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authorHauke Mehrtens <hauke@hauke-m.de>2012-10-03 11:34:16 +0000
committerJohn Crispin <blogic@openwrt.org>2012-11-09 11:37:17 +0100
commitd3dce3d676373b1519546721ee5f3a8c613f40f5 (patch)
tree07eae00399f41cbc19c6e18177d86ab04c2ee647
parentb5b64f2ba434cd2082a89aecec4b4c1eaec742c0 (diff)
MIPS: BCM47XX: ignore last memory page
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. Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de> Patchwork: http://patchwork.linux-mips.org/patch/4365 Signed-off-by: John Crispin <blogic@openwrt.org>
-rw-r--r--arch/mips/bcm47xx/prom.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/mips/bcm47xx/prom.c b/arch/mips/bcm47xx/prom.c
index f6e9063cc4c2..22258a4c652b 100644
--- a/arch/mips/bcm47xx/prom.c
+++ b/arch/mips/bcm47xx/prom.c
@@ -27,6 +27,7 @@
#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 +128,7 @@ static __init void prom_init_mem(void)
{
unsigned long mem;
unsigned long max;
+ struct cpuinfo_mips *c = &current_cpu_data;
/* Figure out memory size by finding aliases.
*
@@ -155,6 +157,14 @@ static __init void prom_init_mem(void)
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);
}