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authorAndrey Petrov <andrey.petrov@intel.com>2016-11-30 17:58:38 -0800
committerAaron Durbin <adurbin@chromium.org>2016-12-02 16:39:55 +0100
commit89e39b5c55cd7612c70cb25d2b2000965cc25539 (patch)
tree86dffb03b8280f1eb34ea66a2bee4f041dc00ad2
parent3b637531c91d0cb290dcff26584274f41c06ec85 (diff)
downloadcoreboot-89e39b5c55cd7612c70cb25d2b2000965cc25539.tar.xz
soc/intel/apollolake: Drop privilege level to IA_UNTRUSTED
As per guidelines CPU security level should be dropped before OS start, so that certain MSRs are locked out. Drop privilege levels on all logical CPUs. BUG=chrome-os-partner:60454 TEST=iotools rdmsr x 0x120, make sure bit 6 is set, rdmsr x 0x121 results in io error. Change-Id: I67540f6da16f58b822db9160d00b7a5e235188db Signed-off-by: Andrey Petrov <andrey.petrov@intel.com> Reviewed-on: https://review.coreboot.org/17665 Reviewed-by: Aaron Durbin <adurbin@chromium.org> Tested-by: build bot (Jenkins)
-rw-r--r--src/soc/intel/apollolake/car.c2
-rw-r--r--src/soc/intel/apollolake/cpu.c9
-rw-r--r--src/soc/intel/apollolake/include/soc/cpu.h2
3 files changed, 12 insertions, 1 deletions
diff --git a/src/soc/intel/apollolake/car.c b/src/soc/intel/apollolake/car.c
index 68bcb31eb1..d58dc0a403 100644
--- a/src/soc/intel/apollolake/car.c
+++ b/src/soc/intel/apollolake/car.c
@@ -28,7 +28,7 @@
static void flush_l1d_to_l2(void)
{
msr_t msr = rdmsr(MSR_POWER_MISC);
- msr.lo |= (1 << 8);
+ msr.lo |= FLUSH_DL1_L2;
wrmsr(MSR_POWER_MISC, msr);
}
diff --git a/src/soc/intel/apollolake/cpu.c b/src/soc/intel/apollolake/cpu.c
index 949736821e..8b8f963e4c 100644
--- a/src/soc/intel/apollolake/cpu.c
+++ b/src/soc/intel/apollolake/cpu.c
@@ -53,6 +53,13 @@ static const struct reg_script core_msr_script[] = {
REG_SCRIPT_END
};
+static void enable_untrusted_mode(void)
+{
+ msr_t msr = rdmsr(MSR_POWER_MISC);
+ msr.lo |= ENABLE_IA_UNTRUSTED;
+ wrmsr(MSR_POWER_MISC, msr);
+}
+
static void soc_core_init(device_t cpu)
{
/* Set core MSRs */
@@ -63,6 +70,8 @@ static void soc_core_init(device_t cpu)
* implemented in microcode.
*/
enable_pm_timer_emulation();
+ /* Drop privilege level */
+ enable_untrusted_mode();
}
static struct device_operations cpu_dev_ops = {
diff --git a/src/soc/intel/apollolake/include/soc/cpu.h b/src/soc/intel/apollolake/include/soc/cpu.h
index 38ce4ff913..db9d3dde05 100644
--- a/src/soc/intel/apollolake/include/soc/cpu.h
+++ b/src/soc/intel/apollolake/include/soc/cpu.h
@@ -31,6 +31,8 @@ void set_max_freq(void);
#define MSR_PLATFORM_INFO 0xce
#define MSR_POWER_MISC 0x120
+#define ENABLE_IA_UNTRUSTED (1 << 6)
+#define FLUSH_DL1_L2 (1 << 8)
#define MSR_CORE_THREAD_COUNT 0x35
#define MSR_EVICT_CTL 0x2e0
#define MSR_EMULATE_PM_TMR 0x121