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>
diff --git a/arch/x86/kernel/bios_uv.c b/arch/x86/kernel/bios_uv.c
new file mode 100644
index 0000000..c639bd5
--- /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);