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3c14b73454
Adds a syscall interface to represent the energy and frequency related
PAPR attributes on the system using the new H_CALL
"H_GET_ENERGY_SCALE_INFO".
H_GET_EM_PARMS H_CALL was previously responsible for exporting this
information in the lparcfg, however the H_GET_EM_PARMS H_CALL
will be deprecated P10 onwards.
The H_GET_ENERGY_SCALE_INFO H_CALL is of the following call format:
hcall(
uint64 H_GET_ENERGY_SCALE_INFO, // Get energy scale info
uint64 flags, // Per the flag request
uint64 firstAttributeId,// The attribute id
uint64 bufferAddress, // Guest physical address of the output buffer
uint64 bufferSize // The size in bytes of the output buffer
);
As specified in PAPR+ v2.11, section 14.14.3.
This H_CALL can query either all the attributes at once with
firstAttributeId = 0, flags = 0 as well as query only one attribute
at a time with firstAttributeId = id, flags = 1.
The output buffer consists of the following
1. number of attributes - 8 bytes
2. array offset to the data location - 8 bytes
3. version info - 1 byte
4. A data array of size num attributes, which contains the following:
a. attribute ID - 8 bytes
b. attribute value in number - 8 bytes
c. attribute name in string - 64 bytes
d. attribute value in string - 64 bytes
The new H_CALL exports information in direct string value format, hence
a new interface has been introduced in
/sys/firmware/papr/energy_scale_info to export this information to
userspace so that the firmware can add new values without the need for
the kernel to be changed.
The H_CALL returns the name, numeric value and string value (if exists)
The format of exposing the sysfs information is as follows:
/sys/firmware/papr/energy_scale_info/
|-- <id>/
|-- desc
|-- value
|-- value_desc (if exists)
|-- <id>/
|-- desc
|-- value
|-- value_desc (if exists)
...
The energy information that is exported is useful for userspace tools
such as powerpc-utils. Currently these tools infer the
"power_mode_data" value in the lparcfg, which in turn is obtained from
the to be deprecated H_GET_EM_PARMS H_CALL.
On future platforms, such userspace utilities will have to look at the
data returned from the new H_CALL being populated in this new sysfs
interface and report this information directly without the need of
interpretation.
Signed-off-by: Pratik R. Sampat <psampat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220217105321.52941-2-psampat@linux.ibm.com
36 lines
1.2 KiB
Makefile
36 lines
1.2 KiB
Makefile
# SPDX-License-Identifier: GPL-2.0
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ccflags-$(CONFIG_PPC64) := $(NO_MINIMAL_TOC)
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ccflags-$(CONFIG_PPC_PSERIES_DEBUG) += -DDEBUG
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obj-y := lpar.o hvCall.o nvram.o reconfig.o \
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of_helpers.o \
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setup.o iommu.o event_sources.o ras.o \
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firmware.o power.o dlpar.o mobility.o rng.o \
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pci.o pci_dlpar.o eeh_pseries.o msi.o \
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papr_platform_attributes.o
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obj-$(CONFIG_SMP) += smp.o
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obj-$(CONFIG_KEXEC_CORE) += kexec.o
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obj-$(CONFIG_PSERIES_ENERGY) += pseries_energy.o
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obj-$(CONFIG_HOTPLUG_CPU) += hotplug-cpu.o
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obj-$(CONFIG_MEMORY_HOTPLUG) += hotplug-memory.o pmem.o
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obj-$(CONFIG_HVC_CONSOLE) += hvconsole.o
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obj-$(CONFIG_HVCS) += hvcserver.o
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obj-$(CONFIG_HCALL_STATS) += hvCall_inst.o
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obj-$(CONFIG_CMM) += cmm.o
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obj-$(CONFIG_DTL) += dtl.o
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obj-$(CONFIG_IO_EVENT_IRQ) += io_event_irq.o
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obj-$(CONFIG_LPARCFG) += lparcfg.o
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obj-$(CONFIG_IBMVIO) += vio.o
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obj-$(CONFIG_IBMEBUS) += ibmebus.o
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obj-$(CONFIG_PAPR_SCM) += papr_scm.o
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obj-$(CONFIG_PPC_SPLPAR) += vphn.o
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obj-$(CONFIG_PPC_SVM) += svm.o
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obj-$(CONFIG_FA_DUMP) += rtas-fadump.o
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obj-$(CONFIG_SUSPEND) += suspend.o
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obj-$(CONFIG_PPC_VAS) += vas.o vas-sysfs.o
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obj-$(CONFIG_ARCH_HAS_CC_PLATFORM) += cc_platform.o
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