1 files changed, 66 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/i915_ptr_util.h b/drivers/gpu/drm/i915/i915_ptr_util.h
new file mode 100644
index 000000000000..9f8931d7d99b
--- /dev/null
+++ b/drivers/gpu/drm/i915/i915_ptr_util.h
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: MIT */
+/* Copyright © 2025 Intel Corporation */
+
+#ifndef __I915_PTR_UTIL_H__
+#define __I915_PTR_UTIL_H__
+
+#include <linux/types.h>
+
+#define ptr_mask_bits(ptr, n) ({					\
+	unsigned long __v = (unsigned long)(ptr);			\
+	(typeof(ptr))(__v & -BIT(n));					\
+})
+
+#define ptr_unmask_bits(ptr, n) ((unsigned long)(ptr) & (BIT(n) - 1))
+
+#define ptr_unpack_bits(ptr, bits, n) ({				\
+	unsigned long __v = (unsigned long)(ptr);			\
+	*(bits) = __v & (BIT(n) - 1);					\
+	(typeof(ptr))(__v & -BIT(n));					\
+})
+
+#define ptr_pack_bits(ptr, bits, n) ({					\
+	unsigned long __bits = (bits);					\
+	GEM_BUG_ON(__bits & -BIT(n));					\
+	((typeof(ptr))((unsigned long)(ptr) | __bits));			\
+})
+
+#define ptr_dec(ptr) ({							\
+	unsigned long __v = (unsigned long)(ptr);			\
+	(typeof(ptr))(__v - 1);						\
+})
+
+#define ptr_inc(ptr) ({							\
+	unsigned long __v = (unsigned long)(ptr);			\
+	(typeof(ptr))(__v + 1);						\
+})
+
+#define page_mask_bits(ptr) ptr_mask_bits(ptr, PAGE_SHIFT)
+#define page_unmask_bits(ptr) ptr_unmask_bits(ptr, PAGE_SHIFT)
+#define page_pack_bits(ptr, bits) ptr_pack_bits(ptr, bits, PAGE_SHIFT)
+#define page_unpack_bits(ptr, bits) ptr_unpack_bits(ptr, bits, PAGE_SHIFT)
+
+static __always_inline ptrdiff_t ptrdiff(const void *a, const void *b)
+{
+	return a - b;
+}
+
+#define u64_to_ptr(T, x) ({						\
+	typecheck(u64, x);						\
+	(T *)(uintptr_t)(x);						\
+})
+
+/*
+ * container_of_user: Extract the superclass from a pointer to a member.
+ *
+ * Exactly like container_of() with the exception that it plays nicely
+ * with sparse for __user @ptr.
+ */
+#define container_of_user(ptr, type, member) ({				\
+	void __user *__mptr = (void __user *)(ptr);			\
+	BUILD_BUG_ON_MSG(!__same_type(*(ptr), typeof_member(type, member)) && \
+			 !__same_type(*(ptr), void),			\
+			 "pointer type mismatch in container_of()");	\
+	((type __user *)(__mptr - offsetof(type, member))); })
+
+#endif /* __I915_PTR_UTIL_H__ */