STRUCT SHDMA_OPS(9)

✨ struct shdma_ops(9) ✨

okay so this is from the Kernel API Manual and it's literally the whole vibe of "simple DMA driver operations" 💅 like if you've ever wondered what a DMA driver has to bring to the group chat, it's this struct, and she does not come to play.

🌸 SYNOPSIS 🌸

bestie, here's the whole squad, character for character, no cap:

struct shdma_ops {
    bool (*desc_completed)(struct shdma_chan *, struct shdma_desc *);
    void (*halt_channel)(struct shdma_chan *);
    bool (*channel_busy)(struct shdma_chan *);
    dma_addr_t (*slave_addr)(struct shdma_chan *);
    int (*desc_setup)(struct shdma_chan *, struct shdma_desc *,
dma_addr_t, dma_addr_t, size_t *);
    int (*set_slave)(struct shdma_chan *, int, dma_addr_t, bool);
    int (*setup_xfer)(struct shdma_chan *, int);
    void (*start_xfer)(struct shdma_chan *, struct shdma_desc *);
    struct shdma_desc *(*embedded_desc)(void *, int);
    bool (*chan_irq)(struct shdma_chan *, int);
    size_t (*get_partial)(struct shdma_chan *, struct shdma_desc *);
 };

like yes, that's a lot of function pointers, but she's organized 🎀

🦋 Members 🦋

• desc_completed — returns true if this is the descriptor that just has completed. this one's atomic, so don't be weird about it 😭
• halt_channel — stop DMA channel operation. also atomic. she stops, she doesn't negotiate 💅
• channel_busy — returns true if the channel is busy. atomic, obviously, because asking "are you busy" while stuff is happening is the whole point
• slave_addr — returns the slave DMA address. no drama, just the address 🫶
• desc_setup — sets up the hardware specific descriptor portion. atomic! hardware-specific means hardware-specific, don't come for her
• set_slave — binds the channel to a slave. it's giving commitment ✨
• setup_xfer — configures the channel hardware for operation. atomic ⚡
• start_xfer — starts the DMA transfer. atomic. and then she goes 🏃‍♀️💨
• embedded_desc — returns the Nth struct shdma_desc pointer from the descriptor array. Nth, bestie, count them properly 🔢
• chan_irq — processes channel IRQ, returns true if a transfer has completed. atomic 🌈
• get_partial — wait, hold on 🙈

ok so real talk, get_partial is listed in the members of the synopsis, but the original page gives her no one-liner description. so she's just standing there, iconic and mysterious, minding her own business. no invented facts, no cap 💀

👑 SEE ALSO 👑

• Kernel file ./include/linux/shdma-base.h
• enum shdma_pm_state(9)

🎀 sign-off 🎀

that's the whole page, bestie — sourced from ./include/linux, dated October 2026, filed under struct shdma_ops(9). go forth and slay your DMA ops 💖✨🦋