brcm47xx: add kernel 2.6.35 preliminary support
[openwrt/svn-archive/archive.git] / target / linux / brcm47xx / patches-2.6.35 / 170-128MB_ram_bugfix.patch
1 --- a/arch/mips/bcm47xx/prom.c
2 +++ b/arch/mips/bcm47xx/prom.c
3 @@ -126,6 +126,7 @@ static __init void prom_init_cmdline(voi
4 static __init void prom_init_mem(void)
5 {
6 unsigned long mem;
7 + unsigned long max;
8
9 /* Figure out memory size by finding aliases.
10 *
11 @@ -134,21 +135,26 @@ static __init void prom_init_mem(void)
12 * want to reuse the memory used by CFE (around 4MB). That means cfe_*
13 * functions stop to work at some point during the boot, we should only
14 * call them at the beginning of the boot.
15 + *
16 + * BCM47XX uses 128MB for addressing the ram, if the system contains
17 + * less that that amount of ram it remaps the ram more often into the
18 + * available space.
19 + * Accessing memory after 128MB will cause an exception.
20 + * max contains the biggest possible address supported by the platform.
21 + * If the method wants to try something above we assume 128MB ram.
22 */
23 + max = ((unsigned long)(prom_init) | ((128 << 20) - 1));
24 for (mem = (1 << 20); mem < (128 << 20); mem += (1 << 20)) {
25 + if (((unsigned long)(prom_init) + mem) > max) {
26 + mem = (128 << 20);
27 + printk("assume 128MB RAM\n");
28 + break;
29 + }
30 if (*(unsigned long *)((unsigned long)(prom_init) + mem) ==
31 *(unsigned long *)(prom_init))
32 break;
33 }
34
35 - /* Ignoring the last page when ddr size is 128M. Cached
36 - * accesses to last page is causing the processor to prefetch
37 - * using address above 128M stepping out of the ddr address
38 - * space.
39 - */
40 - if (mem == 0x8000000)
41 - mem -= 0x1000;
42 -
43 add_memory_region(0, mem, BOOT_MEM_RAM);
44 }
45