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    SubjectRe: [PATCH v2 0/7] CPPC optional registers AMD support
    Date
    On 4/4/19 4:25 PM, Natarajan, Janakarajan wrote:
    > CPPC (Collaborative Processor Performance Control) offers optional
    > registers which can be used to tune the system based on energy and/or
    > performance requirements.
    >
    > Newer AMD processors add support for a subset of these optional CPPC
    > registers, based on ACPI v6.1.
    >
    > The following are the supported CPPC registers for which sysfs entries
    > are created:
    > * enable (NEW)
    > * max_perf (NEW)
    > * min_perf (NEW)
    > * energy_perf
    > * lowest_perf
    > * nominal_perf
    > * desired_perf (NEW)
    > * feedback_ctrs
    > * auto_sel_enable (NEW)
    > * lowest_nonlinear_perf
    >
    > The CPPC driver is updated to enable the OSPM and the userspace to
    > access
    > the newly supported registers.
    >
    > The purpose of exposing the registers via the sysfs entries is to allow
    > the userspace to:
    > * Tweak the values to fit its workload.
    > * Apply a profile from AMD's optimization guides.
    >
    > Profiles will be documented in the performance/optimization guides.
    >
    > Note:
    > * AMD systems will not have a policy applied in the kernel at this time.
    > * By default, acpi_cpufreq will still be used.
    >
    > TODO:
    > * Create a linux userspace tool that will help users generate a CPPC
    > * profile
    > for their target workload.
    > * Create or update a driver to apply a general CPPC policy in the
    > * kernel.
    >
    > v1->v2:
    > * Add macro to ensure BUFFER only registers have BUFFER type.
    > * Add support macro to make the right check based on register type.
    > * Remove support checks for registers which are mandatory.


    Are there any concerns regarding this patchset?


    Thanks.


    >
    > Janakarajan Natarajan (2):
    > acpi/cppc: Add macro for CPPC register BUFFER only check
    > acpi/cppc: Ensure only supported CPPC sysfs entries are created
    >
    > Yazen Ghannam (5):
    > acpi/cppc: Modify show_cppc_data macro
    > acpi/cppc: Rework cppc_set_perf() to use cppc_regs index
    > acpi/cppc: Add macros to define a R/W sysfs entry for CPPC registers
    > acpi/cppc: Add support for optional CPPC registers
    > acpi/cppc: Add support for CPPC Enable register
    >
    > drivers/acpi/cppc_acpi.c | 402 +++++++++++++++++++++++++++++----
    > drivers/cpufreq/cppc_cpufreq.c | 6 +-
    > include/acpi/cppc_acpi.h | 6 +-
    > 3 files changed, 372 insertions(+), 42 deletions(-)
    >
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