->mm_lock);
+}
+
 #define NUM_FAULT_PAGES (SZ_2M / PAGE_SIZE)
 
 static int panfrost_mmu_map_fault_addr(struct panfrost_device *pfdev, int as,
diff --git a/drivers/gpu/drm/panfrost/panfrost_mmu.h b/drivers/gpu/drm/panfrost/panfrost_mmu.h
index cc2a0d307feb..bbffd39deaf3 100644
--- a/drivers/gpu/drm/panfrost/panfrost_mmu.h
+++ b/drivers/gpu/drm/panfrost/panfrost_mmu.h
@@ -8,6 +8,13 @@ struct panfrost_gem_mapping;
 struct panfrost_file_priv;
 struct panfrost_mmu;
 
+struct panfrost_mmu_stats {
+	u64 all;
+	u64 resident;
+	u64 purgeable;
+	u64 shared;
+};
+
 int panfrost_mmu_map(struct panfrost_gem_mapping *mapping);
 void panfrost_mmu_unmap(struct panfrost_gem_mapping *mapping);
 
@@ -22,4 +29,7 @@ struct panfrost_mmu *panfrost_mmu_ctx_get(struct panfrost_mmu *mmu);
 void panfrost_mmu_ctx_put(struct panfrost_mmu *mmu);
 struct panfrost_mmu *panfrost_mmu_ctx_create(struct panfrost_device *pfdev);
 
+void panfrost_mmu_get_stats(struct panfrost_mmu *mmu,
+			    struct panfrost_mmu_stats *stats);
+
 #endif
-- 
2.38.1