Vortex86 Processors Finally Seeing Work In 2021 For Proper Handling Under Linux
([Operating Systems] 6 Hours Ago
Vortex86)
- Reference: 0001285076
- News link: https://www.phoronix.com/?page=news_item&px=Vortex86-Linux-Detection
- Source link:
The Vortex86 32-bit SoCs have worked under Linux for those distributions still maintaining 32-bit x86 support and where not hitting corner-cases of some i686 level features not being supported by some Vortex86 cores, but there is finally a pending kernel patch to provide proper CPU detection for Vortex86 hardware.
The DM&P Electronics Vortex86 SoCs work with [1]various older Linux distributions just fine without catering the Linux kernel to these CPUs in not requiring any special handling compared to the generic x86 32-bit paths. This formal detection and support for DM&P Vortex processors being worked on now though in late 2021 is motivated by Spectre and Meltdown mitigations being incorrectly applied to them.
[2]
Vortex86 CPUs aren't vulnerable to Spectre and Meltdown since they are an in-order design and also lack the CLFLUSH instruction. But because the Linux kernel hasn't properly catered to Vortex86 and properly identified them, the performance-hitting mitigations were being incorrectly applied for those on these 32-bit SoCs that are slow enough as is without the unneeded mitigations.
Thus [3]a patch is pending to provide support for properly recognizing DM&P Electronics Vortex86 processors so any quirks and tunings can be correctly applied. For now the only tuning / quirk handling just means Spectre and Meltdown mitigations will no longer be applied when booting on said hardware.
[1] https://www.vortex86.com/news/2
[2] https://www.phoronix.com/image-viewer.php?id=2021&image=dmp_vortex86_linux_lrg
[3] https://lore.kernel.org/lkml/20211017094408.1512158-1-marcos@orca.pet/T/#u
The DM&P Electronics Vortex86 SoCs work with [1]various older Linux distributions just fine without catering the Linux kernel to these CPUs in not requiring any special handling compared to the generic x86 32-bit paths. This formal detection and support for DM&P Vortex processors being worked on now though in late 2021 is motivated by Spectre and Meltdown mitigations being incorrectly applied to them.
[2]
Vortex86 CPUs aren't vulnerable to Spectre and Meltdown since they are an in-order design and also lack the CLFLUSH instruction. But because the Linux kernel hasn't properly catered to Vortex86 and properly identified them, the performance-hitting mitigations were being incorrectly applied for those on these 32-bit SoCs that are slow enough as is without the unneeded mitigations.
Thus [3]a patch is pending to provide support for properly recognizing DM&P Electronics Vortex86 processors so any quirks and tunings can be correctly applied. For now the only tuning / quirk handling just means Spectre and Meltdown mitigations will no longer be applied when booting on said hardware.
[1] https://www.vortex86.com/news/2
[2] https://www.phoronix.com/image-viewer.php?id=2021&image=dmp_vortex86_linux_lrg
[3] https://lore.kernel.org/lkml/20211017094408.1512158-1-marcos@orca.pet/T/#u
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