[PATCH v3 3/8] iommu/riscv: Add HPM support for performance monitoring

[Andrew Jones]

On Thu, Feb 05, 2026 at 02:11:48PM +0800, Lv Zheng wrote:
> On 2/5/2026 11:47 AM, Zong Li wrote:
> > On Thu, Feb 5, 2026 at 11:35 AM Lv Zheng <lv.zheng at linux.spacemit.com> wrote:
> > > 
> > > On 2/5/2026 2:39 AM, Andrew Jones wrote:
> > > > How does this relate to
> > > > 
> > > > https://lore.kernel.org/all/20250115030306.29735-1-zong.li@sifive.com/
> > > > 
> > > >   From a quick skim it looks like there's plenty of overlap.
> > > 
> > > We developed the driver in 2024 and demonstrated it in China summit. We
> > > didn't notice that a patch is on-going now in the community.
> > > 
> > > Now it looks our approach solved more issues, and we'll check and update
> > > if there are any community concerns still not addressed in this patchset.
> > > 
> > > We can add Reviewed-by/Tested-by and Signed-off-by of Zong Li to this
> > > patch if he wishes.
> > > 
> > > Thanks,
> > > Lv
> > > 
> > 
> > Perhaps I can first post my next revision to the mailing list (hope it
> > won't waste the community resource), so that you could have a chance
> > to review it and see whether that version is architecturally closer to
> > what the community is looking for, while also addressing your issue.
> > If you also feel that my next revision meets your needs, perhaps you
> > could append your additional implementations on top of it.
> > 
> 
> It seems we all composed the RISC-V iommu HPM support by referencing
> drivers/perf/arm_smmuv3_pmu.
> 
> Robin's comments should all be addressed IMHO.
> 
> > Of course, if the community would prefer to go your version, I’m
> > perfectly fine with that as well.
> 
> OK. If we send a next version, we will add your SOB and please help to
> review and test.

Zong Li's SOB should only be on the patches he authored. Don't put
anybody's SOB on patches they haven't been involved in. See
Documentation/process/submitting-patches.rst
"""
The Signed-off-by: tag indicates that the signer was involved in the
development of the patch, or that he/she was in the patch's delivery path.
"""

Since Zong Li's patches were already on the list then your series should
at least discuss them in the cover letter, explaining why you've opted
not to adopt them. But, most likely some of the patches can be adopted,
so those should be extracted from Zong Li's work (with authorship
preserved) and based upon in order to respect that prior work.

Thanks,
drew