x86/cpu: Add a steppings field to struct x86_cpu_id

Intel uses the same family/model for several CPUs. Sometimes the
stepping must be checked to tell them apart.

On x86 there can be at most 16 steppings. Add a steppings bitmask to
x86_cpu_id and a X86_MATCH_VENDOR_FAMILY_MODEL_STEPPING_FEATURE macro
and support for matching against family/model/stepping.

 [ bp: Massage. ]

Signed-off-by: Mark Gross <mgross@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>

diff --git a/arch/x86/include/asm/cpu_device_id.h b/arch/x86/include/asm/cpu_device_id.h
index cf3d621..10426cd 100644 (file)
--- a/arch/x86/include/asm/cpu_device_id.h
+++ b/arch/x86/include/asm/cpu_device_id.h
@@ -20,12 +20,14 @@
 #define X86_CENTAUR_FAM6_C7_D          0xd
 #define X86_CENTAUR_FAM6_NANO          0xf
 
+#define X86_STEPPINGS(mins, maxs)    GENMASK(maxs, mins)
 /**
- * X86_MATCH_VENDOR_FAM_MODEL_FEATURE - Base macro for CPU matching
+ * X86_MATCH_VENDOR_FAM_MODEL_STEPPINGS_FEATURE - Base macro for CPU matching
  * @_vendor:   The vendor name, e.g. INTEL, AMD, HYGON, ..., ANY
  *             The name is expanded to X86_VENDOR_@_vendor
  * @_family:   The family number or X86_FAMILY_ANY
  * @_model:    The model number, model constant or X86_MODEL_ANY
+ * @_steppings:        Bitmask for steppings, stepping constant or X86_STEPPING_ANY
  * @_feature:  A X86_FEATURE bit or X86_FEATURE_ANY
  * @_data:     Driver specific data or NULL. The internal storage
  *             format is unsigned long. The supplied value, pointer
@@ -37,16 +39,35 @@
  * into another macro at the usage site for good reasons, then please
  * start this local macro with X86_MATCH to allow easy grepping.
  */
-#define X86_MATCH_VENDOR_FAM_MODEL_FEATURE(_vendor, _family, _model,   \
-                                          _feature, _data) {           \
+#define X86_MATCH_VENDOR_FAM_MODEL_STEPPINGS_FEATURE(_vendor, _family, _model, \
+                                                   _steppings, _feature, _data) { \
        .vendor         = X86_VENDOR_##_vendor,                         \
        .family         = _family,                                      \
        .model          = _model,                                       \
+       .steppings      = _steppings,                                   \
        .feature        = _feature,                                     \
        .driver_data    = (unsigned long) _data                         \
 }
 
 /**
+ * X86_MATCH_VENDOR_FAM_MODEL_FEATURE - Macro for CPU matching
+ * @_vendor:   The vendor name, e.g. INTEL, AMD, HYGON, ..., ANY
+ *             The name is expanded to X86_VENDOR_@_vendor
+ * @_family:   The family number or X86_FAMILY_ANY
+ * @_model:    The model number, model constant or X86_MODEL_ANY
+ * @_feature:  A X86_FEATURE bit or X86_FEATURE_ANY
+ * @_data:     Driver specific data or NULL. The internal storage
+ *             format is unsigned long. The supplied value, pointer
+ *             etc. is casted to unsigned long internally.
+ *
+ * The steppings arguments of X86_MATCH_VENDOR_FAM_MODEL_STEPPINGS_FEATURE() is
+ * set to wildcards.
+ */
+#define X86_MATCH_VENDOR_FAM_MODEL_FEATURE(vendor, family, model, feature, data) \
+       X86_MATCH_VENDOR_FAM_MODEL_STEPPINGS_FEATURE(vendor, family, model, \
+                                               X86_STEPPING_ANY, feature, data)
+
+/**
  * X86_MATCH_VENDOR_FAM_FEATURE - Macro for matching vendor, family and CPU feature
  * @vendor:    The vendor name, e.g. INTEL, AMD, HYGON, ..., ANY
  *             The name is expanded to X86_VENDOR_@vendor

diff --git a/arch/x86/kernel/cpu/match.c b/arch/x86/kernel/cpu/match.c
index d3482eb..ad67760 100644 (file)
--- a/arch/x86/kernel/cpu/match.c
+++ b/arch/x86/kernel/cpu/match.c
@@ -39,13 +39,18 @@ const struct x86_cpu_id *x86_match_cpu(const struct x86_cpu_id *match)
        const struct x86_cpu_id *m;
        struct cpuinfo_x86 *c = &boot_cpu_data;
 
-       for (m = match; m->vendor | m->family | m->model | m->feature; m++) {
+       for (m = match;
+            m->vendor | m->family | m->model | m->steppings | m->feature;
+            m++) {
                if (m->vendor != X86_VENDOR_ANY && c->x86_vendor != m->vendor)
                        continue;
                if (m->family != X86_FAMILY_ANY && c->x86 != m->family)
                        continue;
                if (m->model != X86_MODEL_ANY && c->x86_model != m->model)
                        continue;
+               if (m->steppings != X86_STEPPING_ANY &&
+                   !(BIT(c->x86_stepping) & m->steppings))
+                       continue;
                if (m->feature != X86_FEATURE_ANY && !cpu_has(c, m->feature))
                        continue;
                return m;

diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
index 4c2ddd0..0754b8d 100644 (file)
--- a/include/linux/mod_devicetable.h
+++ b/include/linux/mod_devicetable.h
@@ -663,6 +663,7 @@ struct x86_cpu_id {
        __u16 vendor;
        __u16 family;
        __u16 model;
+       __u16 steppings;
        __u16 feature;  /* bit index */
        kernel_ulong_t driver_data;
 };
@@ -671,6 +672,7 @@ struct x86_cpu_id {
 #define X86_VENDOR_ANY 0xffff
 #define X86_FAMILY_ANY 0
 #define X86_MODEL_ANY  0
+#define X86_STEPPING_ANY 0
 #define X86_FEATURE_ANY 0      /* Same as FPU, you can't test for that */
 
 /*