powerpc/85xx: verify the current address of CCSR before relocating it

Verify that CCSR is actually located where it is supposed to be before
we relocate it.  This is useful in detecting U-Boot configurations that
are broken (e.g. an incorrect value for CONFIG_SYS_CCSRBAR_DEFAULT).
If the current value is wrong, we enter an infinite loop, which is handy
for debuggers.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
This commit is contained in:
Timur Tabi 2011-10-31 13:30:44 -05:00 committed by Kumar Gala
parent 452ad61c3f
commit 19e4384124

View file

@ -411,6 +411,33 @@ create_ccsr_old_tlb:
msync msync
tlbwe tlbwe
/*
* We have a TLB for what we think is the current (old) CCSR. Let's
* verify that, otherwise we won't be able to move it.
* CONFIG_SYS_CCSRBAR_DEFAULT is always a 32-bit number, so we only
* need to compare the lower 32 bits of CCSRBAR on CoreNet systems.
*/
verify_old_ccsr:
lis r0, CONFIG_SYS_CCSRBAR_DEFAULT@h
ori r0, r0, CONFIG_SYS_CCSRBAR_DEFAULT@l
#ifdef CONFIG_FSL_CORENET
lwz r1, 4(r9) /* CCSRBARL */
#else
lwz r1, 0(r9) /* CCSRBAR, shifted right by 12 */
slwi r1, r1, 12
#endif
cmpl 0, r0, r1
/*
* If the value we read from CCSRBARL is not what we expect, then
* enter an infinite loop. This will at least allow a debugger to
* halt execution and examine TLBs, etc. There's no point in going
* on.
*/
infinite_debug_loop:
bne infinite_debug_loop
#ifdef CONFIG_FSL_CORENET #ifdef CONFIG_FSL_CORENET
#define CCSR_LAWBARH0 (CONFIG_SYS_CCSRBAR + 0x1000) #define CCSR_LAWBARH0 (CONFIG_SYS_CCSRBAR + 0x1000)