Emil Renner Berthing wrote: > Joshua Yeong wrote: > > Emil Renner Berthing wrote: > > > Joshua Yeong wrote: > > > > > > > > > > > > Emil Renner Berthing wrote: > > > > > Joshua Yeong wrote: > > > > > > Emil Renner Berthing wrote: > > > > > > > Joshua Yeong wrote: > > > > > > > > Add StarFive Starlink cache management driver for > > > > > > > > JH8100 SoC. This driver enables RISC-V non-standard cache > > > > > > > > operation on > > > > > > > > JH8100 that does not support Zicbom extension instructions. > > > > > > > > > > > > > > > > Signed-off-by: Joshua Yeong > > > > > > > > <joshua.yeong@xxxxxxxxxxxxxxxx> > > > > > > > > --- > > > > > > > > drivers/cache/Kconfig | 9 ++ > > > > > > > > drivers/cache/Makefile | 5 +- > > > > > > > > drivers/cache/starfive_starlink_cache.c | 135 > > > > > > > > ++++++++++++++++++++++++ > > > > > > > > 3 files changed, 147 insertions(+), 2 deletions(-) > > > > > > > > create mode > > > > > > > > 100644 drivers/cache/starfive_starlink_cache.c > > > > > > > > > > > > > > > > diff --git a/drivers/cache/Kconfig b/drivers/cache/Kconfig > > > > > > > > index > > > > > > > > 9345ce4976d7..9181cd391f53 100644 > > > > > > > > --- a/drivers/cache/Kconfig > > > > > > > > +++ b/drivers/cache/Kconfig > > > > > > > > @@ -14,4 +14,13 @@ config SIFIVE_CCACHE > > > > > > > > help > > > > > > > > Support for the composable cache controller on SiFive > > > platforms. > > > > > > > > > > > > > > > > +config STARFIVE_STARLINK_CACHE > > > > > > > > + bool "StarFive StarLink Cache controller" > > > > > > > > + depends on RISCV > > > > > > > > + depends on ARCH_STARFIVE > > > > > > > > + select RISCV_DMA_NONCOHERENT > > > > > > > > + select RISCV_NONSTANDARD_CACHE_OPS > > > > > > > > + help > > > > > > > > + Support for the StarLink cache controller on StarFive > > > platforms. > > > > > > > > > > > > > > This is a bit misleading. The JH71x0s don't have this. It's > > > > > > > only on the JH8100 so far, and hopefully later SoCs will > > > > > > > just implement RISC-V > > > > > standards for this. > > > > > > > So maybe something like > > > > > > > > > > > > > > "Support for the StarLink cache controller on the StarFive JH8100 > SoC." > > > > > > > > > > > > > > > > > > > Hi Emil, > > > > > > > > > > > > The StarLink-500 cache controller is not designed exclusively > > > > > > for JH8100 > > > SoC. > > > > > > While it is true that it currently exists on the StarFive > > > > > > platform, CPU/SoC that does not come with Zicbom extensions > > > > > > supported would need to rely on this cache drive to do cache > > > > > > management operations. I think we don’t need to mentioned > > > > > > 'JH8100 > > > SoC' here. > > > > > > > > > > Wait, in the previous mail you said that future designs will > > > > > implement Zicbom and not need this work-around, but here you're > > > > > talking about other SoCs that do need it. So which is it? > > > > > > > > If you visit the company website and look for StarLink-500, you > > > > will find that it is a standalone IP that the company is selling > > > > as an interconnect. Anyone who integrates StarLink without Zicbom > > > > extensions may utilize the cache management operation from this IP. > > > > > > So then the "on StarFive platforms" part is wrong? Or will this > > > always go together with the Dubhe cores? > > > > It would be 'on StarFive platform' without 'JH8100 SoC' that you suggested. > > StarFive's newer cores that will have Zicbom extensions supported. > > Those CPU core will not need to have this cache controller enabled. > > No, what I meant was that if you're selling the "StarLink-500" IP to other SoC > manufacturors then it will not be restricted to StarFive platforms. So then > "Support for the StarLink cache controller _on StarFive platforms_" is no longer > true, right? Yes, you are right on this. AFAIK JH8100 integrates StarLink-500 and which is why we need this cache controller driver, I do not know who/what else products that might use this IP. > > /Emil
