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* pm-cpufreq: (51 commits)
  Documentation: intel_pstate: Document HWP energy/performance hints
  cpufreq: intel_pstate: Support for energy performance hints with HWP
  cpufreq: intel_pstate: Add locking around HWP requests
  cpufreq: ondemand: Set MIN_FREQUENCY_UP_THRESHOLD to 1
  cpufreq: intel_pstate: Add Knights Mill CPUID
  MAINTAINERS: Add bug tracking system location entry for cpufreq
  cpufreq: dt: Add support for zx296718
  cpufreq: acpi-cpufreq: drop rdmsr_on_cpus() usage
  cpufreq: acpi-cpufreq: Convert to hotplug state machine
  cpufreq: intel_pstate: fix intel_pstate_exit_perf_limits() prototype
  cpufreq: intel_pstate: Set EPP/EPB to 0 in performance mode
  cpufreq: schedutil: Rectify comment in sugov_irq_work() function
  cpufreq: intel_pstate: increase precision of performance limits
  cpufreq: intel_pstate: round up min_perf limits
  cpufreq: Make cpufreq_update_policy() void
  ACPI / processor: Make acpi_processor_ppc_has_changed() void
  cpufreq: Avoid using inactive policies
  cpufreq: intel_pstate: Generic governors support
  cpufreq: intel_pstate: Request P-states control from SMM if needed
  cpufreq: dt: Add support for r8a7743 and r8a7745
  ...
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Rafael J. Wysocki committed Dec 12, 2016
2 parents 57def85 + 2bf3b68 commit fecc8c0
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6 changes: 6 additions & 0 deletions Documentation/cpu-freq/cpufreq-stats.txt
Original file line number Diff line number Diff line change
Expand Up @@ -44,11 +44,17 @@ the stats driver insertion.
total 0
drwxr-xr-x 2 root root 0 May 14 16:06 .
drwxr-xr-x 3 root root 0 May 14 15:58 ..
--w------- 1 root root 4096 May 14 16:06 reset
-r--r--r-- 1 root root 4096 May 14 16:06 time_in_state
-r--r--r-- 1 root root 4096 May 14 16:06 total_trans
-r--r--r-- 1 root root 4096 May 14 16:06 trans_table
--------------------------------------------------------------------------------

- reset
Write-only attribute that can be used to reset the stat counters. This can be
useful for evaluating system behaviour under different governors without the
need for a reboot.

- time_in_state
This gives the amount of time spent in each of the frequencies supported by
this CPU. The cat output will have "<frequency> <time>" pair in each line, which
Expand Down
54 changes: 49 additions & 5 deletions Documentation/cpu-freq/intel-pstate.txt
Original file line number Diff line number Diff line change
Expand Up @@ -48,7 +48,7 @@ In addition to the frequency-controlling interfaces provided by the cpufreq
core, the driver provides its own sysfs files to control the P-State selection.
These files have been added to /sys/devices/system/cpu/intel_pstate/.
Any changes made to these files are applicable to all CPUs (even in a
multi-package system).
multi-package system, Refer to later section on placing "Per-CPU limits").

max_perf_pct: Limits the maximum P-State that will be requested by
the driver. It states it as a percentage of the available performance. The
Expand Down Expand Up @@ -120,13 +120,57 @@ frequency is fictional for Intel Core processors. Even if the scaling
driver selects a single P-State, the actual frequency the processor
will run at is selected by the processor itself.

Per-CPU limits

The kernel command line option "intel_pstate=per_cpu_perf_limits" forces
the intel_pstate driver to use per-CPU performance limits. When it is set,
the sysfs control interface described above is subject to limitations.
- The following controls are not available for both read and write
/sys/devices/system/cpu/intel_pstate/max_perf_pct
/sys/devices/system/cpu/intel_pstate/min_perf_pct
- The following controls can be used to set performance limits, as far as the
architecture of the processor permits:
/sys/devices/system/cpu/cpu*/cpufreq/scaling_max_freq
/sys/devices/system/cpu/cpu*/cpufreq/scaling_min_freq
/sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
- User can still observe turbo percent and number of P-States from
/sys/devices/system/cpu/intel_pstate/turbo_pct
/sys/devices/system/cpu/intel_pstate/num_pstates
- User can read write system wide turbo status
/sys/devices/system/cpu/no_turbo

Support of energy performance hints
It is possible to provide hints to the HWP algorithms in the processor
to be more performance centric to more energy centric. When the driver
is using HWP, two additional cpufreq sysfs attributes are presented for
each logical CPU.
These attributes are:
- energy_performance_available_preferences
- energy_performance_preference

To get list of supported hints:
$ cat energy_performance_available_preferences
default performance balance_performance balance_power power

The current preference can be read or changed via cpufreq sysfs
attribute "energy_performance_preference". Reading from this attribute
will display current effective setting. User can write any of the valid
preference string to this attribute. User can always restore to power-on
default by writing "default".

Since threads can migrate to different CPUs, this is possible that the
new CPU may have different energy performance preference than the previous
one. To avoid such issues, either threads can be pinned to specific CPUs
or set the same energy performance preference value to all CPUs.

Tuning Intel P-State driver

When HWP mode is not used, debugfs files have also been added to allow the
tuning of the internal governor algorithm. These files are located at
/sys/kernel/debug/pstate_snb/. The algorithm uses a PID (Proportional
Integral Derivative) controller. The PID tunable parameters are:
When the performance can be tuned using PID (Proportional Integral
Derivative) controller, debugfs files are provided for adjusting performance.
They are presented under:
/sys/kernel/debug/pstate_snb/

The PID tunable parameters are:
deadband
d_gain_pct
i_gain_pct
Expand Down
Original file line number Diff line number Diff line change
@@ -0,0 +1,78 @@
Broadcom AVS mail box and interrupt register bindings
=====================================================

A total of three DT nodes are required. One node (brcm,avs-cpu-data-mem)
references the mailbox register used to communicate with the AVS CPU[1]. The
second node (brcm,avs-cpu-l2-intr) is required to trigger an interrupt on
the AVS CPU. The interrupt tells the AVS CPU that it needs to process a
command sent to it by a driver. Interrupting the AVS CPU is mandatory for
commands to be processed.

The interface also requires a reference to the AVS host interrupt controller,
so a driver can react to interrupts generated by the AVS CPU whenever a command
has been processed. See [2] for more information on the brcm,l2-intc node.

[1] The AVS CPU is an independent co-processor that runs proprietary
firmware. On some SoCs, this firmware supports DFS and DVFS in addition to
Adaptive Voltage Scaling.

[2] Documentation/devicetree/bindings/interrupt-controller/brcm,l2-intc.txt


Node brcm,avs-cpu-data-mem
--------------------------

Required properties:
- compatible: must include: brcm,avs-cpu-data-mem and
should include: one of brcm,bcm7271-avs-cpu-data-mem or
brcm,bcm7268-avs-cpu-data-mem
- reg: Specifies base physical address and size of the registers.
- interrupts: The interrupt that the AVS CPU will use to interrupt the host
when a command completed.
- interrupt-parent: The interrupt controller the above interrupt is routed
through.
- interrupt-names: The name of the interrupt used to interrupt the host.

Optional properties:
- None

Node brcm,avs-cpu-l2-intr
-------------------------

Required properties:
- compatible: must include: brcm,avs-cpu-l2-intr and
should include: one of brcm,bcm7271-avs-cpu-l2-intr or
brcm,bcm7268-avs-cpu-l2-intr
- reg: Specifies base physical address and size of the registers.

Optional properties:
- None


Example
=======

avs_host_l2_intc: interrupt-controller@f04d1200 {
#interrupt-cells = <1>;
compatible = "brcm,l2-intc";
interrupt-parent = <&intc>;
reg = <0xf04d1200 0x48>;
interrupt-controller;
interrupts = <0x0 0x19 0x0>;
interrupt-names = "avs";
};

avs-cpu-data-mem@f04c4000 {
compatible = "brcm,bcm7271-avs-cpu-data-mem",
"brcm,avs-cpu-data-mem";
reg = <0xf04c4000 0x60>;
interrupts = <0x1a>;
interrupt-parent = <&avs_host_l2_intc>;
interrupt-names = "sw_intr";
};

avs-cpu-l2-intr@f04d1100 {
compatible = "brcm,bcm7271-avs-cpu-l2-intr",
"brcm,avs-cpu-l2-intr";
reg = <0xf04d1100 0x10>;
};
9 changes: 9 additions & 0 deletions Documentation/kernel-parameters.txt
Original file line number Diff line number Diff line change
Expand Up @@ -1760,6 +1760,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
disable
Do not enable intel_pstate as the default
scaling driver for the supported processors
passive
Use intel_pstate as a scaling driver, but configure it
to work with generic cpufreq governors (instead of
enabling its internal governor). This mode cannot be
used along with the hardware-managed P-states (HWP)
feature.
force
Enable intel_pstate on systems that prohibit it by default
in favor of acpi-cpufreq. Forcing the intel_pstate driver
Expand All @@ -1780,6 +1786,9 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
Description Table, specifies preferred power management
profile as "Enterprise Server" or "Performance Server",
then this feature is turned on by default.
per_cpu_perf_limits
Allow per-logical-CPU P-State performance control limits using
cpufreq sysfs interface

intremap= [X86-64, Intel-IOMMU]
on enable Interrupt Remapping (default)
Expand Down
9 changes: 9 additions & 0 deletions MAINTAINERS
Original file line number Diff line number Diff line change
Expand Up @@ -2749,6 +2749,14 @@ L: bcm-kernel-feedback-list@broadcom.com
S: Maintained
F: drivers/mtd/nand/brcmnand/

BROADCOM STB AVS CPUFREQ DRIVER
M: Markus Mayer <mmayer@broadcom.com>
M: bcm-kernel-feedback-list@broadcom.com
L: linux-pm@vger.kernel.org
S: Maintained
F: Documentation/devicetree/bindings/cpufreq/brcm,stb-avs-cpu-freq.txt
F: drivers/cpufreq/brcmstb*

BROADCOM SPECIFIC AMBA DRIVER (BCMA)
M: Rafał Miłecki <zajec5@gmail.com>
L: linux-wireless@vger.kernel.org
Expand Down Expand Up @@ -3341,6 +3349,7 @@ L: linux-pm@vger.kernel.org
S: Maintained
T: git git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git
T: git git://git.linaro.org/people/vireshk/linux.git (For ARM Updates)
B: https://bugzilla.kernel.org
F: Documentation/cpu-freq/
F: drivers/cpufreq/
F: include/linux/cpufreq.h
Expand Down
55 changes: 32 additions & 23 deletions drivers/acpi/processor_perflib.c
Original file line number Diff line number Diff line change
Expand Up @@ -157,7 +157,7 @@ static void acpi_processor_ppc_ost(acpi_handle handle, int status)
status, NULL);
}

int acpi_processor_ppc_has_changed(struct acpi_processor *pr, int event_flag)
void acpi_processor_ppc_has_changed(struct acpi_processor *pr, int event_flag)
{
int ret;

Expand All @@ -168,7 +168,7 @@ int acpi_processor_ppc_has_changed(struct acpi_processor *pr, int event_flag)
*/
if (event_flag)
acpi_processor_ppc_ost(pr->handle, 1);
return 0;
return;
}

ret = acpi_processor_get_platform_limit(pr);
Expand All @@ -182,10 +182,8 @@ int acpi_processor_ppc_has_changed(struct acpi_processor *pr, int event_flag)
else
acpi_processor_ppc_ost(pr->handle, 0);
}
if (ret < 0)
return (ret);
else
return cpufreq_update_policy(pr->id);
if (ret >= 0)
cpufreq_update_policy(pr->id);
}

int acpi_processor_get_bios_limit(int cpu, unsigned int *limit)
Expand Down Expand Up @@ -465,11 +463,33 @@ int acpi_processor_get_performance_info(struct acpi_processor *pr)
return result;
}
EXPORT_SYMBOL_GPL(acpi_processor_get_performance_info);
int acpi_processor_notify_smm(struct module *calling_module)

int acpi_processor_pstate_control(void)
{
acpi_status status;
static int is_done = 0;

if (!acpi_gbl_FADT.smi_command || !acpi_gbl_FADT.pstate_control)
return 0;

ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Writing pstate_control [0x%x] to smi_command [0x%x]\n",
acpi_gbl_FADT.pstate_control, acpi_gbl_FADT.smi_command));

status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
(u32)acpi_gbl_FADT.pstate_control, 8);
if (ACPI_SUCCESS(status))
return 1;

ACPI_EXCEPTION((AE_INFO, status,
"Failed to write pstate_control [0x%x] to smi_command [0x%x]",
acpi_gbl_FADT.pstate_control, acpi_gbl_FADT.smi_command));
return -EIO;
}

int acpi_processor_notify_smm(struct module *calling_module)
{
static int is_done = 0;
int result;

if (!(acpi_processor_ppc_status & PPC_REGISTERED))
return -EBUSY;
Expand All @@ -492,26 +512,15 @@ int acpi_processor_notify_smm(struct module *calling_module)

is_done = -EIO;

/* Can't write pstate_control to smi_command if either value is zero */
if ((!acpi_gbl_FADT.smi_command) || (!acpi_gbl_FADT.pstate_control)) {
result = acpi_processor_pstate_control();
if (!result) {
ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No SMI port or pstate_control\n"));
module_put(calling_module);
return 0;
}

ACPI_DEBUG_PRINT((ACPI_DB_INFO,
"Writing pstate_control [0x%x] to smi_command [0x%x]\n",
acpi_gbl_FADT.pstate_control, acpi_gbl_FADT.smi_command));

status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
(u32) acpi_gbl_FADT.pstate_control, 8);
if (ACPI_FAILURE(status)) {
ACPI_EXCEPTION((AE_INFO, status,
"Failed to write pstate_control [0x%x] to "
"smi_command [0x%x]", acpi_gbl_FADT.pstate_control,
acpi_gbl_FADT.smi_command));
if (result < 0) {
module_put(calling_module);
return status;
return result;
}

/* Success. If there's no _PPC, we need to fear nothing, so
Expand Down
29 changes: 21 additions & 8 deletions drivers/cpufreq/Kconfig.arm
Original file line number Diff line number Diff line change
Expand Up @@ -12,6 +12,27 @@ config ARM_BIG_LITTLE_CPUFREQ
help
This enables the Generic CPUfreq driver for ARM big.LITTLE platforms.

config ARM_BRCMSTB_AVS_CPUFREQ
tristate "Broadcom STB AVS CPUfreq driver"
depends on ARCH_BRCMSTB || COMPILE_TEST
default y
help
Some Broadcom STB SoCs use a co-processor running proprietary firmware
("AVS") to handle voltage and frequency scaling. This driver provides
a standard CPUfreq interface to to the firmware.

Say Y, if you have a Broadcom SoC with AVS support for DFS or DVFS.

config ARM_BRCMSTB_AVS_CPUFREQ_DEBUG
bool "Broadcom STB AVS CPUfreq driver sysfs debug capability"
depends on ARM_BRCMSTB_AVS_CPUFREQ
help
Enabling this option turns on debug support via sysfs under
/sys/kernel/debug/brcmstb-avs-cpufreq. It is possible to read all and
write some AVS mailbox registers through sysfs entries.

If in doubt, say N.

config ARM_DT_BL_CPUFREQ
tristate "Generic probing via DT for ARM big LITTLE CPUfreq driver"
depends on ARM_BIG_LITTLE_CPUFREQ && OF
Expand Down Expand Up @@ -60,14 +81,6 @@ config ARM_IMX6Q_CPUFREQ

If in doubt, say N.

config ARM_INTEGRATOR
tristate "CPUfreq driver for ARM Integrator CPUs"
depends on ARCH_INTEGRATOR
default y
help
This enables the CPUfreq driver for ARM Integrator CPUs.
If in doubt, say Y.

config ARM_KIRKWOOD_CPUFREQ
def_bool MACH_KIRKWOOD
help
Expand Down
2 changes: 1 addition & 1 deletion drivers/cpufreq/Makefile
Original file line number Diff line number Diff line change
Expand Up @@ -51,12 +51,12 @@ obj-$(CONFIG_ARM_BIG_LITTLE_CPUFREQ) += arm_big_little.o
# LITTLE drivers, so that it is probed last.
obj-$(CONFIG_ARM_DT_BL_CPUFREQ) += arm_big_little_dt.o

obj-$(CONFIG_ARM_BRCMSTB_AVS_CPUFREQ) += brcmstb-avs-cpufreq.o
obj-$(CONFIG_ARCH_DAVINCI) += davinci-cpufreq.o
obj-$(CONFIG_UX500_SOC_DB8500) += dbx500-cpufreq.o
obj-$(CONFIG_ARM_EXYNOS5440_CPUFREQ) += exynos5440-cpufreq.o
obj-$(CONFIG_ARM_HIGHBANK_CPUFREQ) += highbank-cpufreq.o
obj-$(CONFIG_ARM_IMX6Q_CPUFREQ) += imx6q-cpufreq.o
obj-$(CONFIG_ARM_INTEGRATOR) += integrator-cpufreq.o
obj-$(CONFIG_ARM_KIRKWOOD_CPUFREQ) += kirkwood-cpufreq.o
obj-$(CONFIG_ARM_MT8173_CPUFREQ) += mt8173-cpufreq.o
obj-$(CONFIG_ARM_OMAP2PLUS_CPUFREQ) += omap-cpufreq.o
Expand Down
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