STRUCT HISI_PTT_TRACE_CTRL(9)

💅 struct hisi_ptt_trace_ctrl(9) — like, the whole Kernel API Manual page, bestie 🎀

okay so first things first: this is the manual page for struct hisi_ptt_trace_ctrl from the Kernel API Manual, and no cap it is the literal control room and status board for PTT trace. everything u need to know about this struct, we're going through it together, one member at a time. grab a snack 🍓

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✨ NAME ✨

struct hisi_ptt_trace_ctrl — the control and status of PTT trace, both at once. it's giving main character energy: it holds the vibes AND the receipts 💅

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🌸 SYNOPSIS 🌸

struct hisi_ptt_trace_ctrl {
    struct hisi_ptt_dma_buffer *trace_buf;
    struct perf_output_handle handle;
    u32 buf_index;
    int on_cpu;
    bool started;
    bool is_port;
    u32 direction:2;
    u32 filter:16;
    u32 format:1;
    u32 type:4;
 };

yes bestie, look at those bitfields — direction:2, filter:16, format:1, type:4. the way they packed those in there is honestly iconic 🔥 note the little }; on its own line with a space before it, that's canon, we don't touch it.

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🦋 Members 🦋

so these are all the members and what each one is doing. no skipping, we love a complete list 💖

• trace_buf — an array of the trace buffers, and their whole job is holding the trace data. the length is HISI_PTT_TRACE_BUF_CNT, okay? not vibes-based, it's that constant. periodt.
• handle — the perf output handle of the current trace session. current one only, don't go looking for exes 🙈
• buf_index — the index of the trace buffer that's currently being used. like, which one is on aux rn 🎧
• on_cpu — the cpu we're currently tracing. yes girl, tracking which cpu.
• started — the current trace status. true means started. that's it, that's the field 🫶
• is_port — tells u whether we're tracing a root port or not. cute little bool for identity crisis purposes.
• direction — the direction of the TLP headers we're tracing. it's a u32 with a :2 width, so it's living small.
• filter — the filter value for tracing the TLP headers. it's a u32 but sized :16 — highkey specific.
• format — the format of the TLP headers to trace. tiny :1 field, doing big things 💫
• type — the type of the TLP headers to trace. :4 bits of pure personality ✨

ngl the TLP header gang — direction, filter, format, type — are all bitfields inside u32. keep their exact widths if ur ever touching this, or it's a whole mess 😭

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👑 SEE ALSO 👑

go read these next, i'm literally obsessed:

• Kernel file ./drivers/hwtracing/ptt/hisi_ptt.h struct
• hisi_ptt_tune_desc(9)
• struct hisi_ptt_dma_buffer(9)
• struct hisi_ptt_filter_desc(9)
• struct hisi_ptt_filter_update_info(9)
• struct hisi_ptt_pmu_buf(9)
• struct hisi_ptt(9)

the whole friend group fr fr 🌈

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that's the page bestie, u ate that 🍓 — this lil drop came from ./drivers/hwtracing/ptt, dated October 2026, and it lives in/signs off as struct hisi_ptt_trace_ctrl(9). k bye, ily, go read the source 💜