forked from Minki/linux
Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq
* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/davej/cpufreq: [CPUFREQ] Fix cast warning in pcc driver. [CPUFREQ] Processor Clocking Control interface driver
This commit is contained in:
Linus Torvalds
commit
08b8499bdd
207
Documentation/cpu-freq/pcc-cpufreq.txt
Normal file
207
Documentation/cpu-freq/pcc-cpufreq.txt
Normal file
@ -0,0 +1,207 @@
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/*
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* pcc-cpufreq.txt - PCC interface documentation
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*
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* Copyright (C) 2009 Red Hat, Matthew Garrett <mjg@redhat.com>
|
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* Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
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* Nagananda Chumbalkar <nagananda.chumbalkar@hp.com>
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||||
*
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* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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||||
*
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||||
* 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, GOOD TITLE or NON
|
||||
* INFRINGEMENT. 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.,
|
||||
* 675 Mass Ave, Cambridge, MA 02139, USA.
|
||||
*
|
||||
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
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*/
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Processor Clocking Control Driver
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---------------------------------
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Contents:
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---------
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1. Introduction
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1.1 PCC interface
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1.1.1 Get Average Frequency
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1.1.2 Set Desired Frequency
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1.2 Platforms affected
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||||
2. Driver and /sys details
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||||
2.1 scaling_available_frequencies
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2.2 cpuinfo_transition_latency
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2.3 cpuinfo_cur_freq
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2.4 related_cpus
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||||
3. Caveats
|
||||
|
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1. Introduction:
|
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----------------
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Processor Clocking Control (PCC) is an interface between the platform
|
||||
firmware and OSPM. It is a mechanism for coordinating processor
|
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performance (ie: frequency) between the platform firmware and the OS.
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The PCC driver (pcc-cpufreq) allows OSPM to take advantage of the PCC
|
||||
interface.
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|
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OS utilizes the PCC interface to inform platform firmware what frequency the
|
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OS wants for a logical processor. The platform firmware attempts to achieve
|
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the requested frequency. If the request for the target frequency could not be
|
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satisfied by platform firmware, then it usually means that power budget
|
||||
conditions are in place, and "power capping" is taking place.
|
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1.1 PCC interface:
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------------------
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The complete PCC specification is available here:
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http://www.acpica.org/download/Processor-Clocking-Control-v1p0.pdf
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|
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PCC relies on a shared memory region that provides a channel for communication
|
||||
between the OS and platform firmware. PCC also implements a "doorbell" that
|
||||
is used by the OS to inform the platform firmware that a command has been
|
||||
sent.
|
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|
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The ACPI PCCH() method is used to discover the location of the PCC shared
|
||||
memory region. The shared memory region header contains the "command" and
|
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"status" interface. PCCH() also contains details on how to access the platform
|
||||
doorbell.
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|
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The following commands are supported by the PCC interface:
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* Get Average Frequency
|
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* Set Desired Frequency
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|
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The ACPI PCCP() method is implemented for each logical processor and is
|
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used to discover the offsets for the input and output buffers in the shared
|
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memory region.
|
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|
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When PCC mode is enabled, the platform will not expose processor performance
|
||||
or throttle states (_PSS, _TSS and related ACPI objects) to OSPM. Therefore,
|
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the native P-state driver (such as acpi-cpufreq for Intel, powernow-k8 for
|
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AMD) will not load.
|
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|
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However, OSPM remains in control of policy. The governor (eg: "ondemand")
|
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computes the required performance for each processor based on server workload.
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The PCC driver fills in the command interface, and the input buffer and
|
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communicates the request to the platform firmware. The platform firmware is
|
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responsible for delivering the requested performance.
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|
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Each PCC command is "global" in scope and can affect all the logical CPUs in
|
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the system. Therefore, PCC is capable of performing "group" updates. With PCC
|
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the OS is capable of getting/setting the frequency of all the logical CPUs in
|
||||
the system with a single call to the BIOS.
|
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|
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1.1.1 Get Average Frequency:
|
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----------------------------
|
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This command is used by the OSPM to query the running frequency of the
|
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processor since the last time this command was completed. The output buffer
|
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indicates the average unhalted frequency of the logical processor expressed as
|
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a percentage of the nominal (ie: maximum) CPU frequency. The output buffer
|
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also signifies if the CPU frequency is limited by a power budget condition.
|
||||
|
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1.1.2 Set Desired Frequency:
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||||
----------------------------
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This command is used by the OSPM to communicate to the platform firmware the
|
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desired frequency for a logical processor. The output buffer is currently
|
||||
ignored by OSPM. The next invocation of "Get Average Frequency" will inform
|
||||
OSPM if the desired frequency was achieved or not.
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|
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1.2 Platforms affected:
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-----------------------
|
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The PCC driver will load on any system where the platform firmware:
|
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* supports the PCC interface, and the associated PCCH() and PCCP() methods
|
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* assumes responsibility for managing the hardware clocking controls in order
|
||||
to deliver the requested processor performance
|
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|
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Currently, certain HP ProLiant platforms implement the PCC interface. On those
|
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platforms PCC is the "default" choice.
|
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|
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However, it is possible to disable this interface via a BIOS setting. In
|
||||
such an instance, as is also the case on platforms where the PCC interface
|
||||
is not implemented, the PCC driver will fail to load silently.
|
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|
||||
2. Driver and /sys details:
|
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---------------------------
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When the driver loads, it merely prints the lowest and the highest CPU
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frequencies supported by the platform firmware.
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|
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The PCC driver loads with a message such as:
|
||||
pcc-cpufreq: (v1.00.00) driver loaded with frequency limits: 1600 MHz, 2933
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||||
MHz
|
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|
||||
This means that the OPSM can request the CPU to run at any frequency in
|
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between the limits (1600 MHz, and 2933 MHz) specified in the message.
|
||||
|
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Internally, there is no need for the driver to convert the "target" frequency
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to a corresponding P-state.
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The VERSION number for the driver will be of the format v.xy.ab.
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eg: 1.00.02
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----- --
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||||
| |
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| -- this will increase with bug fixes/enhancements to the driver
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|-- this is the version of the PCC specification the driver adheres to
|
||||
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||||
|
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The following is a brief discussion on some of the fields exported via the
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/sys filesystem and how their values are affected by the PCC driver:
|
||||
|
||||
2.1 scaling_available_frequencies:
|
||||
----------------------------------
|
||||
scaling_available_frequencies is not created in /sys. No intermediate
|
||||
frequencies need to be listed because the BIOS will try to achieve any
|
||||
frequency, within limits, requested by the governor. A frequency does not have
|
||||
to be strictly associated with a P-state.
|
||||
|
||||
2.2 cpuinfo_transition_latency:
|
||||
-------------------------------
|
||||
The cpuinfo_transition_latency field is 0. The PCC specification does
|
||||
not include a field to expose this value currently.
|
||||
|
||||
2.3 cpuinfo_cur_freq:
|
||||
---------------------
|
||||
A) Often cpuinfo_cur_freq will show a value different than what is declared
|
||||
in the scaling_available_frequencies or scaling_cur_freq, or scaling_max_freq.
|
||||
This is due to "turbo boost" available on recent Intel processors. If certain
|
||||
conditions are met the BIOS can achieve a slightly higher speed than requested
|
||||
by OSPM. An example:
|
||||
|
||||
scaling_cur_freq : 2933000
|
||||
cpuinfo_cur_freq : 3196000
|
||||
|
||||
B) There is a round-off error associated with the cpuinfo_cur_freq value.
|
||||
Since the driver obtains the current frequency as a "percentage" (%) of the
|
||||
nominal frequency from the BIOS, sometimes, the values displayed by
|
||||
scaling_cur_freq and cpuinfo_cur_freq may not match. An example:
|
||||
|
||||
scaling_cur_freq : 1600000
|
||||
cpuinfo_cur_freq : 1583000
|
||||
|
||||
In this example, the nominal frequency is 2933 MHz. The driver obtains the
|
||||
current frequency, cpuinfo_cur_freq, as 54% of the nominal frequency:
|
||||
|
||||
54% of 2933 MHz = 1583 MHz
|
||||
|
||||
Nominal frequency is the maximum frequency of the processor, and it usually
|
||||
corresponds to the frequency of the P0 P-state.
|
||||
|
||||
2.4 related_cpus:
|
||||
-----------------
|
||||
The related_cpus field is identical to affected_cpus.
|
||||
|
||||
affected_cpus : 4
|
||||
related_cpus : 4
|
||||
|
||||
Currently, the PCC driver does not evaluate _PSD. The platforms that support
|
||||
PCC do not implement SW_ALL. So OSPM doesn't need to perform any coordination
|
||||
to ensure that the same frequency is requested of all dependent CPUs.
|
||||
|
||||
3. Caveats:
|
||||
-----------
|
||||
The "cpufreq_stats" module in its present form cannot be loaded and
|
||||
expected to work with the PCC driver. Since the "cpufreq_stats" module
|
||||
provides information wrt each P-state, it is not applicable to the PCC driver.
|
||||
@ -10,6 +10,20 @@ if CPU_FREQ
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||||
|
||||
comment "CPUFreq processor drivers"
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||||
|
||||
config X86_PCC_CPUFREQ
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tristate "Processor Clocking Control interface driver"
|
||||
depends on ACPI && ACPI_PROCESSOR
|
||||
help
|
||||
This driver adds support for the PCC interface.
|
||||
|
||||
For details, take a look at:
|
||||
<file:Documentation/cpu-freq/pcc-cpufreq.txt>.
|
||||
|
||||
To compile this driver as a module, choose M here: the
|
||||
module will be called pcc-cpufreq.
|
||||
|
||||
If in doubt, say N.
|
||||
|
||||
config X86_ACPI_CPUFREQ
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||||
tristate "ACPI Processor P-States driver"
|
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select CPU_FREQ_TABLE
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@ -4,6 +4,7 @@
|
||||
|
||||
obj-$(CONFIG_X86_POWERNOW_K8) += powernow-k8.o
|
||||
obj-$(CONFIG_X86_ACPI_CPUFREQ) += acpi-cpufreq.o
|
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obj-$(CONFIG_X86_PCC_CPUFREQ) += pcc-cpufreq.o
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||||
obj-$(CONFIG_X86_POWERNOW_K6) += powernow-k6.o
|
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obj-$(CONFIG_X86_POWERNOW_K7) += powernow-k7.o
|
||||
obj-$(CONFIG_X86_LONGHAUL) += longhaul.o
|
||||
|
||||
620
arch/x86/kernel/cpu/cpufreq/pcc-cpufreq.c
Normal file
620
arch/x86/kernel/cpu/cpufreq/pcc-cpufreq.c
Normal file
@ -0,0 +1,620 @@
|
||||
/*
|
||||
* pcc-cpufreq.c - Processor Clocking Control firmware cpufreq interface
|
||||
*
|
||||
* Copyright (C) 2009 Red Hat, Matthew Garrett <mjg@redhat.com>
|
||||
* Copyright (C) 2009 Hewlett-Packard Development Company, L.P.
|
||||
* Nagananda Chumbalkar <nagananda.chumbalkar@hp.com>
|
||||
*
|
||||
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
||||
*
|
||||
* 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, GOOD TITLE or NON
|
||||
* INFRINGEMENT. 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.,
|
||||
* 675 Mass Ave, Cambridge, MA 02139, USA.
|
||||
*
|
||||
* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
||||
*/
|
||||
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/module.h>
|
||||
#include <linux/init.h>
|
||||
#include <linux/smp.h>
|
||||
#include <linux/sched.h>
|
||||
#include <linux/cpufreq.h>
|
||||
#include <linux/compiler.h>
|
||||
|
||||
#include <linux/acpi.h>
|
||||
#include <linux/io.h>
|
||||
#include <linux/spinlock.h>
|
||||
#include <linux/uaccess.h>
|
||||
|
||||
#include <acpi/processor.h>
|
||||
|
||||
#define PCC_VERSION "1.00.00"
|
||||
#define POLL_LOOPS 300
|
||||
|
||||
#define CMD_COMPLETE 0x1
|
||||
#define CMD_GET_FREQ 0x0
|
||||
#define CMD_SET_FREQ 0x1
|
||||
|
||||
#define BUF_SZ 4
|
||||
|
||||
#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, \
|
||||
"pcc-cpufreq", msg)
|
||||
|
||||
struct pcc_register_resource {
|
||||
u8 descriptor;
|
||||
u16 length;
|
||||
u8 space_id;
|
||||
u8 bit_width;
|
||||
u8 bit_offset;
|
||||
u8 access_size;
|
||||
u64 address;
|
||||
} __attribute__ ((packed));
|
||||
|
||||
struct pcc_memory_resource {
|
||||
u8 descriptor;
|
||||
u16 length;
|
||||
u8 space_id;
|
||||
u8 resource_usage;
|
||||
u8 type_specific;
|
||||
u64 granularity;
|
||||
u64 minimum;
|
||||
u64 maximum;
|
||||
u64 translation_offset;
|
||||
u64 address_length;
|
||||
} __attribute__ ((packed));
|
||||
|
||||
static struct cpufreq_driver pcc_cpufreq_driver;
|
||||
|
||||
struct pcc_header {
|
||||
u32 signature;
|
||||
u16 length;
|
||||
u8 major;
|
||||
u8 minor;
|
||||
u32 features;
|
||||
u16 command;
|
||||
u16 status;
|
||||
u32 latency;
|
||||
u32 minimum_time;
|
||||
u32 maximum_time;
|
||||
u32 nominal;
|
||||
u32 throttled_frequency;
|
||||
u32 minimum_frequency;
|
||||
};
|
||||
|
||||
static void __iomem *pcch_virt_addr;
|
||||
static struct pcc_header __iomem *pcch_hdr;
|
||||
|
||||
static DEFINE_SPINLOCK(pcc_lock);
|
||||
|
||||
static struct acpi_generic_address doorbell;
|
||||
|
||||
static u64 doorbell_preserve;
|
||||
static u64 doorbell_write;
|
||||
|
||||
static u8 OSC_UUID[16] = {0x63, 0x9B, 0x2C, 0x9F, 0x70, 0x91, 0x49, 0x1f,
|
||||
0xBB, 0x4F, 0xA5, 0x98, 0x2F, 0xA1, 0xB5, 0x46};
|
||||
|
||||
struct pcc_cpu {
|
||||
u32 input_offset;
|
||||
u32 output_offset;
|
||||
};
|
||||
|
||||
static struct pcc_cpu *pcc_cpu_info;
|
||||
|
||||
static int pcc_cpufreq_verify(struct cpufreq_policy *policy)
|
||||
{
|
||||
cpufreq_verify_within_limits(policy, policy->cpuinfo.min_freq,
|
||||
policy->cpuinfo.max_freq);
|
||||
return 0;
|
||||
}
|
||||
|
||||
static inline void pcc_cmd(void)
|
||||
{
|
||||
u64 doorbell_value;
|
||||
int i;
|
||||
|
||||
acpi_read(&doorbell_value, &doorbell);
|
||||
acpi_write((doorbell_value & doorbell_preserve) | doorbell_write,
|
||||
&doorbell);
|
||||
|
||||
for (i = 0; i < POLL_LOOPS; i++) {
|
||||
if (ioread16(&pcch_hdr->status) & CMD_COMPLETE)
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
static inline void pcc_clear_mapping(void)
|
||||
{
|
||||
if (pcch_virt_addr)
|
||||
iounmap(pcch_virt_addr);
|
||||
pcch_virt_addr = NULL;
|
||||
}
|
||||
|
||||
static unsigned int pcc_get_freq(unsigned int cpu)
|
||||
{
|
||||
struct pcc_cpu *pcc_cpu_data;
|
||||
unsigned int curr_freq;
|
||||
unsigned int freq_limit;
|
||||
u16 status;
|
||||
u32 input_buffer;
|
||||
u32 output_buffer;
|
||||
|
||||
spin_lock(&pcc_lock);
|
||||
|
||||
dprintk("get: get_freq for CPU %d\n", cpu);
|
||||
pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
|
||||
|
||||
input_buffer = 0x1;
|
||||
iowrite32(input_buffer,
|
||||
(pcch_virt_addr + pcc_cpu_data->input_offset));
|
||||
iowrite16(CMD_GET_FREQ, &pcch_hdr->command);
|
||||
|
||||
pcc_cmd();
|
||||
|
||||
output_buffer =
|
||||
ioread32(pcch_virt_addr + pcc_cpu_data->output_offset);
|
||||
|
||||
/* Clear the input buffer - we are done with the current command */
|
||||
memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
|
||||
|
||||
status = ioread16(&pcch_hdr->status);
|
||||
if (status != CMD_COMPLETE) {
|
||||
dprintk("get: FAILED: for CPU %d, status is %d\n",
|
||||
cpu, status);
|
||||
goto cmd_incomplete;
|
||||
}
|
||||
iowrite16(0, &pcch_hdr->status);
|
||||
curr_freq = (((ioread32(&pcch_hdr->nominal) * (output_buffer & 0xff))
|
||||
/ 100) * 1000);
|
||||
|
||||
dprintk("get: SUCCESS: (virtual) output_offset for cpu %d is "
|
||||
"0x%x, contains a value of: 0x%x. Speed is: %d MHz\n",
|
||||
cpu, (pcch_virt_addr + pcc_cpu_data->output_offset),
|
||||
output_buffer, curr_freq);
|
||||
|
||||
freq_limit = (output_buffer >> 8) & 0xff;
|
||||
if (freq_limit != 0xff) {
|
||||
dprintk("get: frequency for cpu %d is being temporarily"
|
||||
" capped at %d\n", cpu, curr_freq);
|
||||
}
|
||||
|
||||
spin_unlock(&pcc_lock);
|
||||
return curr_freq;
|
||||
|
||||
cmd_incomplete:
|
||||
iowrite16(0, &pcch_hdr->status);
|
||||
spin_unlock(&pcc_lock);
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
static int pcc_cpufreq_target(struct cpufreq_policy *policy,
|
||||
unsigned int target_freq,
|
||||
unsigned int relation)
|
||||
{
|
||||
struct pcc_cpu *pcc_cpu_data;
|
||||
struct cpufreq_freqs freqs;
|
||||
u16 status;
|
||||
u32 input_buffer;
|
||||
int cpu;
|
||||
|
||||
spin_lock(&pcc_lock);
|
||||
cpu = policy->cpu;
|
||||
pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
|
||||
|
||||
dprintk("target: CPU %d should go to target freq: %d "
|
||||
"(virtual) input_offset is 0x%x\n",
|
||||
cpu, target_freq,
|
||||
(pcch_virt_addr + pcc_cpu_data->input_offset));
|
||||
|
||||
freqs.new = target_freq;
|
||||
freqs.cpu = cpu;
|
||||
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
|
||||
|
||||
input_buffer = 0x1 | (((target_freq * 100)
|
||||
/ (ioread32(&pcch_hdr->nominal) * 1000)) << 8);
|
||||
iowrite32(input_buffer,
|
||||
(pcch_virt_addr + pcc_cpu_data->input_offset));
|
||||
iowrite16(CMD_SET_FREQ, &pcch_hdr->command);
|
||||
|
||||
pcc_cmd();
|
||||
|
||||
/* Clear the input buffer - we are done with the current command */
|
||||
memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
|
||||
|
||||
status = ioread16(&pcch_hdr->status);
|
||||
if (status != CMD_COMPLETE) {
|
||||
dprintk("target: FAILED for cpu %d, with status: 0x%x\n",
|
||||
cpu, status);
|
||||
goto cmd_incomplete;
|
||||
}
|
||||
iowrite16(0, &pcch_hdr->status);
|
||||
|
||||
cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
|
||||
dprintk("target: was SUCCESSFUL for cpu %d\n", cpu);
|
||||
spin_unlock(&pcc_lock);
|
||||
|
||||
return 0;
|
||||
|
||||
cmd_incomplete:
|
||||
iowrite16(0, &pcch_hdr->status);
|
||||
spin_unlock(&pcc_lock);
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
static int pcc_get_offset(int cpu)
|
||||
{
|
||||
acpi_status status;
|
||||
struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
|
||||
union acpi_object *pccp, *offset;
|
||||
struct pcc_cpu *pcc_cpu_data;
|
||||
struct acpi_processor *pr;
|
||||
int ret = 0;
|
||||
|
||||
pr = per_cpu(processors, cpu);
|
||||
pcc_cpu_data = per_cpu_ptr(pcc_cpu_info, cpu);
|
||||
|
||||
status = acpi_evaluate_object(pr->handle, "PCCP", NULL, &buffer);
|
||||
if (ACPI_FAILURE(status))
|
||||
return -ENODEV;
|
||||
|
||||
pccp = buffer.pointer;
|
||||
if (!pccp || pccp->type != ACPI_TYPE_PACKAGE) {
|
||||
ret = -ENODEV;
|
||||
goto out_free;
|
||||
};
|
||||
|
||||
offset = &(pccp->package.elements[0]);
|
||||
if (!offset || offset->type != ACPI_TYPE_INTEGER) {
|
||||
ret = -ENODEV;
|
||||
goto out_free;
|
||||
}
|
||||
|
||||
pcc_cpu_data->input_offset = offset->integer.value;
|
||||
|
||||
offset = &(pccp->package.elements[1]);
|
||||
if (!offset || offset->type != ACPI_TYPE_INTEGER) {
|
||||
ret = -ENODEV;
|
||||
goto out_free;
|
||||
}
|
||||
|
||||
pcc_cpu_data->output_offset = offset->integer.value;
|
||||
|
||||
memset_io((pcch_virt_addr + pcc_cpu_data->input_offset), 0, BUF_SZ);
|
||||
memset_io((pcch_virt_addr + pcc_cpu_data->output_offset), 0, BUF_SZ);
|
||||
|
||||
dprintk("pcc_get_offset: for CPU %d: pcc_cpu_data "
|
||||
"input_offset: 0x%x, pcc_cpu_data output_offset: 0x%x\n",
|
||||
cpu, pcc_cpu_data->input_offset, pcc_cpu_data->output_offset);
|
||||
out_free:
|
||||
kfree(buffer.pointer);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int __init pcc_cpufreq_do_osc(acpi_handle *handle)
|
||||
{
|
||||
acpi_status status;
|
||||
struct acpi_object_list input;
|
||||
struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
|
||||
union acpi_object in_params[4];
|
||||
union acpi_object *out_obj;
|
||||
u32 capabilities[2];
|
||||
u32 errors;
|
||||
u32 supported;
|
||||
int ret = 0;
|
||||
|
||||
input.count = 4;
|
||||
input.pointer = in_params;
|
||||
input.count = 4;
|
||||
input.pointer = in_params;
|
||||
in_params[0].type = ACPI_TYPE_BUFFER;
|
||||
in_params[0].buffer.length = 16;
|
||||
in_params[0].buffer.pointer = OSC_UUID;
|
||||
in_params[1].type = ACPI_TYPE_INTEGER;
|
||||
in_params[1].integer.value = 1;
|
||||
in_params[2].type = ACPI_TYPE_INTEGER;
|
||||
in_params[2].integer.value = 2;
|
||||
in_params[3].type = ACPI_TYPE_BUFFER;
|
||||
in_params[3].buffer.length = 8;
|
||||
in_params[3].buffer.pointer = (u8 *)&capabilities;
|
||||
|
||||
capabilities[0] = OSC_QUERY_ENABLE;
|
||||
capabilities[1] = 0x1;
|
||||
|
||||
status = acpi_evaluate_object(*handle, "_OSC", &input, &output);
|
||||
if (ACPI_FAILURE(status))
|
||||
return -ENODEV;
|
||||
|
||||
if (!output.length)
|
||||
return -ENODEV;
|
||||
|
||||
out_obj = output.pointer;
|
||||
if (out_obj->type != ACPI_TYPE_BUFFER) {
|
||||
ret = -ENODEV;
|
||||
goto out_free;
|
||||
}
|
||||
|
||||
errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
|
||||
if (errors) {
|
||||
ret = -ENODEV;
|
||||
goto out_free;
|
||||
}
|
||||
|
||||
supported = *((u32 *)(out_obj->buffer.pointer + 4));
|
||||
if (!(supported & 0x1)) {
|
||||
ret = -ENODEV;
|
||||
goto out_free;
|
||||
}
|
||||
|
||||
kfree(output.pointer);
|
||||
capabilities[0] = 0x0;
|
||||
capabilities[1] = 0x1;
|
||||
|
||||
status = acpi_evaluate_object(*handle, "_OSC", &input, &output);
|
||||
if (ACPI_FAILURE(status))
|
||||
return -ENODEV;
|
||||
|
||||
if (!output.length)
|
||||
return -ENODEV;
|
||||
|
||||
out_obj = output.pointer;
|
||||
if (out_obj->type != ACPI_TYPE_BUFFER) {
|
||||
ret = -ENODEV;
|
||||
goto out_free;
|
||||
}
|
||||
|
||||
errors = *((u32 *)out_obj->buffer.pointer) & ~(1 << 0);
|
||||
if (errors) {
|
||||
ret = -ENODEV;
|
||||
goto out_free;
|
||||
}
|
||||
|
||||
supported = *((u32 *)(out_obj->buffer.pointer + 4));
|
||||
if (!(supported & 0x1)) {
|
||||
ret = -ENODEV;
|
||||
goto out_free;
|
||||
}
|
||||
|
||||
out_free:
|
||||
kfree(output.pointer);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int __init pcc_cpufreq_probe(void)
|
||||
{
|
||||
acpi_status status;
|
||||
struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
|
||||
struct pcc_memory_resource *mem_resource;
|
||||
struct pcc_register_resource *reg_resource;
|
||||
union acpi_object *out_obj, *member;
|
||||
acpi_handle handle, osc_handle;
|
||||
int ret = 0;
|
||||
|
||||
status = acpi_get_handle(NULL, "\\_SB", &handle);
|
||||
if (ACPI_FAILURE(status))
|
||||
return -ENODEV;
|
||||
|
||||
status = acpi_get_handle(handle, "_OSC", &osc_handle);
|
||||
if (ACPI_SUCCESS(status)) {
|
||||
ret = pcc_cpufreq_do_osc(&osc_handle);
|
||||
if (ret)
|
||||
dprintk("probe: _OSC evaluation did not succeed\n");
|
||||
/* Firmware's use of _OSC is optional */
|
||||
ret = 0;
|
||||
}
|
||||
|
||||
status = acpi_evaluate_object(handle, "PCCH", NULL, &output);
|
||||
if (ACPI_FAILURE(status))
|
||||
return -ENODEV;
|
||||
|
||||
out_obj = output.pointer;
|
||||
if (out_obj->type != ACPI_TYPE_PACKAGE) {
|
||||
ret = -ENODEV;
|
||||
goto out_free;
|
||||
}
|
||||
|
||||
member = &out_obj->package.elements[0];
|
||||
if (member->type != ACPI_TYPE_BUFFER) {
|
||||
ret = -ENODEV;
|
||||
goto out_free;
|
||||
}
|
||||
|
||||
mem_resource = (struct pcc_memory_resource *)member->buffer.pointer;
|
||||
|
||||
dprintk("probe: mem_resource descriptor: 0x%x,"
|
||||
" length: %d, space_id: %d, resource_usage: %d,"
|
||||
" type_specific: %d, granularity: 0x%llx,"
|
||||
" minimum: 0x%llx, maximum: 0x%llx,"
|
||||
" translation_offset: 0x%llx, address_length: 0x%llx\n",
|
||||
mem_resource->descriptor, mem_resource->length,
|
||||
mem_resource->space_id, mem_resource->resource_usage,
|
||||
mem_resource->type_specific, mem_resource->granularity,
|
||||
mem_resource->minimum, mem_resource->maximum,
|
||||
mem_resource->translation_offset,
|
||||
mem_resource->address_length);
|
||||
|
||||
if (mem_resource->space_id != ACPI_ADR_SPACE_SYSTEM_MEMORY) {
|
||||
ret = -ENODEV;
|
||||
goto out_free;
|
||||
}
|
||||
|
||||
pcch_virt_addr = ioremap_nocache(mem_resource->minimum,
|
||||
mem_resource->address_length);
|
||||
if (pcch_virt_addr == NULL) {
|
||||
dprintk("probe: could not map shared mem region\n");
|
||||
goto out_free;
|
||||
}
|
||||
pcch_hdr = pcch_virt_addr;
|
||||
|
||||
dprintk("probe: PCCH header (virtual) addr: 0x%p\n", pcch_hdr);
|
||||
dprintk("probe: PCCH header is at physical address: 0x%llx,"
|
||||
" signature: 0x%x, length: %d bytes, major: %d, minor: %d,"
|
||||
" supported features: 0x%x, command field: 0x%x,"
|
||||
" status field: 0x%x, nominal latency: %d us\n",
|
||||
mem_resource->minimum, ioread32(&pcch_hdr->signature),
|
||||
ioread16(&pcch_hdr->length), ioread8(&pcch_hdr->major),
|
||||
ioread8(&pcch_hdr->minor), ioread32(&pcch_hdr->features),
|
||||
ioread16(&pcch_hdr->command), ioread16(&pcch_hdr->status),
|
||||
ioread32(&pcch_hdr->latency));
|
||||
|
||||
dprintk("probe: min time between commands: %d us,"
|
||||
" max time between commands: %d us,"
|
||||
" nominal CPU frequency: %d MHz,"
|
||||
" minimum CPU frequency: %d MHz,"
|
||||
" minimum CPU frequency without throttling: %d MHz\n",
|
||||
ioread32(&pcch_hdr->minimum_time),
|
||||
ioread32(&pcch_hdr->maximum_time),
|
||||
ioread32(&pcch_hdr->nominal),
|
||||
ioread32(&pcch_hdr->throttled_frequency),
|
||||
ioread32(&pcch_hdr->minimum_frequency));
|
||||
|
||||
member = &out_obj->package.elements[1];
|
||||
if (member->type != ACPI_TYPE_BUFFER) {
|
||||
ret = -ENODEV;
|
||||
goto pcch_free;
|
||||
}
|
||||
|
||||
reg_resource = (struct pcc_register_resource *)member->buffer.pointer;
|
||||
|
||||
doorbell.space_id = reg_resource->space_id;
|
||||
doorbell.bit_width = reg_resource->bit_width;
|
||||
doorbell.bit_offset = reg_resource->bit_offset;
|
||||
doorbell.access_width = 64;
|
||||
doorbell.address = reg_resource->address;
|
||||
|
||||
dprintk("probe: doorbell: space_id is %d, bit_width is %d, "
|
||||
"bit_offset is %d, access_width is %d, address is 0x%llx\n",
|
||||
doorbell.space_id, doorbell.bit_width, doorbell.bit_offset,
|
||||
doorbell.access_width, reg_resource->address);
|
||||
|
||||
member = &out_obj->package.elements[2];
|
||||
if (member->type != ACPI_TYPE_INTEGER) {
|
||||
ret = -ENODEV;
|
||||
goto pcch_free;
|
||||
}
|
||||
|
||||
doorbell_preserve = member->integer.value;
|
||||
|
||||
member = &out_obj->package.elements[3];
|
||||
if (member->type != ACPI_TYPE_INTEGER) {
|
||||
ret = -ENODEV;
|
||||
goto pcch_free;
|
||||
}
|
||||
|
||||
doorbell_write = member->integer.value;
|
||||
|
||||
dprintk("probe: doorbell_preserve: 0x%llx,"
|
||||
" doorbell_write: 0x%llx\n",
|
||||
doorbell_preserve, doorbell_write);
|
||||
|
||||
pcc_cpu_info = alloc_percpu(struct pcc_cpu);
|
||||
if (!pcc_cpu_info) {
|
||||
ret = -ENOMEM;
|
||||
goto pcch_free;
|
||||
}
|
||||
|
||||
printk(KERN_DEBUG "pcc-cpufreq: (v%s) driver loaded with frequency"
|
||||
" limits: %d MHz, %d MHz\n", PCC_VERSION,
|
||||
ioread32(&pcch_hdr->minimum_frequency),
|
||||
ioread32(&pcch_hdr->nominal));
|
||||
kfree(output.pointer);
|
||||
return ret;
|
||||
pcch_free:
|
||||
pcc_clear_mapping();
|
||||
out_free:
|
||||
kfree(output.pointer);
|
||||
return ret;
|
||||
}
|
||||
|
||||
static int pcc_cpufreq_cpu_init(struct cpufreq_policy *policy)
|
||||
{
|
||||
unsigned int cpu = policy->cpu;
|
||||
unsigned int result = 0;
|
||||
|
||||
if (!pcch_virt_addr) {
|
||||
result = -1;
|
||||
goto pcch_null;
|
||||
}
|
||||
|
||||
result = pcc_get_offset(cpu);
|
||||
if (result) {
|
||||
dprintk("init: PCCP evaluation failed\n");
|
||||
goto free;
|
||||
}
|
||||
|
||||
policy->max = policy->cpuinfo.max_freq =
|
||||
ioread32(&pcch_hdr->nominal) * 1000;
|
||||
policy->min = policy->cpuinfo.min_freq =
|
||||
ioread32(&pcch_hdr->minimum_frequency) * 1000;
|
||||
policy->cur = pcc_get_freq(cpu);
|
||||
|
||||
dprintk("init: policy->max is %d, policy->min is %d\n",
|
||||
policy->max, policy->min);
|
||||
|
||||
return 0;
|
||||
free:
|
||||
pcc_clear_mapping();
|
||||
free_percpu(pcc_cpu_info);
|
||||
pcch_null:
|
||||
return result;
|
||||
}
|
||||
|
||||
static int pcc_cpufreq_cpu_exit(struct cpufreq_policy *policy)
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
|
||||
static struct cpufreq_driver pcc_cpufreq_driver = {
|
||||
.flags = CPUFREQ_CONST_LOOPS,
|
||||
.get = pcc_get_freq,
|
||||
.verify = pcc_cpufreq_verify,
|
||||
.target = pcc_cpufreq_target,
|
||||
.init = pcc_cpufreq_cpu_init,
|
||||
.exit = pcc_cpufreq_cpu_exit,
|
||||
.name = "pcc-cpufreq",
|
||||
.owner = THIS_MODULE,
|
||||
};
|
||||
|
||||
static int __init pcc_cpufreq_init(void)
|
||||
{
|
||||
int ret;
|
||||
|
||||
if (acpi_disabled)
|
||||
return 0;
|
||||
|
||||
ret = pcc_cpufreq_probe();
|
||||
if (ret) {
|
||||
dprintk("pcc_cpufreq_init: PCCH evaluation failed\n");
|
||||
return ret;
|
||||
}
|
||||
|
||||
ret = cpufreq_register_driver(&pcc_cpufreq_driver);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static void __exit pcc_cpufreq_exit(void)
|
||||
{
|
||||
cpufreq_unregister_driver(&pcc_cpufreq_driver);
|
||||
|
||||
pcc_clear_mapping();
|
||||
|
||||
free_percpu(pcc_cpu_info);
|
||||
}
|
||||
|
||||
MODULE_AUTHOR("Matthew Garrett, Naga Chumbalkar");
|
||||
MODULE_VERSION(PCC_VERSION);
|
||||
MODULE_DESCRIPTION("Processor Clocking Control interface driver");
|
||||
MODULE_LICENSE("GPL");
|
||||
|
||||
late_initcall(pcc_cpufreq_init);
|
||||
module_exit(pcc_cpufreq_exit);
|
||||
@ -123,6 +123,8 @@ static const struct file_operations acpi_processor_info_fops = {
|
||||
#endif
|
||||
|
||||
DEFINE_PER_CPU(struct acpi_processor *, processors);
|
||||
EXPORT_PER_CPU_SYMBOL(processors);
|
||||
|
||||
struct acpi_processor_errata errata __read_mostly;
|
||||
|
||||
/* --------------------------------------------------------------------------
|
||||
|
||||
Loading…
Reference in New Issue
Block a user