aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/brcm47xx/patches-2.6.35/011-MIPS-BCM47xx-Really-fix-128MB-RAM-problem.patch
diff options
context:
space:
mode:
Diffstat (limited to 'target/linux/brcm47xx/patches-2.6.35/011-MIPS-BCM47xx-Really-fix-128MB-RAM-problem.patch')
-rw-r--r--target/linux/brcm47xx/patches-2.6.35/011-MIPS-BCM47xx-Really-fix-128MB-RAM-problem.patch66
1 files changed, 66 insertions, 0 deletions
diff --git a/target/linux/brcm47xx/patches-2.6.35/011-MIPS-BCM47xx-Really-fix-128MB-RAM-problem.patch b/target/linux/brcm47xx/patches-2.6.35/011-MIPS-BCM47xx-Really-fix-128MB-RAM-problem.patch
new file mode 100644
index 0000000000..0030a7da4f
--- /dev/null
+++ b/target/linux/brcm47xx/patches-2.6.35/011-MIPS-BCM47xx-Really-fix-128MB-RAM-problem.patch
@@ -0,0 +1,66 @@
+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(-)
+
+--- 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);
+ }
+