Add the minimalist elan-mmcr device driver.

This driver allows a userland program to mmap the MMCR of the AMD
Elan sc520 CPU.

3 files changed, 87 insertions, 0 deletions

diff --git a/sys/conf/files.i386 b/sys/conf/files.i386
index 883e084..b2feccd 100644
--- a/sys/conf/files.i386
+++ b/sys/conf/files.i386
@@ -192,6 +192,7 @@ i386/i386/db_disasm.c		optional	ddb
 i386/i386/db_interface.c	optional	ddb
 i386/i386/db_trace.c		optional	ddb
 i386/i386/dump_machdep.c	standard
+i366/i386/elan-mmcr.c		optional	elan-mmcr
 i386/i386/elf_machdep.c		standard
 i386/i386/exception.s		standard
 i386/i386/i386-gdbstub.c	optional	ddb
diff --git a/sys/i386/conf/NOTES b/sys/i386/conf/NOTES
index d74576b..ad6e6ec 100644
--- a/sys/i386/conf/NOTES
+++ b/sys/i386/conf/NOTES
@@ -183,6 +183,10 @@ options 	GPL_MATH_EMULATE	#Support for x87 emulation via
 #
 options 	PERFMON
 
+#
+# Stuff specific to the AMD Elan Sc520 cpu.
+device 		elan-mmcr		# Support mapping MMCR in userland.
+
 
 #####################################################################
 # NETWORKING OPTIONS
diff --git a/sys/i386/i386/elan-mmcr.c b/sys/i386/i386/elan-mmcr.c
new file mode 100644
index 0000000..28e8769
--- /dev/null
+++ b/sys/i386/i386/elan-mmcr.c
@@ -0,0 +1,82 @@
+/*
+ * ----------------------------------------------------------------------------
+ * "THE BEER-WARE LICENSE" (Revision 42):
+ * <phk@FreeBSD.org> wrote this file.  As long as you retain this notice you
+ * can do whatever you want with this stuff. If we meet some day, and you think
+ * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
+ * ----------------------------------------------------------------------------
+ *
+ * $FreeBSD$
+ *
+ */
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/conf.h>
+
+#include <machine/md_var.h>
+
+/*
+ * Device driver initialization stuff
+ */
+
+static d_open_t	elan_open;
+static d_close_t elan_close;
+static d_ioctl_t elan_ioctl;
+static d_mmap_t elan_mmap;
+
+#define CDEV_MAJOR 100			/* Share with xrpu */
+static struct cdevsw elan_cdevsw = {
+	/* open */	elan_open,
+	/* close */	elan_close,
+	/* read */	noread,
+	/* write */	nowrite,
+	/* ioctl */	elan_ioctl,
+	/* poll */	nopoll,
+	/* mmap */	elan_mmap,
+	/* strategy */	nostrategy,
+	/* name */	"elan",
+	/* maj */	CDEV_MAJOR,
+	/* dump */	nodump,
+	/* psize */	nopsize,
+	/* flags */	0,
+};
+
+static int
+elan_open(dev_t dev, int flag, int mode, struct  thread *td)
+{
+	return (0);
+}
+
+static int
+elan_close(dev_t dev, int flag, int mode, struct  thread *td)
+{ 
+	return (0);
+}
+
+static int
+elan_mmap(dev_t dev, vm_offset_t offset, int nprot)
+{
+	if (offset >= 0x1000) 
+		return (-1);
+	return (i386_btop(0xfffef000));
+}
+
+static int
+elan_ioctl(dev_t dev, u_long cmd, caddr_t arg, int flag, struct  thread *tdr)
+{
+	return(ENOENT);
+}
+
+static void
+elan_drvinit(void)
+{
+
+	if (elan_mmcr == NULL)
+		return;
+	make_dev(&elan_cdevsw, 0, UID_ROOT, GID_WHEEL, 0600, "elan-mmcr");
+	return;
+}
+
+ 
+SYSINIT(elan, SI_SUB_DRIVERS, SI_ORDER_MIDDLE+CDEV_MAJOR,elan_drvinit,NULL);