[U-Boot] [U-Boot, v4, 3/5] api: bootelf: go: flush cache before starting

[Alexander Graf]

On 02/08/2017 04:00 PM, Tom Rini wrote:
> On Tue, Jan 31, 2017 at 12:17:06PM +0100, Emmanuel Vadot wrote:
>
>> From: Warner Losh <imp at freebsd.org>
>>
>> Some application might load some code at location that contain stale
>> cache entries. Before running a elf or raw binary, flush the caches
>> if they are enabled.
>>
>> Reviewed-by: Tom Rini <trini at konsulko.com>
>> Signed-off-by: Emmanuel Vadot <manu at bidouilliste.com>
>> Reviewed-by: Simon Glass <sjg at chromium.org>
>> ---
>>   api/api.c  | 5 +++++
>>   cmd/boot.c | 4 ++++
>>   cmd/elf.c  | 5 +++++
>>   3 files changed, 14 insertions(+)
>>
>> diff --git a/api/api.c b/api/api.c
>> index c368511704..88b5df77c0 100644
>> --- a/api/api.c
>> +++ b/api/api.c
>> @@ -290,6 +290,11 @@ static int API_dev_close(va_list ap)
>>   	if (!err)
>>   		di->state = DEV_STA_CLOSED;
>>   
>> +	if (dcache_status())
>> +		flush_dcache_all();
>> +	if (icache_status())
>> +		invalidate_icache_all();
>> +
> So this runs into a problem.  Building for sandbox, or many many other
> platforms gives us:
> undefined reference to `dcache_status'
> undefined reference to `flush_dcache_all'
> undefined reference to `icache_status'
> undefined reference to `invalidate_icache_all'
>
> At the high level, we have a few problems.  We don't have a global "has
> icache" and "has dcache" support CONFIG symbol.  We also have a few
> instances of weak functions that end up being no-ops in these cases, but
> it's not quite correct to use them in this case, possibly.  For example,
> PowerPC does have dcache support and functions but no flush_dcache_all
> (and only sometimes a flush_dcache() that looks like it would be
> _all()), and same for icache.

Well, if we want to keep the API consistent (which I think we do) we 
should probably fix that :). It's quite a good chunk of unpleasant work 
though...


Alex