[U-Boot] powerpc flush_cache() roll over bug

[Kumar Gala]

My brian stopped working but I figured I'd send my issue and hopefully  
I'll wake up and someone will have a solution for me.

The problem is we can call flush_cache(0xfffff000, 0x1000) which will  
never exit the loop:

void flush_cache(ulong start_addr, ulong size)
{
#ifndef CONFIG_5xx
         ulong addr, start;
         u64 end;

         start = start_addr & ~(CONFIG_SYS_CACHELINE_SIZE - 1);
         end = start_addr + size - 1;

         for (addr = start; addr <= end; addr +=  
CONFIG_SYS_CACHELINE_SIZE) {
                 asm volatile("dcbst 0,%0" : : "r" (addr) : "memory");
                 WATCHDOG_RESET();
         }
...

since end = 0xffffffff.  There are some other situations (like  
flush_cache(0, 0)) that cause similar issues, but less concerned about  
that.

Any suggestions on how to best to re-write the code to correctly  
handle flush_cache(0xfffff000, 0x1000) are welcome.

- k