From: Kan Liang <kan.li...@linux.intel.com> 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 <t...@linutronix.de> Based-on-code-from: Andi Kleen <a...@linux.intel.com> Signed-off-by: Kan Liang <kan.li...@linux.intel.com> --- 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 + * 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 { + u8 vendor; + u8 family; + u8 model; + u8 stepping; + u32 microcode_rev; +}; + +#define INTEL_CHECK_UCODE(mod, step, rev) { \ + .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); -- 2.7.4
