iwl_pcie_prep_tso(9)

💅 iwl_pcie_prep_tso(9) — from the Kernel API Manual, bestie ✨

Okay so today we're doing iwl_pcie_prep_tso, straight out of the Kernel API Manual. It's a kernel function, it's got six arguments, and yes we're gonna get through all of them together. Buckle up 🎀

---

🌸 NAME 🌸

iwl_pcie_prep_tso — literally just: Prepare TSO page and SKB for sending. That's the whole vibe. 💅

---

✨ SYNOPSIS ✨

struct sg_table * iwl_pcie_prep_tso (struct iwl_trans *trans , struct
sk_buff *skb , struct iwl_cmd_meta *cmd_meta , u8 **hdr , unsigned int
hdr_room , unsigned int offset );

Yup that's the signature, copy it exactly if you're calling it, no cap 🫶

---

🦋 ARGUMENTS 🦋

Every single one, in order, because we do not skip:

• trans — the transport private data. The main character of the transport world 👑
• skb — the SKB to map. This is the payload bestie, the thing we're actually shipping out 📦
• cmd_meta — command meta to store the scatter list information for unmapping. Yes, unmapping is the whole point — remember this one, it comes back later 😭
• hdr — output argument for TSO headers. It's an output argument so like… it's giving "I'll tell you later" energy ✨
• hdr_room — requested length for TSO headers. Gotta reserve the space, periodt 🎀
• offset — offset into the data from which mapping should start. Not from the beginning, from here 💅

---

🔥 DESCRIPTION 🔥

So what does it actually do? Simple:

Allocate space for a scatter gather list and TSO headers, then map the SKB using the scatter gather list. That's the whole job, and it ate, honestly 💀✨

And the important part — the part where you need to pay attention, bestie 👀 — the SKB is unmapped again when the page is free'ed again at the end of the operation. So it's like a whole little lifecycle moment. Map it, live your life, free the page, get unmapped. Iconic. 🌈

Lowkey important: the unmapping happens when the page is free'ed again at the end of the operation — so don't go freeing pages early and acting surprised 😭

---

💖 RETURN 💖

Returns the newly allocated and mapped scatter gather table with list. So you get a struct sg_table * back — freshly allocated, freshly mapped, ready to go 🫶

---

🌟 SEE ALSO 🌟

• Kernel file ./drivers/net/wireless/intel/iwlwifi/pcie/gen1_2/tx.c
• iwl_txq_free_tfd(9)
• iwl_pcie_get_sgt_tb_phys(9)

Go read those next, iykyk 📚

---

Okay that's the whole page, bestie — go forth and map those SKBs 💜

Signed off with love from ./drivers/net/wireless/intel/i..., dated October 2026, and living in the iwl_pcie_prep_tso(9) era forever 🌸🎀✨