drm: Add fdinfo memory stats

Add support to dump GEM stats to fdinfo.

v2: Fix typos, change size units to match docs, use div_u64
v3: Do it in core
v4: more kerneldoc
v5: doc fixes
v6: Actually use u64, bit more comment docs

Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Acked-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230524155956.382440-6-robdclark@gmail.com

1 files changed, 98 insertions, 1 deletions

diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
index 37b4f76a5191..883d83bc0e3d 100644
--- a/drivers/gpu/drm/drm_file.c
+++ b/drivers/gpu/drm/drm_file.c
@@ -42,6 +42,7 @@
 #include <drm/drm_client.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_file.h>
+#include <drm/drm_gem.h>
 #include <drm/drm_print.h>
 
 #include "drm_crtc_internal.h"
@@ -871,9 +872,105 @@ void drm_send_event(struct drm_device *dev, struct drm_pending_event *e)
 }
 EXPORT_SYMBOL(drm_send_event);
 
+static void print_size(struct drm_printer *p, const char *stat,
+		       const char *region, u64 sz)
+{
+	const char *units[] = {"", " KiB", " MiB"};
+	unsigned u;
+
+	for (u = 0; u < ARRAY_SIZE(units) - 1; u++) {
+		if (sz < SZ_1K)
+			break;
+		sz = div_u64(sz, SZ_1K);
+	}
+
+	drm_printf(p, "drm-%s-%s:\t%llu%s\n", stat, region, sz, units[u]);
+}
+
+/**
+ * drm_print_memory_stats - A helper to print memory stats
+ * @p: The printer to print output to
+ * @stats: The collected memory stats
+ * @supported_status: Bitmask of optional stats which are available
+ * @region: The memory region
+ *
+ */
+void drm_print_memory_stats(struct drm_printer *p,
+			    const struct drm_memory_stats *stats,
+			    enum drm_gem_object_status supported_status,
+			    const char *region)
+{
+	print_size(p, "total", region, stats->private + stats->shared);
+	print_size(p, "shared", region, stats->shared);
+	print_size(p, "active", region, stats->active);
+
+	if (supported_status & DRM_GEM_OBJECT_RESIDENT)
+		print_size(p, "resident", region, stats->resident);
+
+	if (supported_status & DRM_GEM_OBJECT_PURGEABLE)
+		print_size(p, "purgeable", region, stats->purgeable);
+}
+EXPORT_SYMBOL(drm_print_memory_stats);
+
+/**
+ * drm_show_memory_stats - Helper to collect and show standard fdinfo memory stats
+ * @p: the printer to print output to
+ * @file: the DRM file
+ *
+ * Helper to iterate over GEM objects with a handle allocated in the specified
+ * file.
+ */
+void drm_show_memory_stats(struct drm_printer *p, struct drm_file *file)
+{
+	struct drm_gem_object *obj;
+	struct drm_memory_stats status = {};
+	enum drm_gem_object_status supported_status;
+	int id;
+
+	spin_lock(&file->table_lock);
+	idr_for_each_entry (&file->object_idr, obj, id) {
+		enum drm_gem_object_status s = 0;
+
+		if (obj->funcs && obj->funcs->status) {
+			s = obj->funcs->status(obj);
+			supported_status = DRM_GEM_OBJECT_RESIDENT |
+					DRM_GEM_OBJECT_PURGEABLE;
+		}
+
+		if (obj->handle_count > 1) {
+			status.shared += obj->size;
+		} else {
+			status.private += obj->size;
+		}
+
+		if (s & DRM_GEM_OBJECT_RESIDENT) {
+			status.resident += obj->size;
+		} else {
+			/* If already purged or not yet backed by pages, don't
+			 * count it as purgeable:
+			 */
+			s &= ~DRM_GEM_OBJECT_PURGEABLE;
+		}
+
+		if (!dma_resv_test_signaled(obj->resv, dma_resv_usage_rw(true))) {
+			status.active += obj->size;
+
+			/* If still active, don't count as purgeable: */
+			s &= ~DRM_GEM_OBJECT_PURGEABLE;
+		}
+
+		if (s & DRM_GEM_OBJECT_PURGEABLE)
+			status.purgeable += obj->size;
+	}
+	spin_unlock(&file->table_lock);
+
+	drm_print_memory_stats(p, &status, supported_status, "memory");
+}
+EXPORT_SYMBOL(drm_show_memory_stats);
+
 /**
  * drm_show_fdinfo - helper for drm file fops
- * @seq_file: output stream
+ * @m: output stream
  * @f: the device file instance
  *
  * Helper to implement fdinfo, for userspace to query usage stats, etc, of a