Messages in this thread Patch in this message | | | From | Andi Kleen <> | Subject | [PATCH v2 1/2] x86/cpufeature: Add facility to match microcode revisions | Date | Wed, 10 Oct 2018 09:26:07 -0700 |
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From: Andi Kleen <ak@linux.intel.com>
For bug workarounds or checks it is useful to check for specific microcode versions. Add a new table format to check for steppings with min microcode revisions.
This does not change the existing x86_cpu_id because it's an ABI shared with modutils, and also has quite difference requirements, as in no wildcards, but everything has to be matched exactly.
Signed-off-by: Andi Kleen <ak@linux.intel.com> --- v2: Remove all CPU match, only check boot cpu Move INTEL_MIN_UCODE macro to header. Minor cleanups. Remove max ucode and driver data --- arch/x86/include/asm/cpu_device_id.h | 26 ++++++++++++++++++++++++++ arch/x86/kernel/cpu/match.c | 21 +++++++++++++++++++++ 2 files changed, 47 insertions(+)
diff --git a/arch/x86/include/asm/cpu_device_id.h b/arch/x86/include/asm/cpu_device_id.h index baeba0567126..1b90bd1d0b95 100644 --- a/arch/x86/include/asm/cpu_device_id.h +++ b/arch/x86/include/asm/cpu_device_id.h @@ -11,4 +11,30 @@ extern const struct x86_cpu_id *x86_match_cpu(const struct x86_cpu_id *match); +/* + * Match specific microcodes + * + * vendor/family/model/stepping must be all set. + * min_ucode is optional and can be 0. + */ + +struct x86_ucode_id { + u8 vendor; + u8 family; + u16 model; + u16 stepping; + u32 min_ucode; +}; + +#define INTEL_MIN_UCODE(mod, step, rev) { \ + .vendor = X86_VENDOR_INTEL, \ + .family = 6, \ + .model = mod, \ + .stepping = step, \ + .min_ucode = rev, \ +} + +extern const struct x86_ucode_id * +x86_match_ucode(const struct x86_ucode_id *match); + #endif diff --git a/arch/x86/kernel/cpu/match.c b/arch/x86/kernel/cpu/match.c index 3fed38812eea..ec8ee31699cd 100644 --- a/arch/x86/kernel/cpu/match.c +++ b/arch/x86/kernel/cpu/match.c @@ -48,3 +48,24 @@ const struct x86_cpu_id *x86_match_cpu(const struct x86_cpu_id *match) return NULL; } EXPORT_SYMBOL(x86_match_cpu); + +const struct x86_ucode_id *x86_match_ucode(const struct x86_ucode_id *match) +{ + struct cpuinfo_x86 *c = &boot_cpu_data; + const struct x86_ucode_id *m; + + for (m = match; m->vendor | 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; + if (c->microcode < m->min_ucode) + continue; + return m; + } + return NULL; +} -- 2.17.1
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