x86 BIOS interface for RTC on SGI UV

Real-time code needs to know the number of cycles per second
on SGI UV.  The information is provided via a run time BIOS
call.  This patch provides the linux side of that interface.
This is the first of several run time BIOS calls to be defined
in uv/bios.h and bios_uv.c.

Note that BIOS_CALL() is just a stub for now.  The bios
side is being worked on.

Signed-off-by: Russ Anderson <rja@sgi.com>
Cc: Jack Steiner <steiner@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 48 insertions, 0 deletions

diff --git a/arch/x86/kernel/bios_uv.c b/arch/x86/kernel/bios_uv.c
new file mode 100644
index 00000000000..c639bd55391
--- /dev/null
+++ b/arch/x86/kernel/bios_uv.c
@@ -0,0 +1,48 @@
+/*
+ * BIOS run time interface routines.
+ *
+ *  Copyright (c) 2008 Silicon Graphics, Inc.  All Rights Reserved.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+ */
+
+#include <asm/uv/bios.h>
+
+const char *
+x86_bios_strerror(long status)
+{
+	const char *str;
+	switch (status) {
+	case  0: str = "Call completed without error"; break;
+	case -1: str = "Not implemented"; break;
+	case -2: str = "Invalid argument"; break;
+	case -3: str = "Call completed with error"; break;
+	default: str = "Unknown BIOS status code"; break;
+	}
+	return str;
+}
+
+long
+x86_bios_freq_base(unsigned long which, unsigned long *ticks_per_second,
+		   unsigned long *drift_info)
+{
+	struct uv_bios_retval isrv;
+
+	BIOS_CALL(isrv, BIOS_FREQ_BASE, which, 0, 0, 0, 0, 0, 0);
+	*ticks_per_second = isrv.v0;
+	*drift_info = isrv.v1;
+	return isrv.status;
+}
+EXPORT_SYMBOL_GPL(x86_bios_freq_base);