phys_to_virt(9)

💖 NAME 💖

okay so bestie, we're looking at phys_to_virt(9) from the Kernel API Manual, and it's literally the function that maps a physical address to a virtual one. iconic behavior, no cap ✨

---

🎀 SYNOPSIS 🎀

void * phys_to_virt (phys_addr_t address );

like that's the whole vibe check 🫶

---

🌸 ARGUMENTS 🌸

• address — address to remap 💅 that's the one and only argument, bestie.

---

🦋 DESCRIPTION 🦋

The returned virtual address is a current CPU mapping for the memory address given. it's only valid to use this function on addresses that have a kernel mapping, periodt.

⚠️ so like… only valid on addresses that have a kernel mapping. don't come for me if you ignore that, i warned you 😭

This function does not handle bus mappings for DMA transfers. nope, not its job, not its lane 🚫

In almost all conceivable cases a device driver should not be using this function. like… fr fr, almost all conceivable cases, bestie. it's giving "not for your driver, actually" 💀

---

🌈 SEE ALSO 🌈

• Kernel file ./arch/x86/include/asm/io.h
• virt_to_phys(9)
• ioremap(9)
• iosubmit_cmds512(9)

go read those too, iykyk 👑

---

mwah 💋 source/version: ./arch/x86/include/asm, dated October 2026. slay and read your manpages, bestie 🎀🦋💜