cpu/intel: Configure IA32_FEATURE_CONTROL for alternative SMRR

Some CPUs, (Intel core2 and pineview) have slightly different SMRR
MTRR mechanism. The MSR_SMRR_PHYSBASE/MASK MSRs are at a different
location, have slightly different semantics and need SMRR enable in a
locked down IA32_FEATURE_CONTROL MSR.

This change takes away the possibility to (not) lock
IA32_FEATURE_CONTROL on these CPUs, as this is needed for SMRR MSR to
work. Since sockets cover multiple CPUs of which only some support
SMRR, the Kconfig option CONFIG_SET_IA32_FC_LOCK_BIT is kept in place,
even though it gets meaningless on those CPUs. Locking that bit was
the default anyway.

With this patch Intel Netburst CPUs also configure
IA32_FEATURE_CONTROL. According to Intel 64 and IA-32 Architectures
Software Developer's Manual those CPUs support that MSR so issues are
not to be expected.

Change-Id: Ia85602e75385e24ebded75e6e6dd38ccc969a76b
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/27586
Tested-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Martin Roth <martinroth@google.com>

5 files changed, 18 insertions, 12 deletions

diff --git a/src/cpu/intel/model_1067x/model_1067x_init.c b/src/cpu/intel/model_1067x/model_1067x_init.c
index 275ff70267..6068be166d 100644
--- a/src/cpu/intel/model_1067x/model_1067x_init.c
+++ b/src/cpu/intel/model_1067x/model_1067x_init.c
@@ -287,9 +287,6 @@ static void model_1067x_init(struct device *cpu)
 	/* Initialize the APIC timer */
 	init_timer();
 
-	/* Set virtualization based on Kconfig option */
-	set_vmx_and_lock();
-
 	/* Configure C States */
 	configure_c_states(quad);
 
diff --git a/src/cpu/intel/model_1067x/mp_init.c b/src/cpu/intel/model_1067x/mp_init.c
index 52e9d3f010..ab7785989d 100644
--- a/src/cpu/intel/model_1067x/mp_init.c
+++ b/src/cpu/intel/model_1067x/mp_init.c
@@ -49,8 +49,26 @@ static void pre_mp_smm_init(void)
 	smm_initialize();
 }
 
+#define SMRR_SUPPORTED (1 << 11)
+
 static void per_cpu_smm_trigger(void)
 {
+	msr_t mtrr_cap = rdmsr(MTRR_CAP_MSR);
+	if (cpu_has_alternative_smrr() && mtrr_cap.lo & SMRR_SUPPORTED) {
+		set_feature_ctrl_vmx();
+		msr_t ia32_ft_ctrl = rdmsr(IA32_FEATURE_CONTROL);
+		/* 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);
+	} else {
+		set_vmx_and_lock();
+	}
+
 	/* Relocate the SMM handler. */
 	smm_relocate();
 
diff --git a/src/cpu/intel/model_106cx/model_106cx_init.c b/src/cpu/intel/model_106cx/model_106cx_init.c
index 75e110683e..e44302606e 100644
--- a/src/cpu/intel/model_106cx/model_106cx_init.c
+++ b/src/cpu/intel/model_106cx/model_106cx_init.c
@@ -88,9 +88,6 @@ static void model_106cx_init(struct device *cpu)
 	/* Enable the local CPU APICs */
 	setup_lapic();
 
-	/* Set virtualization based on Kconfig option */
-	set_vmx_and_lock();
-
 	/* Configure C States */
 	configure_c_states();
 
diff --git a/src/cpu/intel/model_6ex/model_6ex_init.c b/src/cpu/intel/model_6ex/model_6ex_init.c
index 72a259d34f..19a22f1839 100644
--- a/src/cpu/intel/model_6ex/model_6ex_init.c
+++ b/src/cpu/intel/model_6ex/model_6ex_init.c
@@ -125,9 +125,6 @@ static void model_6ex_init(struct device *cpu)
 	/* Enable the local CPU APICs */
 	setup_lapic();
 
-	/* Set virtualization based on Kconfig option */
-	set_vmx_and_lock();
-
 	/* Configure C States */
 	configure_c_states();
 
diff --git a/src/cpu/intel/model_6fx/model_6fx_init.c b/src/cpu/intel/model_6fx/model_6fx_init.c
index 16ddcc4c28..4e198961ce 100644
--- a/src/cpu/intel/model_6fx/model_6fx_init.c
+++ b/src/cpu/intel/model_6fx/model_6fx_init.c
@@ -139,9 +139,6 @@ static void model_6fx_init(struct device *cpu)
 	/* Enable the local CPU APICs */
 	setup_lapic();
 
-	/* Set virtualization based on Kconfig option */
-	set_vmx_and_lock();
-
 	/* Configure C States */
 	configure_c_states();