[PATCH v2 4/6] drm/vram: add vram-mm debugfs file

[Gerd Hoffmann]

Wire up drm_mm_print() for vram helpers, using a new
debugfs file, so one can see how vram is used:

   # cat /sys/kernel/debug/dri/0/vram-mm
   0x0000000000000000-0x0000000000000300: 768: used
   0x0000000000000300-0x0000000000000600: 768: used
   0x0000000000000600-0x0000000000000900: 768: used
   0x0000000000000900-0x0000000000000c00: 768: used
   0x0000000000000c00-0x0000000000004000: 13312: free
   total: 16384, used 3072 free 13312

Signed-off-by: Gerd Hoffmann <kraxel@xxxxxxxxxx>
Acked-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
---
 include/drm/drm_gem_vram_helper.h    |  1 +
 include/drm/drm_vram_mm_helper.h     |  1 +
 drivers/gpu/drm/drm_vram_mm_helper.c | 44 ++++++++++++++++++++++++++++
 3 files changed, 46 insertions(+)

diff --git a/include/drm/drm_gem_vram_helper.h b/include/drm/drm_gem_vram_helper.h
index ac217d768456..91c6934138f2 100644
--- a/include/drm/drm_gem_vram_helper.h
+++ b/include/drm/drm_gem_vram_helper.h
@@ -122,6 +122,7 @@ int drm_gem_vram_driver_dumb_mmap_offset(struct drm_file *file,
  * &struct drm_driver with default functions.
  */
 #define DRM_GEM_VRAM_DRIVER \
+	.debugfs_init             = drm_vram_mm_debugfs_init, \
 	.dumb_create		  = drm_gem_vram_driver_dumb_create, \
 	.dumb_map_offset	  = drm_gem_vram_driver_dumb_mmap_offset, \
 	.gem_prime_mmap		  = drm_gem_prime_mmap
diff --git a/include/drm/drm_vram_mm_helper.h b/include/drm/drm_vram_mm_helper.h
index 2aacfb1ccfae..9e0ac9aaac7d 100644
--- a/include/drm/drm_vram_mm_helper.h
+++ b/include/drm/drm_vram_mm_helper.h
@@ -60,6 +60,7 @@ static inline struct drm_vram_mm *drm_vram_mm_of_bdev(
 	return container_of(bdev, struct drm_vram_mm, bdev);
 }
 
+int drm_vram_mm_debugfs_init(struct drm_minor *minor);
 int drm_vram_mm_init(struct drm_vram_mm *vmm, struct drm_device *dev,
 		     uint64_t vram_base, size_t vram_size,
 		     const struct drm_vram_mm_funcs *funcs);
diff --git a/drivers/gpu/drm/drm_vram_mm_helper.c b/drivers/gpu/drm/drm_vram_mm_helper.c
index c911781d6728..3c2f0cbcad5b 100644
--- a/drivers/gpu/drm/drm_vram_mm_helper.c
+++ b/drivers/gpu/drm/drm_vram_mm_helper.c
@@ -1,7 +1,9 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 
+#include <drm/drm_debugfs.h>
 #include <drm/drm_device.h>
 #include <drm/drm_file.h>
+#include <drm/drm_gem_ttm_helper.h>
 #include <drm/drm_vram_mm_helper.h>
 
 #include <drm/ttm/ttm_page_alloc.h>
@@ -148,6 +150,48 @@ static struct ttm_bo_driver bo_driver = {
  * struct drm_vram_mm
  */
 
+#if defined(CONFIG_DEBUG_FS)
+static int drm_vram_mm_debugfs(struct seq_file *m, void *data)
+{
+	struct drm_info_node *node = (struct drm_info_node *) m->private;
+	struct drm_vram_mm *vmm = node->minor->dev->vram_mm;
+	struct drm_mm *mm = vmm->bdev.man[TTM_PL_VRAM].priv;
+	struct ttm_bo_global *glob = vmm->bdev.glob;
+	struct drm_printer p = drm_seq_file_printer(m);
+
+	spin_lock(&glob->lru_lock);
+	drm_mm_print(mm, &p);
+	spin_unlock(&glob->lru_lock);
+	return 0;
+}
+
+static const struct drm_info_list drm_vram_mm_debugfs_list[] = {
+	{ "vram-mm", drm_vram_mm_debugfs, 0, NULL },
+};
+#endif
+
+/**
+ * drm_vram_mm_debugfs_init() - Register VRAM MM debugfs file.
+ *
+ * @minor: drm minor device.
+ *
+ * Returns:
+ * 0 on success, or
+ * a negative error code otherwise.
+ */
+int drm_vram_mm_debugfs_init(struct drm_minor *minor)
+{
+	int ret = 0;
+
+#if defined(CONFIG_DEBUG_FS)
+	ret = drm_debugfs_create_files(drm_vram_mm_debugfs_list,
+				       ARRAY_SIZE(drm_vram_mm_debugfs_list),
+				       minor->debugfs_root, minor);
+#endif
+	return ret;
+}
+EXPORT_SYMBOL(drm_vram_mm_debugfs_init);
+
 /**
  * drm_vram_mm_init() - Initialize an instance of VRAM MM.
  * @vmm:	the VRAM MM instance to initialize
-- 
2.18.1