nfp_xpb_writelm(9)

💅 nfp_xpb_writelm — the kernel API manual, bestie edition ✨

okay so you're here about nfp_xpb_writelm(9)?? that's the kernel API manual page for it, and honestly? it's a little cutie. let me walk you through it 🫶

---

✨ NAME ✨

nfp_xpb_writelm — modify bits of a 32-bit value from the XPB bus 🌸

like, it's a partial write. a masked write. it's giving "surgical little bit-flip era" 💅

---

✨ SYNOPSIS ✨

int nfp_xpb_writelm (struct nfp_cpp *cpp , u32 xpb_tgt , u32 mask , u32
value );

takes four things, returns an int. that's the whole vibe. 🎀

---

✨ ARGUMENTS ✨

• cpp — your NFP CPP device handle 💖 (the whole device, basically)
• xpb_tgt — the XPB target and address, bundled together, iconic
• mask — the mask of bits you wanna alter 🎯 like, which bits are we touching, bestie
• value — the value to modify. the actual payload. the main character 🌟

---

✨ DESCRIPTION ✨

so the description here is literally just:

KERNEL: this operation is safe to call in interrupt or softirq context 🔥

no cap, that's the entire description. and it's kind of a big deal?? because being interrupt-safe means you can just call it from a context where you absolutely cannot sleep — so no blocking, no napping, no "brb gotta schedule", periodt. ⭐

💀 reminder: it being safe in interrupt/softirq context is the only thing the page claims, so don't go reading extra promises into it, okay? iykyk.

---

✨ RETURN ✨

• 0 on success 🎉
• -ERRNO if it's not 💔

that's it. that's the return section. clean, minimal, slay.

---

✨ SEE ALSO ✨

okay this section is LONG and it ate, so buckle up 🦋 — everything below is literally listed on the page:

Kernel file

./drivers/net/ethernet/netronome/nfp/nfpcore/nfp_cppcore.c

Related functions

• struct nfp_cpp(9)
• nfp_cpp_free(9)
• nfp_cpp_model(9)
• nfp_cpp_interface(9)
• nfp_cpp_serial(9)
• nfp_cpp_area_alloc_with_name(9)
• nfp_cpp_area_alloc(9)
• nfp_cpp_area_alloc_acquire(9)
• nfp_cpp_area_free(9)
• nfp_cpp_area_acquire(9)
• nfp_cpp_area_acquire_nonblocking(9)
• nfp_cpp_area_release(9)
• nfp_cpp_area_release_free(9)
• nfp_cpp_area_read(9)
• nfp_cpp_area_write(9)
• nfp_cpp_area_size(9)
• nfp_cpp_area_name(9)
• nfp_cpp_area_priv(9)
• nfp_cpp_area_cpp(9)
• nfp_cpp_area_resource(9)
• nfp_cpp_area_phys(9)
• nfp_cpp_area_iomem(9)
• nfp_cpp_area_readl(9)
• nfp_cpp_area_writel(9)
• nfp_cpp_area_readq(9)
• nfp_cpp_area_writeq(9)
• nfp_cpp_area_fill(9)
• nfp_cpp_area_cache_add(9)
• nfp_cpp_read(9)
• nfp_cpp_write(9)
• nfp_xpb_readl(9)
• nfp_xpb_writel(9)
• nfp_cpp_from_operations(9)
• nfp_cpp_priv(9)
• nfp_cpp_device(9)
• nfp_cpp_explicit_acquire(9)
• nfp_cpp_explicit_set_target(9)
• nfp_cpp_explicit_set_data(9)
• nfp_cpp_explicit_set_signal(9)
• nfp_cpp_explicit_set_posted(9)
• nfp_cpp_explicit_put(9)
• nfp_cpp_explicit_do(9)
• nfp_cpp_explicit_get(9)
• nfp_cpp_explicit_release(9)
• nfp_cpp_explicit_cpp(9)
• nfp_cpp_explicit_priv(9)

also peep nfp_xpb_writel(9) up there — yes, that's the other one, the full-write sibling. this page is the masked one. don't mix 'em up 🙈

---

🎀 sign-off 🎀

this whole thing lives in the kernel source tree, file ./drivers/net/ethernet/netrono... (that's the trailing bit of the path as shown in the footer, bestie — the full kernel file path is the one listed in SEE ALSO above 💜), and the page is dated October 2026. that's the version/date energy at the bottom. mwah. go flip some bits responsibly ✨💅🦋