[U-Boot] bootcount: Add dcache flush to bootcount_store()

[York Sun <yorksun@freescale.com>]

Tom,

On 03/15/2015 11:30 AM, Tom Rini wrote:
> ... Add a few more PowerPC people.
> 
> On Fri, Mar 13, 2015 at 10:34:03AM -0400, Tom Rini wrote:
>> On Fri, Mar 13, 2015 at 09:48:56AM -0400, Tom Rini wrote:
>>> On Wed, Mar 11, 2015 at 09:51:38AM +0100, Stefan Roese wrote:
>>>
>>>> Without this dcache_flush the updated bootcounter may not be saved to
>>>> its location.
>>>>
>>>> This was detected on an iMX.6 platform using the OCRAM (internal SRAM)
>>>> as bootcounter storage area. And issuing "reset" from within U-Boot
>>>> cause the bootcounter to stay on its initial value.
>>>>
>>>> Signed-off-by: Stefan Roese <sr@denx.de>
>>>> Reviewed-by: Tom Rini <trini@konsulko.com>
>>>
>>> OK, this breaks some platforms:
>>>    powerpc:  +   TQM850L
>>> +(TQM850L) drivers/built-in.o: In function `bootcount_store':
>>> +(TQM850L) build/../drivers/bootcount/bootcount.c:64: undefined reference to `flush_dcache_range'
>>> +(TQM850L) make[1]: *** [u-boot] Error 1
>>> +(TQM850L) make: *** [sub-make] Error 2
>>>
>>> We'll see how many others have the same problem soon and then I'll
>>> decide on nuking the old platforms of holding off on this change.
>>
>> Aside from the TQM 8xx family that Wolfgang owns we have mgcoge and
>> mgcoge3ne also breaking from this
>> (http://patchwork.ozlabs.org/patch/448849/) change.  Wolfgang, Holger,
>> how do you want to proceed?  We either need cache operations or dropping
>> bootcount from the platforms or dropping the platforms.
>>
>> Frankly, after looking at most of arch/powerpc/cpu/*/cache.c I suspect
>> 8xx and 83xx just need the dummy files copied over.
> 
> OK, I went and poked at going one direction on this and then dug into
> the higher level problem more.  PowerPC _needs_ the current kernel's
> arch/powerpc/kernel/misc_32.S relevant cache functions ported over for
> everyone and we should kill the dummy functions we have today.  To try
> and encourage some folks to do this I'm going to drop this bootcount
> patch for now.
> 

FWIW, powerpc mpc83xx, mpc85xx, mpc86xx all have flush_dcache_range() function
defined.

York