From 2c2e1ade7ce90e731ab9645eed3546db1e4ed6f3 Mon Sep 17 00:00:00 2001 From: hauke Date: Mon, 8 Mar 2010 22:03:00 +0000 Subject: brcm47xx: fix commit r18413 "128MB ram problem" The patch commited in r18413 was wrong. This patch prevents prom_init_mem from scanning over 128MB ram. This is from #6765 and #3177 Refresh all patches git-svn-id: svn://svn.openwrt.org/openwrt/trunk@20072 3c298f89-4303-0410-b956-a3cf2f4a3e73 --- .../patches-2.6.31/170-128MB_ram_bugfix.patch | 43 +++++++++++++++------- 1 file changed, 29 insertions(+), 14 deletions(-) (limited to 'target/linux/brcm47xx/patches-2.6.31/170-128MB_ram_bugfix.patch') diff --git a/target/linux/brcm47xx/patches-2.6.31/170-128MB_ram_bugfix.patch b/target/linux/brcm47xx/patches-2.6.31/170-128MB_ram_bugfix.patch index e54e3de40..93f4b1f10 100644 --- a/target/linux/brcm47xx/patches-2.6.31/170-128MB_ram_bugfix.patch +++ b/target/linux/brcm47xx/patches-2.6.31/170-128MB_ram_bugfix.patch @@ -1,17 +1,32 @@ --- a/arch/mips/bcm47xx/prom.c +++ b/arch/mips/bcm47xx/prom.c -@@ -141,6 +141,14 @@ 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 (mem == 0x8000000) -+ mem -= 0x1000; -+ - add_memory_region(0, mem, BOOT_MEM_RAM); - } +@@ -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. + * +@@ -134,8 +135,21 @@ 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; -- cgit v1.2.3