Am Mittwoch, den 08.05.2013, 09:07 -0500 schrieb Aaron Durbin:
On Wed, May 8, 2013 at 8:50 AM, Paul Menzel wrote:
Am Mittwoch, den 08.05.2013, 08:18 -0500 schrieb Aaron Durbin:
I think what you'll find is that determining this is cpu specific.
understood.
I'm fairly sure it's not worth trying to generalize it. The implementations are already associated with the chipset/cpu code. Why move them?
Because there would be a lot of copies. 19 if I am not mistaken.
$ ls src/cpu/intel/ car model_65x model_f2x socket_mFCPGA478 ep80579 model_67x model_f3x socket_mPGA478 fit model_68x model_f4x socket_mPGA479M haswell model_69x slot_1 socket_mPGA603 hyperthreading model_6bx slot_2 socket_mPGA604 Kconfig model_6dx socket_441 socket_PGA370 Makefile.inc model_6ex socket_BGA956 socket_rPGA989 microcode model_6fx socket_FC_PGA370 speedstep model_1067x model_6xx socket_LGA771 thermal_monitoring model_106cx model_f0x socket_LGA775 turbo model_206ax model_f1x socket_mFCBGA479A989I guess that is also the reason, why `udelay.c` was put into the northbridge code beforehand?
The reason udelay was put in northbridge was for SMM if I am not mistaken. How similar are the implementations?
Of `udelay.c`? Besides the register differences it is the same. Sandy Bridge (and Haswell) define `fsb` to 100 MHz, where i945 and i5000 use 400 MHz and divide it by four later on.
For example the `udelay.c` in Sandy Bridge could use the `tsc_freq.c` from Haswell.
I know sandy/ivy and haswell are the same (they happen to use the same blck). But are all the other ones? And is it 19 copies of the *same* code?
As no code has been written yet, I do not know. But judging from the three `udelay.c` files I looked at, they should be.
What you would be getting rid of is 19 copies of the udelay logic. Not necessarily the tsc frequency implementation. I was talking about the latter w.r.t. keeping that code (tsc freq) associated w/ the chipset/cpu. We can definitely cleanup the tsc udelay copies though.
I am still wondering why originally four `udelay.c` were enough and now it has to be done for each CPU model. I think a lot of the CPU models are similar in the TSC regard.
Not sure, what I am missing.
Thanks,
Paul