On Friday 19 August 2011 06:25 PM, Marek Vasut wrote:
On Friday, August 19, 2011 12:43:30 PM Aneesh V wrote:
Hi Marek,
On Friday 19 August 2011 03:16 PM, Marek Vasut wrote:
On Friday, August 19, 2011 11:37:29 AM Aneesh V wrote:
Hi Hong,
On Friday 19 August 2011 02:53 PM, Hong Xu wrote:
Add a new file arch/arm/cpu/arm926ejs/cache.c and put cache operations into this file.
How about converting as much as possible of these to armv5/armv6 generic code as I mentioned in this thread:
http://thread.gmane.org/gmane.comp.boot-loaders.u-boot/105385/focus=1055 26
On a quick look everything below except the "flush_dcache_all()" seems to be armv5 generic.
I'd be _VERY_ careful here. And this "seems" doesn't sound very convincing. Are you dead sure it won't break any v5 CPU we support?
What Hong has used is operations mentioned in the ARMv5 architecture and these are not marked as IMPLEMENTATION DEFINED. So, compliant implementations should implement those CP15 operations. They may enhance the operations by adding their own like ARM926EJS seems to be doing with 'flush d-cache all'.
However, I think that's immaterial. Hong can provide this as a library and define a CONFIG_* flag to enable it. Let the platform maintainers decide whether to use it or not. IMHO, it will definitely be an improvement over what we have today.
Hi,
It certainly will, but I'm quite relucant to that as it'll also -- since CONFIG_SYS_DCACHE_OFF and CONFIG_SYS_ICACHE_OFF isn't defined by default -- break some things. Even though what I said is not exactly an argument for what you said.
If you're firm all ARMv5 implement it this way, I'm all for it being done the way you suggest it!
I can not vouch for all the CPUs. But I checked one more - ARM946ES. This one is also implementing all the standard operations that Hong has used('flush d-cache all' used by Hong is not a standard armv5 operation - that seems to be a 926ejs specific one).
best regards, Aneesh