brcm47xx: prepare brcm47xx patches for sending to mainline.

SVN-Revision: 22296

1 files changed, 66 insertions, 0 deletions

diff --git a/target/linux/brcm47xx/patches-2.6.34/011-MIPS-BCM47xx-Really-fix-128MB-RAM-problem.patch b/target/linux/brcm47xx/patches-2.6.34/011-MIPS-BCM47xx-Really-fix-128MB-RAM-problem.patch
new file mode 100644
index 0000000000..0030a7da4f
--- /dev/null
+++ b/target/linux/brcm47xx/patches-2.6.34/011-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);
+ }
+