aboutsummaryrefslogtreecommitdiffstats
path: root/arch/x86/kernel/cpu/cpufreq/speedstep-smi.c
diff options
context:
space:
mode:
authorThomas Gleixner <tglx@linutronix.de>2007-10-11 11:16:27 +0200
committerThomas Gleixner <tglx@linutronix.de>2007-10-11 11:16:27 +0200
commitee580dc91efd83e6b55955e7261e8ad2a0e08d1a (patch)
treea6f0884e77913df35ae4219fa66fa0c95359c5cf /arch/x86/kernel/cpu/cpufreq/speedstep-smi.c
parentc18db0d7e299791c73d4dbe5ae7905b2ab8ba332 (diff)
i386: move kernel/cpu/cpufreq
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/cpu/cpufreq/speedstep-smi.c')
-rw-r--r--arch/x86/kernel/cpu/cpufreq/speedstep-smi.c424
1 files changed, 424 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/cpufreq/speedstep-smi.c b/arch/x86/kernel/cpu/cpufreq/speedstep-smi.c
new file mode 100644
index 000000000000..e1c509aa3054
--- /dev/null
+++ b/arch/x86/kernel/cpu/cpufreq/speedstep-smi.c
@@ -0,0 +1,424 @@
+/*
+ * Intel SpeedStep SMI driver.
+ *
+ * (C) 2003 Hiroshi Miura <miura@da-cha.org>
+ *
+ * Licensed under the terms of the GNU GPL License version 2.
+ *
+ */
+
+
+/*********************************************************************
+ * SPEEDSTEP - DEFINITIONS *
+ *********************************************************************/
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/init.h>
+#include <linux/cpufreq.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <asm/ist.h>
+#include <asm/io.h>
+
+#include "speedstep-lib.h"
+
+/* speedstep system management interface port/command.
+ *
+ * These parameters are got from IST-SMI BIOS call.
+ * If user gives it, these are used.
+ *
+ */
+static int smi_port = 0;
+static int smi_cmd = 0;
+static unsigned int smi_sig = 0;
+
+/* info about the processor */
+static unsigned int speedstep_processor = 0;
+
+/*
+ * There are only two frequency states for each processor. Values
+ * are in kHz for the time being.
+ */
+static struct cpufreq_frequency_table speedstep_freqs[] = {
+ {SPEEDSTEP_HIGH, 0},
+ {SPEEDSTEP_LOW, 0},
+ {0, CPUFREQ_TABLE_END},
+};
+
+#define GET_SPEEDSTEP_OWNER 0
+#define GET_SPEEDSTEP_STATE 1
+#define SET_SPEEDSTEP_STATE 2
+#define GET_SPEEDSTEP_FREQS 4
+
+/* how often shall the SMI call be tried if it failed, e.g. because
+ * of DMA activity going on? */
+#define SMI_TRIES 5
+
+#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "speedstep-smi", msg)
+
+/**
+ * speedstep_smi_ownership
+ */
+static int speedstep_smi_ownership (void)
+{
+ u32 command, result, magic;
+ u32 function = GET_SPEEDSTEP_OWNER;
+ unsigned char magic_data[] = "Copyright (c) 1999 Intel Corporation";
+
+ command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);
+ magic = virt_to_phys(magic_data);
+
+ dprintk("trying to obtain ownership with command %x at port %x\n", command, smi_port);
+
+ __asm__ __volatile__(
+ "out %%al, (%%dx)\n"
+ : "=D" (result)
+ : "a" (command), "b" (function), "c" (0), "d" (smi_port),
+ "D" (0), "S" (magic)
+ : "memory"
+ );
+
+ dprintk("result is %x\n", result);
+
+ return result;
+}
+
+/**
+ * speedstep_smi_get_freqs - get SpeedStep preferred & current freq.
+ * @low: the low frequency value is placed here
+ * @high: the high frequency value is placed here
+ *
+ * Only available on later SpeedStep-enabled systems, returns false results or
+ * even hangs [cf. bugme.osdl.org # 1422] on earlier systems. Empirical testing
+ * shows that the latter occurs if !(ist_info.event & 0xFFFF).
+ */
+static int speedstep_smi_get_freqs (unsigned int *low, unsigned int *high)
+{
+ u32 command, result = 0, edi, high_mhz, low_mhz;
+ u32 state=0;
+ u32 function = GET_SPEEDSTEP_FREQS;
+
+ if (!(ist_info.event & 0xFFFF)) {
+ dprintk("bug #1422 -- can't read freqs from BIOS\n");
+ return -ENODEV;
+ }
+
+ command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);
+
+ dprintk("trying to determine frequencies with command %x at port %x\n", command, smi_port);
+
+ __asm__ __volatile__("movl $0, %%edi\n"
+ "out %%al, (%%dx)\n"
+ : "=a" (result), "=b" (high_mhz), "=c" (low_mhz), "=d" (state), "=D" (edi)
+ : "a" (command), "b" (function), "c" (state), "d" (smi_port), "S" (0)
+ );
+
+ dprintk("result %x, low_freq %u, high_freq %u\n", result, low_mhz, high_mhz);
+
+ /* abort if results are obviously incorrect... */
+ if ((high_mhz + low_mhz) < 600)
+ return -EINVAL;
+
+ *high = high_mhz * 1000;
+ *low = low_mhz * 1000;
+
+ return result;
+}
+
+/**
+ * speedstep_get_state - set the SpeedStep state
+ * @state: processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH)
+ *
+ */
+static int speedstep_get_state (void)
+{
+ u32 function=GET_SPEEDSTEP_STATE;
+ u32 result, state, edi, command;
+
+ command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);
+
+ dprintk("trying to determine current setting with command %x at port %x\n", command, smi_port);
+
+ __asm__ __volatile__("movl $0, %%edi\n"
+ "out %%al, (%%dx)\n"
+ : "=a" (result), "=b" (state), "=D" (edi)
+ : "a" (command), "b" (function), "c" (0), "d" (smi_port), "S" (0)
+ );
+
+ dprintk("state is %x, result is %x\n", state, result);
+
+ return (state & 1);
+}
+
+
+/**
+ * speedstep_set_state - set the SpeedStep state
+ * @state: new processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH)
+ *
+ */
+static void speedstep_set_state (unsigned int state)
+{
+ unsigned int result = 0, command, new_state;
+ unsigned long flags;
+ unsigned int function=SET_SPEEDSTEP_STATE;
+ unsigned int retry = 0;
+
+ if (state > 0x1)
+ return;
+
+ /* Disable IRQs */
+ local_irq_save(flags);
+
+ command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);
+
+ dprintk("trying to set frequency to state %u with command %x at port %x\n", state, command, smi_port);
+
+ do {
+ if (retry) {
+ dprintk("retry %u, previous result %u, waiting...\n", retry, result);
+ mdelay(retry * 50);
+ }
+ retry++;
+ __asm__ __volatile__(
+ "movl $0, %%edi\n"
+ "out %%al, (%%dx)\n"
+ : "=b" (new_state), "=D" (result)
+ : "a" (command), "b" (function), "c" (state), "d" (smi_port), "S" (0)
+ );
+ } while ((new_state != state) && (retry <= SMI_TRIES));
+
+ /* enable IRQs */
+ local_irq_restore(flags);
+
+ if (new_state == state) {
+ dprintk("change to %u MHz succeeded after %u tries with result %u\n", (speedstep_freqs[new_state].frequency / 1000), retry, result);
+ } else {
+ printk(KERN_ERR "cpufreq: change failed with new_state %u and result %u\n", new_state, result);
+ }
+
+ return;
+}
+
+
+/**
+ * speedstep_target - set a new CPUFreq policy
+ * @policy: new policy
+ * @target_freq: new freq
+ * @relation:
+ *
+ * Sets a new CPUFreq policy/freq.
+ */
+static int speedstep_target (struct cpufreq_policy *policy,
+ unsigned int target_freq, unsigned int relation)
+{
+ unsigned int newstate = 0;
+ struct cpufreq_freqs freqs;
+
+ if (cpufreq_frequency_table_target(policy, &speedstep_freqs[0], target_freq, relation, &newstate))
+ return -EINVAL;
+
+ freqs.old = speedstep_freqs[speedstep_get_state()].frequency;
+ freqs.new = speedstep_freqs[newstate].frequency;
+ freqs.cpu = 0; /* speedstep.c is UP only driver */
+
+ if (freqs.old == freqs.new)
+ return 0;
+
+ cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
+ speedstep_set_state(newstate);
+ cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
+
+ return 0;
+}
+
+
+/**
+ * speedstep_verify - verifies a new CPUFreq policy
+ * @policy: new policy
+ *
+ * Limit must be within speedstep_low_freq and speedstep_high_freq, with
+ * at least one border included.
+ */
+static int speedstep_verify (struct cpufreq_policy *policy)
+{
+ return cpufreq_frequency_table_verify(policy, &speedstep_freqs[0]);
+}
+
+
+static int speedstep_cpu_init(struct cpufreq_policy *policy)
+{
+ int result;
+ unsigned int speed,state;
+
+ /* capability check */
+ if (policy->cpu != 0)
+ return -ENODEV;
+
+ result = speedstep_smi_ownership();
+ if (result) {
+ dprintk("fails in aquiring ownership of a SMI interface.\n");
+ return -EINVAL;
+ }
+
+ /* detect low and high frequency */
+ result = speedstep_smi_get_freqs(&speedstep_freqs[SPEEDSTEP_LOW].frequency,
+ &speedstep_freqs[SPEEDSTEP_HIGH].frequency);
+ if (result) {
+ /* fall back to speedstep_lib.c dection mechanism: try both states out */
+ dprintk("could not detect low and high frequencies by SMI call.\n");
+ result = speedstep_get_freqs(speedstep_processor,
+ &speedstep_freqs[SPEEDSTEP_LOW].frequency,
+ &speedstep_freqs[SPEEDSTEP_HIGH].frequency,
+ NULL,
+ &speedstep_set_state);
+
+ if (result) {
+ dprintk("could not detect two different speeds -- aborting.\n");
+ return result;
+ } else
+ dprintk("workaround worked.\n");
+ }
+
+ /* get current speed setting */
+ state = speedstep_get_state();
+ speed = speedstep_freqs[state].frequency;
+
+ dprintk("currently at %s speed setting - %i MHz\n",
+ (speed == speedstep_freqs[SPEEDSTEP_LOW].frequency) ? "low" : "high",
+ (speed / 1000));
+
+ /* cpuinfo and default policy values */
+ policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
+ policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
+ policy->cur = speed;
+
+ result = cpufreq_frequency_table_cpuinfo(policy, speedstep_freqs);
+ if (result)
+ return (result);
+
+ cpufreq_frequency_table_get_attr(speedstep_freqs, policy->cpu);
+
+ return 0;
+}
+
+static int speedstep_cpu_exit(struct cpufreq_policy *policy)
+{
+ cpufreq_frequency_table_put_attr(policy->cpu);
+ return 0;
+}
+
+static unsigned int speedstep_get(unsigned int cpu)
+{
+ if (cpu)
+ return -ENODEV;
+ return speedstep_get_processor_frequency(speedstep_processor);
+}
+
+
+static int speedstep_resume(struct cpufreq_policy *policy)
+{
+ int result = speedstep_smi_ownership();
+
+ if (result)
+ dprintk("fails in re-aquiring ownership of a SMI interface.\n");
+
+ return result;
+}
+
+static struct freq_attr* speedstep_attr[] = {
+ &cpufreq_freq_attr_scaling_available_freqs,
+ NULL,
+};
+
+static struct cpufreq_driver speedstep_driver = {
+ .name = "speedstep-smi",
+ .verify = speedstep_verify,
+ .target = speedstep_target,
+ .init = speedstep_cpu_init,
+ .exit = speedstep_cpu_exit,
+ .get = speedstep_get,
+ .resume = speedstep_resume,
+ .owner = THIS_MODULE,
+ .attr = speedstep_attr,
+};
+
+/**
+ * speedstep_init - initializes the SpeedStep CPUFreq driver
+ *
+ * Initializes the SpeedStep support. Returns -ENODEV on unsupported
+ * BIOS, -EINVAL on problems during initiatization, and zero on
+ * success.
+ */
+static int __init speedstep_init(void)
+{
+ speedstep_processor = speedstep_detect_processor();
+
+ switch (speedstep_processor) {
+ case SPEEDSTEP_PROCESSOR_PIII_T:
+ case SPEEDSTEP_PROCESSOR_PIII_C:
+ case SPEEDSTEP_PROCESSOR_PIII_C_EARLY:
+ break;
+ default:
+ speedstep_processor = 0;
+ }
+
+ if (!speedstep_processor) {
+ dprintk ("No supported Intel CPU detected.\n");
+ return -ENODEV;
+ }
+
+ dprintk("signature:0x%.8lx, command:0x%.8lx, event:0x%.8lx, perf_level:0x%.8lx.\n",
+ ist_info.signature, ist_info.command, ist_info.event, ist_info.perf_level);
+
+ /* Error if no IST-SMI BIOS or no PARM
+ sig= 'ISGE' aka 'Intel Speedstep Gate E' */
+ if ((ist_info.signature != 0x47534943) && (
+ (smi_port == 0) || (smi_cmd == 0)))
+ return -ENODEV;
+
+ if (smi_sig == 1)
+ smi_sig = 0x47534943;
+ else
+ smi_sig = ist_info.signature;
+
+ /* setup smi_port from MODLULE_PARM or BIOS */
+ if ((smi_port > 0xff) || (smi_port < 0))
+ return -EINVAL;
+ else if (smi_port == 0)
+ smi_port = ist_info.command & 0xff;
+
+ if ((smi_cmd > 0xff) || (smi_cmd < 0))
+ return -EINVAL;
+ else if (smi_cmd == 0)
+ smi_cmd = (ist_info.command >> 16) & 0xff;
+
+ return cpufreq_register_driver(&speedstep_driver);
+}
+
+
+/**
+ * speedstep_exit - unregisters SpeedStep support
+ *
+ * Unregisters SpeedStep support.
+ */
+static void __exit speedstep_exit(void)
+{
+ cpufreq_unregister_driver(&speedstep_driver);
+}
+
+module_param(smi_port, int, 0444);
+module_param(smi_cmd, int, 0444);
+module_param(smi_sig, uint, 0444);
+
+MODULE_PARM_DESC(smi_port, "Override the BIOS-given IST port with this value -- Intel's default setting is 0xb2");
+MODULE_PARM_DESC(smi_cmd, "Override the BIOS-given IST command with this value -- Intel's default setting is 0x82");
+MODULE_PARM_DESC(smi_sig, "Set to 1 to fake the IST signature when using the SMI interface.");
+
+MODULE_AUTHOR ("Hiroshi Miura");
+MODULE_DESCRIPTION ("Speedstep driver for IST applet SMI interface.");
+MODULE_LICENSE ("GPL");
+
+module_init(speedstep_init);
+module_exit(speedstep_exit);

Privacy Policy