mb/ocp/wedge100s/romstage: Workaround broken platform state

Sometimes the platform boots in an invalid state, that will cause
FSP-M to fail. As a board_reset() doesn't fix it, issue an full_reset()
as soon as the IA32_FEATURE_CONTROL MSR is locked at beging of romstage.

Tested on wedge100s. After full reset the system behaves as normal.

Change-Id: I1a382b8fb650311b0c24b48e0986d22edfa2d261
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/30290
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com>

src/mainboard/ocp/wedge100s/romstage.c

@@ -17,6 +17,9 @@
 #include <stddef.h>
 #include <soc/romstage.h>
 #include <drivers/intel/fsp1_0/fsp_util.h>
+#include <cpu/x86/msr.h>
+#include <cf9_reset.h>
+#include <console/console.h>
 
 /**
  * /brief mainboard call for setup that needs to be done before fsp init
@@ -24,7 +27,22 @@
  */
 void early_mainboard_romstage_entry(void)
 {
-
+	/*
+	 * Sometimes the system boots in an invalid state, where random values
+	 * have been written to MSRs and then the MSRs are locked.
+	 * Seems to always happen on warm reset.
+	 *
+	 * Power cycling or a board_reset() isn't sufficient in this case, so
+	 * issue a full_reset() to "fix" this issue.
+	 *
+	 * It seems to be a deficiency in the reset logic, as other
+	 * FSP broadwell DE boards are not affected.
+	 */
+	msr_t msr = rdmsr(IA32_FEATURE_CONTROL);
+	if (msr.lo & 1) {
+		printk(BIOS_EMERG, "Detected broken platform state. Issuing full reset\n");
+		full_reset();
+	}
 }
 
 /**