STRUCT POWERCAP_ZONE_CONSTRAINT_OPS(9)

💅 struct powercap_zone_constraint_ops — the Kernel API Manual moment 🎀

okay so bestie, you've stumbled into the Kernel API Manual page for struct powe...nstraint_ops(9) and honestly? it's giving "the blueprint for constraint callbacks" and we're gonna get through it together, no cap 💖

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✨ NAME ✨

struct powercap_zone_constraint_ops — literally the place where you Define constraint callbacks, bestie. that's the whole vibe 🦋

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🌸 SYNOPSIS 🌸

like, here's the whole shape of it, verbatim, don't touch a single character 👑

struct powercap_zone_constraint_ops {
    int (*set_power_limit_uw) (struct powercap_zone *, int, u64);
    int (*get_power_limit_uw) (struct powercap_zone *, int, u64 *);
    int (*set_time_window_us) (struct powercap_zone *, int, u64);
    int (*get_time_window_us) (struct powercap_zone *, int, u64 *);
    int (*get_max_power_uw) (struct powercap_zone *, int, u64 *);
    int (*get_min_power_uw) (struct powercap_zone *, int, u64 *);
    int (*get_max_time_window_us) (struct powercap_zone *, int, u64 *);
    int (*get_min_time_window_us) (struct powercap_zone *, int, u64 *);
    const char *(*get_name) (struct powercap_zone *, int);
};

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🧚 Members 🧚

okay so every single one of these function pointers, and what it's actually about:

• set_power_limit_uw — Set power limit in micro-watts. 🔥
• get_power_limit_uw — Get power limit in micro-watts. 👀
• set_time_window_us — Set time window in micro-seconds. ⏱️
• get_time_window_us — Get time window in micro-seconds. ⏱️
• get_max_power_uw — Get max power allowed in micro-watts. ⭐
• get_min_power_uw — Get min power allowed in micro-watts. ⭐
• get_max_time_window_us — Get max time window allowed in micro-seconds. 🌈
• get_min_time_window_us — Get min time window allowed in micro-seconds. 🌈
• get_name — Get the name of constraint. 🎀

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Description 🫶

so, the whole point of this structure is that it's used to define the constraint callbacks for the client drivers. main character energy, honestly 💅

here's the part you cannot skip — these callbacks are mandatory and can't be NULL:

• set_power_limit_uw
• get_power_limit_uw
• set_time_window_us
• get_time_window_us
• get_name

⚠️ bestie listen to me. those five? mandatory. NULL? no. not happening. 🙈

and also: client drivers should handle mutual exclusion, if required in callbacks. so like, that's on you, not on the struct, iykyk 😭

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💜 SEE ALSO 💜

go read these next, fr fr — Kernel file ./include/linux/powercap.h:

• struct powercap_control_type_ops(9)
• struct powercap_control_type(9)
• struct powercap_zone_ops(9)
• struct powercap_zone(9)
• struct powercap_zone_constraint(9)
• powercap_set_zone_data(9)
• powercap_get_zone_data(9)
• powercap_register_control_type(9)
• powercap_unregister_control_type(9)
• powercap_register_zone(9)
• powercap_unregister_zone(9)

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aaaand that's the page, bestie 🌸 sign-off szn: this lil masterpiece lives in ./include/linux, stamped October 2026, filed under struct powe...nstraint_ops(9) 💖 slay, you read the whole thing, so proud of you 🫶✨