Messages in this thread | | | Date | Fri, 3 Dec 2021 16:40:26 -0800 | Subject | Re: [RFC 5/6] RISC-V: Move spinwait booting method to its own config | From | Randy Dunlap <> |
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Hi--
On 12/3/21 16:20, Atish Patra wrote: > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index 821252b65f89..4afb42d5707d 100644 > --- a/arch/riscv/Kconfig > +++ b/arch/riscv/Kconfig > @@ -403,6 +403,20 @@ config RISCV_SBI_V01 > This config allows kernel to use SBI v0.1 APIs. This will be > deprecated in future once legacy M-mode software are no longer in use. > > +config RISCV_BOOT_SPINWAIT > + bool "Spinwait booting method" > + depends on SMP > + default y > + help > + This enables support for booting Linux via spinwait method. In the > + spinwait method, all cores randomly jump to Linux. One of the core
cores
> + gets chosen via lottery and all other keeps spinning on a percpu
others keep
> + variable. This method can not support cpu hotplug and sparse hartid
cannot support CPU hotplug and sparse hartid
> + scheme. It should be only enabled for M-mode Linux or platforms relying > + on older firmware without SBI HSM extension. All other platform should
platforms
> + rely on ordered booing via SBI HSM extension which gets chosen
booting
> + dynamically at runtime if the firmware supports it.
dynamically at runtime if the firmware supports it.
(Last line should be indented with tab + 2 spaces, not 10 spaces.)
-- ~Randy
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