RE: [PATCH v2 1/4] power: refactor core power management library

["Tummala, Sivaprasad" <Sivaprasad.Tummala@amd.com>]

[AMD Official Use Only - AMD Internal Distribution Only]

> -----Original Message-----
> From: lihuisong (C) <lihuisong@huawei.com>
> Sent: Friday, September 13, 2024 1:05 PM
> To: Tummala, Sivaprasad <Sivaprasad.Tummala@amd.com>
> Cc: dev@dpdk.org; david.hunt@intel.com; anatoly.burakov@intel.com;
> radu.nicolau@intel.com; cristian.dumitrescu@intel.com; jerinj@marvell.com;
> konstantin.ananyev@huawei.com; Yigit, Ferruh <Ferruh.Yigit@amd.com>;
> gakhil@marvell.com
> Subject: Re: [PATCH v2 1/4] power: refactor core power management library
>
> Caution: This message originated from an External Source. Use proper caution
> when opening attachments, clicking links, or responding.
>
>
> 在 2024/9/12 19:17, Tummala, Sivaprasad 写道:
> > [AMD Official Use Only - AMD Internal Distribution Only]
> >
> > Hi Huisong,
> >
> > Please find my response inline.
> >
> >> -----Original Message-----
> >> From: lihuisong (C) <lihuisong@huawei.com>
> >> Sent: Tuesday, August 27, 2024 1:51 PM
> >> To: Tummala, Sivaprasad <Sivaprasad.Tummala@amd.com>
> >> Cc: dev@dpdk.org; david.hunt@intel.com; anatoly.burakov@intel.com;
> >> radu.nicolau@intel.com; cristian.dumitrescu@intel.com;
> >> jerinj@marvell.com; konstantin.ananyev@huawei.com; Yigit, Ferruh
> >> <Ferruh.Yigit@amd.com>; gakhil@marvell.com
> >> Subject: Re: [PATCH v2 1/4] power: refactor core power management
> >> library
> >>
> >> Caution: This message originated from an External Source. Use proper
> >> caution when opening attachments, clicking links, or responding.
> >>
> >>
> >> Hi Sivaprasa,
> >>
> >> Some comments inline.
> >>
> >> /Huisong
> >>
> >> 在 2024/8/26 21:06, Sivaprasad Tummala 写道:
> >>> This patch introduces a comprehensive refactor to the core power
> >>> management library. The primary focus is on improving modularity and
> >>> organization by relocating specific driver implementations from the
> >>> 'lib/power' directory to dedicated directories within
> >>> 'drivers/power/core/*'. The adjustment of meson.build files enables
> >>> the selective activation of individual drivers.
> >>> These changes contribute to a significant enhancement in code
> >>> organization, providing a clearer structure for driver implementations.
> >>> The refactor aims to improve overall code clarity and boost
> >>> maintainability. Additionally, it establishes a foundation for
> >>> future development, allowing for more focused work on individual
> >>> drivers and seamless integration of forthcoming enhancements.
> >>>
> >>> v2:
> >>>    - added NULL check for global_core_ops in rte_power_get_core_ops
> >>>
> >>> Signed-off-by: Sivaprasad Tummala <sivaprasad.tummala@amd.com>
> >>> ---
> >>>    drivers/meson.build                           |   1 +
> >>>    .../power/acpi/acpi_cpufreq.c                 |  22 +-
> >>>    .../power/acpi/acpi_cpufreq.h                 |   6 +-
> >>>    drivers/power/acpi/meson.build                |  10 +
> >>>    .../power/amd_pstate/amd_pstate_cpufreq.c     |  24 +-
> >>>    .../power/amd_pstate/amd_pstate_cpufreq.h     |   8 +-
> >>>    drivers/power/amd_pstate/meson.build          |  10 +
> >>>    .../power/cppc/cppc_cpufreq.c                 |  22 +-
> >>>    .../power/cppc/cppc_cpufreq.h                 |   8 +-
> >>>    drivers/power/cppc/meson.build                |  10 +
> >>>    .../power/kvm_vm}/guest_channel.c             |   0
> >>>    .../power/kvm_vm}/guest_channel.h             |   0
> >>>    .../power/kvm_vm/kvm_vm.c                     |  22 +-
> >>>    .../power/kvm_vm/kvm_vm.h                     |   6 +-
> >>>    drivers/power/kvm_vm/meson.build              |  16 +
> >>>    drivers/power/meson.build                     |  12 +
> >>>    drivers/power/pstate/meson.build              |  10 +
> >>>    .../power/pstate/pstate_cpufreq.c             |  22 +-
> >>>    .../power/pstate/pstate_cpufreq.h             |   6 +-
> >>>    lib/power/meson.build                         |   7 +-
> >>>    lib/power/power_common.c                      |   2 +-
> >>>    lib/power/power_common.h                      |  16 +-
> >>>    lib/power/rte_power.c                         | 291 ++++++------------
> >>>    lib/power/rte_power.h                         | 139 ++++++---
> >>>    lib/power/rte_power_core_ops.h                | 208 +++++++++++++
> >>>    lib/power/version.map                         |  14 +
> >>>    26 files changed, 621 insertions(+), 271 deletions(-)
> >>>    rename lib/power/power_acpi_cpufreq.c =>
> >>> drivers/power/acpi/acpi_cpufreq.c
> >> (95%)
> >>>    rename lib/power/power_acpi_cpufreq.h =>
> >>> drivers/power/acpi/acpi_cpufreq.h
> >> (98%)
> >>>    create mode 100644 drivers/power/acpi/meson.build
> >>>    rename lib/power/power_amd_pstate_cpufreq.c =>
> >> drivers/power/amd_pstate/amd_pstate_cpufreq.c (95%)
> >>>    rename lib/power/power_amd_pstate_cpufreq.h =>
> >> drivers/power/amd_pstate/amd_pstate_cpufreq.h (97%)
> >>>    create mode 100644 drivers/power/amd_pstate/meson.build
> >>>    rename lib/power/power_cppc_cpufreq.c =>
> >>> drivers/power/cppc/cppc_cpufreq.c
> >> (95%)
> >>>    rename lib/power/power_cppc_cpufreq.h =>
> >>> drivers/power/cppc/cppc_cpufreq.h
> >> (97%)
> >>>    create mode 100644 drivers/power/cppc/meson.build
> >>>    rename {lib/power => drivers/power/kvm_vm}/guest_channel.c (100%)
> >>>    rename {lib/power => drivers/power/kvm_vm}/guest_channel.h (100%)
> >>>    rename lib/power/power_kvm_vm.c => drivers/power/kvm_vm/kvm_vm.c
> (82%)
> >>>    rename lib/power/power_kvm_vm.h => drivers/power/kvm_vm/kvm_vm.h
> (98%)
> >>>    create mode 100644 drivers/power/kvm_vm/meson.build
> >>>    create mode 100644 drivers/power/meson.build
> >>>    create mode 100644 drivers/power/pstate/meson.build
> >>>    rename lib/power/power_pstate_cpufreq.c =>
> >> drivers/power/pstate/pstate_cpufreq.c (96%)
> >>>    rename lib/power/power_pstate_cpufreq.h =>
> >> drivers/power/pstate/pstate_cpufreq.h (98%)
> >>>    create mode 100644 lib/power/rte_power_core_ops.h
> >> How about use the following directory structure?
> >> *For power libs*
> >> lib/power/power_common.*
> >> lib/power/rte_power_pmd_mgmt.*
> >> lib/power/rte_power_cpufreq_api.* （replacing rte_power.c file maybe simple for
> us.
> >> but I'm not sure if we can put the init of core, uncore and pmd mgmt
> >> to rte_power_init.c in rte_power.c.)
> >> lib/power/rte_power_uncore_freq_api.*
> > Yes, renaming rte_power.c is definitely a possible incremental change that could
> be considered later.
> > However, for the time being, our focus will be on refactoring the cpufreq drivers
> only.
> The rte_power.c just works for the initialization of cpufreq driver. Now that you are
> reworking core and uncore power library and rearrange the directory under power.
> I think renaming this file name should be more appropriate in this series.
> >> *And has directories under drivers/power:*
> >> 1> For core dvfs driver:
> >> drivers/power/cpufreq/acpi_cpufreq.c
> >> drivers/power/cpufreq/cppc_cpufreq.c
> >> drivers/power/cpufreq/amd_pstate_cpufreq.c
> >> drivers/power/cpufreq/intel_pstate_cpufreq.c
> >> drivers/power/cpufreq/kvm_cpufreq.c
> >> The code of each cpufreq driver is not too much and doesn't probably
> >> increase. So don't need to use a directory for it.
> >>
> >> 2> For uncore dvfs driver:
> >> drivers/power/uncorefreq/intel_uncore.*
> >>> diff --git a/drivers/meson.build b/drivers/meson.build index
> >>> 66931d4241..9d77e0deab 100644
> >>> --- a/drivers/meson.build
> >>> +++ b/drivers/meson.build
> >>> @@ -29,6 +29,7 @@ subdirs = [
> >>>            'event',          # depends on common, bus, mempool and net.
> >>>            'baseband',       # depends on common and bus.
> >>>            'gpu',            # depends on common and bus.
> >>> +        'power',          # depends on common (in future).
> >>>    ]
> >>>
> >>>    if meson.is_cross_build()
> >>> diff --git a/lib/power/power_acpi_cpufreq.c
> >>> b/drivers/power/acpi/acpi_cpufreq.c
> >>> similarity index 95%
> >>> rename from lib/power/power_acpi_cpufreq.c rename to
> >>> drivers/power/acpi/acpi_cpufreq.c
> >> do not suggest to create one directory for each cpufreq driver.
> >> Because pstate drivers also comply with ACPI spec, right？
> >> In addition, the code of each cpufreq drivers are not too much.
> >> There is just one file under one directory which is not good.
> > One of our objectives for the refactoring is to selectively disable non-essential
> drivers using Meson build options.
> > However, by rearranging the driver structure, we risk disrupting this capability.
> I get your purpose.
> The cpufreq library has the feature and interface to detect which driver to use, right?
> So it is not necessary for cpufreq library to introduce the Meson build options, which
> probably makes it complicate.
In Meson, you can reduce code size by disabling specific drivers or components through build options,
allowing you to exclude unnecessary features. At runtime, the library will automatically detect the available driver,
and if it's not present in the build, initialization will fail.
We're not introducing any new complexities; rather, we aim to ensure that the drivers in drivers/power/*
are consistent with the other drivers.
> >>> index 81996e1c13..8637c69703 100644
> >>> --- a/lib/power/power_acpi_cpufreq.c
> >>> +++ b/drivers/power/acpi/acpi_cpufreq.c
> >>> @@ -10,7 +10,7 @@
> >>>    #include <rte_stdatomic.h>
> >>>    #include <rte_string_fns.h>
> >>>
> >>> -#include "power_acpi_cpufreq.h"
> >>> +#include "acpi_cpufreq.h"
> >>>    #include "power_common.h"
> >>>
> >> <...>
> >>> +if not is_linux
> >>> +    build = false
> >>> +    reason = 'only supported on Linux'
> >>> +endif
> >>> +sources = files('pstate_cpufreq.c')
> >>> +
> >>> +deps += ['power']
> >>> diff --git a/lib/power/power_pstate_cpufreq.c
> >>> b/drivers/power/pstate/pstate_cpufreq.c
> >>> similarity index 96%
> >>> rename from lib/power/power_pstate_cpufreq.c rename to
> >>> drivers/power/pstate/pstate_cpufreq.c
> >> pstate_cpufreq.c is actually intel_pstate cpufreq driver, right?
> >> So how about modify this file name to intel_pstate_cpufreq.c?
> > Yes, will fix this in next version.
> >>> index 2343121621..c32b1adabc 100644
> >>> --- a/lib/power/power_pstate_cpufreq.c
> >>> +++ b/drivers/power/pstate/pstate_cpufreq.c
> >>> @@ -15,7 +15,7 @@
> >>>    #include <rte_stdatomic.h>
> >>>
> >>>    #include "rte_power_pmd_mgmt.h"
> >>> -#include "power_pstate_cpufreq.h"
> >>> +#include "pstate_cpufreq.h"
> >>>    #include "power_common.h"
> >>>
> >>>    /* macros used for rounding frequency to nearest 100000 */ @@
> >>> -888,3
> >>> +888,23 @@ int power_pstate_get_capabilities(unsigned int lcore_id,
> >>>
> >>>        return 0;
> >>>    }
> >>> +
> >> <...>
> >>> diff --git a/lib/power/power_common.c b/lib/power/power_common.c
> >>> index 590986d5ef..6c06411e8b 100644
> >>> --- a/lib/power/power_common.c
> >>> +++ b/lib/power/power_common.c
> >>> @@ -12,7 +12,7 @@
> >>>
> >>>    #include "power_common.h"
> >>>
> >>> -RTE_LOG_REGISTER_DEFAULT(power_logtype, INFO);
> >>> +RTE_LOG_REGISTER_DEFAULT(rte_power_logtype, INFO);
> >>>
> >>>    #define POWER_SYSFILE_SCALING_DRIVER   \
> >>>                "/sys/devices/system/cpu/cpu%u/cpufreq/scaling_driver"
> >>> diff --git a/lib/power/power_common.h b/lib/power/power_common.h
> >>> index
> >>> 83f742f42a..767686ee12 100644
> >>> --- a/lib/power/power_common.h
> >>> +++ b/lib/power/power_common.h
> >>> @@ -6,12 +6,13 @@
> >>>    #define _POWER_COMMON_H_
> >>>
> >>>    #include <rte_common.h>
> >>> +#include <rte_compat.h>
> >>>    #include <rte_log.h>
> >>>
> >>>    #define RTE_POWER_INVALID_FREQ_INDEX (~0)
> >>>
> >>> -extern int power_logtype;
> >>> -#define RTE_LOGTYPE_POWER power_logtype
> >>> +extern int rte_power_logtype;
> >>> +#define RTE_LOGTYPE_POWER rte_power_logtype
> >>>    #define POWER_LOG(level, ...) \
> >>>        RTE_LOG_LINE(level, POWER, "" __VA_ARGS__)
> >>>
> >>> @@ -23,13 +24,24 @@ extern int power_logtype;
> >>>    #endif
> >>>
> >>>    /* check if scaling driver matches one we want */
> >>> +__rte_internal
> >>>    int cpufreq_check_scaling_driver(const char *driver);
> >>> +
> >>> +__rte_internal
> >>>    int power_set_governor(unsigned int lcore_id, const char *new_governor,
> >>>                char *orig_governor, size_t orig_governor_len);
> >> suggest that move cpufreq interfaces like this to the
> >> rte_power_cpufreq_api.* I proposed above.
> > This is an internal API and isn’t intended for direct use by applications.
> > By moving it to rte_power_*, we risk exposing it inadvertently.
> we don't expose these to applications. application do not include this header file.
> power_set_governor() and cpufreq_check_scaling_driver() is just used by cpufreq
> driver. So they just can be seen by cpufreq lib or module, right?
> But if these interface are in power_common.h, pmd_mgmt and uncore driver also
> include this header file and can see them. This is not good.
> AFAIS, the power_common.h should just contain the kind of interfaces that are used
> by all power libs or sub-modules, like cpufreq, uncore, pmd_mgmt and so on.
OK., Will move this internal APIs from power_common.h to a separate header file.
> >
> >> The interfaces in power_comm.* can be used by all power modules, like
> >> core/uncore/pmd mgmt.
> >>> +
> >>> +__rte_internal
> >>>    int open_core_sysfs_file(FILE **f, const char *mode, const char *format, ...)
> >>>                __rte_format_printf(3, 4);
> >>> +
> >>> +__rte_internal
> >>>    int read_core_sysfs_u32(FILE *f, uint32_t *val);
> >>> +
> >>> +__rte_internal
> >>>    int read_core_sysfs_s(FILE *f, char *buf, unsigned int len);
> >>> +
> >>> +__rte_internal
> >>>    int write_core_sysfs_s(FILE *f, const char *str);
> >>>
> >>>    #endif /* _POWER_COMMON_H_ */
> >>> diff --git a/lib/power/rte_power.c b/lib/power/rte_power.c
> >> The name of the rte_power.c file is impropriate now. The context in
> >> this file is just for cpufreq, right?
> >> So I suggest that we need to rename this file as the
> >> rte_power_cpufreq_api.c
> > Yes, renaming rte_power.c to rte_power_cpufreq.c is definitely a
> > possible incremental change and will fix this as a separate patch.
> > .
> >
> >>> index 36c3f3da98..2bf6d40517 100644
> >>> --- a/lib/power/rte_power.c
> >>> +++ b/lib/power/rte_power.c
> >>> @@ -8,153 +8,86 @@
> >>>    #include <rte_spinlock.h>
> >>>
> >>>    #include "rte_power.h"
> >>> -#include "power_acpi_cpufreq.h"
> >>> -#include "power_cppc_cpufreq.h"
> >>>    #include "power_common.h"
> >>> -#include "power_kvm_vm.h"
> >>> -#include "power_pstate_cpufreq.h"
> >>> -#include "power_amd_pstate_cpufreq.h"
> >>>
> >>> -enum power_management_env global_default_env = PM_ENV_NOT_SET;
> >>> +static enum power_management_env global_default_env =
> >> PM_ENV_NOT_SET;
> >>> +static struct rte_power_core_ops *global_power_core_ops;
> >>>
> >>>    static rte_spinlock_t global_env_cfg_lock =
> >>> RTE_SPINLOCK_INITIALIZER;
> >>> +static RTE_TAILQ_HEAD(, rte_power_core_ops) core_ops_list =
> >>> +                     TAILQ_HEAD_INITIALIZER(core_ops_list);
> >>>
> >>> -/* function pointers */
> >>> -rte_power_freqs_t rte_power_freqs  = NULL; -rte_power_get_freq_t
> >>> rte_power_get_freq = NULL; -rte_power_set_freq_t rte_power_set_freq
> >>> = NULL; -rte_power_freq_change_t rte_power_freq_up = NULL;
> >>> -rte_power_freq_change_t rte_power_freq_down = NULL;
> >>> -rte_power_freq_change_t rte_power_freq_max = NULL;
> >>> -rte_power_freq_change_t rte_power_freq_min = NULL;
> >>> -rte_power_freq_change_t rte_power_turbo_status;
> >>> -rte_power_freq_change_t rte_power_freq_enable_turbo;
> >>> -rte_power_freq_change_t rte_power_freq_disable_turbo;
> >>> -rte_power_get_capabilities_t rte_power_get_capabilities;
> >>> -
> >>> -static void
> >>> -reset_power_function_ptrs(void)
> >>> +
> >>> +const char *power_env_str[] = {
> >>> +     "not set",
> >>> +     "acpi",
> >>> +     "kvm-vm",
> >>> +     "pstate",
> >>> +     "cppc",
> >>> +     "amd-pstate"
> >>> +};
> >>> +
> >>> +/* register the ops struct in rte_power_core_ops, return 0 on
> >>> +success. */ int rte_power_register_ops(struct rte_power_core_ops
> >>> +*driver_ops)
> >>>    {
> >>> -     rte_power_freqs  = NULL;
> >>> -     rte_power_get_freq = NULL;
> >>> -     rte_power_set_freq = NULL;
> >>> -     rte_power_freq_up = NULL;
> >>> -     rte_power_freq_down = NULL;
> >>> -     rte_power_freq_max = NULL;
> >>> -     rte_power_freq_min = NULL;
> >>> -     rte_power_turbo_status = NULL;
> >>> -     rte_power_freq_enable_turbo = NULL;
> >>> -     rte_power_freq_disable_turbo = NULL;
> >>> -     rte_power_get_capabilities = NULL;
> >>> +     if (!driver_ops->init || !driver_ops->exit ||
> >>> +             !driver_ops->check_env_support || !driver_ops->get_avail_freqs ||
> >>> +             !driver_ops->get_freq || !driver_ops->set_freq ||
> >>> +             !driver_ops->freq_up || !driver_ops->freq_down ||
> >>> +             !driver_ops->freq_max || !driver_ops->freq_min ||
> >>> +             !driver_ops->turbo_status || !driver_ops->enable_turbo ||
> >>> +             !driver_ops->disable_turbo || !driver_ops->get_caps) {
> >>> +             POWER_LOG(ERR, "Missing callbacks while registering
> >>> + power ops");
> >> turbo_status(), enable_turbo() and disable turbo() are not necessary, right?
> > Nope, this is required to get the current status unlike the capability API
> (get_caps()).
> ok
> >> These depand on the capabilities from get_caps().
> >>> +             return -EINVAL;
> >>> +     }
> >>> +
> >>> +     TAILQ_INSERT_TAIL(&core_ops_list, driver_ops, next);
> >>> +
> >>> +     return 0;
> >>>    }
> >>>
> >>>    int
> >>>    rte_power_check_env_supported(enum power_management_env env)
> >>>    {
> >>> -     switch (env) {
> >>> -     case PM_ENV_ACPI_CPUFREQ:
> >>> -             return power_acpi_cpufreq_check_supported();
> >>> -     case PM_ENV_PSTATE_CPUFREQ:
> >>> -             return power_pstate_cpufreq_check_supported();
> >>> -     case PM_ENV_KVM_VM:
> >>> -             return power_kvm_vm_check_supported();
> >>> -     case PM_ENV_CPPC_CPUFREQ:
> >>> -             return power_cppc_cpufreq_check_supported();
> >>> -     case PM_ENV_AMD_PSTATE_CPUFREQ:
> >>> -             return power_amd_pstate_cpufreq_check_supported();
> >>> -     default:
> >>> -             rte_errno = EINVAL;
> >>> -             return -1;
> >>> -     }
> >>> +     struct rte_power_core_ops *ops;
> >>> +
> >>> +     if (env >= RTE_DIM(power_env_str))
> >>> +             return 0;
> >>> +
> >>> +     RTE_TAILQ_FOREACH(ops, &core_ops_list, next)
> >>> +             if (strncmp(ops->name, power_env_str[env],
> >>> +                             RTE_POWER_DRIVER_NAMESZ) == 0)
> >>> +                     return ops->check_env_support();
> >>> +
> >>> +     return 0;
> >>>    }
> >>>
> >>>    int
> >>>    rte_power_set_env(enum power_management_env env)
> >>>    {
> >>> +     struct rte_power_core_ops *ops;
> >>> +     int ret = -1;
> >>> +
> >>>        rte_spinlock_lock(&global_env_cfg_lock);
> >>>
> >>>        if (global_default_env != PM_ENV_NOT_SET) {
> >>>                POWER_LOG(ERR, "Power Management Environment already
> set.");
> >>> -             rte_spinlock_unlock(&global_env_cfg_lock);
> >>> -             return -1;
> >>> -     }
> >>> -
> >> <...>
> >>> -     if (ret == 0)
> >>> -             global_default_env = env;
> >>> -     else {
> >>> -             global_default_env = PM_ENV_NOT_SET;
> >>> -             reset_power_function_ptrs();
> >>> -     }
> >>> +     RTE_TAILQ_FOREACH(ops, &core_ops_list, next)
> >>> +             if (strncmp(ops->name, power_env_str[env],
> >>> +                             RTE_POWER_DRIVER_NAMESZ) == 0) {
> >>> +                     global_power_core_ops = ops;
> >>> +                     global_default_env = env;
> >>> +                     ret = 0;
> >>> +                     goto out;
> >>> +             }
> >>> +     POWER_LOG(ERR, "Invalid Power Management Environment(%d) set",
> >>> +                     env);
> >>>
> >>> +out:
> >>>        rte_spinlock_unlock(&global_env_cfg_lock);
> >>>        return ret;
> >>>    }
> >>> @@ -164,94 +97,66 @@ rte_power_unset_env(void)
> >>>    {
> >>>        rte_spinlock_lock(&global_env_cfg_lock);
> >>>        global_default_env = PM_ENV_NOT_SET;
> >>> -     reset_power_function_ptrs();
> >>> +     global_power_core_ops = NULL;
> >>>        rte_spinlock_unlock(&global_env_cfg_lock);
> >>>    }
> >>>
> >>>    enum power_management_env
> >>> -rte_power_get_env(void) {
> >>> +rte_power_get_env(void)
> >>> +{
> >>>        return global_default_env;
> >>>    }
> >>>
> >>> -int
> >>> -rte_power_init(unsigned int lcore_id)
> >>> +struct rte_power_core_ops *
> >>> +rte_power_get_core_ops(void)
> >>>    {
> >>> -     int ret = -1;
> >>> +     RTE_ASSERT(global_power_core_ops != NULL);
> >>>
> >>> -     switch (global_default_env) {
> >>> -     case PM_ENV_ACPI_CPUFREQ:
> >>> -             return power_acpi_cpufreq_init(lcore_id);
> >>> -     case PM_ENV_KVM_VM:
> >>> -             return power_kvm_vm_init(lcore_id);
> >>> -     case PM_ENV_PSTATE_CPUFREQ:
> >>> -             return power_pstate_cpufreq_init(lcore_id);
> >>> -     case PM_ENV_CPPC_CPUFREQ:
> >>> -             return power_cppc_cpufreq_init(lcore_id);
> >>> -     case PM_ENV_AMD_PSTATE_CPUFREQ:
> >>> -             return power_amd_pstate_cpufreq_init(lcore_id);
> >>> -     default:
> >>> -             POWER_LOG(INFO, "Env isn't set yet!");
> >>> -     }
> >>> +     return global_power_core_ops;
> >>> +}
> >>>
> >>> -     /* Auto detect Environment */
> >>> -     POWER_LOG(INFO, "Attempting to initialise ACPI cpufreq power
> >> management...");
> >>> -     ret = power_acpi_cpufreq_init(lcore_id);
> >>> -     if (ret == 0) {
> >>> -             rte_power_set_env(PM_ENV_ACPI_CPUFREQ);
> >>> -             goto out;
> >>> -     }
> >>> +int
> >>> +rte_power_init(unsigned int lcore_id) {
> >>> +     struct rte_power_core_ops *ops;
> >>> +     uint8_t env;
> >>>
> >>> -     POWER_LOG(INFO, "Attempting to initialise PSTAT power
> management...");
> >>> -     ret = power_pstate_cpufreq_init(lcore_id);
> >>> -     if (ret == 0) {
> >>> -             rte_power_set_env(PM_ENV_PSTATE_CPUFREQ);
> >>> -             goto out;
> >>> -     }
> >>> +     if (global_default_env != PM_ENV_NOT_SET)
> >>> +             return global_power_core_ops->init(lcore_id);
> >>>
> >>> -     POWER_LOG(INFO, "Attempting to initialise AMD PSTATE power
> >> management...");
> >>> -     ret = power_amd_pstate_cpufreq_init(lcore_id);
> >>> -     if (ret == 0) {
> >>> -             rte_power_set_env(PM_ENV_AMD_PSTATE_CPUFREQ);
> >>> -             goto out;
> >>> -     }
> >>> +     POWER_LOG(INFO, "Env isn't set yet!");
> >> remove this log?
> >>> -     POWER_LOG(INFO, "Attempting to initialise CPPC power
> management...");
> >>> -     ret = power_cppc_cpufreq_init(lcore_id);
> >>> -     if (ret == 0) {
> >>> -             rte_power_set_env(PM_ENV_CPPC_CPUFREQ);
> >>> -             goto out;
> >>> -     }
> >>> +     /* Auto detect Environment */
> >>> +     RTE_TAILQ_FOREACH(ops, &core_ops_list, next)
> >>> +             if (ops) {
> >>> +                     POWER_LOG(INFO,
> >>> +                             "Attempting to initialise %s cpufreq power management...",
> >>> +                             ops->name);
> >>> +                     if (ops->init(lcore_id) == 0) {
> >>> +                             for (env = 0; env < RTE_DIM(power_env_str); env++)
> >>> +                                     if (strncmp(ops->name, power_env_str[env],
> >>> +                                                     RTE_POWER_DRIVER_NAMESZ) == 0) {
> >>> +                                             rte_power_set_env(env);
> >>> +                                             return 0;
> >>> +                                     }
> >>> +                     }
> >>> +             }
> >> Can we change the logic of rte_power_set_env()? like:
> >>       RTE_TAILQ_FOREACH(ops, &core_ops_list, next) {
> >>           for (env = 0; env < RTE_DIM(power_env_str); env++) {
> >>                   if (strncmp(ops->name, power_env_str[env],
> >> RTE_POWER_DRIVER_NAMESZ) == 0 &&
> >>                       ops->init(lcore_id) == 0) {
> >>                       global_power_core_ops = ops;
> >>                       global_default_env = env;
> >>                   }
> >>           }
> >>       }
> >> That is easier to follow code.
> > Yes, will fix in next version.
> >
> >>> +
> >>> +     POWER_LOG(ERR,
> >>> +             "Unable to set Power Management Environment for lcore %u",
> >>> +             lcore_id);
> >>>
> >>> -     POWER_LOG(INFO, "Attempting to initialise VM power management...");
> >>> -     ret = power_kvm_vm_init(lcore_id);
> >>> -     if (ret == 0) {
> >>> -             rte_power_set_env(PM_ENV_KVM_VM);
> >>> -             goto out;
> >>> -     }
> >>> -     POWER_LOG(ERR, "Unable to set Power Management Environment for
> lcore
> >> "
> >>> -                     "%u", lcore_id);
> >>> -out:
> >>> -     return ret;
> >>> +     return -1;
> >>>    }
> >>>
> >>>    int
> >>>    rte_power_exit(unsigned int lcore_id)
> >>>    {
> >>> -     switch (global_default_env) {
> >>> -     case PM_ENV_ACPI_CPUFREQ:
> >>> -             return power_acpi_cpufreq_exit(lcore_id);
> >>> -     case PM_ENV_KVM_VM:
> >>> -             return power_kvm_vm_exit(lcore_id);
> >>> -     case PM_ENV_PSTATE_CPUFREQ:
> >>> -             return power_pstate_cpufreq_exit(lcore_id);
> >>> -     case PM_ENV_CPPC_CPUFREQ:
> >>> -             return power_cppc_cpufreq_exit(lcore_id);
> >>> -     case PM_ENV_AMD_PSTATE_CPUFREQ:
> >>> -             return power_amd_pstate_cpufreq_exit(lcore_id);
> >>> -     default:
> >>> -             POWER_LOG(ERR, "Environment has not been set, unable to exit
> >> gracefully");
> >>> +     if (global_default_env != PM_ENV_NOT_SET)
> >>> +             return global_power_core_ops->exit(lcore_id);
> >>>
> >>> -     }
> >>> -     return -1;
> >>> +     POWER_LOG(ERR,
> >>> +             "Environment has not been set, unable to exit
> >>> + gracefully");
> >>>
> >>> +     return -1;
> >>>    }
> >>> diff --git a/lib/power/rte_power.h b/lib/power/rte_power.h index
> >>> 4fa4afe399..5e4aacf08b 100644
> >>> --- a/lib/power/rte_power.h
> >>> +++ b/lib/power/rte_power.h
> >>> @@ -1,5 +1,6 @@
> >>>    /* SPDX-License-Identifier: BSD-3-Clause
> >>>     * Copyright(c) 2010-2014 Intel Corporation
> >>> + * Copyright(c) 2024 Advanced Micro Devices, Inc.
> >>>     */
> >>>
> >>>    #ifndef _RTE_POWER_H
> >>> @@ -14,14 +15,21 @@
> >>>    #include <rte_log.h>
> >>>    #include <rte_power_guest_channel.h>
> >>>
> >>> +#include "rte_power_core_ops.h"
> >>> +
> >>>    #ifdef __cplusplus
> >>>    extern "C" {
> >>>    #endif
> >>>
> >>>    /* Power Management Environment State */ -enum
> >>> power_management_env {PM_ENV_NOT_SET, PM_ENV_ACPI_CPUFREQ,
> PM_ENV_KVM_VM,
> >>> -             PM_ENV_PSTATE_CPUFREQ, PM_ENV_CPPC_CPUFREQ,
> >>> -             PM_ENV_AMD_PSTATE_CPUFREQ};
> >>> +enum power_management_env {
> >>> +     PM_ENV_NOT_SET = 0,
> >>> +     PM_ENV_ACPI_CPUFREQ,
> >>> +     PM_ENV_KVM_VM,
> >>> +     PM_ENV_PSTATE_CPUFREQ,
> >>> +     PM_ENV_CPPC_CPUFREQ,
> >>> +     PM_ENV_AMD_PSTATE_CPUFREQ
> >>> +};
> >>>
> >>>    /**
> >>>     * Check if a specific power management environment type is
> >>> supported on a @@ -66,6 +74,15 @@ void rte_power_unset_env(void);
> >>>     */
> >>>    enum power_management_env rte_power_get_env(void);
> >> I'd like to let user not know used which cpufreq driver, which is friendly to user.
> >>
> >> So we can rethink if this API is necessary.
> > For any API changes, could we handle this as a separate RFC for discussion?
> > It’s important that these changes are not included within the scope of this patch.
> Agreed.
> Can you post a separate RFC to disscuss this improvement later?
> >>> +/**
> >>> + * @internal Get the power ops struct from its index.
> >>> + *
> >>> + * @return
> >>> + *   The pointer to the ops struct in the table if registered.
> >>> + */
> >>> +struct rte_power_core_ops *
> >>> +rte_power_get_core_ops(void);
> >>> +
> >>>    /**
> >>>     * Initialize power management for a specific lcore. If rte_power_set_env()
> has
> >>>     * not been called then an auto-detect of the environment will
> >>> start and @@ -108,10 +125,13 @@ int rte_power_exit(unsigned int lcore_id);
> >>>     * @return
> >>>     *  The number of available frequencies.
> >>>     */
> >>> -typedef uint32_t (*rte_power_freqs_t)(unsigned int lcore_id, uint32_t *freqs,
> >>> -             uint32_t num);
> >>> +static inline uint32_t
> >>> +rte_power_freqs(unsigned int lcore_id, uint32_t *freqs, uint32_t n) {
> >>> +     struct rte_power_core_ops *ops = rte_power_get_core_ops();
> >>>
> >>> -extern rte_power_freqs_t rte_power_freqs;
> >>> +     return ops->get_avail_freqs(lcore_id, freqs, n); }
> >>>
> >>>    /**
> >>>     * Return the current index of available frequencies of a specific lcore.
> >>> @@ -124,9 +144,13 @@ extern rte_power_freqs_t rte_power_freqs;
> >>>     * @return
> >>>     *  The current index of available frequencies.
> >>>     */
> >>> -typedef uint32_t (*rte_power_get_freq_t)(unsigned int lcore_id);
> >>> +static inline uint32_t
> >>> +rte_power_get_freq(unsigned int lcore_id) {
> >>> +     struct rte_power_core_ops *ops = rte_power_get_core_ops();
> >>>
> >>> -extern rte_power_get_freq_t rte_power_get_freq;
> >>> +     return ops->get_freq(lcore_id); }
> >>>
> >>>    /**
> >>>     * Set the new frequency for a specific lcore by indicating the
> >>> index of @@ -144,82 +168,101 @@ extern rte_power_get_freq_t
> >> rte_power_get_freq;
> >>>     *  - 0 on success without frequency changed.
> >>>     *  - Negative on error.
> >>>     */
> >>> -typedef int (*rte_power_set_freq_t)(unsigned int lcore_id, uint32_t
> >>> index);
> >>> -
> >>> -extern rte_power_set_freq_t rte_power_set_freq;
> >>> +static inline uint32_t
> >>> +rte_power_set_freq(unsigned int lcore_id, uint32_t index) {
> >>> +     struct rte_power_core_ops *ops = rte_power_get_core_ops();
> >>>
> >>> -/**
> >>> - * Function pointer definition for generic frequency change
> >>> functions. Review
> >>> - * each environments specific documentation for usage.
> >>> - *
> >>> - * @param lcore_id
> >>> - *  lcore id.
> >>> - *
> >>> - * @return
> >>> - *  - 1 on success with frequency changed.
> >>> - *  - 0 on success without frequency changed.
> >>> - *  - Negative on error.
> >>> - */
> >>> -typedef int (*rte_power_freq_change_t)(unsigned int lcore_id);
> >>> +     return ops->set_freq(lcore_id, index); }
> >>>
> >>>    /**
> >>>     * Scale up the frequency of a specific lcore according to the available
> >>>     * frequencies.
> >>>     * Review each environments specific documentation for usage.
> >>>     */
> >>> -extern rte_power_freq_change_t rte_power_freq_up;
> >>> +static inline int
> >>> +rte_power_freq_up(unsigned int lcore_id) {
> >>> +     struct rte_power_core_ops *ops = rte_power_get_core_ops();
> >>> +
> >>> +     return ops->freq_up(lcore_id); }
> >>>
> >>>    /**
> >>>     * Scale down the frequency of a specific lcore according to the available
> >>>     * frequencies.
> >>>     * Review each environments specific documentation for usage.
> >>>     */
> >>> -extern rte_power_freq_change_t rte_power_freq_down;
> >>> +static inline int
> >>> +rte_power_freq_down(unsigned int lcore_id) {
> >>> +     struct rte_power_core_ops *ops = rte_power_get_core_ops();
> >>> +
> >>> +     return ops->freq_down(lcore_id); }
> >>>
> >>>    /**
> >>>     * Scale up the frequency of a specific lcore to the highest according to the
> >>>     * available frequencies.
> >>>     * Review each environments specific documentation for usage.
> >>>     */
> >>> -extern rte_power_freq_change_t rte_power_freq_max;
> >>> +static inline int
> >>> +rte_power_freq_max(unsigned int lcore_id) {
> >>> +     struct rte_power_core_ops *ops = rte_power_get_core_ops();
> >>> +
> >>> +     return ops->freq_max(lcore_id); }
> >>>
> >>>    /**
> >>>     * Scale down the frequency of a specific lcore to the lowest according to the
> >>>     * available frequencies.
> >>>     * Review each environments specific documentation for usage..
> >>>     */
> >>> -extern rte_power_freq_change_t rte_power_freq_min;
> >>> +static inline int
> >>> +rte_power_freq_min(unsigned int lcore_id) {
> >>> +     struct rte_power_core_ops *ops = rte_power_get_core_ops();
> >>> +
> >>> +     return ops->freq_min(lcore_id); }
> >>>
> >>>    /**
> >>>     * Query the Turbo Boost status of a specific lcore.
> >>>     * Review each environments specific documentation for usage..
> >>>     */
> >>> -extern rte_power_freq_change_t rte_power_turbo_status;
> >>> +static inline int
> >>> +rte_power_turbo_status(unsigned int lcore_id) {
> >>> +     struct rte_power_core_ops *ops = rte_power_get_core_ops();
> >>> +
> >>> +     return ops->turbo_status(lcore_id); }
> >>>
> >>>    /**
> >>>     * Enable Turbo Boost for this lcore.
> >>>     * Review each environments specific documentation for usage..
> >>>     */
> >>> -extern rte_power_freq_change_t rte_power_freq_enable_turbo;
> >>> +static inline int
> >>> +rte_power_freq_enable_turbo(unsigned int lcore_id) {
> >>> +     struct rte_power_core_ops *ops = rte_power_get_core_ops();
> >>> +
> >>> +     return ops->enable_turbo(lcore_id); }
> >>>
> >>>    /**
> >>>     * Disable Turbo Boost for this lcore.
> >>>     * Review each environments specific documentation for usage..
> >>>     */
> >>> -extern rte_power_freq_change_t rte_power_freq_disable_turbo;
> >>> +static inline int
> >>> +rte_power_freq_disable_turbo(unsigned int lcore_id) {
> >>> +     struct rte_power_core_ops *ops = rte_power_get_core_ops();
> >>>
> >>> -/**
> >>> - * Power capabilities summary.
> >>> - */
> >>> -struct rte_power_core_capabilities {
> >>> -     union {
> >>> -             uint64_t capabilities;
> >>> -             struct {
> >>> -                     uint64_t turbo:1;       /**< Turbo can be enabled. */
> >>> -                     uint64_t priority:1;    /**< SST-BF high freq core */
> >>> -             };
> >>> -     };
> >>> -};
> >>> +     return ops->disable_turbo(lcore_id); }
> >>>
> >>>    /**
> >>>     * Returns power capabilities for a specific lcore.
> >>> @@ -235,10 +278,14 @@ struct rte_power_core_capabilities {
> >>>     *  - 0 on success.
> >>>     *  - Negative on error.
> >>>     */
> >>> -typedef int (*rte_power_get_capabilities_t)(unsigned int lcore_id,
> >>> -             struct rte_power_core_capabilities *caps);
> >>> +static inline int
> >>> +rte_power_get_capabilities(unsigned int lcore_id,
> >>> +             struct rte_power_core_capabilities *caps) {
> >>> +     struct rte_power_core_ops *ops = rte_power_get_core_ops();
> >>>
> >>> -extern rte_power_get_capabilities_t rte_power_get_capabilities;
> >>> +     return ops->get_caps(lcore_id, caps); }
> >>>
> >>>    #ifdef __cplusplus
> >>>    }
> >>> diff --git a/lib/power/rte_power_core_ops.h
> >>> b/lib/power/rte_power_core_ops.h new file mode 100644 index
> >>> 0000000000..356a64df79
> >>> --- /dev/null
> >>> +++ b/lib/power/rte_power_core_ops.h
> >>> @@ -0,0 +1,208 @@
> >>> +/* SPDX-License-Identifier: BSD-3-Clause
> >>> + * Copyright(c) 2010-2014 Intel Corporation
> >>> + * Copyright(c) 2024 Advanced Micro Devices, Inc.
> >>> + */
> >>> +
> >>> +#ifndef _RTE_POWER_CORE_OPS_H
> >>> +#define _RTE_POWER_CORE_OPS_H
> >>> +
> >> suggest rename the file as rte_power_cpufreq_api.h.
> >> If so, the role of this file is more clearly.
> >>> +__rte_internal
> >>> +int rte_power_register_ops(struct rte_power_core_ops *ops);
> >>> +
> >>> +/**
> >>> + * Macro to statically register the ops of a cpufreq driver.
> >>> + */
> >>> +#define RTE_POWER_REGISTER_OPS(ops)          \
> >>> +     RTE_INIT(power_hdlr_init_##ops)         \
> >>> +     {                                       \
> >>> +             rte_power_register_ops(&ops);   \
> >>> +     }
> >>> +
> >>> +/**
> >>> + * @internal Get the power ops struct from its index.
> >>> + *
> >>> + * @return
> >>> + *   The pointer to the ops struct in the table if registered.
> >>> + */
> >>> +struct rte_power_core_ops *
> >>> +rte_power_get_core_ops(void);
> >>> +
> >>> +#ifdef __cplusplus
> >>> +}
> >>> +#endif
> >>> +
> >>> +#endif
> >>> diff --git a/lib/power/version.map b/lib/power/version.map index
> >>> c9a226614e..bd64e0828f 100644
> >>> --- a/lib/power/version.map
> >>> +++ b/lib/power/version.map
> >>> @@ -51,4 +51,18 @@ EXPERIMENTAL {
> >>>        rte_power_set_uncore_env;
> >>>        rte_power_uncore_freqs;
> >>>        rte_power_unset_uncore_env;
> >>> +     # added in 24.07
> >> 24.07-->24.11?
> >>> +     rte_power_logtype;
> >>> +};
> >>> +
> >>> +INTERNAL {
> >>> +     global:
> >>> +
> >>> +     rte_power_register_ops;
> >>> +     cpufreq_check_scaling_driver;
> >>> +     power_set_governor;
> >>> +     open_core_sysfs_file;
> >>> +     read_core_sysfs_u32;
> >>> +     read_core_sysfs_s;
> >>> +     write_core_sysfs_s;
> >>>    };