acpi_check_dsm(9)

💅 acpi_check_dsm — the kernel API manual, bestie edition

okay so this is acpi_check_dsm from the Kernel API Manual, and honestly? she's a little vibe-checker for _DSM methods. let's get into it 🎀

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✨ NAME ✨

acpi_check_dsm — literally just checks if the _DSM method supports the functions you're asking about. that's it. that's her whole job 🫶

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🌸 SYNOPSIS 🌸

bool acpi_check_dsm (acpi_handle handle , const guid_t *guid , u64 rev ,
       u64 funcs );

she returns a bool btw — yes/no energy only 👑

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🦋 ARGUMENTS 🦋

• handle — the ACPI device handle. like, which device are we even talking about, bestie 💅
• guid — the GUID of the requested functions. important: it should be 16 bytes at least, no cap. don't come at her with a short one 🙈
• rev — the revision number of the requested functions. which version of the vibe are we on 🔥
• funcs — a bitmap of the requested functions. yes, bitmap. yes, it's giving bit manipulation 🧚

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⭐ DESCRIPTION ⭐

so what she does is evaluate the device's _DSM method to check whether it actually supports the functions you're requesting. very "does this spark joy" of her 💖

and a heads up: currently she only supports 64 functions at maximum. which, per the docs, should be enough for now. iconic confidence, honestly 😭👑

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🌈 SEE ALSO 🌈

kernel file ./drivers/acpi/utils.c — and all her friends, fr fr:

• acpi_handle_list_equal(9)
• acpi_handle_list_replace(9)
• acpi_handle_list_free(9)
• acpi_device_dep(9)
• acpi_evaluate_ost(9)
• acpi_handle_path(9)
• acpi_handle_printk(9)
• __acpi_handle_debug(9)
• acpi_evaluation_failure_warn(9)
• acpi_has_method(9)
• acpi_evaluate_ej0(9)
• acpi_evaluate_lck(9)
• acpi_evaluate_reg(9)
• acpi_evaluate_dsm(9)
• acpi_dev_uid_to_integer(9)
• acpi_dev_found(9)
• acpi_dev_present(9)
• acpi_dev_get_next_match_dev(9)
• acpi_dev_get_first_match_dev(9)
• acpi_reduced_hardware(9)
• acpi_dev_is_video_device(9)
• acpi_match_platform_list(9)

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ngl she's a whole squad. go read them too, iykyk 💜

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okay and finally, the sign-off: this page lives under ./drivers/acpi, dated October 2026, and it's page acpi_check_dsm(9) of the Kernel API Manual. slay, go check your _DSM methods responsibly 🍓✨