From: Andi Kleen <a...@linux.intel.com>
For bug workarounds or checks it is useful to check for specific
microcode revisionss. 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 different requirements,
as in no wildcards, but everything has to be matched exactly.
Signed-off-by: Andi Kleen <a...@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
v3:
Rename function
Update comments.
Document mixed stepping caveats.
Use u8 for model
Remove vendor 0 check.
Change return check
v4:
Rename to x86_min_microcode
Change return value to bool
---
arch/x86/include/asm/cpu_device_id.h | 28 ++++++++++++++++++++++++++++
arch/x86/kernel/cpu/match.c | 19 +++++++++++++++++++
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..28847d5ea1fa 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_ucode_id {
+ u8 vendor;
+ u8 family;
+ u8 model;
+ u8 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 bool x86_min_microcode(const struct x86_ucode_id *mt);
+
#endif
diff --git a/arch/x86/kernel/cpu/match.c b/arch/x86/kernel/cpu/match.c
index 3fed38812eea..12db14232d62 100644
--- a/arch/x86/kernel/cpu/match.c
+++ b/arch/x86/kernel/cpu/match.c
@@ -48,3 +48,22 @@ const struct x86_cpu_id *x86_match_cpu(const struct
x86_cpu_id *match)
return NULL;
}
EXPORT_SYMBOL(x86_match_cpu);
+
+bool x86_min_microcode(const struct x86_ucode_id *mt)
+{
+ struct cpuinfo_x86 *c = &boot_cpu_data;
+ const struct x86_ucode_id *m;
+
+ for (m = mt; 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 c->microcode >= m->min_ucode;
+ }
+ return false;
+}
--
2.17.2
