ppc/powerpc: workarounds for old Open Firmware versions

This adds code to work around some problems with old versions of
Open Firmware, such as on the early powermacs (7500 etc.) and the
"Longtrail" CHRP machine.  On these machines we have to claim
the physical and virtual address ranges explicitly when claiming
memory and then set up a V->P mapping.

The Longtrail has more problems: setprop doesn't work, and we have
to set an "allow-reclaim" variable to 0 in order to get claim on
physical memory ranges to fail if the memory is already claimed.

Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 74 insertions, 0 deletions

diff --git a/arch/ppc/boot/of1275/call_prom.c b/arch/ppc/boot/of1275/call_prom.c
new file mode 100644
index 000000000000..9479a3a2b8c7
--- /dev/null
+++ b/arch/ppc/boot/of1275/call_prom.c
@@ -0,0 +1,74 @@
+/*
+ * Copyright (C) 1996-2005 Paul Mackerras.
+ *
+ * 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.
+ */
+
+#include "of1275.h"
+#include <stdarg.h>
+
+int call_prom(const char *service, int nargs, int nret, ...)
+{
+	int i;
+	struct prom_args {
+		const char *service;
+		int nargs;
+		int nret;
+		unsigned int args[12];
+	} args;
+	va_list list;
+
+	args.service = service;
+	args.nargs = nargs;
+	args.nret = nret;
+
+	va_start(list, nret);
+	for (i = 0; i < nargs; i++)
+		args.args[i] = va_arg(list, unsigned int);
+	va_end(list);
+
+	for (i = 0; i < nret; i++)
+		args.args[nargs+i] = 0;
+
+	if (of_prom_entry(&args) < 0)
+		return -1;
+
+	return (nret > 0)? args.args[nargs]: 0;
+}
+
+int call_prom_ret(const char *service, int nargs, int nret,
+		  unsigned int *rets, ...)
+{
+	int i;
+	struct prom_args {
+		const char *service;
+		int nargs;
+		int nret;
+		unsigned int args[12];
+	} args;
+	va_list list;
+
+	args.service = service;
+	args.nargs = nargs;
+	args.nret = nret;
+
+	va_start(list, rets);
+	for (i = 0; i < nargs; i++)
+		args.args[i] = va_arg(list, unsigned int);
+	va_end(list);
+
+	for (i = 0; i < nret; i++)
+		args.args[nargs+i] = 0;
+
+	if (of_prom_entry(&args) < 0)
+		return -1;
+
+	if (rets != (void *) 0)
+		for (i = 1; i < nret; ++i)
+			rets[i-1] = args.args[nargs+i];
+
+	return (nret > 0)? args.args[nargs]: 0;
+}