[PATCH] RISC-V: cpu.c: remove nonexistent ext from cpuinfo

[PATCH] RISC-V: cpu.c: remove nonexistent ext from cpuinfo

[Hongren (Zenithal) Zheng]

There are no single-letter B/K/J extentions,
as they are never ratified. For P, it is still in
progress and not ratified.

The ordering constraint of these placerholders is now removed
from the spec. By commit ("Delete more nonexistent
extensions from the naming constraints") of riscv/riscv-isa-manual

Signed-off-by: Hongren (Zenithal) Zheng <i@zenithal.me>
---
 arch/riscv/kernel/cpu.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index ccb617791e56..53a061ab0743 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -113,10 +113,8 @@ static void print_isa_ext(struct seq_file *f)
 /*
  * These are the only valid base (single letter) ISA extensions as per the spec.
  * It also specifies the canonical order in which it appears in the spec.
- * Some of the extension may just be a place holder for now (B, K, P, J).
- * This should be updated once corresponding extensions are ratified.
  */
-static const char base_riscv_exts[13] = "imafdqcbkjpvh";
+static const char base_riscv_exts[9] = "imafdqcvh";
 
 static void print_isa(struct seq_file *f, const char *isa)
 {
-- 
2.35.1

Re: [PATCH] RISC-V: cpu.c: remove nonexistent ext from cpuinfo

[Hongren (Zenithal) Zheng]

On Tue, Apr 26, 2022 at 06:08:01AM +0800, Hongren (Zenithal) Zheng wrote:
> There are no single-letter B/K/J extentions,
> as they are never ratified. For P, it is still in
> progress and not ratified.
> 
> The ordering constraint of these placerholders is now removed
> from the spec. By commit ("Delete more nonexistent
> extensions from the naming constraints") of riscv/riscv-isa-manual

Hi, is there any further update on this patch?

> 
> Signed-off-by: Hongren (Zenithal) Zheng <i@zenithal.me>
> ---
>  arch/riscv/kernel/cpu.c | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
> index ccb617791e56..53a061ab0743 100644
> --- a/arch/riscv/kernel/cpu.c
> +++ b/arch/riscv/kernel/cpu.c
> @@ -113,10 +113,8 @@ static void print_isa_ext(struct seq_file *f)
>  /*
>   * These are the only valid base (single letter) ISA extensions as per the spec.
>   * It also specifies the canonical order in which it appears in the spec.
> - * Some of the extension may just be a place holder for now (B, K, P, J).
> - * This should be updated once corresponding extensions are ratified.
>   */
> -static const char base_riscv_exts[13] = "imafdqcbkjpvh";
> +static const char base_riscv_exts[9] = "imafdqcvh";

The base_riscv_exts "imafdqcvh" is exactly the spec now, as
https://github.com/riscv/riscv-isa-manual/commit/db7a4a0dad0e99d1ec1fc67b582624fc0aeae98e
(Add single-letter "H" extension to the table)
has shown

>  
>  static void print_isa(struct seq_file *f, const char *isa)
>  {
> -- 
> 2.35.1
> 

Re: [PATCH] RISC-V: cpu.c: remove nonexistent ext from cpuinfo

[Palmer Dabbelt]

On Wed, 18 May 2022 01:40:18 PDT (-0700), i@zenithal.me wrote:
> On Tue, Apr 26, 2022 at 06:08:01AM +0800, Hongren (Zenithal) Zheng wrote:
>> There are no single-letter B/K/J extentions,
>> as they are never ratified. For P, it is still in
>> progress and not ratified.
>>
>> The ordering constraint of these placerholders is now removed
>> from the spec. By commit ("Delete more nonexistent
>> extensions from the naming constraints") of riscv/riscv-isa-manual
>
> Hi, is there any further update on this patch?

IIRC there was some debate as to whether that change constituted an 
incompatible change to the spec, but I guess it's stuck around for long 
enough that maybe we should count on it being canon now?  I added Kito 
and Nelson, there's a GNU toolchain call tomorrow morning so hopefully 
we can remember to talk about it...

>
>>
>> Signed-off-by: Hongren (Zenithal) Zheng <i@zenithal.me>
>> ---
>>  arch/riscv/kernel/cpu.c | 4 +---
>>  1 file changed, 1 insertion(+), 3 deletions(-)
>>
>> diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
>> index ccb617791e56..53a061ab0743 100644
>> --- a/arch/riscv/kernel/cpu.c
>> +++ b/arch/riscv/kernel/cpu.c
>> @@ -113,10 +113,8 @@ static void print_isa_ext(struct seq_file *f)
>>  /*
>>   * These are the only valid base (single letter) ISA extensions as per the spec.
>>   * It also specifies the canonical order in which it appears in the spec.
>> - * Some of the extension may just be a place holder for now (B, K, P, J).
>> - * This should be updated once corresponding extensions are ratified.
>>   */
>> -static const char base_riscv_exts[13] = "imafdqcbkjpvh";
>> +static const char base_riscv_exts[9] = "imafdqcvh";
>
> The base_riscv_exts "imafdqcvh" is exactly the spec now, as
> https://github.com/riscv/riscv-isa-manual/commit/db7a4a0dad0e99d1ec1fc67b582624fc0aeae98e
> (Add single-letter "H" extension to the table)
> has shown

Oddly enough I stumbled upon that one this morning, it's another one of 
these like the HPM stuff: we used to say "there's no letter describing 
the hypervisor behavior, so it's part of the base" (see the commentary 
on the binutils patch), but now that there's a letter I'm assuming we 
should split that out?

Not clear if the RISC-V folks want H to be ignored by software like 
those other recent changes, and if so it's also not clear that's a good 
idea.

Anyway, sorry this is taking a while but I think it's going to be too 
late for this merge window -- kind of silly for such a small patch, but 
it's got interface implications and it's all a bit of a hot topic right 
now.

>
>>
>>  static void print_isa(struct seq_file *f, const char *isa)
>>  {
>> --
>> 2.35.1
>>

Re: [PATCH] RISC-V: cpu.c: remove nonexistent ext from cpuinfo

[Hongren Zheng]

On Wed, Jun 01, 2022 at 08:52:42PM -0700, Palmer Dabbelt wrote:
> On Wed, 18 May 2022 01:40:18 PDT (-0700), i@zenithal.me wrote:
> > On Tue, Apr 26, 2022 at 06:08:01AM +0800, Hongren (Zenithal) Zheng wrote:
> > > There are no single-letter B/K/J extentions,
> > > as they are never ratified. For P, it is still in
> > > progress and not ratified.
> > > 
> > > The ordering constraint of these placerholders is now removed
> > > from the spec. By commit ("Delete more nonexistent
> > > extensions from the naming constraints") of riscv/riscv-isa-manual
> > 
> > Hi, is there any further update on this patch?
> 
> IIRC there was some debate as to whether that change constituted an
> incompatible change to the spec, but I guess it's stuck around for long
> enough that maybe we should count on it being canon now?  I added Kito and
> Nelson, there's a GNU toolchain call tomorrow morning so hopefully we can
> remember to talk about it...

Hi, I'm curious about the output of the meeting, any update on this?

> 
> > 
> > > 
> > > Signed-off-by: Hongren (Zenithal) Zheng <i@zenithal.me>
> > > ---
> > >  arch/riscv/kernel/cpu.c | 4 +---
> > >  1 file changed, 1 insertion(+), 3 deletions(-)
> > > 
> > > diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
> > > index ccb617791e56..53a061ab0743 100644
> > > --- a/arch/riscv/kernel/cpu.c
> > > +++ b/arch/riscv/kernel/cpu.c
> > > @@ -113,10 +113,8 @@ static void print_isa_ext(struct seq_file *f)
> > >  /*
> > >   * These are the only valid base (single letter) ISA extensions as per the spec.
> > >   * It also specifies the canonical order in which it appears in the spec.
> > > - * Some of the extension may just be a place holder for now (B, K, P, J).
> > > - * This should be updated once corresponding extensions are ratified.
> > >   */
> > > -static const char base_riscv_exts[13] = "imafdqcbkjpvh";
> > > +static const char base_riscv_exts[9] = "imafdqcvh";
> > 
> > The base_riscv_exts "imafdqcvh" is exactly the spec now, as
> > https://github.com/riscv/riscv-isa-manual/commit/db7a4a0dad0e99d1ec1fc67b582624fc0aeae98e
> > (Add single-letter "H" extension to the table)
> > has shown
> 
> Oddly enough I stumbled upon that one this morning, it's another one of
> these like the HPM stuff: we used to say "there's no letter describing the
> hypervisor behavior, so it's part of the base" (see the commentary on the
> binutils patch), but now that there's a letter I'm assuming we should split
> that out?

I'm afraid I could not help here because I'm not familiar with this area.

> 
> Not clear if the RISC-V folks want H to be ignored by software like those
> other recent changes, and if so it's also not clear that's a good idea.
> 
> Anyway, sorry this is taking a while but I think it's going to be too late
> for this merge window -- kind of silly for such a small patch, but it's got
> interface implications and it's all a bit of a hot topic right now.
> 
> > 
> > > 
> > >  static void print_isa(struct seq_file *f, const char *isa)
> > >  {
> > > --
> > > 2.35.1
> > > 

Re: [PATCH] RISC-V: cpu.c: remove nonexistent ext from cpuinfo

[Hongren Zheng]

On Mon, Jun 13, 2022 at 02:20:57AM +0800, Hongren Zheng wrote:
> On Wed, Jun 01, 2022 at 08:52:42PM -0700, Palmer Dabbelt wrote:
> > On Wed, 18 May 2022 01:40:18 PDT (-0700), i@zenithal.me wrote:
> > > On Tue, Apr 26, 2022 at 06:08:01AM +0800, Hongren (Zenithal) Zheng wrote:
> > > > There are no single-letter B/K/J extentions,
> > > > as they are never ratified. For P, it is still in
> > > > progress and not ratified.
> > > > 
> > > > The ordering constraint of these placerholders is now removed
> > > > from the spec. By commit ("Delete more nonexistent
> > > > extensions from the naming constraints") of riscv/riscv-isa-manual
> > > 
> > > Hi, is there any further update on this patch?
> > 
> > IIRC there was some debate as to whether that change constituted an
> > incompatible change to the spec, but I guess it's stuck around for long
> > enough that maybe we should count on it being canon now?  I added Kito and
> > Nelson, there's a GNU toolchain call tomorrow morning so hopefully we can
> > remember to talk about it...
> 
> Hi, I'm curious about the output of the meeting, any update on this?
> 
> > 
> > > 
> > > > 
> > > > Signed-off-by: Hongren (Zenithal) Zheng <i@zenithal.me>
> > > > ---
> > > >  arch/riscv/kernel/cpu.c | 4 +---
> > > >  1 file changed, 1 insertion(+), 3 deletions(-)
> > > > 
> > > > diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
> > > > index ccb617791e56..53a061ab0743 100644
> > > > --- a/arch/riscv/kernel/cpu.c
> > > > +++ b/arch/riscv/kernel/cpu.c
> > > > @@ -113,10 +113,8 @@ static void print_isa_ext(struct seq_file *f)
> > > >  /*
> > > >   * These are the only valid base (single letter) ISA extensions as per the spec.
> > > >   * It also specifies the canonical order in which it appears in the spec.
> > > > - * Some of the extension may just be a place holder for now (B, K, P, J).
> > > > - * This should be updated once corresponding extensions are ratified.
> > > >   */
> > > > -static const char base_riscv_exts[13] = "imafdqcbkjpvh";
> > > > +static const char base_riscv_exts[9] = "imafdqcvh";
> > > 
> > > The base_riscv_exts "imafdqcvh" is exactly the spec now, as
> > > https://github.com/riscv/riscv-isa-manual/commit/db7a4a0dad0e99d1ec1fc67b582624fc0aeae98e
> > > (Add single-letter "H" extension to the table)
> > > has shown
> > 
> > Oddly enough I stumbled upon that one this morning, it's another one of
> > these like the HPM stuff: we used to say "there's no letter describing the
> > hypervisor behavior, so it's part of the base" (see the commentary on the
> > binutils patch), but now that there's a letter I'm assuming we should split
> > that out?
> 
> I'm afraid I could not help here because I'm not familiar with this area.
> 
> > 
> > Not clear if the RISC-V folks want H to be ignored by software like those
> > other recent changes, and if so it's also not clear that's a good idea.
> > 
> > Anyway, sorry this is taking a while but I think it's going to be too late
> > for this merge window -- kind of silly for such a small patch, but it's got
> > interface implications and it's all a bit of a hot topic right now.

This PATCH still applies. Might there be some update? Can we safely
pick this PATCH?

> > 
> > > 
> > > > 
> > > >  static void print_isa(struct seq_file *f, const char *isa)
> > > >  {
> > > > --
> > > > 2.35.1
> > > >