From 667108199a04972ebd83c8a0430f2dddd6009879 Mon Sep 17 00:00:00 2001 From: Arthur Heymans Date: Wed, 6 Feb 2019 13:47:58 +0100 Subject: [PATCH] cpu/intel/model_1067x: Check for lock bit on IA32_FEATURE_CONTROL df7aecd "cpu/intel: Configure IA32_FEATURE_CONTROL for alternative SMRR" introduced a regression because it unconditionally writes to IA32_FEATURE_CONTROL, which if it is already locked results in an unhandled exception. The lock bit is already set on a system reboot. Change-Id: I7d2df9e1b9d767809da7a61ccd877c6c40f132eb Signed-off-by: Arthur Heymans Reviewed-on: https://review.coreboot.org/c/31255 Reviewed-by: Patrick Rudolph Reviewed-by: Bill XIE Reviewed-by: Paul Menzel Tested-by: build bot (Jenkins) --- src/cpu/intel/model_1067x/mp_init.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/src/cpu/intel/model_1067x/mp_init.c b/src/cpu/intel/model_1067x/mp_init.c index ab7785989d..acd56c82a8 100644 --- a/src/cpu/intel/model_1067x/mp_init.c +++ b/src/cpu/intel/model_1067x/mp_init.c @@ -60,11 +60,19 @@ static void per_cpu_smm_trigger(void) /* We don't care if the lock is already setting as our smm relocation handler is able to handle setups where SMRR is not enabled here. */ - if (!IS_ENABLED(CONFIG_SET_IA32_FC_LOCK_BIT)) - printk(BIOS_INFO, - "Overriding CONFIG_SET_IA32_FC_LOCK_BIT to enable SMRR\n"); - ia32_ft_ctrl.lo |= (1 << 3) | (1 << 0); - wrmsr(IA32_FEATURE_CONTROL, ia32_ft_ctrl); + if (ia32_ft_ctrl.lo & (1 << 0)) { + /* IA32_FEATURE_CONTROL locked. If we set it again we + get an illegal instruction. */ + printk(BIOS_DEBUG, "IA32_FEATURE_CONTROL already locked\n"); + printk(BIOS_DEBUG, "SMRR status: %senabled\n", + ia32_ft_ctrl.lo & (1 << 3) ? "" : "not "); + } else { + if (!IS_ENABLED(CONFIG_SET_IA32_FC_LOCK_BIT)) + printk(BIOS_INFO, + "Overriding CONFIG_SET_IA32_FC_LOCK_BIT to enable SMRR\n"); + ia32_ft_ctrl.lo |= (1 << 3) | (1 << 0); + wrmsr(IA32_FEATURE_CONTROL, ia32_ft_ctrl); + } } else { set_vmx_and_lock(); }