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-rw-r--r--arch/mips/bcm47xx/prom.c20
1 files changed, 16 insertions, 4 deletions
diff --git a/arch/mips/bcm47xx/prom.c b/arch/mips/bcm47xx/prom.c
index f6e9063..8c155af 100644
--- a/arch/mips/bcm47xx/prom.c
+++ b/arch/mips/bcm47xx/prom.c
@@ -1,6 +1,7 @@
/*
* Copyright (C) 2004 Florian Schirmer <jolt@tuxbox.org>
* Copyright (C) 2007 Aurelien Jarno <aurelien@aurel32.net>
+ * Copyright (C) 2010-2012 Hauke Mehrtens <hauke@hauke-m.de>
*
* 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
@@ -27,6 +28,7 @@
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/spinlock.h>
+#include <linux/smp.h>
#include <asm/bootinfo.h>
#include <asm/fw/cfe/cfe_api.h>
#include <asm/fw/cfe/cfe_error.h>
@@ -127,6 +129,8 @@ static __init void prom_init_mem(void)
{
unsigned long mem;
unsigned long max;
+ unsigned long off;
+ struct cpuinfo_mips *c = &current_cpu_data;
/* Figure out memory size by finding aliases.
*
@@ -143,18 +147,26 @@ static __init void prom_init_mem(void)
* max contains the biggest possible address supported by the platform.
* If the method wants to try something above we assume 128MB ram.
*/
- max = ((unsigned long)(prom_init) | ((128 << 20) - 1));
+ off = (unsigned long)prom_init;
+ max = off | ((128 << 20) - 1);
for (mem = (1 << 20); mem < (128 << 20); mem += (1 << 20)) {
- if (((unsigned long)(prom_init) + mem) > max) {
+ if ((off + mem) > max) {
mem = (128 << 20);
printk(KERN_DEBUG "assume 128MB RAM\n");
break;
}
- if (*(unsigned long *)((unsigned long)(prom_init) + mem) ==
- *(unsigned long *)(prom_init))
+ if (!memcmp(prom_init, prom_init + mem, 32))
break;
}
+ /* Ignoring the last page when ddr size is 128M. Cached
+ * accesses to last page is causing the processor to prefetch
+ * using address above 128M stepping out of the ddr address
+ * space.
+ */
+ if (c->cputype == CPU_74K && (mem == (128 << 20)))
+ mem -= 0x1000;
+
add_memory_region(0, mem, BOOT_MEM_RAM);
}
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