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-rw-r--r--src/cpu/intel/turbo/Makefile.inc1
-rw-r--r--src/cpu/intel/turbo/turbo.c90
-rw-r--r--src/include/cpu/intel/turbo.h44
3 files changed, 135 insertions, 0 deletions
diff --git a/src/cpu/intel/turbo/Makefile.inc b/src/cpu/intel/turbo/Makefile.inc
new file mode 100644
index 0000000000..48ec55db1d
--- /dev/null
+++ b/src/cpu/intel/turbo/Makefile.inc
@@ -0,0 +1 @@
+ramstage-y += turbo.c
diff --git a/src/cpu/intel/turbo/turbo.c b/src/cpu/intel/turbo/turbo.c
new file mode 100644
index 0000000000..779550e26b
--- /dev/null
+++ b/src/cpu/intel/turbo/turbo.c
@@ -0,0 +1,90 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2011 The ChromiumOS Authors. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; version 2 of
+ * the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
+ * MA 02110-1301 USA
+ */
+
+#include <console/console.h>
+#include <cpu/intel/turbo.h>
+#include <cpu/x86/msr.h>
+#include <arch/cpu.h>
+
+static int turbo_state = TURBO_UNKNOWN;
+
+static const char *turbo_state_desc[] = {
+ [TURBO_UNKNOWN] = "unknown",
+ [TURBO_UNAVAILABLE] = "unavailable",
+ [TURBO_DISABLED] = "available but hidden",
+ [TURBO_ENABLED] = "available and visible"
+};
+
+/*
+ * 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.
+ */
+int get_turbo_state(void)
+{
+ struct cpuid_result cpuid_regs;
+ int turbo_en, turbo_cap;
+ msr_t msr;
+
+ /* 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);
+
+ msr = rdmsr(MSR_IA32_MISC_ENABLES);
+ turbo_en = !(msr.hi & H_MISC_DISABLE_TURBO);
+
+ if (!turbo_cap && turbo_en) {
+ /* Unavailable */
+ turbo_state = TURBO_UNAVAILABLE;
+ } else if (!turbo_cap && !turbo_en) {
+ /* Available but disabled */
+ turbo_state = TURBO_DISABLED;
+ } else if (turbo_cap && turbo_en) {
+ /* Available */
+ turbo_state = TURBO_ENABLED;
+ }
+
+ printk(BIOS_INFO, "Turbo is %s\n", turbo_state_desc[turbo_state]);
+ return turbo_state;
+}
+
+/*
+ * Try to enable Turbo mode.
+ */
+void enable_turbo(void)
+{
+ msr_t msr;
+
+ /* Only possible if turbo is available but hidden */
+ if (get_turbo_state() == TURBO_DISABLED) {
+ /* Clear Turbo Disable bit in Misc Enables */
+ msr = rdmsr(MSR_IA32_MISC_ENABLES);
+ msr.hi &= ~H_MISC_DISABLE_TURBO;
+ wrmsr(MSR_IA32_MISC_ENABLES, msr);
+
+ /* Update cached turbo state */
+ turbo_state = TURBO_ENABLED;
+ printk(BIOS_INFO, "Turbo has been enabled\n");
+ }
+}
diff --git a/src/include/cpu/intel/turbo.h b/src/include/cpu/intel/turbo.h
new file mode 100644
index 0000000000..b60c8cf817
--- /dev/null
+++ b/src/include/cpu/intel/turbo.h
@@ -0,0 +1,44 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2011 The ChromiumOS Authors. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; version 2 of
+ * the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
+ * MA 02110-1301 USA
+ */
+
+#ifndef _CPU_INTEL_TURBO_H
+#define _CPU_INTEL_TURBO_H
+
+#define CPUID_LEAF_PM 6
+#define PM_CAP_TURBO_MODE (1 << 1)
+
+#define MSR_IA32_MISC_ENABLES 0x1a0
+#define H_MISC_DISABLE_TURBO (1 << 6)
+
+enum {
+ TURBO_UNKNOWN,
+ TURBO_UNAVAILABLE,
+ TURBO_DISABLED,
+ TURBO_ENABLED,
+};
+
+/* Return current turbo state */
+int get_turbo_state(void);
+
+/* Enable turbo */
+void enable_turbo(void);
+
+#endif