From 64fc74f5f6055e8470208a7d9cfc8d3994fff34d Mon Sep 17 00:00:00 2001
From: Wu Zhangjin <wuzhangjin@gmail.com>
Date: Sat, 10 Apr 2010 20:07:13 +0800
Subject: MIPS: Loongson 2F: Fix of problems introduced by
-mfix-loongson2f-jump
The -mfix-loongson2f-jump option provided by latest CVS binutils have fixed
the out-of-order issue of Loongson-2F described in chapter 15 of the
Loongson2F User Manual [1, 2], but introduced some problems.
The option changes all of the jump target to "addr & 0xcfffffff" through the
at($1) register, but for the reboot address of Loongson 2F 0xbfc00000 this is
wrong. Avoids the problem via telling the assembler to not use the $at
register.
[1] Loongson2F User Manual (Chinese Version)
http://www.loongson.cn/uploadfile/file/200808211
[2] English Version of Chapter 15:
http://groups.google.com.hk/group/loongson-dev/msg/e0d2e220958f10a6?dmode=source
Reported-and-tested-by: Liu Shiwei <liushiwei@gmail.com>
Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: linux-mips <linux-mips@linux-mips.org>
Patchwork: http://patchwork.linux-mips.org/patch/1109/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
---
arch/mips/loongson/common/reset.c | 20 +++++++++++++++++++-
1 file changed, 19 insertions(+), 1 deletion(-)
(limited to 'arch')
diff --git a/arch/mips/loongson/common/reset.c b/arch/mips/loongson/common/reset.c
index 4bd9c18b07a5..9e10d6225d9b 100644
--- a/arch/mips/loongson/common/reset.c
+++ b/arch/mips/loongson/common/reset.c
@@ -16,13 +16,31 @@
#include <loongson.h>
+static inline void loongson_reboot(void)
+{
+#ifndef CONFIG_CPU_JUMP_WORKAROUNDS
+ ((void (*)(void))ioremap_nocache(LOONGSON_BOOT_BASE, 4)) ();
+#else
+ void (*func)(void);
+
+ func = (void *)ioremap_nocache(LOONGSON_BOOT_BASE, 4);
+
+ __asm__ __volatile__(
+ " .set noat \n"
+ " jr %[func] \n"
+ " .set at \n"
+ : /* No outputs */
+ : [func] "r" (func));
+#endif
+}
+
static void loongson_restart(char *command)
{
/* do preparation for reboot */
mach_prepare_reboot();
/* reboot via jumping to boot base address */
- ((void (*)(void))ioremap_nocache(LOONGSON_BOOT_BASE, 4)) ();
+ loongson_reboot();
}
static void loongson_poweroff(void)
--
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