New patch to review for coreboot: soc/intel/apollolake: Drop CPU privilege mode later on

[Andrey Petrov]

Andrey Petrov ([e-mail]) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/17769

-gerrit

commit bd1f0c7dc6ce3acb3e98da7d65453f4a350db463
Author: Andrey Petrov 
Date:   Wed Dec 7 10:47:46 2016 -0800

soc/intel/apollolake: Drop CPU privilege mode later on

Drop CPU privilege mode later, after all the FSP stages are
    complete.

BRANCH=reef
    BUG=chrome-os-partner:60657
    TEST=iotools rdmsr X 0x121, make sure they can't be read

Change-Id: Ia3a774aee5fbf92805a5c69093bfbd3d7682c3a7
    Signed-off-by: Andrey Petrov 
---
 src/soc/intel/apollolake/cpu.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/src/soc/intel/apollolake/cpu.c b/src/soc/intel/apollolake/cpu.c
index 8b8f963..d46bcbe 100644
--- a/src/soc/intel/apollolake/cpu.c
+++ b/src/soc/intel/apollolake/cpu.c
@@ -211,3 +211,20 @@ void apollolake_init_cpus(device_t dev)
    	mtrr_use_temp_range(-CONFIG_ROM_SIZE, CONFIG_ROM_SIZE,
    				MTRR_TYPE_WRPROT);
 }
+
+void soc_coreboot_exit(void)
+{
+	/* Drop privilege level on BSP first */
+	enable_untrusted_mode();
+	/* .. then all APs */
+	if (mp_run_on_aps(&enable_untrusted_mode, 1000) < 0)
+		printk(BIOS_ERR, "failed to enable untrusted mode\n");
+
+	/* Since we use PARALLEL_MP_AP_WORK, park APs */
+	mp_park_aps();
+}
+
+void arch_bootstate_coreboot_exit(void)
+{
+	soc_coreboot_exit();
+}