--- /dev/null
+/*
+ * acpi-cpufreq.c - ACPI Processor P-States Driver ($Revision: 1.3 $)
+ *
+ * Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
+ * Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ * Copyright (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * 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; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * 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.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#include <linux/config.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/cpufreq.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <asm/io.h>
+#include <asm/delay.h>
+#include <asm/uaccess.h>
+
+#include <linux/acpi.h>
+#include <acpi/processor.h>
+
+#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "acpi-cpufreq", msg)
+
+MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
+MODULE_DESCRIPTION("ACPI Processor P-States Driver");
+MODULE_LICENSE("GPL");
+
+
+struct cpufreq_acpi_io {
+ struct acpi_processor_performance acpi_data;
+ struct cpufreq_frequency_table *freq_table;
+};
+
+static struct cpufreq_acpi_io *acpi_io_data[NR_CPUS];
+
+
+static int
+acpi_processor_write_port(
+ u16 port,
+ u8 bit_width,
+ u32 value)
+{
+ if (bit_width <= 8) {
+ outb(value, port);
+ } else if (bit_width <= 16) {
+ outw(value, port);
+ } else if (bit_width <= 32) {
+ outl(value, port);
+ } else {
+ return -ENODEV;
+ }
+ return 0;
+}
+
+static int
+acpi_processor_read_port(
+ u16 port,
+ u8 bit_width,
+ u32 *ret)
+{
+ *ret = 0;
+ if (bit_width <= 8) {
+ *ret = inb(port);
+ } else if (bit_width <= 16) {
+ *ret = inw(port);
+ } else if (bit_width <= 32) {
+ *ret = inl(port);
+ } else {
+ return -ENODEV;
+ }
+ return 0;
+}
+
+static int
+acpi_processor_set_performance (
+ struct cpufreq_acpi_io *data,
+ unsigned int cpu,
+ int state)
+{
+ u16 port = 0;
+ u8 bit_width = 0;
+ int ret = 0;
+ u32 value = 0;
+ int i = 0;
+ struct cpufreq_freqs cpufreq_freqs;
+ cpumask_t saved_mask;
+ int retval;
+
+ dprintk("acpi_processor_set_performance\n");
+
+ /*
+ * TBD: Use something other than set_cpus_allowed.
+ * As set_cpus_allowed is a bit racy,
+ * with any other set_cpus_allowed for this process.
+ */
+ saved_mask = current->cpus_allowed;
+ set_cpus_allowed(current, cpumask_of_cpu(cpu));
+ if (smp_processor_id() != cpu) {
+ return (-EAGAIN);
+ }
+
+ if (state == data->acpi_data.state) {
+ dprintk("Already at target state (P%d)\n", state);
+ retval = 0;
+ goto migrate_end;
+ }
+
+ dprintk("Transitioning from P%d to P%d\n",
+ data->acpi_data.state, state);
+
+ /* cpufreq frequency struct */
+ cpufreq_freqs.cpu = cpu;
+ cpufreq_freqs.old = data->freq_table[data->acpi_data.state].frequency;
+ cpufreq_freqs.new = data->freq_table[state].frequency;
+
+ /* notify cpufreq */
+ cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);
+
+ /*
+ * First we write the target state's 'control' value to the
+ * control_register.
+ */
+
+ port = data->acpi_data.control_register.address;
+ bit_width = data->acpi_data.control_register.bit_width;
+ value = (u32) data->acpi_data.states[state].control;
+
+ dprintk("Writing 0x%08x to port 0x%04x\n", value, port);
+
+ ret = acpi_processor_write_port(port, bit_width, value);
+ if (ret) {
+ dprintk("Invalid port width 0x%04x\n", bit_width);
+ retval = ret;
+ goto migrate_end;
+ }
+
+ /*
+ * Then we read the 'status_register' and compare the value with the
+ * target state's 'status' to make sure the transition was successful.
+ * Note that we'll poll for up to 1ms (100 cycles of 10us) before
+ * giving up.
+ */
+
+ port = data->acpi_data.status_register.address;
+ bit_width = data->acpi_data.status_register.bit_width;
+
+ dprintk("Looking for 0x%08x from port 0x%04x\n",
+ (u32) data->acpi_data.states[state].status, port);
+
+ for (i=0; i<100; i++) {
+ ret = acpi_processor_read_port(port, bit_width, &value);
+ if (ret) {
+ dprintk("Invalid port width 0x%04x\n", bit_width);
+ retval = ret;
+ goto migrate_end;
+ }
+ if (value == (u32) data->acpi_data.states[state].status)
+ break;
+ udelay(10);
+ }
+
+ /* notify cpufreq */
+ cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
+
+ if (value != (u32) data->acpi_data.states[state].status) {
+ unsigned int tmp = cpufreq_freqs.new;
+ cpufreq_freqs.new = cpufreq_freqs.old;
+ cpufreq_freqs.old = tmp;
+ cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);
+ cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
+ printk(KERN_WARNING "acpi-cpufreq: Transition failed\n");
+ retval = -ENODEV;
+ goto migrate_end;
+ }
+
+ dprintk("Transition successful after %d microseconds\n", i * 10);
+
+ data->acpi_data.state = state;
+
+ retval = 0;
+migrate_end:
+ set_cpus_allowed(current, saved_mask);
+ return (retval);
+}
+
+
+static int
+acpi_cpufreq_target (
+ struct cpufreq_policy *policy,
+ unsigned int target_freq,
+ unsigned int relation)
+{
+ struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
+ unsigned int next_state = 0;
+ unsigned int result = 0;
+
+ dprintk("acpi_cpufreq_setpolicy\n");
+
+ result = cpufreq_frequency_table_target(policy,
+ data->freq_table,
+ target_freq,
+ relation,
+ &next_state);
+ if (result)
+ return (result);
+
+ result = acpi_processor_set_performance (data, policy->cpu, next_state);
+
+ return (result);
+}
+
+
+static int
+acpi_cpufreq_verify (
+ struct cpufreq_policy *policy)
+{
+ unsigned int result = 0;
+ struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
+
+ dprintk("acpi_cpufreq_verify\n");
+
+ result = cpufreq_frequency_table_verify(policy,
+ data->freq_table);
+
+ return (result);
+}
+
+
+static unsigned long
+acpi_cpufreq_guess_freq (
+ struct cpufreq_acpi_io *data,
+ unsigned int cpu)
+{
+ if (cpu_khz) {
+ /* search the closest match to cpu_khz */
+ unsigned int i;
+ unsigned long freq;
+ unsigned long freqn = data->acpi_data.states[0].core_frequency * 1000;
+
+ for (i=0; i < (data->acpi_data.state_count - 1); i++) {
+ freq = freqn;
+ freqn = data->acpi_data.states[i+1].core_frequency * 1000;
+ if ((2 * cpu_khz) > (freqn + freq)) {
+ data->acpi_data.state = i;
+ return (freq);
+ }
+ }
+ data->acpi_data.state = data->acpi_data.state_count - 1;
+ return (freqn);
+ } else
+ /* assume CPU is at P0... */
+ data->acpi_data.state = 0;
+ return data->acpi_data.states[0].core_frequency * 1000;
+
+}
+
+
+/*
+ * acpi_processor_cpu_init_pdc_est - let BIOS know about the SMP capabilities
+ * of this driver
+ * @perf: processor-specific acpi_io_data struct
+ * @cpu: CPU being initialized
+ *
+ * To avoid issues with legacy OSes, some BIOSes require to be informed of
+ * the SMP capabilities of OS P-state driver. Here we set the bits in _PDC
+ * accordingly, for Enhanced Speedstep. Actual call to _PDC is done in
+ * driver/acpi/processor.c
+ */
+static void
+acpi_processor_cpu_init_pdc_est(
+ struct acpi_processor_performance *perf,
+ unsigned int cpu,
+ struct acpi_object_list *obj_list
+ )
+{
+ union acpi_object *obj;
+ u32 *buf;
+ struct cpuinfo_x86 *c = cpu_data + cpu;
+ dprintk("acpi_processor_cpu_init_pdc_est\n");
+
+ if (!cpu_has(c, X86_FEATURE_EST))
+ return;
+
+ /* Initialize pdc. It will be used later. */
+ if (!obj_list)
+ return;
+
+ if (!(obj_list->count && obj_list->pointer))
+ return;
+
+ obj = obj_list->pointer;
+ if ((obj->buffer.length == 12) && obj->buffer.pointer) {
+ buf = (u32 *)obj->buffer.pointer;
+ buf[0] = ACPI_PDC_REVISION_ID;
+ buf[1] = 1;
+ buf[2] = ACPI_PDC_EST_CAPABILITY_SMP;
+ perf->pdc = obj_list;
+ }
+ return;
+}
+
+
+/* CPU specific PDC initialization */
+static void
+acpi_processor_cpu_init_pdc(
+ struct acpi_processor_performance *perf,
+ unsigned int cpu,
+ struct acpi_object_list *obj_list
+ )
+{
+ struct cpuinfo_x86 *c = cpu_data + cpu;
+ dprintk("acpi_processor_cpu_init_pdc\n");
+ perf->pdc = NULL;
+ if (cpu_has(c, X86_FEATURE_EST))
+ acpi_processor_cpu_init_pdc_est(perf, cpu, obj_list);
+ return;
+}
+
+
+static int
+acpi_cpufreq_cpu_init (
+ struct cpufreq_policy *policy)
+{
+ unsigned int i;
+ unsigned int cpu = policy->cpu;
+ struct cpufreq_acpi_io *data;
+ unsigned int result = 0;
+
+ union acpi_object arg0 = {ACPI_TYPE_BUFFER};
+ u32 arg0_buf[3];
+ struct acpi_object_list arg_list = {1, &arg0};
+
+ dprintk("acpi_cpufreq_cpu_init\n");
+ /* setup arg_list for _PDC settings */
+ arg0.buffer.length = 12;
+ arg0.buffer.pointer = (u8 *) arg0_buf;
+
+ data = kmalloc(sizeof(struct cpufreq_acpi_io), GFP_KERNEL);
+ if (!data)
+ return (-ENOMEM);
+ memset(data, 0, sizeof(struct cpufreq_acpi_io));
+
+ acpi_io_data[cpu] = data;
+
+ acpi_processor_cpu_init_pdc(&data->acpi_data, cpu, &arg_list);
+ result = acpi_processor_register_performance(&data->acpi_data, cpu);
+ data->acpi_data.pdc = NULL;
+
+ if (result)
+ goto err_free;
+
+ /* capability check */
+ if (data->acpi_data.state_count <= 1) {
+ dprintk("No P-States\n");
+ result = -ENODEV;
+ goto err_unreg;
+ }
+ if ((data->acpi_data.control_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO) ||
+ (data->acpi_data.status_register.space_id != ACPI_ADR_SPACE_SYSTEM_IO)) {
+ dprintk("Unsupported address space [%d, %d]\n",
+ (u32) (data->acpi_data.control_register.space_id),
+ (u32) (data->acpi_data.status_register.space_id));
+ result = -ENODEV;
+ goto err_unreg;
+ }
+
+ /* alloc freq_table */
+ data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) * (data->acpi_data.state_count + 1), GFP_KERNEL);
+ if (!data->freq_table) {
+ result = -ENOMEM;
+ goto err_unreg;
+ }
+
+ /* detect transition latency */
+ policy->cpuinfo.transition_latency = 0;
+ for (i=0; i<data->acpi_data.state_count; i++) {
+ if ((data->acpi_data.states[i].transition_latency * 1000) > policy->cpuinfo.transition_latency)
+ policy->cpuinfo.transition_latency = data->acpi_data.states[i].transition_latency * 1000;
+ }
+ policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
+
+ /* The current speed is unknown and not detectable by ACPI... */
+ policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
+
+ /* table init */
+ for (i=0; i<=data->acpi_data.state_count; i++)
+ {
+ data->freq_table[i].index = i;
+ if (i<data->acpi_data.state_count)
+ data->freq_table[i].frequency = data->acpi_data.states[i].core_frequency * 1000;
+ else
+ data->freq_table[i].frequency = CPUFREQ_TABLE_END;
+ }
+
+ result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
+ if (result) {
+ goto err_freqfree;
+ }
+
+ /* notify BIOS that we exist */
+ acpi_processor_notify_smm(THIS_MODULE);
+
+ printk(KERN_INFO "acpi-cpufreq: CPU%u - ACPI performance management activated.\n",
+ cpu);
+ for (i = 0; i < data->acpi_data.state_count; i++)
+ dprintk(" %cP%d: %d MHz, %d mW, %d uS\n",
+ (i == data->acpi_data.state?'*':' '), i,
+ (u32) data->acpi_data.states[i].core_frequency,
+ (u32) data->acpi_data.states[i].power,
+ (u32) data->acpi_data.states[i].transition_latency);
+
+ cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
+ return (result);
+
+ err_freqfree:
+ kfree(data->freq_table);
+ err_unreg:
+ acpi_processor_unregister_performance(&data->acpi_data, cpu);
+ err_free:
+ kfree(data);
+ acpi_io_data[cpu] = NULL;
+
+ return (result);
+}
+
+
+static int
+acpi_cpufreq_cpu_exit (
+ struct cpufreq_policy *policy)
+{
+ struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
+
+
+ dprintk("acpi_cpufreq_cpu_exit\n");
+
+ if (data) {
+ cpufreq_frequency_table_put_attr(policy->cpu);
+ acpi_io_data[policy->cpu] = NULL;
+ acpi_processor_unregister_performance(&data->acpi_data, policy->cpu);
+ kfree(data);
+ }
+
+ return (0);
+}
+
+
+static struct freq_attr* acpi_cpufreq_attr[] = {
+ &cpufreq_freq_attr_scaling_available_freqs,
+ NULL,
+};
+
+static struct cpufreq_driver acpi_cpufreq_driver = {
+ .verify = acpi_cpufreq_verify,
+ .target = acpi_cpufreq_target,
+ .init = acpi_cpufreq_cpu_init,
+ .exit = acpi_cpufreq_cpu_exit,
+ .name = "acpi-cpufreq",
+ .owner = THIS_MODULE,
+ .attr = acpi_cpufreq_attr,
+};
+
+
+static int __init
+acpi_cpufreq_init (void)
+{
+ int result = 0;
+
+ dprintk("acpi_cpufreq_init\n");
+
+ result = cpufreq_register_driver(&acpi_cpufreq_driver);
+
+ return (result);
+}
+
+
+static void __exit
+acpi_cpufreq_exit (void)
+{
+ dprintk("acpi_cpufreq_exit\n");
+
+ cpufreq_unregister_driver(&acpi_cpufreq_driver);
+
+ return;
+}
+
+
+late_initcall(acpi_cpufreq_init);
+module_exit(acpi_cpufreq_exit);
+
+MODULE_ALIAS("acpi");
git://git.onelab.eu / linux-2.6.git / blobdiff