From 70b97048a051958be37b650b8a67c89203fd6b70 Mon Sep 17 00:00:00 2001
From: "Bjoern A. Zeeb" <bz@FreeBSD.org>
Date: Sat, 28 Jan 2023 16:00:55 +0000
Subject: [PATCH] LinuxKPI: mm.h: implement virt_to_head_page()

Implement virt_to_head_page().

Sponsored by:	The FreeBSD Foundation
MFC after:	3 days
Reviewed by:	markj
Differential Revision: https://reviews.freebsd.org/D38240
---
 sys/compat/linuxkpi/common/include/linux/mm.h | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/sys/compat/linuxkpi/common/include/linux/mm.h b/sys/compat/linuxkpi/common/include/linux/mm.h
index 40f63c2cffd..2dcf32cbe84 100644
--- a/sys/compat/linuxkpi/common/include/linux/mm.h
+++ b/sys/compat/linuxkpi/common/include/linux/mm.h
@@ -41,6 +41,7 @@
 #include <linux/list.h>
 #include <linux/mmap_lock.h>
 #include <linux/shrinker.h>
+#include <linux/page.h>
 
 #include <asm/pgtable.h>
 
@@ -151,6 +152,13 @@ struct sysinfo {
 	uint32_t mem_unit;	/* Memory unit size in bytes */
 };
 
+static inline struct page *
+virt_to_head_page(const void *p)
+{
+
+	return (virt_to_page(p));
+}
+
 /*
  * Compute log2 of the power of two rounded up count of pages
  * needed for size bytes.