intel microcode: split up microcode loading stages

This patch only applies to CONFIG_MICROCODE_IN_CBFS. The intel microcode
update routine would always walk the CBFS for the microcode file. Then
it would loop through the whole file looking for a match then load the
microcode. This process was maintained for intel_update_microcode_from_cbfs(),
however 2 new functions were exported:
	1.  const void *intel_microcode_find(void)
	2.  void intel_microcode_load_unlocked(const void *microcode_patch)

The first locates a matching microcode while the second loads that
mircocode. These new functions can then be used to cache the found
microcode blob w/o having to re-walk the CBFS.

Booted baskingridge board to Linux and noted that all microcode
revisions match on all the CPUs.

Change-Id: Ifde3f3e5c100911c4f984dd56d36664a8acdf7d5
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/2778
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/src/include/cpu/intel/microcode.h b/src/include/cpu/intel/microcode.h
index e9c13f978c43..7a291e2f27c1 100644
--- a/src/include/cpu/intel/microcode.h
+++ b/src/include/cpu/intel/microcode.h
@@ -23,6 +23,13 @@
 #ifndef __PRE_RAM__
 #if CONFIG_CPU_MICROCODE_IN_CBFS
 void intel_update_microcode_from_cbfs(void);
+/* Find a microcode that matches the revision and platform family returning
+ * NULL if none found. */
+const void *intel_microcode_find(void);
+/* It is up to the caller to determine if parallel loading is possible as
+ * well as ensuring the micrcode matches the family and revision (i.e. with
+ * intel_microcode_find()). */
+void intel_microcode_load_unlocked(const void *microcode_patch);
 #else
 void intel_update_microcode(const void *microcode_updates);
 #endif