soc/intel/common/cpu: Use SoC overrides to set CPU privilege level

This patch implements a SoC overrides to set CPU privilege level
as the MSR is not consistent across platforms. For example:
On APL/GLK/DNV, it's MSR 0x120 and CNL onwards it's MSR 0x151.

BUG=b:233199592
TEST=Build and boot google/taeko to ChromeOS.

Signed-off-by: Subrata Banik <subratabanik@google.com>
Change-Id: I4584516102560e6bb2a4ae8c0d036be40ed96990
Reviewed-on: https://review.coreboot.org/c/coreboot/+/64806
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
Reviewed-by: Lean Sheng Tan <sheng.tan@9elements.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/src/soc/intel/skylake/cpu.c b/src/soc/intel/skylake/cpu.c
index 3439836f24..26ab2712a9 100644
--- a/src/soc/intel/skylake/cpu.c
+++ b/src/soc/intel/skylake/cpu.c
@@ -27,6 +27,10 @@
 
 bool cpu_soc_is_in_untrusted_mode(void)
 {
+	/*
+	 * TODO: Add dynamic detection to identify if skylake SoC
+	 * is in coffeelake board.
+	 */
 	if (!CONFIG(MAINBOARD_SUPPORTS_COFFEELAKE_CPU))
 		return false;
 
@@ -35,6 +39,18 @@ bool cpu_soc_is_in_untrusted_mode(void)
 	return !!(msr.lo & ENABLE_IA_UNTRUSTED);
 }
 
+void cpu_soc_bios_done(void)
+{
+	if (!CONFIG(MAINBOARD_SUPPORTS_COFFEELAKE_CPU))
+		return;
+
+	msr_t msr;
+
+	msr = rdmsr(MSR_BIOS_DONE);
+	msr.lo |= ENABLE_IA_UNTRUSTED;
+	wrmsr(MSR_BIOS_DONE, msr);
+}
+
 static void configure_misc(void)
 {
 	config_t *conf = config_of_soc();