#include <linux/cpufreq.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
+#include <linux/compiler.h>
+#include <linux/sched.h> /* current */
#include <asm/io.h>
#include <asm/delay.h>
#include <asm/uaccess.h>
#include <linux/acpi.h>
#include <acpi/processor.h>
-#include "speedstep-est-common.h"
-
#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "acpi-cpufreq", msg)
MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
static struct cpufreq_driver acpi_cpufreq_driver;
+static unsigned int acpi_pstate_strict;
+
static int
acpi_processor_write_port(
u16 port,
}
/*
- * 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.
+ * Assume the write went through when acpi_pstate_strict is not used.
+ * As read status_register is an expensive operation and there
+ * are no specific error cases where an IO port write will fail.
*/
-
- 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 (acpi_pstate_strict) {
+ /* 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);
}
- if (value == (u32) data->acpi_data.states[state].status)
- break;
- udelay(10);
+ } else {
+ i = 0;
+ value = (u32) data->acpi_data.states[state].status;
}
/* notify cpufreq */
cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
- if (value != (u32) data->acpi_data.states[state].status) {
+ if (unlikely(value != (u32) data->acpi_data.states[state].status)) {
unsigned int tmp = cpufreq_freqs.new;
cpufreq_freqs.new = cpufreq_freqs.old;
cpufreq_freqs.old = tmp;
}
-/*
- * 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 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};
+ struct cpuinfo_x86 *c = &cpu_data[policy->cpu];
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);
+ data = kzalloc(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;
- if (is_const_loops_cpu(cpu)) {
+ if (cpu_has(c, X86_FEATURE_CONSTANT_TSC)) {
acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
}
(u32) data->acpi_data.states[i].transition_latency);
cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
+
+ /*
+ * the first call to ->target() should result in us actually
+ * writing something to the appropriate registers.
+ */
+ data->resume = 1;
+
return (result);
err_freqfree:
.name = "acpi-cpufreq",
.owner = THIS_MODULE,
.attr = acpi_cpufreq_attr,
+ .flags = CPUFREQ_STICKY,
};
return;
}
+module_param(acpi_pstate_strict, uint, 0644);
+MODULE_PARM_DESC(acpi_pstate_strict, "value 0 or non-zero. non-zero -> strict ACPI checks are performed during frequency changes.");
late_initcall(acpi_cpufreq_init);
module_exit(acpi_cpufreq_exit);
git://git.onelab.eu / linux-2.6.git / blobdiff