STRUCT PPC440SPE_ADMA_CHAN(9)

💅 NAME 💅

struct ppc440spe_adma_chan — the internal representation of an ADMA channel, bestie. It's from the Kernel API Manual, and it's giving "backstage pass to the whole channel" energy ✨

🎀 SYNOPSIS 🎀

struct ppc440spe_adma_chan {
    spinlock_t lock;
    struct ppc440spe_adma_device *device;
    struct list_head chain;
    struct dma_chan common;
    struct list_head all_slots;
    struct ppc440spe_adma_desc_slot *last_used;
    int pending;
    int slots_allocated;
    int hw_chain_inited;
    struct tasklet_struct irq_tasklet;
    u8 needs_unmap;
    struct page *pdest_page;
    struct page *qdest_page;
    dma_addr_t pdest;
    dma_addr_t qdest;
 };

Copy that exactly, ok? Every field, every semicolon, no cap 🫶

🦋 Members 🦋

• lock — this one serializes enqueue/dequeue operations to the slot pool. Basically the bouncer at the door keeping the queue from turning into chaos 🔥
• device — the parent device. Its ride-or-die origin story 💖
• chain — the device chain view of the descriptors. Like the group chat view of who's in the chat 👀
• common — the common dmaengine channel object members. Shared queen behavior, iconic 🌈
• all_slots — the complete domain of slots usable by the channel. Every slot it's allowed to touch, periodt ✨
• pending — allows batching of hardware operations. Lowkey the "wait, stack a few more in before we go" field 🎀
• slots_allocated — records the actual size of the descriptor slot pool. Receipts, literally 🧾
• hw_chain_inited — the h/w descriptor chain initialization flag. Is the chain set up or not? This knows 💅
• irq_tasklet — bottom half where ppc440spe_adma_slot_cleanup runs. The cleanup crew, working quietly in the background 🧚
• needs_unmap — if buffers should not be unmapped upon final processing. Yeah — read that again 🙈
• pdest_page — P destination page for async validate operation 🍓
• qdest_page — Q destination page for async validate operation 🍓
• pdest — P dma addr for async validate operation ⭐
• qdest — Q dma addr for async validate operation ⭐

Not me pointing out that last_used is chillin' in the struct but has no little blurb in the Members list — that's just how it is in the original, so we're not gonna invent one 💀

👑 SEE ALSO 👑

• Kernel file ./drivers/dma/ppc4xx/adma.h
• struct ppc440spe_adma_device(9)
• struct ppc440spe_adma_desc_slot(9)

Go read them, iykyk 📚

That's the whole page, bestie — slayed, no facts lost 🌸 This cutie came from the Kernel API Manual, source/version ./drivers/dma/ppc4xx, dated October 2026, and the page itself is struct ppc440spe_adma_chan(9). Byeee 🫶💜