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Diffstat (limited to 'src/cpu/intel/turbo')
-rw-r--r--src/cpu/intel/turbo/turbo.c45
1 files changed, 28 insertions, 17 deletions
diff --git a/src/cpu/intel/turbo/turbo.c b/src/cpu/intel/turbo/turbo.c
index 12cbfc0b81..ae97f9a8cf 100644
--- a/src/cpu/intel/turbo/turbo.c
+++ b/src/cpu/intel/turbo/turbo.c
@@ -50,21 +50,15 @@ static const char *const turbo_state_desc[] = {
};
/*
- * Determine the current state of Turbo and cache it for later.
- * Turbo is a package level config so it does not need to be
- * enabled on every core.
+ * Try to update the global Turbo state.
*/
-int get_turbo_state(void)
+static int update_turbo_state(void)
{
struct cpuid_result cpuid_regs;
int turbo_en, turbo_cap;
msr_t msr;
int turbo_state = get_global_turbo_state();
- /* Return cached state if available */
- if (turbo_state != TURBO_UNKNOWN)
- return turbo_state;
-
cpuid_regs = cpuid(CPUID_LEAF_PM);
turbo_cap = !!(cpuid_regs.eax & PM_CAP_TURBO_MODE);
@@ -84,6 +78,22 @@ int get_turbo_state(void)
set_global_turbo_state(turbo_state);
printk(BIOS_INFO, "Turbo is %s\n", turbo_state_desc[turbo_state]);
+
+ return turbo_state;
+}
+
+/*
+ * Determine the current state of Turbo and cache it for later. Turbo is package
+ * level config so it does not need to be enabled on every core.
+ */
+int get_turbo_state(void)
+{
+ int turbo_state = get_global_turbo_state();
+
+ /* Return cached state if available */
+ if (turbo_state == TURBO_UNKNOWN)
+ turbo_state = update_turbo_state();
+
return turbo_state;
}
@@ -102,8 +112,7 @@ void enable_turbo(void)
wrmsr(IA32_MISC_ENABLE, msr);
/* Update cached turbo state */
- set_global_turbo_state(TURBO_ENABLED);
- printk(BIOS_INFO, "Turbo has been enabled\n");
+ update_turbo_state();
}
}
@@ -114,12 +123,14 @@ void disable_turbo(void)
{
msr_t msr;
- /* Set Turbo Disable bit in Misc Enables */
- msr = rdmsr(IA32_MISC_ENABLE);
- msr.hi |= H_MISC_DISABLE_TURBO;
- wrmsr(IA32_MISC_ENABLE, msr);
+ /* Only possible if turbo is available and visible */
+ if (get_turbo_state() == TURBO_ENABLED) {
+ /* Set Turbo Disable bit in Misc Enables */
+ msr = rdmsr(IA32_MISC_ENABLE);
+ msr.hi |= H_MISC_DISABLE_TURBO;
+ wrmsr(IA32_MISC_ENABLE, msr);
- /* Update cached turbo state */
- set_global_turbo_state(TURBO_UNAVAILABLE);
- printk(BIOS_INFO, "Turbo has been disabled\n");
+ /* Update cached turbo state */
+ update_turbo_state();
+ }
}