linux/include/acpi/processor.h
Thomas Renninger e2f74f355e [ACPI/CPUFREQ] Introduce bios_limit per cpu cpufreq sysfs interface
This interface is mainly intended (and implemented) for ACPI _PPC BIOS
frequency limitations, but other cpufreq drivers can also use it for
similar use-cases.

Why is this needed:

Currently it's not obvious why cpufreq got limited.
People see cpufreq/scaling_max_freq reduced, but this could have
happened by:
  - any userspace prog writing to scaling_max_freq
  - thermal limitations
  - hardware (_PPC in ACPI case) limitiations

Therefore export bios_limit (in kHz) to:
  - Point the user that it's the BIOS (broken or intended) which limits
    frequency
  - Export it as a sysfs interface for userspace progs.
    While this was a rarely used feature on laptops, there will appear
    more and more server implemenations providing "Green IT" features like
    allowing the service processor to limit the frequency. People want
    to know about HW/BIOS frequency limitations.

All ACPI P-state driven cpufreq drivers are covered with this patch:
  - powernow-k8
  - powernow-k7
  - acpi-cpufreq

Tested with a patched DSDT which limits the first two cores (_PPC returns 1)
via _PPC, exposed by bios_limit:
# echo 2200000 >cpu2/cpufreq/scaling_max_freq
# cat cpu*/cpufreq/scaling_max_freq
2600000
2600000
2200000
2200000
# #scaling_max_freq shows general user/thermal/BIOS limitations

# cat cpu*/cpufreq/bios_limit
2600000
2600000
2800000
2800000
# #bios_limit only shows the HW/BIOS limitation

CC: Pallipadi Venkatesh <venkatesh.pallipadi@intel.com>
CC: Len Brown <lenb@kernel.org>
CC: davej@codemonkey.org.uk
CC: linux@dominikbrodowski.net

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
2009-11-24 13:33:34 -05:00

363 lines
9.1 KiB
C

#ifndef __ACPI_PROCESSOR_H
#define __ACPI_PROCESSOR_H
#include <linux/kernel.h>
#include <linux/cpu.h>
#include <linux/cpuidle.h>
#include <linux/thermal.h>
#include <asm/acpi.h>
#define ACPI_PROCESSOR_BUSY_METRIC 10
#define ACPI_PROCESSOR_MAX_POWER 8
#define ACPI_PROCESSOR_MAX_C2_LATENCY 100
#define ACPI_PROCESSOR_MAX_C3_LATENCY 1000
#define ACPI_PROCESSOR_MAX_THROTTLING 16
#define ACPI_PROCESSOR_MAX_THROTTLE 250 /* 25% */
#define ACPI_PROCESSOR_MAX_DUTY_WIDTH 4
#define ACPI_PDC_REVISION_ID 0x1
#define ACPI_PSD_REV0_REVISION 0 /* Support for _PSD as in ACPI 3.0 */
#define ACPI_PSD_REV0_ENTRIES 5
#define ACPI_TSD_REV0_REVISION 0 /* Support for _PSD as in ACPI 3.0 */
#define ACPI_TSD_REV0_ENTRIES 5
/*
* Types of coordination defined in ACPI 3.0. Same macros can be used across
* P, C and T states
*/
#define DOMAIN_COORD_TYPE_SW_ALL 0xfc
#define DOMAIN_COORD_TYPE_SW_ANY 0xfd
#define DOMAIN_COORD_TYPE_HW_ALL 0xfe
#define ACPI_CSTATE_SYSTEMIO 0
#define ACPI_CSTATE_FFH 1
#define ACPI_CSTATE_HALT 2
#define ACPI_CX_DESC_LEN 32
/* Power Management */
struct acpi_processor_cx;
struct acpi_power_register {
u8 descriptor;
u16 length;
u8 space_id;
u8 bit_width;
u8 bit_offset;
u8 reserved;
u64 address;
} __attribute__ ((packed));
struct acpi_processor_cx_policy {
u32 count;
struct acpi_processor_cx *state;
struct {
u32 time;
u32 ticks;
u32 count;
u32 bm;
} threshold;
};
struct acpi_processor_cx {
u8 valid;
u8 type;
u32 address;
u8 entry_method;
u8 index;
u32 latency;
u32 latency_ticks;
u32 power;
u32 usage;
u64 time;
struct acpi_processor_cx_policy promotion;
struct acpi_processor_cx_policy demotion;
char desc[ACPI_CX_DESC_LEN];
};
struct acpi_processor_power {
struct cpuidle_device dev;
struct acpi_processor_cx *state;
unsigned long bm_check_timestamp;
u32 default_state;
int count;
struct acpi_processor_cx states[ACPI_PROCESSOR_MAX_POWER];
int timer_broadcast_on_state;
};
/* Performance Management */
struct acpi_psd_package {
acpi_integer num_entries;
acpi_integer revision;
acpi_integer domain;
acpi_integer coord_type;
acpi_integer num_processors;
} __attribute__ ((packed));
struct acpi_pct_register {
u8 descriptor;
u16 length;
u8 space_id;
u8 bit_width;
u8 bit_offset;
u8 reserved;
u64 address;
} __attribute__ ((packed));
struct acpi_processor_px {
acpi_integer core_frequency; /* megahertz */
acpi_integer power; /* milliWatts */
acpi_integer transition_latency; /* microseconds */
acpi_integer bus_master_latency; /* microseconds */
acpi_integer control; /* control value */
acpi_integer status; /* success indicator */
};
struct acpi_processor_performance {
unsigned int state;
unsigned int platform_limit;
struct acpi_pct_register control_register;
struct acpi_pct_register status_register;
unsigned int state_count;
struct acpi_processor_px *states;
struct acpi_psd_package domain_info;
cpumask_var_t shared_cpu_map;
unsigned int shared_type;
};
/* Throttling Control */
struct acpi_tsd_package {
acpi_integer num_entries;
acpi_integer revision;
acpi_integer domain;
acpi_integer coord_type;
acpi_integer num_processors;
} __attribute__ ((packed));
struct acpi_ptc_register {
u8 descriptor;
u16 length;
u8 space_id;
u8 bit_width;
u8 bit_offset;
u8 reserved;
u64 address;
} __attribute__ ((packed));
struct acpi_processor_tx_tss {
acpi_integer freqpercentage; /* */
acpi_integer power; /* milliWatts */
acpi_integer transition_latency; /* microseconds */
acpi_integer control; /* control value */
acpi_integer status; /* success indicator */
};
struct acpi_processor_tx {
u16 power;
u16 performance;
};
struct acpi_processor;
struct acpi_processor_throttling {
unsigned int state;
unsigned int platform_limit;
struct acpi_pct_register control_register;
struct acpi_pct_register status_register;
unsigned int state_count;
struct acpi_processor_tx_tss *states_tss;
struct acpi_tsd_package domain_info;
cpumask_var_t shared_cpu_map;
int (*acpi_processor_get_throttling) (struct acpi_processor * pr);
int (*acpi_processor_set_throttling) (struct acpi_processor * pr,
int state, bool force);
u32 address;
u8 duty_offset;
u8 duty_width;
u8 tsd_valid_flag;
unsigned int shared_type;
struct acpi_processor_tx states[ACPI_PROCESSOR_MAX_THROTTLING];
};
/* Limit Interface */
struct acpi_processor_lx {
int px; /* performance state */
int tx; /* throttle level */
};
struct acpi_processor_limit {
struct acpi_processor_lx state; /* current limit */
struct acpi_processor_lx thermal; /* thermal limit */
struct acpi_processor_lx user; /* user limit */
};
struct acpi_processor_flags {
u8 power:1;
u8 performance:1;
u8 throttling:1;
u8 limit:1;
u8 bm_control:1;
u8 bm_check:1;
u8 has_cst:1;
u8 power_setup_done:1;
u8 bm_rld_set:1;
};
struct acpi_processor {
acpi_handle handle;
u32 acpi_id;
u32 id;
u32 pblk;
int performance_platform_limit;
int throttling_platform_limit;
/* 0 - states 0..n-th state available */
struct acpi_processor_flags flags;
struct acpi_processor_power power;
struct acpi_processor_performance *performance;
struct acpi_processor_throttling throttling;
struct acpi_processor_limit limit;
struct thermal_cooling_device *cdev;
/* the _PDC objects for this processor, if any */
struct acpi_object_list *pdc;
};
struct acpi_processor_errata {
u8 smp;
struct {
u8 throttle:1;
u8 fdma:1;
u8 reserved:6;
u32 bmisx;
} piix4;
};
extern int acpi_processor_preregister_performance(struct
acpi_processor_performance
*performance);
extern int acpi_processor_register_performance(struct acpi_processor_performance
*performance, unsigned int cpu);
extern void acpi_processor_unregister_performance(struct
acpi_processor_performance
*performance,
unsigned int cpu);
/* note: this locks both the calling module and the processor module
if a _PPC object exists, rmmod is disallowed then */
int acpi_processor_notify_smm(struct module *calling_module);
/* for communication between multiple parts of the processor kernel module */
DECLARE_PER_CPU(struct acpi_processor *, processors);
extern struct acpi_processor_errata errata;
void arch_acpi_processor_init_pdc(struct acpi_processor *pr);
void arch_acpi_processor_cleanup_pdc(struct acpi_processor *pr);
#ifdef ARCH_HAS_POWER_INIT
void acpi_processor_power_init_bm_check(struct acpi_processor_flags *flags,
unsigned int cpu);
int acpi_processor_ffh_cstate_probe(unsigned int cpu,
struct acpi_processor_cx *cx,
struct acpi_power_register *reg);
void acpi_processor_ffh_cstate_enter(struct acpi_processor_cx *cstate);
#else
static inline void acpi_processor_power_init_bm_check(struct
acpi_processor_flags
*flags, unsigned int cpu)
{
flags->bm_check = 1;
return;
}
static inline int acpi_processor_ffh_cstate_probe(unsigned int cpu,
struct acpi_processor_cx *cx,
struct acpi_power_register
*reg)
{
return -1;
}
static inline void acpi_processor_ffh_cstate_enter(struct acpi_processor_cx
*cstate)
{
return;
}
#endif
/* in processor_perflib.c */
#ifdef CONFIG_CPU_FREQ
void acpi_processor_ppc_init(void);
void acpi_processor_ppc_exit(void);
int acpi_processor_ppc_has_changed(struct acpi_processor *pr);
extern int acpi_processor_get_bios_limit(int cpu, unsigned int *limit);
#else
static inline void acpi_processor_ppc_init(void)
{
return;
}
static inline void acpi_processor_ppc_exit(void)
{
return;
}
static inline int acpi_processor_ppc_has_changed(struct acpi_processor *pr)
{
static unsigned int printout = 1;
if (printout) {
printk(KERN_WARNING
"Warning: Processor Platform Limit event detected, but not handled.\n");
printk(KERN_WARNING
"Consider compiling CPUfreq support into your kernel.\n");
printout = 0;
}
return 0;
}
static inline int acpi_processor_get_bios_limit(int cpu, unsigned int *limit)
{
return -ENODEV;
}
#endif /* CONFIG_CPU_FREQ */
/* in processor_throttling.c */
int acpi_processor_tstate_has_changed(struct acpi_processor *pr);
int acpi_processor_get_throttling_info(struct acpi_processor *pr);
extern int acpi_processor_set_throttling(struct acpi_processor *pr,
int state, bool force);
extern const struct file_operations acpi_processor_throttling_fops;
extern void acpi_processor_throttling_init(void);
/* in processor_idle.c */
int acpi_processor_power_init(struct acpi_processor *pr,
struct acpi_device *device);
int acpi_processor_cst_has_changed(struct acpi_processor *pr);
int acpi_processor_power_exit(struct acpi_processor *pr,
struct acpi_device *device);
int acpi_processor_suspend(struct acpi_device * device, pm_message_t state);
int acpi_processor_resume(struct acpi_device * device);
extern struct cpuidle_driver acpi_idle_driver;
/* in processor_thermal.c */
int acpi_processor_get_limit_info(struct acpi_processor *pr);
extern const struct file_operations acpi_processor_limit_fops;
extern struct thermal_cooling_device_ops processor_cooling_ops;
#ifdef CONFIG_CPU_FREQ
void acpi_thermal_cpufreq_init(void);
void acpi_thermal_cpufreq_exit(void);
#else
static inline void acpi_thermal_cpufreq_init(void)
{
return;
}
static inline void acpi_thermal_cpufreq_exit(void)
{
return;
}
#endif
#endif