Broadcom VK Accelerator Driver, More Intel ACRN Code Arrives For Linux 5.12

Greg Kroah-Hartman this week sent in "the large set of char/misc/whatever driver subsystem updates", which as usual -- given it's a catch-all area of kernel drivers not fitting well into other subsystems -- there is an interesting mix of additions.

Linux 5.12 still isn't moving forward with any "accelerator" subsystem for the likes of the Habana Labs driver and other accelerators / offload cards, even with Linux 5.12 bringing the Broadcom VK accelerator driver, so for now the char/misc area of the kernel continues to expand. The char/misc highlights for Linux 5.12 include:

- The Broadcom VK accelerator driver has been merged. This is for the Broadcom Valkyrie and Viper PCIe accelerators / offload engines for video transcoding and other tasks. Details on Broadcom's "Valkyrie" and "Viper" hardware is still light but the Linux driver support is now at least mainlined.

- Intel has pushed up more of their ACRN hypervisor code after mainlining the initial ACRN guest support back in 2019. ACRN is Intel's hypervisor framework focused on safety critical and IoT use-cases. See the aforelinked article for more details.

- A wide variety of improvements to the Habana Labs AI training/inference accelerator driver. There is now support for staged submissions, a new memory ioctl interface for mapping hardware blocks, security improvements, scheduling work, and other additions.

- A new "NVMEM_RMEM" driver that maps reserved memory by firmware/co-processors into a non-volatile memory (NVMEM) device. This allows for exposing the reserved memory to other drivers or user-space, such as for EEPROM memory.

- Alder Lake Point S and LP device IDs added to the MEI driver.

- The Qualcomm Modem Host Interface (MHI) PCI code now has support for burst mode for hardware channels, reset support, PCI error handling, and more.

The lengthy list of char/misc patches for the 5.12 cycle can be found via this pull request.

The Linux 5.12 merge window is set to close tomorrow.