[PATCH 1/3] x86/ucode: Break out compare_revisions() from existing infrastructure

[Andrew Cooper <andrew.cooper3@xxxxxxxxxx>]

Drop some unnecesserily verbose pr_debug()'s on the AMD side.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
CC: Jan Beulich <JBeulich@xxxxxxxx>
CC: Roger Pau Monné <roger.pau@xxxxxxxxxx>
CC: Wei Liu <wl@xxxxxxx>
CC: Juergen Gross <jgross@xxxxxxxx>
CC: Igor Druzhinin <igor.druzhinin@xxxxxxxxxx>
---
 xen/arch/x86/cpu/microcode/amd.c   | 22 +++++++++++-----------
 xen/arch/x86/cpu/microcode/intel.c | 15 ++++++++++++---
 2 files changed, 23 insertions(+), 14 deletions(-)

diff --git a/xen/arch/x86/cpu/microcode/amd.c b/xen/arch/x86/cpu/microcode/amd.c
index e80f7cd3e4..7d2f57c4cb 100644
--- a/xen/arch/x86/cpu/microcode/amd.c
+++ b/xen/arch/x86/cpu/microcode/amd.c
@@ -168,6 +168,15 @@ static bool check_final_patch_levels(const struct 
cpu_signature *sig)
     return false;
 }
 
+static enum microcode_match_result compare_revisions(
+    uint32_t old_rev, uint32_t new_rev)
+{
+    if ( new_rev > old_rev )
+        return NEW_UCODE;
+
+    return OLD_UCODE;
+}
+
 static enum microcode_match_result microcode_fits(
     const struct microcode_patch *patch)
 {
@@ -178,16 +187,7 @@ static enum microcode_match_result microcode_fits(
          equiv.id  != patch->processor_rev_id )
         return MIS_UCODE;
 
-    if ( patch->patch_id <= sig->rev )
-    {
-        pr_debug("microcode: patch is already at required level or 
greater.\n");
-        return OLD_UCODE;
-    }
-
-    pr_debug("microcode: CPU%d found a matching microcode update with version 
%#x (current=%#x)\n",
-             cpu, patch->patch_id, sig->rev);
-
-    return NEW_UCODE;
+    return compare_revisions(sig->rev, patch->patch_id);
 }
 
 static enum microcode_match_result compare_header(
@@ -196,7 +196,7 @@ static enum microcode_match_result compare_header(
     if ( new->processor_rev_id != old->processor_rev_id )
         return MIS_UCODE;
 
-    return new->patch_id > old->patch_id ? NEW_UCODE : OLD_UCODE;
+    return compare_revisions(old->patch_id, new->patch_id);
 }
 
 static enum microcode_match_result compare_patch(
diff --git a/xen/arch/x86/cpu/microcode/intel.c 
b/xen/arch/x86/cpu/microcode/intel.c
index 72c07fcd1d..e1ccb5d232 100644
--- a/xen/arch/x86/cpu/microcode/intel.c
+++ b/xen/arch/x86/cpu/microcode/intel.c
@@ -222,6 +222,15 @@ static int microcode_sanity_check(const struct 
microcode_patch *patch)
     return 0;
 }
 
+static enum microcode_match_result compare_revisions(
+    uint32_t old_rev, uint32_t new_rev)
+{
+    if ( new_rev > old_rev )
+        return NEW_UCODE;
+
+    return OLD_UCODE;
+}
+
 /* Check an update against the CPU signature and current update revision */
 static enum microcode_match_result microcode_update_match(
     const struct microcode_patch *mc)
@@ -245,7 +254,7 @@ static enum microcode_match_result microcode_update_match(
     return MIS_UCODE;
 
  found:
-    return mc->rev > cpu_sig->rev ? NEW_UCODE : OLD_UCODE;
+    return compare_revisions(cpu_sig->rev, mc->rev);
 }
 
 static enum microcode_match_result compare_patch(
@@ -258,7 +267,7 @@ static enum microcode_match_result compare_patch(
     ASSERT(microcode_update_match(old) != MIS_UCODE);
     ASSERT(microcode_update_match(new) != MIS_UCODE);
 
-    return new->rev > old->rev ? NEW_UCODE : OLD_UCODE;
+    return compare_revisions(old->rev, new->rev);
 }
 
 static int apply_microcode(const struct microcode_patch *patch)
@@ -332,7 +341,7 @@ static struct microcode_patch *cpu_request_microcode(const 
void *buf,
          * one with higher revision.
          */
         if ( (microcode_update_match(mc) != MIS_UCODE) &&
-             (!saved || (mc->rev > saved->rev)) )
+             (!saved || compare_revisions(saved->rev, mc->rev) == NEW_UCODE) )
             saved = mc;
 
         buf  += blob_size;
-- 
2.11.0