1 files changed, 102 insertions, 0 deletions
diff --git a/include/drm/drm_vram_mm_helper.h b/include/drm/drm_vram_mm_helper.h
new file mode 100644
index 000000000000..a8ffd8599b08
--- /dev/null
+++ b/include/drm/drm_vram_mm_helper.h
@@ -0,0 +1,102 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#ifndef DRM_VRAM_MM_HELPER_H
+#define DRM_VRAM_MM_HELPER_H
+
+#include <drm/ttm/ttm_bo_driver.h>
+
+struct drm_device;
+
+/**
+ * struct drm_vram_mm_funcs - Callback functions for &struct drm_vram_mm
+ * @evict_flags:	Provides an implementation for struct \
+	&ttm_bo_driver.evict_flags
+ * @verify_access:	Provides an implementation for \
+	struct &ttm_bo_driver.verify_access
+ *
+ * These callback function integrate VRAM MM with TTM buffer objects. New
+ * functions can be added if necessary.
+ */
+struct drm_vram_mm_funcs {
+	void (*evict_flags)(struct ttm_buffer_object *bo,
+			    struct ttm_placement *placement);
+	int (*verify_access)(struct ttm_buffer_object *bo, struct file *filp);
+};
+
+/**
+ * struct drm_vram_mm - An instance of VRAM MM
+ * @vram_base:	Base address of the managed video memory
+ * @vram_size:	Size of the managed video memory in bytes
+ * @bdev:	The TTM BO device.
+ * @funcs:	TTM BO functions
+ *
+ * The fields &struct drm_vram_mm.vram_base and
+ * &struct drm_vram_mm.vrm_size are managed by VRAM MM, but are
+ * available for public read access. Use the field
+ * &struct drm_vram_mm.bdev to access the TTM BO device.
+ */
+struct drm_vram_mm {
+	uint64_t vram_base;
+	size_t vram_size;
+
+	struct ttm_bo_device bdev;
+
+	const struct drm_vram_mm_funcs *funcs;
+};
+
+/**
+ * drm_vram_mm_of_bdev() - \
+	Returns the container of type &struct ttm_bo_device for field bdev.
+ * @bdev:	the TTM BO device
+ *
+ * Returns:
+ * The containing instance of &struct drm_vram_mm
+ */
+static inline struct drm_vram_mm *drm_vram_mm_of_bdev(
+	struct ttm_bo_device *bdev)
+{
+	return container_of(bdev, struct drm_vram_mm, bdev);
+}
+
+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);
+void drm_vram_mm_cleanup(struct drm_vram_mm *vmm);
+
+int drm_vram_mm_mmap(struct file *filp, struct vm_area_struct *vma,
+		     struct drm_vram_mm *vmm);
+
+/*
+ * Helpers for integration with struct drm_device
+ */
+
+struct drm_vram_mm *drm_vram_helper_alloc_mm(
+	struct drm_device *dev, uint64_t vram_base, size_t vram_size,
+	const struct drm_vram_mm_funcs *funcs);
+void drm_vram_helper_release_mm(struct drm_device *dev);
+
+/*
+ * Helpers for &struct file_operations
+ */
+
+int drm_vram_mm_file_operations_mmap(
+	struct file *filp, struct vm_area_struct *vma);
+
+/**
+ * define DRM_VRAM_MM_FILE_OPERATIONS - default callback functions for \
+	&struct file_operations
+ *
+ * Drivers that use VRAM MM can use this macro to initialize
+ * &struct file_operations with default functions.
+ */
+#define DRM_VRAM_MM_FILE_OPERATIONS \
+	.llseek		= no_llseek, \
+	.read		= drm_read, \
+	.poll		= drm_poll, \
+	.unlocked_ioctl = drm_ioctl, \
+	.compat_ioctl	= drm_compat_ioctl, \
+	.mmap		= drm_vram_mm_file_operations_mmap, \
+	.open		= drm_open, \
+	.release	= drm_release \
+
+#endif