[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v2 6/9] x86/intel_pstate: the main boby of the intel_pstate driver
On 08/06/2015 14:50, Jan Beulich wrote: > >>> On 08.06.15 at 03:47, <wei.w.wang@xxxxxxxxx> wrote: > > On 26/05/2015 21:58, Jan Beulich wrote > >> >>> On 13.05.16 at 09:50, <wei.w.wang@xxxxxxxxx> wrote: > >> > +static int byt_get_min_pstate(void) { > >> > + u64 value; > >> > + > >> > + rdmsrl(BYT_RATIOS, value); > >> > + return (value >> 8) & 0x7F; > >> > +} > >> > + > >> > +static int byt_get_max_pstate(void) { > >> > + u64 value; > >> > + > >> > + rdmsrl(BYT_RATIOS, value); > >> > + return (value >> 16) & 0x7F; > >> > +} > >> > + > >> > +static int byt_get_turbo_pstate(void) { > >> > + u64 value; > >> > + > >> > + rdmsrl(BYT_TURBO_RATIOS, value); > >> > + return value & 0x7F; > >> > +} > >> > + > >> > +static void byt_set_pstate(struct cpudata *cpudata, int pstate) { > >> > + u64 val; > >> > + int32_t vid_fp; > >> > + u32 vid; > >> > + > >> > + val = pstate << 8; > >> > + if (limits.no_turbo && !limits.turbo_disabled) > >> > + val |= (u64)1 << 32; > >> > >> All of the literal numbers above (and there are more further down) > >> would better become self-documenting manifest constants. > > > > I just realized that it would be better to remove these bay trail > > platform related code. What do you think? > > First of all - why? Unless these are 32-bit only systems, I don't see why we > wouldn't want to support Atoms at least on a best effort basis. And if you > consider removal of code present in Linux, then this also needs to be done > with the earlier mentioned "as little changes as possible compared to the > Linux original" in mind. I don't have an objection to keeping it. Probably, some people are running Xen on tablets. Regarding the self-documenting related comment here, which of the following do you think is better? 1) #define BYT_MIN_PSTATE_SHIFT 8 #define BYT_MAX_PSTATE_SHIFT 16 #define BYT_PSTATE_MASK 0x7f #define BYT_TURBO_CONTROL_BIT 32 2) #define BYT_MIN_PSTATE(value) (((value) >> 8) & 0x7F) #define BYT_MAX_PSTATE(value) (((value) >> 16) & 0x7F) #define BYT_SET_TURBO_CONTROL_BIT(value) ((val) |= (u64)1 << 32) Best, Wei _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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