Messages in this thread | | | Date | Sun, 3 May 2009 11:09:08 +0200 | From | Ingo Molnar <> | Subject | Re: [git-pull -tip] x86: cpu_debug patches |
| |
* Jaswinder Singh Rajput <jaswinder@kernel.org> wrote:
> We can use cpu_has tests for unknown processors but 'cpu model' is > accurate and cover all range. > > cpu_has does not cover following registers: > 1. platform > 2. poweron > 3. control > 4. bios > 5. freq > 6. cache > 7. misc > 8. base > 9. ver > 10. conf
Firstly these should be added to cpufeatures.h.
Then add cpu_has_xxx() accessors need to be added for them and during CPU init they have to be properly set, via two methods:
- via CPUID (where this is possible+specified in docs) - or via "later than CPU version X" checks
Your cpu-model table is equivalent to an explicitly enumerated CPU version check, but this breaks every time a new CPU comes out.
"Later than" or CPUID based feature bits are a lot more future-proof - we only have to add support for new _features_ (and quirks, occasionally), and dont have to maintain that full table of specific models to specific features mapping tables.
Ingo
| |