drivers/intel/fsp2_0: Do AP re-init after FSP-S if USE_INTEL_FSP_MP_INIT enable

This patch ensures that coreboot is able to take control of APs back
by doing a full AP re-initialization after FSP-S is done.

TEST=Able to see all cores available after booting to OS using below command
when coreboot is built with USE_INTEL_FSP_MP_INIT enable.

> cat /proc/cpuinfo

Without this CL :

shows only 1 core (only BSP)

With this CL :

shows all possible cores available (BSP + APs)

Change-Id: I247d8d1166c77bd01922323b6a0f14ec6640a666
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/44077
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Patrick Rudolph <siro@das-labor.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/src/drivers/intel/fsp2_0/fsp_mpinit.c b/src/drivers/intel/fsp2_0/fsp_mpinit.c
new file mode 100644
index 0000000000..cda9269cb8
--- /dev/null
+++ b/src/drivers/intel/fsp2_0/fsp_mpinit.c
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <fsp/api.h>
+#include <intelblocks/mp_init.h>
+
+/*
+ * As per FSP integration guide:
+ * If bootloader needs to take control of APs back, a full AP re-initialization is
+ * required after FSP-S is completed and control has been transferred back to bootloader
+ */
+void do_mpinit_after_fsp(void)
+{
+	init_cpus();
+}