Major changes in upstream Linux kernel for ARC cores - foss-for-synopsys-dwc-arc-processors/linux GitHub Wiki

This page provides highlights of Linux kernel changes relevant to the ARC architecture, broken down by release. These include architecture specific as well as any generic code updates and any relevant driver updates.

Lengthy changelogs per release for the entire source tree can be found here: https://kernelnewbies.org/LinuxVersions.

Note: the ARC Linux port is developed and maintained with upstream first mindset. All of the new code and fixes are submitted to upstream kernel.org repository via pull requests to Linus. This model brings all the benefits from community review and feedback as well as sweeping cross-architecture and generic changes. We follow upstream practices including back-porting of patches. Only patches that conform to defined "stable kernel" rules are back-ported to older kernel versions. Specifically, one consequence of backporting rules is that new features or new compiler support can't be back-ported to upstream stable kernels by ARC Linux developers.

Linux 4.16 (changes)

  • ARC: MCIP (ARConnect): Minor improvements

Linux 4.15 (changes)

  • ARC: Support for ARC HS48 cores (MMUv5)
  • ARC: Perf: Clean-up and micro-optimizations
  • ARC: Platforms
    • HSDK: Switch DisplayLink driver from FBDEV to DRM version

Linux 4.14 (changes), LTS - projected EOL Jan, 2020,

  • ARC: Platforms
    • HSDK: Added initial support
    • AXS10x: Switch to CLK driver
    • NPS400: Fixes and improvements

Linux 4.13 (changes)

  • ARC: PAE40
    • Fixes
    • Prepare AXS103 for use of PAE40

Linux 4.12 (changes)

  • ARC: ARCv2: Implement regional operations for L1 data- and instruction caches

Linux 4.11 (changes)

  • ARC: Read CPU clock value from CLK driver
  • ARC: ARCv2
    • Save accumulator regs (r58, r59) if present
    • IDU INTC: Fixes and improvements
  • ARC: Platforms
    • VDK: Add support of MMC and UIO

Linux 4.10 (changes)

  • ARC: Move ARC Timers to clocksource
  • ARC: Minor improvements for IRQs
  • ARC: ARCompact
    • Fix unaligned access handler
    • Accommodate 4-color aliased data cache
  • ARC: ARCv2
    • Clean-up of MCIP (ARConnect) code
    • Fixes and improvements for IO-Coherency
    • Re-enable IO-Coherency by default
    • Save user-space r30 on kernel entry
    • GFRC, RTC fixes and improvements
  • ARC: Platforms
    • AXS10X: Enable ARC PGU as kernel module by default
    • NPS400: Support hardware scheduling
    • Rename ZEBU platform to HAPS

Linux 4.9 (changes), LTS - projected EOL Jan, 2019

  • ARC: Minor improvements for IRQs
  • ARC: Implement arch-specific dma_map_ops.mmap
  • ARC: Bootlog improvements
  • ARC: Syscall for kernel-aasisted atomic operations
  • ARC: Dwarf2 unwinder refactoring (switch from .debug_frame to .eh_frame)
  • ARC: Enable generic "cache-references" and "cache-misses" events in perf for ARC
  • ARC: ARCv2
    • IOC: Disable by default
    • Support 64-bit atomic ops
  • ARC: Platforms
    • NPS400: Minor improvements
    • NSIM: Support perf events with interrupts
    • ZEBU: Add support of emulation platform

Linux 4.8 (changes)

Linux 4.7 (changes)

  • ARC: ARC built-in timers refactoring
  • ARC: Support for reserved memory defined by device tree
  • ARC: Platforms
    • AXS10x: Add support of ARC PGU
    • NPS400: Add new platform

Linux 4.6 (changes)

  • ARC: Enable LOCKDEP
  • ARC: DMA: Support DMA to/from memory beyond 4Gb
  • ARC: PCI: Add support in ARC architecture
  • ARC: Platforms
    • NSIMOSCI: Use NPS_ENET driver for Ethernet controller

Linux 4.5 (changes)

  • ARC: DMA: Convert to dma_map_ops
  • ARC: ARCv2
    • MCIP (ARConnect): IPI Cross-core interrupts fixes and improvements
    • Introduce MMU Super Page Size support (2 and 16MB)

Linux 4.4 (changes), LTS - projected EOL Feb, 2022

  • ARC: Dwarf2 fixes and improvements
  • ARC: ARCv2
    • Add PAE40 support
    • Add HIGHMEM support
    • Add Transparent Huge Pages support

Linux 4.3 (changes)

  • ARC: ARCv2
    • Improvements for perf (support of SMP, overflow IRQs, user-/kernel-mode selection)
    • Initial support of IO-Coherency

Linux 4.2 (changes)

  • ARC: ARCv2
    • Introduce initial port for ARCv2 ISA