igd_opregion_shift_copy(9)

💅 igd_opregion_shift_copy — a little kernel API glow-up

okay so welcome to the Kernel API Manual bestie, today's main character is igd_opregion_shift_copy(9) and honestly the name alone is giving "senior engineer who names variables after their emotional state" 😭 but we love her, no cap 💖

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✨ NAME ✨

igd_opregion_shift_copy — Copy OpRegion to user buffer and shift position.

like... that's it, that's the whole pitch. she copies, she shifts, she leaves ✨

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🌸 SYNOPSIS 🌸

unsigned long igd_opregion_shift_copy (char __user *dst , loff_t *off ,
void *src , loff_t *pos , size_t *remaining , size_t bytes );

literally six arguments. six. she's high-maintenance and honestly? iconic for it 🎀

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🦋 ARGUMENTS 🦋

okay let's do a vibe check on every single one of these bad boys, nobody gets left behind 🫶

• dst — the User buffer ptr you're copying to. that's the destination, the final boss, the place where the data ends up 💅
• off — Offset into the user buffer ptr. she gets increased by bytes on return — so she goes up, she doesn't come back down, she's on her growth arc 📈
• src — the Source buffer you're copying from. the origin story, the parent, the one who gave everything 🌈
• pos — gets increased by bytes on return. yes bestie, another one that levels up on return, we stan consistency 💜
• remaining — gets decreased by bytes on return. she's shrinking, she's humbled, she's not okay but she's trying 😭
• bytes — the number of Bytes to copy, and also the amount used to adjust off, pos and remaining. she's the one pulling the strings fr fr 👑

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🧚 DESCRIPTION 🧚

Copy OpRegion to offset from that specific source ptr, and then shift the offset. that's the whole job. copy → shift → done. clean, simple, slay ✨

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🔥 RETURN 🔥

• 0 on success 🎉 (the good ending)
• -EFAULT otherwise 💀 (the not-good ending, no further comment)

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👑 SEE ALSO 👑

one thing and one thing only, and she's serving:

• Kernel file ./drivers/vfio/pci/vfio_pci_igd.c 🍓

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ngl if you're messing with off, pos, or remaining after this call, remember: they've already been shifted, bestie. don't double-count. that's the whole warning, I'm just being dramatic 🙈

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and that's the page! mwah 💋 this little number lives in ./drivers/vfio/pci, dated October 2026 — go forth and copy responsibly, iykyk 🦋💖🎀