soc/intel/cse: Add API to check if CSE Firmware update is required

This patch adds a function to check if a CSE FW update is required
during this boot. The function is expected to be used during use
cases like Pre-Memory Sign of Life text display to inform user of
a CSE Firmware update.

Bug=279173035
TEST=build and boot on google/rex board. Call the function in romstage
and confirm it returns True during CSE FW update and False otherwise

Signed-off-by: Anil Kumar <anil.kumar.k@intel.com>
Change-Id: If5fae95786d28d586566881bc4436812754636ae
Reviewed-on: https://review.coreboot.org/c/coreboot/+/78243
Reviewed-by: Pratikkumar V Prajapati <pratikkumar.v.prajapati@intel.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Kapil Porwal <kapilporwal@google.com>
Reviewed-by: Eric Lai <ericllai@google.com>
Reviewed-by: Subrata Banik <subratabanik@google.com>

src/soc/intel/common/block/cse/cse_lite.c

@@ -1122,6 +1122,30 @@ static void initiate_psr_data_backup(void)
 	backup_psr_data();
 }
 
+/*
+ * Check if a CSE Firmware update is required
+ * returns true if an update is required, false otherwise
+ */
+bool is_cse_fw_update_required(void)
+{
+	struct fw_version cbfs_rw_version;
+
+	if (!is_cse_fw_update_enabled())
+		return false;
+
+	/*
+	 * First, check if cse_bp_info_rsp global structure is populated.
+	 * If not, it implies that cse_fill_bp_info() function is not called.
+	 */
+	if (!is_cse_bp_info_valid(&cse_bp_info_rsp))
+		return false;
+
+	if (get_cse_ver_from_cbfs(&cbfs_rw_version) == CB_ERR)
+		return false;
+
+	return !!cse_compare_sub_part_version(&cbfs_rw_version, cse_get_rw_version());
+}
+
 static uint8_t cse_fw_update(void)
 {
 	struct region_device target_rdev;

src/soc/intel/common/block/include/intelblocks/cse.h

@@ -611,4 +611,9 @@ enum cb_err cse_get_fw_feature_state(uint32_t *feature_state);
 /* Fills the CSE Boot Partition Info response */
 void cse_fill_bp_info(void);
 
+/*
+ * Check if a CSE Firmware update is required
+ * Returns true if an update is required, false otherwise
+ */
+bool is_cse_fw_update_required(void);
 #endif // SOC_INTEL_COMMON_CSE_H