GitLab

Detail:
  Since the current SMP changes are fairly minor, and the trunk is seeing most development, from a maintenance perspective it makes sense to merge the changes to trunk. This will also make sure they get some wider testing ready for when the next round of SMP development takes place.
  Changes:
  - Docs/SMP - New docs folder describing SMP-related changes to the HAL and interrupt handling. Some of the IRQ changes can also be taken advantage of by single-core devices, since it introduces a way to describe which interrupt sources can be routed to IRQ & FIQ
  - Makefile, hdr/DBellDevice, hdr/HALDevice - New HAL device for an inter-processor software-generated interrupt source ("doorbell")
  - hdr/HALEntries - Reuse the unused matrix keyboard & touchscreen HAL entry points for the new IRQ handling & SMP-related HAL calls
  - hdr/KernelWS - Bump up MaxInterrupts
  - hdr/OSMem, s/MemInfo - Introduce OS_Memory 19, to allow for DMA to/from cacheable memory without actually altering the cacheability of the pages (which can be even more tricky in SMP systems than it is in uniprocessor systems)
  - hdr/Options - Introduce SMP build switch. Currently this controls whether the ARMops will operate in "SMP-friendly" mode or not (when running on MP processors)
  - s/ARMops, s/MemMap2 - Introduce the ARMv7MP ARMop implementation. Simplify DCache_LineLen / ICache_LineLen handling for WB_CR7_Lx so that it's the plain value rather than log2(n)-2
  - s/ExtraSWIs - If ARMops are in SMP-friendly mode, global OS_SynchroniseCodeAreas now only syncs application space and the RMA. This is because there is no trivial MP-safe global IMB operation available. This will also make global OS_SynchroniseCodeAreas significantly slower, but the documentation has always warned against performing a global IMB for just that reason, so code that suffers performance penalties should really try and switch to a ranged IMB.
  - s/NewIRQs - Update some comments regarding IRQ handler entry/exit conditions
Admin:
  Untested


Version 6.09. Tagged as 'Kernel-6_09'