> -----Original Mail-----
> Sender: Thomas Gleixner [mailto:t...@linutronix.de]
> Time: 2018年4月26日 17:12
> Receiver: David Wang <davidw...@zhaoxin.com>
> CC: mi...@redhat.com; h...@zytor.com; gre...@linuxfoundation.org;
> x...@kernel.org; linux-kernel@vger.kernel.org; brucechang@via-
> alliance.com; cooper...@zhaoxin.com; qiyuanw...@zhaoxin.com;
> benjamin...@viatech.com; luke...@viacpu.com; tim...@zhaoxin.com
> Subject: Re: [PATCH v2] x86/centaur: report correct CPU/cache topology
>
> On Wed, 25 Apr 2018, David Wang wrote:
> >
> > +static void early_init_centaur_mc(struct cpuinfo_x86 *c) { #ifdef
> > +CONFIG_SMP
> > + unsigned int eax, ebx, ecx, edx;
> > +
> > + if (c->cpuid_level < 4)
> > + return;
> > +
> > + cpuid_count(4, 0, &eax, &ebx, &ecx, &edx);
> > + if (eax & 0x1f)
> > + c->x86_max_cores = (eax >> 26) + 1;
> > + else
> > + return;
> > +#endif
> > +}
>
> My review comment from last time still stands:
>
> > > This is a bad copy of intel_num_cpu_cores(). See for the subtle
> > > difference. Please rename the intel function and move it to common.c
>
> In other words:
>
> Make a patch which moves intel_num_cpu_cores() into common.c. Rename
> the function into something like detect_num_cpu_cores() and fix up the
call
> site in intel.c.
>
> Then add your patch and use the very same function.
>
OK. I got it.
> > +
> > static void early_init_centaur(struct cpuinfo_x86 *c) {
> > + early_init_centaur_mc(c);
> > switch (c->x86) {
> > #ifdef CONFIG_X86_32
> > case 5:
> > @@ -146,6 +163,7 @@ static void centaur_detect_vmx_virtcap(struct
> > cpuinfo_x86 *c)
> >
> > static void init_centaur(struct cpuinfo_x86 *c) {
> > + unsigned int l2 = 0;
> > #ifdef CONFIG_X86_32
> > char *name;
> > u32 fcr_set = 0;
> > @@ -161,6 +179,17 @@ static void init_centaur(struct cpuinfo_x86 *c)
> > #endif
> > early_init_centaur(c);
> >
> > + l2 = init_intel_cacheinfo(c);
> > +
> > + /* Detect legacy cache sizes if init_intel_cacheinfo did not */
> > + if (l2 == 0) {
> > + cpu_detect_cache_sizes(c);
> > + }
>
> Aside of the pointless parentheses, this really wants to be cleaned up as
well.
>
> init_intel_cacheinfo() is called from the intel init code and it does the
same
> silly thing.
>
> So the right thing to do is in a separate patch first
>
> --- a/arch/x86/kernel/cpu/intel.c
> +++ b/arch/x86/kernel/cpu/intel.c
> @@ -679,12 +679,6 @@ static void init_intel(struct cpuinfo_x8
>
> l2 = init_intel_cacheinfo(c);
>
> - /* Detect legacy cache sizes if init_intel_cacheinfo did not */
> - if (l2 == 0) {
> - cpu_detect_cache_sizes(c);
> - l2 = c->x86_cache_size;
> - }
> -
> if (c->cpuid_level > 9) {
> unsigned eax = cpuid_eax(10);
> /* Check for version and the number of counters */
> --- a/arch/x86/kernel/cpu/intel_cacheinfo.c
> +++ b/arch/x86/kernel/cpu/intel_cacheinfo.c
> @@ -802,6 +802,11 @@ unsigned int init_intel_cacheinfo(struct
>
> c->x86_cache_size = l3 ? l3 : (l2 ? l2 : (l1i+l1d));
>
> + /* Detect legacy cache sizes if the above did not work */
> + if (!l2) {
> + cpu_detect_cache_sizes(c);
> + l2 = c->x86_cache_size;
> + }
> return l2;
> }
>
> Hmm?
>
> tglx
>
OK. I got it.
Patch v3 will be sent later.
Thank you.
---
David
