cppc_get_auto_act_window(9)

💅 cppc_get_auto_act_window(9) 💅

okay so this is a page from the Kernel API Manual bestie, and it's all about cppc_get_auto_act_window — yes that's a whole mouthful, we're gonna get through it together 🫶

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✨ NAME ✨

cppc_get_auto_act_window — literally just reads the autonomous activity window register. that's it. that's the whole job. icon behaviour honestly 👑

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✨ SYNOPSIS ✨

int cppc_get_auto_act_window (int cpu , u64 *auto_act_window );

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✨ ARGUMENTS ✨

• cpu — the CPU you're pulling the register from. like, which one bestie, be specific 💅
• auto_act_window — the return address. it's a pointer, it's where the good stuff lands 🎀

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✨ DESCRIPTION ✨

so per ACPI 6.5, s8.4.6.1.6 (yes we're citing sources, we're academic like that 🧚), the value you read back from the autonomous activity window register is not one single blob — it's two parts glued together:

• a 7 bits value that indicates the significand
• a 3 bits value that indicates the exponent

that's the whole vibe check. significand + exponent, 7 and 3, no cap 🌈

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✨ SEE ALSO ✨

the kernel file ./drivers/acpi/cppc_acpi.c and honestly a whole friend group of functions — here's the full squad, no one left behind 🫶

• acpi_get_psd_map(9)
• cpc_ffh_supported(9)
• cpc_supported_by_cpu(9)
• pcc_data_alloc(9)
• acpi_cppc_processor_probe(9)
• acpi_cppc_processor_exit(9)
• cpc_read_ffh(9)
• cpc_read_ffh_fb_ctrs(9)
• cpc_write_ffh(9)
• cppc_get_desired_perf(9)
• cppc_get_nominal_perf(9)
• cppc_get_highest_perf(9)
• cppc_get_epp_perf(9)
• cppc_get_perf_caps(9)
• cppc_perf_ctrs_in_pcc_cpu(9)
• cppc_perf_ctrs_in_pcc(9)
• cppc_get_perf_ctrs(9)
• cppc_set_epp(9)
• cppc_set_auto_act_window(9)
• cppc_get_auto_sel(9)
• cppc_set_auto_sel(9)
• cppc_set_enable(9)
• cppc_get_perf(9)
• cppc_set_perf(9)
• cppc_get_perf_limited(9)
• cppc_set_perf_limited(9)
• cppc_get_transition_latency(9)

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that's the page bestie, go read a register or whatever 💖

— signed, sealed, delivered from ./drivers/acpi, dated October 2026 — the whole thing is giving kernel documentation main character energy, and honestly? obsessed 🌸👑