dma_sb_map_area_linear(9)

✨ dma_sb_map_area_linear(9) ✨

okay so bestie, we're in the Kernel API Manual, section 9 — yes, the kernel-functions-for-grown-ups section 💅 — and today's main character is dma_sb_map_area_linear. Buckle up, it's short but it's iconic.

---

🎀 NAME 🎀

dma_sb_map_area_linear — Map an area of memory into a device dma region.

---

🦋 SYNOPSIS 🦋

int dma_sb_map_area_linear (struct ps3_dma_region *r , unsigned long
virt_addr , unsigned long len , dma_addr_t *bus_addr , u64 iopte_flag );

that's the whole signature, no cap 🫶

---

💖 ARGUMENTS 💖

• r — Pointer to a struct ps3_dma_region. like, the region in question, yeah.
• virt_addr — Starting virtual address of the area to map.
• len — Length in bytes of the area to map. bytes, bestie. bytes.
• bus_addr — A pointer to return the starting ioc bus address of the area to map. so you hand it a pointer, it fills in the address for you 🎀
• iopte_flag — honestly? -- undescribed --. the manpage literally gives us nothing here 😭 not me being left on read by the documentation. I'm not gonna make something up about it either — that's not the vibe.

---

🌸 DESCRIPTION 🌸

okay so here's the tea: this routine just returns the corresponding bus address. That is literally all it does. It does not do the mapping itself — no ma'am, the actual mapping occurs in dma_region_create_linear.

so like… this function is the friend who tells you where the party is but doesn't drive you there 🚗✨ still useful! just, you know. manage your expectations.

⚠️ heads up: since this returns an existing correspondence rather than creating one, don't go expecting it to set anything up for you. That's dma_region_create_linear's job, periodt.

---

🔥 SEE ALSO 🔥

• Kernel file ./arch/powerpc/platforms/ps3/mm.c
• struct mem_region(9)
• struct map(9)
• ps3_mm_phys_to_lpar(9)
• ps3_mm_vas_create(9)
• ps3_mm_vas_destroy(9)
• ps3_mm_region_create(9)
• ps3_mm_region_destroy(9)
• dma_sb_lpar_to_bus(9)
• dma_sb_map_pages(9)
• dma_sb_region_create(9)
• dma_sb_map_area(9)
• dma_sb_unmap_area(9)
• dma_sb_region_create_linear(9)
• dma_sb_region_free_linear(9)
• ps3_mm_init(9)
• ps3_mm_shutdown(9)

---

and that's the whole page, bestie — go read the rest of the PS3 mm crew, they're all linked above and they all ate 💅

shoutout to the source, ./arch/powerpc/platforms/ps3, dated October 2026 — that's the version + date, mwah, mwah 🫶✨ bye!!