ipa_smem_init(9)

NAME 💖

okay bestie, welcome to ipa_smem_init(9) from the Kernel API Manual — the function that initializes SMEM memory used by the IPA. slay.

SYNOPSIS ✨

int ipa_smem_init (struct ipa *ipa , size_t size );

that's the whole signature, no cap. int coming back, ipa and size going in.

ARGUMENTS 🫶

ipa — the IPA pointer. main character reference, fr.
size — Size (bytes) of SMEM memory region. yes, bytes — not vibes.

DESCRIPTION 🌸

Okay so SMEM is a managed block of shared DRAM, and numbered "items" can be allocated from it. One item is designated for use by the IPA. periodt.

The modem accesses SMEM memory directly, but the IPA accesses it via the IOMMU, using the AP's credentials. iykyk — direct access vs IOMMU access, different lanes.

If size provided is non-zero, we allocate it and map it for access through the IOMMU. that's the whole move.

NOTE 🚨

Careful, bestie: size and the item address are not guaranteed to be page-aligned. no cap, do not assume alignment.