Hi Julien, > On 5 Sep 2022, at 5:37 pm, Julien Grall <[email protected]> wrote: > > > > On 05/09/2022 17:30, Rahul Singh wrote: >> From: Zhou Wang <[email protected]> >> Backport Linux commit a76a37777f2c. Rename __iomb to iomb() while >> merging to get in sync with other Xen definitions. >> Reading the 'prod' MMIO register in order to determine whether or >> not there is valid data beyond 'cons' for a given queue does not >> provide sufficient dependency ordering, as the resulting access is >> address dependent only on 'cons' and can therefore be speculated >> ahead of time, potentially allowing stale data to be read by the >> CPU. >> Use readl() instead of readl_relaxed() when updating the shadow copy >> of the 'prod' pointer, so that all speculated memory reads from the >> corresponding queue can occur only from valid slots. >> Signed-off-by: Zhou Wang <[email protected]> >> Link: >> https://lore.kernel.org/r/[email protected] >> [will: Use readl() instead of explicit barrier. Update 'cons' side to match.] >> Signed-off-by: Will Deacon <[email protected]> >> Origin: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git >> a76a37777f2c >> Signed-off-by: Rahul Singh <[email protected]> >> --- >> Changes in v3: >> - rename __iomb() to iomb() and also move it from common file to >> smmu-v3.c file > > Hmmm... Quoting Bertrand: > > "We need the __iomb as “linux compatibility” in fact so I would suggest for > now to only introduce it at the beginning of smmu-v3.c with other linux > compatibility stuff to prevent adding this to Xen overall." > > Which I also agreed. I couldn't a more recent conversation explaining your > approach. Can you outline why you didn't follow the approached discussed? >
I am really sorry that I missed the naming and when I made the patch in my mind there was a comment from Stefano to rename the __iomb() to iomb(). I will send only this patch after fixing or do you want me to send the whole series? Regards, Rahul
