On Mon, Jan 07, 2019 at 02:34:22PM -0800, [email protected] wrote: > From: Kan Liang <[email protected]> > > For bug workarounds or checks it is useful to check for specific > microcode revisions. > > Add a new generic function to match the CPU with stepping. > Add the other function to check the min microcode revisions for > the matched CPU. > A new table format is introduced to facilitate the quirk to > fill the related information. > > This does not change the existing x86_cpu_id because it's an ABI > shared with modules, and also has quite different requirements, > as in no wildcards, but everything has to be matched exactly. > > Suggested-by: Thomas Gleixner <[email protected]> > Based-on-code-from: Andi Kleen <[email protected]>
The proper tag is: Originally-by > Signed-off-by: Kan Liang <[email protected]> > --- > > Changes since V4: > - Rename to x86_cpu_check and INTEL_CHECK_UCODE > - Split x86_min_microcode() into two functions. One is a generic > CPU match function with stepping. The other is to check the min > microcode revisions. > > The previous discussion can be found here. > https://lkml.org/lkml/2018/10/10/740 > > arch/x86/include/asm/cpu_device_id.h | 28 ++++++++++++++++++++++++++++ > arch/x86/kernel/cpu/match.c | 31 +++++++++++++++++++++++++++++++ > 2 files changed, 59 insertions(+) > > diff --git a/arch/x86/include/asm/cpu_device_id.h > b/arch/x86/include/asm/cpu_device_id.h > index baeba05..43f19af 100644 > --- a/arch/x86/include/asm/cpu_device_id.h > +++ b/arch/x86/include/asm/cpu_device_id.h > @@ -11,4 +11,32 @@ > > extern const struct x86_cpu_id *x86_match_cpu(const struct x86_cpu_id > *match); > > +/* > + * Match specific microcode revisions. > + * > + * vendor/family/model/stepping must be all set. > + * > + * only checks against the boot cpu. When mixed-stepping configs are s/cpu/CPU/g > + * valid for a CPU model, add a quirk for every valid stepping and > + * do the fine-tuning in the quirk handler. > + */ > + > +struct x86_cpu_check { That's not a "check". If anything, it is a descriptor of sorts. I.e., x86_cpu_desc or so. > + u8 vendor; > + u8 family; > + u8 model; > + u8 stepping; > + u32 microcode_rev; Name those the same way as the corresponding members in struct cpuinfo_x86 are named, so that there's no confusion about what is what. > +}; > + > +#define INTEL_CHECK_UCODE(mod, step, rev) { \ INTEL_CPU_DESC or so. > + .vendor = X86_VENDOR_INTEL, \ > + .family = 6, \ > + .model = mod, \ > + .stepping = step, \ > + .microcode_rev = rev, \ > +} > + > +extern bool x86_cpu_has_min_microcode_rev(const struct x86_cpu_check *table); > + > #endif > diff --git a/arch/x86/kernel/cpu/match.c b/arch/x86/kernel/cpu/match.c > index 3fed388..408bed37 100644 > --- a/arch/x86/kernel/cpu/match.c > +++ b/arch/x86/kernel/cpu/match.c > @@ -48,3 +48,34 @@ const struct x86_cpu_id *x86_match_cpu(const struct > x86_cpu_id *match) > return NULL; > } > EXPORT_SYMBOL(x86_match_cpu); > + > +static const struct x86_cpu_check * > +x86_match_cpu_with_stepping(const struct x86_cpu_check *match) > +{ > + struct cpuinfo_x86 *c = &boot_cpu_data; > + const struct x86_cpu_check *m; > + > + for (m = match; m->family | m->model; m++) { > + if (c->x86_vendor != m->vendor) > + continue; > + if (c->x86 != m->family) > + continue; > + if (c->x86_model != m->model) > + continue; > + if (c->x86_stepping != m->stepping) > + continue; > + return m; > + } > + return NULL; > +} > + > +bool x86_cpu_has_min_microcode_rev(const struct x86_cpu_check *table) > +{ > + const struct x86_cpu_check *res = x86_match_cpu_with_stepping(table); > + > + if (!res || res->microcode_rev > boot_cpu_data.microcode) > + return false; > + > + return true; > +} > +EXPORT_SYMBOL(x86_cpu_has_min_microcode_rev); EXPORT_SYMBOL_GPL. -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.
