On Wed, May 29, 2024 at 10:47:40AM +0200, Alexandre Ghiti wrote: > Hi Conor, > > On 28/05/2024 13:11, Conor Dooley wrote: > > From: Conor Dooley > > > > During some discussion on IRC yesterday and on Pu's bpf patch [1] > > I noticed that these RISCV_ISA* Kconfig options are not really clear > > about their implications. Many of these options have no impact on what > > userspace is allowed to do, for example an application can use Zbb > > regardless of whether or not the kernel does. Change the help text to > > try and clarify whether or not an option affects just the kernel, or > > also userspace. None of these options actually control whether or not an > > extension is detected dynamically as that's done regardless of Kconfig > > options, so drop any text that implies the option is required for > > dynamic detection, rewording them as "do x when y is detected". > > > > Link: https://lore.kernel.org/linux-riscv/20240328-ferocity-repose-c554f75a676c@spud/ [1] > > Reviewed-by: Andrew Jones > > Signed-off-by: Conor Dooley > > --- > > arch/riscv/Kconfig | 36 +++++++++++++++++++----------------- > > 1 file changed, 19 insertions(+), 17 deletions(-) > > > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > > index b94176e25be1..3b702e6cc051 100644 > > --- a/arch/riscv/Kconfig > > +++ b/arch/riscv/Kconfig > > @@ -501,7 +501,8 @@ config RISCV_ISA_C > > help > > Adds "C" to the ISA subsets that the toolchain is allowed to emit > > when building Linux, which results in compressed instructions in the > > - Linux binary. > > + Linux binary. This option produces a kernel that will not run on > > + systems that do not support compressed instructions. > > If you don't know what to do here, say Y. > > @@ -511,8 +512,8 @@ config RISCV_ISA_SVNAPOT > > depends on RISCV_ALTERNATIVE > > default y > > help > > - Allow kernel to detect the Svnapot ISA-extension dynamically at boot > > - time and enable its usage. > > + Add support for the Svnapot ISA-extension in the kernel when it > > + is detected at boot. > > > To me, the new version makes things even more confusing: svnapot mappings > will indeed be handled by the kernel (since only the kernel sets up the page > tables) but it will only be used (for now) for HugeTLB mappings in > userspace. How would you suggest that I word it? "Enable the use of the Svnapot ISA-extension when it is detected at boot"? The current text implies that these options control detection of extensions (which they do not) and that is what I am looking to remove as it has caused confusion.