You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
67 lines
2.4 KiB
67 lines
2.4 KiB
15 years ago
|
From b6d850fe4035d6bee7199119358e06f802aa19ed Mon Sep 17 00:00:00 2001
|
||
|
|
From: Hauke Mehrtens <hauke@hauke-m.de>
|
||
|
|
Date: Sun, 18 Jul 2010 12:49:41 +0200
|
||
|
|
Subject: [PATCH 1/5] MIPS: BCM47xx: Really fix 128MB RAM problem
|
||
|
|
|
||
|
|
The previews patch 84a6fcb368a080620d12fc4d79e07902dbee7335 was wrong,
|
||
|
|
I got wrong success reports.
|
||
|
|
|
||
|
|
The bcm47xx architecture maps the ram into a 128MB address space. It
|
||
|
|
will be paced there as often as goes into the 128MB. The detection
|
||
|
|
tries to find the position where the same memory is found. When reading
|
||
|
|
over 128MB the processor will throw an exception. If 128MB ram is
|
||
|
|
installed, it will not find the same memory because it tries to read
|
||
|
|
over the 128MB boarder. Now it just assumes 128MB installed ram if it
|
||
|
|
can not find that the ram is repeating.
|
||
|
|
|
||
|
|
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
|
||
|
|
---
|
||
|
|
arch/mips/bcm47xx/prom.c | 22 ++++++++++++++--------
|
||
|
|
1 files changed, 14 insertions(+), 8 deletions(-)
|
||
|
|
|
||
|
15 years ago
|
--- a/arch/mips/bcm47xx/prom.c
|
||
|
|
+++ b/arch/mips/bcm47xx/prom.c
|
||
|
|
@@ -126,6 +126,7 @@ static __init void prom_init_cmdline(voi
|
||
|
|
static __init void prom_init_mem(void)
|
||
|
|
{
|
||
|
|
unsigned long mem;
|
||
|
|
+ unsigned long max;
|
||
|
|
|
||
|
|
/* Figure out memory size by finding aliases.
|
||
|
|
*
|
||
|
|
@@ -134,21 +135,26 @@ static __init void prom_init_mem(void)
|
||
|
|
* want to reuse the memory used by CFE (around 4MB). That means cfe_*
|
||
|
|
* functions stop to work at some point during the boot, we should only
|
||
|
|
* call them at the beginning of the boot.
|
||
|
|
+ *
|
||
|
|
+ * BCM47XX uses 128MB for addressing the ram, if the system contains
|
||
|
|
+ * less that that amount of ram it remaps the ram more often into the
|
||
|
|
+ * available space.
|
||
|
|
+ * Accessing memory after 128MB will cause an exception.
|
||
|
|
+ * 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));
|
||
|
|
for (mem = (1 << 20); mem < (128 << 20); mem += (1 << 20)) {
|
||
|
|
+ if (((unsigned long)(prom_init) + mem) > max) {
|
||
|
|
+ mem = (128 << 20);
|
||
|
|
+ printk("assume 128MB RAM\n");
|
||
|
|
+ break;
|
||
|
|
+ }
|
||
|
|
if (*(unsigned long *)((unsigned long)(prom_init) + mem) ==
|
||
|
|
*(unsigned long *)(prom_init))
|
||
|
|
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 (mem == 0x8000000)
|
||
|
|
- mem -= 0x1000;
|
||
|
|
-
|
||
|
|
add_memory_region(0, mem, BOOT_MEM_RAM);
|
||
|
|
}
|
||
|
|
|