brcm-2.4: fix commit r18413 "128MB ram problem"

This was missing in commit r20072

SVN-Revision: 20651
This commit is contained in:
Hauke Mehrtens 2010-04-01 17:27:59 +00:00
parent cf4781cfbd
commit bbe4a57177

View file

@ -21,25 +21,32 @@ void __init
prom_init(int argc, const char **argv)
{
unsigned long mem;
unsigned long max;
mips_machgroup = MACH_GROUP_BRCM;
mips_machtype = MACH_BCM947XX;
/* Figure out memory size by finding aliases */
/* Figure out memory size by finding aliases
*
* 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);
}