STRUCT DPSECI_CONGESTION_NOTIFICATION_CFG(9)

🎀 struct dpseci_congestion_notification_cfg — congestion notification configuration 🎀

okay bestie so we're in the Kernel API Manual and today's main character is struct dpseci_congestion_notification_cfg — literally the glow-up config for congestion notifications 💅 no cap, this struct is what tells the hardware when to start freaking out about congestion and when to chill. iconic behavior fr fr.

✨ SYNOPSIS ✨

struct dpseci_congestion_notification_cfg {
    enum dpseci_congestion_unit units;
    u32 threshold_entry;
    u32 threshold_exit;
    u64 message_ctx;
    u64 message_iova;
    struct dpseci_dest_cfg dest_cfg;
    u16 notification_mode;
 };

like, that's the whole vibe right there 🫶 every single field is doing its little job and honestly? obsessed.

🌸 Members 🌸

• units — the units type, i.e. what unit system we're measuring these thresholds in 🧚 it's giving "please be specific about your numbers."
• threshold_entry — above this threshold we enter a congestion state 👑 so yes, once you cross this line the congestion era begins. set it to '0' to disable it — zero means off, no drama, nothing happens 💀
• threshold_exit — below this threshold we exit the congestion state 🦋 so it's the opposite direction of threshold_entry: drop under this and we're free, we're healed, we're out of the congestion situation.
• message_ctx — the context that will be part of the CSCN message 📨 lowkey the little tag that comes along for the ride so you know what it's about.
• message_iova — the I/O virtual address of the message, and important caveat bestie: it must be in DMA-able memory, and it must be 16B aligned ⚠️ like do not skip the alignment, that's not a suggestion.
• dest_cfg — CSCN can be send to either DPIO or DPCON WQ channel 🎯 two destinations, pick your fave.
• notification_mode — a mask of the available options; use the 'DPSECI_CGN_MODE_<X>' values ✨ that's where you select which mode bits you actually want.

ngl the alignment + DMA-able memory thing on message_iova is the one that will bite you if you get cute with it 😭 double-check it before you ship, i'm begging.

💜 SEE ALSO 💜

• Kernel file ./drivers/crypto/caam/dpseci.h
• struct dpseci_cfg(9)
• struct dpseci_attr(9)
• enum dpseci_dest(9)
• struct dpseci_dest_cfg(9)
• struct dpseci_rx_queue_cfg(9)
• struct dpseci_rx_queue_attr(9)
• struct dpseci_tx_queue_attr(9)
• struct dpseci_sec_attr(9)
• enum dpseci_congestion_unit(9)

like go read all of them, they're all in the lore 📚✨

that's the whole page bestie!! mwah 💖 this cutie lives in ./drivers/crypto/caam and this version is dated October 2026 — go forth and configure your congestion notifications responsibly, love u, bye!! 🎀🦋💅