diff --git a/sys/compat/linuxkpi/common/include/linux/slab.h b/sys/compat/linuxkpi/common/include/linux/slab.h
--- a/sys/compat/linuxkpi/common/include/linux/slab.h
+++ b/sys/compat/linuxkpi/common/include/linux/slab.h
@@ -86,18 +86,8 @@
 #define	ARCH_KMALLOC_MINALIGN \
 	__alignof(unsigned long long)
 
-/*
- * Critical section-friendly version of kfree().
- * Requires knowledge of the allocation size at build time.
- */
-#define kfree_async(ptr)	do {					\
-	_Static_assert(sizeof(*(ptr)) >= sizeof(struct llist_node),	\
-	    "Size of object to free is unknown or too small");		\
-	if (curthread->td_critnest != 0)				\
-		linux_kfree_async(ptr);					\
-	else								\
-		kfree(ptr);						\
-} while (0)
+/* drm-kmod 5.4 compat */
+#define kfree_async(ptr)	kfree(ptr);
 
 static inline gfp_t
 linux_check_m_flags(gfp_t flags)
@@ -117,7 +107,8 @@
 static inline void *
 kmalloc(size_t size, gfp_t flags)
 {
-	return (malloc(size, M_KMALLOC, linux_check_m_flags(flags)));
+	return (malloc(MAX(size, sizeof(struct llist_node)), M_KMALLOC,
+	    linux_check_m_flags(flags)));
 }
 
 static inline void *
@@ -186,10 +177,15 @@
 	return (realloc(ptr, size, M_KMALLOC, linux_check_m_flags(flags)));
 }
 
+extern void linux_kfree_async(void *);
+
 static inline void
 kfree(const void *ptr)
 {
-	free(__DECONST(void *, ptr), M_KMALLOC);
+	if (curthread->td_critnest != 0)
+		linux_kfree_async(__DECONST(void *, ptr));
+	else
+		free(__DECONST(void *, ptr), M_KMALLOC);
 }
 
 static __inline void
@@ -210,6 +206,5 @@
 extern void *lkpi_kmem_cache_zalloc(struct linux_kmem_cache *, gfp_t);
 extern void lkpi_kmem_cache_free(struct linux_kmem_cache *, void *);
 extern void linux_kmem_cache_destroy(struct linux_kmem_cache *);
-void linux_kfree_async(void *);
 
 #endif					/* _LINUX_SLAB_H_ */