STRUCT IOATDMA_DEVICE(9)

💅 struct ioatdma_device(9) — from the Kernel API Manual ✨

okay so bestie, this is the page for struct ioatdma_device — the internal representation of a IOAT device 🎀 that's it, that's the whole vibe. it's the struct that holds the whole situation together, and we're gonna go through every single field together, no skipping, no cap 💖

✨ SYNOPSIS ✨

struct ioatdma_device {
    struct pci_dev *pdev;
    void __iomem *reg_base;
    struct dma_pool *completion_pool;
  #define MAX_SED_POOLS   5;
    struct dma_pool *sed_hw_pool[MAX_SED_POOLS];
    struct dma_device dma_dev;
    u8 version;
  #define IOAT_MAX_CHANS 4;
    struct msix_entry msix_entries[IOAT_MAX_CHANS];
    struct ioatdma_chan *idx[IOAT_MAX_CHANS];
    struct dca_provider *dca;
    enum ioat_irq_mode irq_mode;
    u32 cap;
    int chancnt;
    u64 msixtba0;
    u64 msixdata0;
    u32 msixpba;
 };

like, look at her. main character struct energy fr fr 👑

also peep the little defines living inside the struct — MAX_SED_POOLS is 5 and IOAT_MAX_CHANS is 4. iconic behavior, honestly 🌸

🦋 Members 🦋

• pdev — the PCI-Express device. like, the actual hardware she's attached to 💳
• reg_base — MMIO register space base address. where the registers live, address-wise 📍
• completion_pool — DMA buffers for completion ops. the pool of buffers for finishing things off ✨
• sed_hw_pool — DMA super descriptor pools. yes plural, it's an array, she's got layers 🎀
• dma_dev — an embedded struct dma_device, tucked right in there 🫶
• version — version of the ioatdma device. classic, love a version field 💜
• msix_entries — irq handlers 👑
• idx — per channel data. one entry per channel, organized bestie 🗂️
• dca — direct cache access context. fancy 💅
• irq_mode — interrupt mode, and the modes are INTX, MSI, MSIX — pick your fighter ⚡
• cap — read DMA capabilities register. the receipts of what this thing can do 🔥

ngl the struct also carries chancnt, msixtba0, msixdata0 and msixpba 😭 they're right there in the synopsis, so don't act surprised when you see them in the wild — the manpage doesn't spill any tea about those ones, so neither will I 🙈

🌈 SEE ALSO 🌈

• Kernel file ./drivers/dma/ioat/dma.h
• struct ioat_sed_ent(9)
• struct ioat_ring_ent(9)

go read those next, iykyk 📚

that's the whole page bestie, you ate that 🍓 — this little gem comes from ./drivers/dma/ioat, dated October 2026, and the header up top literally just reads struct ioatdma_device(9). slay 💖