find_free_tcs(9)

🌸 find_free_tcs(9) 🌸

okay so bestie, welcome to the Kernel API Manual — today's main character is find_free_tcs(9) and honestly? she's a little legend. let's get into it 💅

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✨ NAME ✨

find_free_tcs — literally just finds free tcs in the given tcs_group. and like, only for active. that part matters, don't @ me 🎀

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✨ SYNOPSIS ✨

int find_free_tcs (struct tcs_group *tcs );

that's it. that's the whole vibe check. one arg, one int coming back at you 🦋

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✨ ARGUMENTS ✨

• tcs — a pointer to the active-only tcs_group (or, plot twist, the wake tcs_group if we borrowed it because there are literally zero active-only ones — like when your bestie has no charger so you lend her yours, no cap 🔥)

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✨ DESCRIPTION ✨

so here's the tea: you must call this with the drv->lock held, because that lock is what protects tcs_in_use. don't skip the lock bestie, that's the whole safety girlie of this operation 😭🔒

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✨ RETURN ✨

it hands you back the first tcs that's free — or, if every single one is in use, -EBUSY. that's it, that's the answer 💀

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✨ SEE ALSO ✨

kernel file ./drivers/soc/qcom/rpmh-rsc.c — and the whole friend group, because nobody does it alone 🫶:

• tcs_invalidate(9)
• rpmh_rsc_invalidate(9)
• get_tcs_for_msg(9)
• get_req_from_tcs(9)
• __tcs_set_trigger(9)
• enable_tcs_irq(9)
• tcs_tx_done(9)
• __tcs_buffer_write(9)
• check_for_req_inflight(9)
• claim_tcs_for_req(9)
• rpmh_rsc_send_data(9)
• find_slots(9)
• rpmh_rsc_write_ctrl_data(9)
• rpmh_rsc_ctrlr_is_busy(9)
• rpmh_rsc_write_next_wakeup(9)
• rpmh_rsc_cpu_pm_callback(9)
• rpmh_rsc_pd_callback(9)

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ok that's the whole page, go be iconic with your tcs 💖

sign-off era: this slay little page lives at ./drivers/soc/qcom, dated October 2026, and yes — it's find_free_tcs(9) again, because we always come back to her 👑✨