__ioread32_copy(9)

💅 __ioread32_copy(9)

okay so bestie, welcome to the Kernel API Manual — this little page is all about __ioread32_copy, and it's literally the function that copies data out of MMIO space, in 32-bit units. no cap. 🎀

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✨ SYNOPSIS ✨

void __ioread32_copy (void *to , const void __iomem *from , size_t count
);

she's a void function, she takes three args, she gets the job done. periodt. 🫶

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🌸 ARGUMENTS 🌸

• to — the destination. and like, it must be 32-bit aligned, no exceptions, don't even try it 🙈
• from — the source, and it lives in MMIO space. also must be 32-bit aligned, twin, i'm so serious ⭐
• count — how many 32-bit quantities you wanna copy. that's the vibes-per-call number 💜

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🦋 DESCRIPTION 🦋

so what she does is copy data from MMIO space over to kernel space, in units of 32 bits at a time. one little 32-bit snack at a time, iconic behavior honestly 🍓

but bestie, hear me: the order of access is not guaranteed, and there is no memory barrier performed afterwards. like, at all. so don't go assuming the reads happen in a nice neat sequence or that everything's fenced up after — it's giving "i do the copy, i don't do the ordering" 💀

⚠️ lowkey important: no ordering guarantee + no memory barrier afterwards. plan accordingly, bestie, don't let this be the plot twist in your driver 😭

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🌈 SEE ALSO 🌈

• Kernel file ./lib/iomap_copy.c
• __iowrite32_copy(9)
• __iowrite64_copy(9)

go read those too, they're the sibling functions and they also ate 🔥

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and that's the page!! mwah 💋 this one comes to you from ./lib, dated October 2026 — ty for reading bestie, go forth and align your pointers 👑✨