From d3c80736fed8293ed8dd3e2ced1f2652915e76dc Mon Sep 17 00:00:00 2001
From: rpaulo <rpaulo@FreeBSD.org>
Date: Fri, 24 Oct 2014 21:08:36 +0000
Subject: [PATCH] Add a sysctl to control the HPET allow_write behaviour.

Requested by:	kib
---
 sys/dev/acpica/acpi_hpet.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/sys/dev/acpica/acpi_hpet.c b/sys/dev/acpica/acpi_hpet.c
index 6cee063f9ce3..6b35f5c4f3d1 100644
--- a/sys/dev/acpica/acpi_hpet.c
+++ b/sys/dev/acpica/acpi_hpet.c
@@ -760,6 +760,11 @@ hpet_attach(device_t dev)
 		    OID_AUTO, "mmap_allow",
 		    CTLFLAG_RW, &sc->mmap_allow, 0,
 		    "Allow userland to memory map HPET");
+		SYSCTL_ADD_INT(device_get_sysctl_ctx(dev),
+		    SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
+		    OID_AUTO, "mmap_allow_write",
+		    CTLFLAG_RW, &sc->mmap_allow_write, 0,
+		    "Allow userland write to the HPET register space");
 	} else
 		device_printf(dev, "could not create /dev/hpet%d\n",
 		    device_get_unit(dev));