* [PATCH 1/1] riscv: default to CONFIG_RISCV_SBI_V01=n
@ 2021-12-16 12:35 ` Heinrich Schuchardt
0 siblings, 0 replies; 16+ messages in thread
From: Heinrich Schuchardt @ 2021-12-16 12:35 UTC (permalink / raw)
To: Paul Walmsley, Palmer Dabbelt, Albert Ou
Cc: linux-riscv, linux-kernel, Heinrich Schuchardt
The SBI 0.1 specification is obsolete. The current version is 0.3.
Hence we should not rely by default on SBI 0.1 being implemented.
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
---
arch/riscv/Kconfig | 1 -
1 file changed, 1 deletion(-)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 09abf62ae0ad..f177ad3bee0f 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -396,7 +396,6 @@ source "kernel/Kconfig.hz"
config RISCV_SBI_V01
bool "SBI v0.1 support"
- default y
depends on RISCV_SBI
help
This config allows kernel to use SBI v0.1 APIs. This will be
--
2.32.0
^ permalink raw reply related [flat|nested] 16+ messages in thread
* [PATCH 1/1] riscv: default to CONFIG_RISCV_SBI_V01=n
@ 2021-12-16 12:35 ` Heinrich Schuchardt
0 siblings, 0 replies; 16+ messages in thread
From: Heinrich Schuchardt @ 2021-12-16 12:35 UTC (permalink / raw)
To: Paul Walmsley, Palmer Dabbelt, Albert Ou
Cc: linux-riscv, linux-kernel, Heinrich Schuchardt
The SBI 0.1 specification is obsolete. The current version is 0.3.
Hence we should not rely by default on SBI 0.1 being implemented.
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
---
arch/riscv/Kconfig | 1 -
1 file changed, 1 deletion(-)
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 09abf62ae0ad..f177ad3bee0f 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -396,7 +396,6 @@ source "kernel/Kconfig.hz"
config RISCV_SBI_V01
bool "SBI v0.1 support"
- default y
depends on RISCV_SBI
help
This config allows kernel to use SBI v0.1 APIs. This will be
--
2.32.0
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply related [flat|nested] 16+ messages in thread
* Re: [PATCH 1/1] riscv: default to CONFIG_RISCV_SBI_V01=n
2021-12-16 12:35 ` Heinrich Schuchardt
@ 2021-12-16 13:49 ` Jessica Clarke
-1 siblings, 0 replies; 16+ messages in thread
From: Jessica Clarke @ 2021-12-16 13:49 UTC (permalink / raw)
To: Heinrich Schuchardt
Cc: Paul Walmsley, Palmer Dabbelt, Albert Ou, linux-riscv, linux-kernel
On 16 Dec 2021, at 12:35, Heinrich Schuchardt <heinrich.schuchardt@canonical.com> wrote:
>
> The SBI 0.1 specification is obsolete. The current version is 0.3.
> Hence we should not rely by default on SBI 0.1 being implemented.
It’s what BBL implements, and some people are still using it,
especially given early hardware shipped before OpenSBI grew in
popularity.
Jess
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 1/1] riscv: default to CONFIG_RISCV_SBI_V01=n
@ 2021-12-16 13:49 ` Jessica Clarke
0 siblings, 0 replies; 16+ messages in thread
From: Jessica Clarke @ 2021-12-16 13:49 UTC (permalink / raw)
To: Heinrich Schuchardt
Cc: Paul Walmsley, Palmer Dabbelt, Albert Ou, linux-riscv, linux-kernel
On 16 Dec 2021, at 12:35, Heinrich Schuchardt <heinrich.schuchardt@canonical.com> wrote:
>
> The SBI 0.1 specification is obsolete. The current version is 0.3.
> Hence we should not rely by default on SBI 0.1 being implemented.
It’s what BBL implements, and some people are still using it,
especially given early hardware shipped before OpenSBI grew in
popularity.
Jess
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 1/1] riscv: default to CONFIG_RISCV_SBI_V01=n
2021-12-16 13:49 ` Jessica Clarke
@ 2021-12-16 14:17 ` Heinrich Schuchardt
-1 siblings, 0 replies; 16+ messages in thread
From: Heinrich Schuchardt @ 2021-12-16 14:17 UTC (permalink / raw)
To: Jessica Clarke
Cc: Paul Walmsley, Palmer Dabbelt, Albert Ou, linux-riscv, linux-kernel
On 12/16/21 14:49, Jessica Clarke wrote:
> On 16 Dec 2021, at 12:35, Heinrich Schuchardt <heinrich.schuchardt@canonical.com> wrote:
>>
>> The SBI 0.1 specification is obsolete. The current version is 0.3.
>> Hence we should not rely by default on SBI 0.1 being implemented.
>
> It’s what BBL implements, and some people are still using it,
> especially given early hardware shipped before OpenSBI grew in
> popularity.
>
> Jess
>
Do you mean BBL is not developed anymore?
Some people may still be using a 0.1 SBI. But that minority stuck on an
outdated software stack does not justify defaulting to deprecated
settings in future Linux releases.
Best regards
Heinrich
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 1/1] riscv: default to CONFIG_RISCV_SBI_V01=n
@ 2021-12-16 14:17 ` Heinrich Schuchardt
0 siblings, 0 replies; 16+ messages in thread
From: Heinrich Schuchardt @ 2021-12-16 14:17 UTC (permalink / raw)
To: Jessica Clarke
Cc: Paul Walmsley, Palmer Dabbelt, Albert Ou, linux-riscv, linux-kernel
On 12/16/21 14:49, Jessica Clarke wrote:
> On 16 Dec 2021, at 12:35, Heinrich Schuchardt <heinrich.schuchardt@canonical.com> wrote:
>>
>> The SBI 0.1 specification is obsolete. The current version is 0.3.
>> Hence we should not rely by default on SBI 0.1 being implemented.
>
> It’s what BBL implements, and some people are still using it,
> especially given early hardware shipped before OpenSBI grew in
> popularity.
>
> Jess
>
Do you mean BBL is not developed anymore?
Some people may still be using a 0.1 SBI. But that minority stuck on an
outdated software stack does not justify defaulting to deprecated
settings in future Linux releases.
Best regards
Heinrich
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 1/1] riscv: default to CONFIG_RISCV_SBI_V01=n
2021-12-16 14:17 ` Heinrich Schuchardt
@ 2021-12-16 16:51 ` Jessica Clarke
-1 siblings, 0 replies; 16+ messages in thread
From: Jessica Clarke @ 2021-12-16 16:51 UTC (permalink / raw)
To: Heinrich Schuchardt
Cc: Paul Walmsley, Palmer Dabbelt, Albert Ou, linux-riscv, linux-kernel
On 16 Dec 2021, at 14:17, Heinrich Schuchardt <heinrich.schuchardt@canonical.com> wrote:
>
> On 12/16/21 14:49, Jessica Clarke wrote:
>> On 16 Dec 2021, at 12:35, Heinrich Schuchardt <heinrich.schuchardt@canonical.com> wrote:
>>>
>>> The SBI 0.1 specification is obsolete. The current version is 0.3.
>>> Hence we should not rely by default on SBI 0.1 being implemented.
>> It’s what BBL implements, and some people are still using it,
>> especially given early hardware shipped before OpenSBI grew in
>> popularity.
>> Jess
>
> Do you mean BBL is not developed anymore?
>
> Some people may still be using a 0.1 SBI. But that minority stuck on an outdated software stack does not justify defaulting to deprecated settings in future Linux releases.
BBL is still actively maintained; its most recent commit was 24 days
ago. Also, the amount of code CONFIG_RISCV_SBI_V01 affects is tiny, so
I see no tangible benefit from making this change, just unnecessary
breakage of perfectly functional systems.
Jess
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 1/1] riscv: default to CONFIG_RISCV_SBI_V01=n
@ 2021-12-16 16:51 ` Jessica Clarke
0 siblings, 0 replies; 16+ messages in thread
From: Jessica Clarke @ 2021-12-16 16:51 UTC (permalink / raw)
To: Heinrich Schuchardt
Cc: Paul Walmsley, Palmer Dabbelt, Albert Ou, linux-riscv, linux-kernel
On 16 Dec 2021, at 14:17, Heinrich Schuchardt <heinrich.schuchardt@canonical.com> wrote:
>
> On 12/16/21 14:49, Jessica Clarke wrote:
>> On 16 Dec 2021, at 12:35, Heinrich Schuchardt <heinrich.schuchardt@canonical.com> wrote:
>>>
>>> The SBI 0.1 specification is obsolete. The current version is 0.3.
>>> Hence we should not rely by default on SBI 0.1 being implemented.
>> It’s what BBL implements, and some people are still using it,
>> especially given early hardware shipped before OpenSBI grew in
>> popularity.
>> Jess
>
> Do you mean BBL is not developed anymore?
>
> Some people may still be using a 0.1 SBI. But that minority stuck on an outdated software stack does not justify defaulting to deprecated settings in future Linux releases.
BBL is still actively maintained; its most recent commit was 24 days
ago. Also, the amount of code CONFIG_RISCV_SBI_V01 affects is tiny, so
I see no tangible benefit from making this change, just unnecessary
breakage of perfectly functional systems.
Jess
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 1/1] riscv: default to CONFIG_RISCV_SBI_V01=n
2021-12-16 16:51 ` Jessica Clarke
@ 2021-12-17 10:42 ` Heinrich Schuchardt
-1 siblings, 0 replies; 16+ messages in thread
From: Heinrich Schuchardt @ 2021-12-17 10:42 UTC (permalink / raw)
To: Jessica Clarke
Cc: Paul Walmsley, Palmer Dabbelt, Albert Ou, linux-riscv, linux-kernel
On 12/16/21 17:51, Jessica Clarke wrote:
> On 16 Dec 2021, at 14:17, Heinrich Schuchardt <heinrich.schuchardt@canonical.com> wrote:
>>
>> On 12/16/21 14:49, Jessica Clarke wrote:
>>> On 16 Dec 2021, at 12:35, Heinrich Schuchardt <heinrich.schuchardt@canonical.com> wrote:
>>>>
>>>> The SBI 0.1 specification is obsolete. The current version is 0.3.
>>>> Hence we should not rely by default on SBI 0.1 being implemented.
>>> It’s what BBL implements, and some people are still using it,
>>> especially given early hardware shipped before OpenSBI grew in
>>> popularity.
>>> Jess
>>
>> Do you mean BBL is not developed anymore?
>>
>> Some people may still be using a 0.1 SBI. But that minority stuck on an outdated software stack does not justify defaulting to deprecated settings in future Linux releases.
>
> BBL is still actively maintained; its most recent commit was 24 days
> ago. Also, the amount of code CONFIG_RISCV_SBI_V01 affects is tiny, so
> I see no tangible benefit from making this change, just unnecessary
> breakage of perfectly functional systems.
Only the default is changed. How could this break any existing system?
You can still compile with the deprecated setting.
I can not see why we should keep a default that will cause issues on
systems complying to the current SBI specification.
Best regards
Heinrich
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 1/1] riscv: default to CONFIG_RISCV_SBI_V01=n
@ 2021-12-17 10:42 ` Heinrich Schuchardt
0 siblings, 0 replies; 16+ messages in thread
From: Heinrich Schuchardt @ 2021-12-17 10:42 UTC (permalink / raw)
To: Jessica Clarke
Cc: Paul Walmsley, Palmer Dabbelt, Albert Ou, linux-riscv, linux-kernel
On 12/16/21 17:51, Jessica Clarke wrote:
> On 16 Dec 2021, at 14:17, Heinrich Schuchardt <heinrich.schuchardt@canonical.com> wrote:
>>
>> On 12/16/21 14:49, Jessica Clarke wrote:
>>> On 16 Dec 2021, at 12:35, Heinrich Schuchardt <heinrich.schuchardt@canonical.com> wrote:
>>>>
>>>> The SBI 0.1 specification is obsolete. The current version is 0.3.
>>>> Hence we should not rely by default on SBI 0.1 being implemented.
>>> It’s what BBL implements, and some people are still using it,
>>> especially given early hardware shipped before OpenSBI grew in
>>> popularity.
>>> Jess
>>
>> Do you mean BBL is not developed anymore?
>>
>> Some people may still be using a 0.1 SBI. But that minority stuck on an outdated software stack does not justify defaulting to deprecated settings in future Linux releases.
>
> BBL is still actively maintained; its most recent commit was 24 days
> ago. Also, the amount of code CONFIG_RISCV_SBI_V01 affects is tiny, so
> I see no tangible benefit from making this change, just unnecessary
> breakage of perfectly functional systems.
Only the default is changed. How could this break any existing system?
You can still compile with the deprecated setting.
I can not see why we should keep a default that will cause issues on
systems complying to the current SBI specification.
Best regards
Heinrich
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 1/1] riscv: default to CONFIG_RISCV_SBI_V01=n
2021-12-17 10:42 ` Heinrich Schuchardt
@ 2021-12-17 12:09 ` Anup Patel
-1 siblings, 0 replies; 16+ messages in thread
From: Anup Patel @ 2021-12-17 12:09 UTC (permalink / raw)
To: Heinrich Schuchardt, Atish Patra, Palmer Dabbelt
Cc: Jessica Clarke, Paul Walmsley, Albert Ou, linux-riscv,
linux-kernel@vger.kernel.org List
+Atish
On Fri, Dec 17, 2021 at 4:12 PM Heinrich Schuchardt
<heinrich.schuchardt@canonical.com> wrote:
>
>
>
> On 12/16/21 17:51, Jessica Clarke wrote:
> > On 16 Dec 2021, at 14:17, Heinrich Schuchardt <heinrich.schuchardt@canonical.com> wrote:
> >>
> >> On 12/16/21 14:49, Jessica Clarke wrote:
> >>> On 16 Dec 2021, at 12:35, Heinrich Schuchardt <heinrich.schuchardt@canonical.com> wrote:
> >>>>
> >>>> The SBI 0.1 specification is obsolete. The current version is 0.3.
> >>>> Hence we should not rely by default on SBI 0.1 being implemented.
> >>> It’s what BBL implements, and some people are still using it,
> >>> especially given early hardware shipped before OpenSBI grew in
> >>> popularity.
> >>> Jess
> >>
> >> Do you mean BBL is not developed anymore?
> >>
> >> Some people may still be using a 0.1 SBI. But that minority stuck on an outdated software stack does not justify defaulting to deprecated settings in future Linux releases.
> >
> > BBL is still actively maintained; its most recent commit was 24 days
> > ago. Also, the amount of code CONFIG_RISCV_SBI_V01 affects is tiny, so
> > I see no tangible benefit from making this change, just unnecessary
> > breakage of perfectly functional systems.
>
> Only the default is changed. How could this break any existing system?
> You can still compile with the deprecated setting.
>
> I can not see why we should keep a default that will cause issues on
> systems complying to the current SBI specification.
I agree with Heinrich.
Almost all SBI implementations (OpenSBI, EDK2, KVM, Xvisor, etc) are
providing at least SBI v0.2 and we can't endlessly wait for BBL to move
away from SBI v0.1. We can't totally remove SBI v0.1 but we should
at least disable it by default.
Same rationale applies to the spinwait CPU operations which are only
required for systems using BBL. The sparse HART id series from Atish
can include a patch to have spinwait CPU operations disabled by
default.
@Atish/Palmer, what do you think ?
Regards,
Anup
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 1/1] riscv: default to CONFIG_RISCV_SBI_V01=n
@ 2021-12-17 12:09 ` Anup Patel
0 siblings, 0 replies; 16+ messages in thread
From: Anup Patel @ 2021-12-17 12:09 UTC (permalink / raw)
To: Heinrich Schuchardt, Atish Patra, Palmer Dabbelt
Cc: Jessica Clarke, Paul Walmsley, Albert Ou, linux-riscv,
linux-kernel@vger.kernel.org List
+Atish
On Fri, Dec 17, 2021 at 4:12 PM Heinrich Schuchardt
<heinrich.schuchardt@canonical.com> wrote:
>
>
>
> On 12/16/21 17:51, Jessica Clarke wrote:
> > On 16 Dec 2021, at 14:17, Heinrich Schuchardt <heinrich.schuchardt@canonical.com> wrote:
> >>
> >> On 12/16/21 14:49, Jessica Clarke wrote:
> >>> On 16 Dec 2021, at 12:35, Heinrich Schuchardt <heinrich.schuchardt@canonical.com> wrote:
> >>>>
> >>>> The SBI 0.1 specification is obsolete. The current version is 0.3.
> >>>> Hence we should not rely by default on SBI 0.1 being implemented.
> >>> It’s what BBL implements, and some people are still using it,
> >>> especially given early hardware shipped before OpenSBI grew in
> >>> popularity.
> >>> Jess
> >>
> >> Do you mean BBL is not developed anymore?
> >>
> >> Some people may still be using a 0.1 SBI. But that minority stuck on an outdated software stack does not justify defaulting to deprecated settings in future Linux releases.
> >
> > BBL is still actively maintained; its most recent commit was 24 days
> > ago. Also, the amount of code CONFIG_RISCV_SBI_V01 affects is tiny, so
> > I see no tangible benefit from making this change, just unnecessary
> > breakage of perfectly functional systems.
>
> Only the default is changed. How could this break any existing system?
> You can still compile with the deprecated setting.
>
> I can not see why we should keep a default that will cause issues on
> systems complying to the current SBI specification.
I agree with Heinrich.
Almost all SBI implementations (OpenSBI, EDK2, KVM, Xvisor, etc) are
providing at least SBI v0.2 and we can't endlessly wait for BBL to move
away from SBI v0.1. We can't totally remove SBI v0.1 but we should
at least disable it by default.
Same rationale applies to the spinwait CPU operations which are only
required for systems using BBL. The sparse HART id series from Atish
can include a patch to have spinwait CPU operations disabled by
default.
@Atish/Palmer, what do you think ?
Regards,
Anup
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 1/1] riscv: default to CONFIG_RISCV_SBI_V01=n
2021-12-17 12:09 ` Anup Patel
@ 2021-12-17 18:35 ` Palmer Dabbelt
-1 siblings, 0 replies; 16+ messages in thread
From: Palmer Dabbelt @ 2021-12-17 18:35 UTC (permalink / raw)
To: anup
Cc: heinrich.schuchardt, atishp, jrtc27, Paul Walmsley, aou,
linux-riscv, linux-kernel
On Fri, 17 Dec 2021 04:09:22 PST (-0800), anup@brainfault.org wrote:
> +Atish
>
> On Fri, Dec 17, 2021 at 4:12 PM Heinrich Schuchardt
> <heinrich.schuchardt@canonical.com> wrote:
>>
>>
>>
>> On 12/16/21 17:51, Jessica Clarke wrote:
>> > On 16 Dec 2021, at 14:17, Heinrich Schuchardt <heinrich.schuchardt@canonical.com> wrote:
>> >>
>> >> On 12/16/21 14:49, Jessica Clarke wrote:
>> >>> On 16 Dec 2021, at 12:35, Heinrich Schuchardt <heinrich.schuchardt@canonical.com> wrote:
>> >>>>
>> >>>> The SBI 0.1 specification is obsolete. The current version is 0.3.
>> >>>> Hence we should not rely by default on SBI 0.1 being implemented.
>> >>> It’s what BBL implements, and some people are still using it,
>> >>> especially given early hardware shipped before OpenSBI grew in
>> >>> popularity.
>> >>> Jess
>> >>
>> >> Do you mean BBL is not developed anymore?
>> >>
>> >> Some people may still be using a 0.1 SBI. But that minority stuck on an outdated software stack does not justify defaulting to deprecated settings in future Linux releases.
>> >
>> > BBL is still actively maintained; its most recent commit was 24 days
>> > ago. Also, the amount of code CONFIG_RISCV_SBI_V01 affects is tiny, so
>> > I see no tangible benefit from making this change, just unnecessary
>> > breakage of perfectly functional systems.
>>
>> Only the default is changed. How could this break any existing system?
>> You can still compile with the deprecated setting.
>>
>> I can not see why we should keep a default that will cause issues on
>> systems complying to the current SBI specification.
>
> I agree with Heinrich.
>
> Almost all SBI implementations (OpenSBI, EDK2, KVM, Xvisor, etc) are
> providing at least SBI v0.2 and we can't endlessly wait for BBL to move
> away from SBI v0.1. We can't totally remove SBI v0.1 but we should
> at least disable it by default.
>
> Same rationale applies to the spinwait CPU operations which are only
> required for systems using BBL. The sparse HART id series from Atish
> can include a patch to have spinwait CPU operations disabled by
> default.
>
> @Atish/Palmer, what do you think ?
I agree with Heinrich: it's just a defconfig change, we're not dropping
support for SBI-0.1. The defconfig is generally meant to reflect what
kernel developers are using, and AFAIK everyone doing upstream
development moved off the legacy SBI implementations as of a while ago.
There's some cost associated with supporting the old SBI, it's not like
this is just some backup calls we're adding.
If vendors are still shipping old firmwares as part of their SDKs that's
fine, they'll just need to flip on support for it in their configs. Who
knows, maybe this will even be the nudge they need to stop shipping
ancient firmware ;)
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 1/1] riscv: default to CONFIG_RISCV_SBI_V01=n
@ 2021-12-17 18:35 ` Palmer Dabbelt
0 siblings, 0 replies; 16+ messages in thread
From: Palmer Dabbelt @ 2021-12-17 18:35 UTC (permalink / raw)
To: anup
Cc: heinrich.schuchardt, atishp, jrtc27, Paul Walmsley, aou,
linux-riscv, linux-kernel
On Fri, 17 Dec 2021 04:09:22 PST (-0800), anup@brainfault.org wrote:
> +Atish
>
> On Fri, Dec 17, 2021 at 4:12 PM Heinrich Schuchardt
> <heinrich.schuchardt@canonical.com> wrote:
>>
>>
>>
>> On 12/16/21 17:51, Jessica Clarke wrote:
>> > On 16 Dec 2021, at 14:17, Heinrich Schuchardt <heinrich.schuchardt@canonical.com> wrote:
>> >>
>> >> On 12/16/21 14:49, Jessica Clarke wrote:
>> >>> On 16 Dec 2021, at 12:35, Heinrich Schuchardt <heinrich.schuchardt@canonical.com> wrote:
>> >>>>
>> >>>> The SBI 0.1 specification is obsolete. The current version is 0.3.
>> >>>> Hence we should not rely by default on SBI 0.1 being implemented.
>> >>> It’s what BBL implements, and some people are still using it,
>> >>> especially given early hardware shipped before OpenSBI grew in
>> >>> popularity.
>> >>> Jess
>> >>
>> >> Do you mean BBL is not developed anymore?
>> >>
>> >> Some people may still be using a 0.1 SBI. But that minority stuck on an outdated software stack does not justify defaulting to deprecated settings in future Linux releases.
>> >
>> > BBL is still actively maintained; its most recent commit was 24 days
>> > ago. Also, the amount of code CONFIG_RISCV_SBI_V01 affects is tiny, so
>> > I see no tangible benefit from making this change, just unnecessary
>> > breakage of perfectly functional systems.
>>
>> Only the default is changed. How could this break any existing system?
>> You can still compile with the deprecated setting.
>>
>> I can not see why we should keep a default that will cause issues on
>> systems complying to the current SBI specification.
>
> I agree with Heinrich.
>
> Almost all SBI implementations (OpenSBI, EDK2, KVM, Xvisor, etc) are
> providing at least SBI v0.2 and we can't endlessly wait for BBL to move
> away from SBI v0.1. We can't totally remove SBI v0.1 but we should
> at least disable it by default.
>
> Same rationale applies to the spinwait CPU operations which are only
> required for systems using BBL. The sparse HART id series from Atish
> can include a patch to have spinwait CPU operations disabled by
> default.
>
> @Atish/Palmer, what do you think ?
I agree with Heinrich: it's just a defconfig change, we're not dropping
support for SBI-0.1. The defconfig is generally meant to reflect what
kernel developers are using, and AFAIK everyone doing upstream
development moved off the legacy SBI implementations as of a while ago.
There's some cost associated with supporting the old SBI, it's not like
this is just some backup calls we're adding.
If vendors are still shipping old firmwares as part of their SDKs that's
fine, they'll just need to flip on support for it in their configs. Who
knows, maybe this will even be the nudge they need to stop shipping
ancient firmware ;)
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 1/1] riscv: default to CONFIG_RISCV_SBI_V01=n
2021-12-16 12:35 ` Heinrich Schuchardt
@ 2022-01-20 16:58 ` Palmer Dabbelt
-1 siblings, 0 replies; 16+ messages in thread
From: Palmer Dabbelt @ 2022-01-20 16:58 UTC (permalink / raw)
To: heinrich.schuchardt
Cc: Paul Walmsley, aou, linux-riscv, linux-kernel, heinrich.schuchardt
On Thu, 16 Dec 2021 04:35:38 PST (-0800), heinrich.schuchardt@canonical.com wrote:
> The SBI 0.1 specification is obsolete. The current version is 0.3.
> Hence we should not rely by default on SBI 0.1 being implemented.
>
> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
> ---
> arch/riscv/Kconfig | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 09abf62ae0ad..f177ad3bee0f 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -396,7 +396,6 @@ source "kernel/Kconfig.hz"
>
> config RISCV_SBI_V01
> bool "SBI v0.1 support"
> - default y
> depends on RISCV_SBI
> help
> This config allows kernel to use SBI v0.1 APIs. This will be
Thanks, this is on for-next.
^ permalink raw reply [flat|nested] 16+ messages in thread
* Re: [PATCH 1/1] riscv: default to CONFIG_RISCV_SBI_V01=n
@ 2022-01-20 16:58 ` Palmer Dabbelt
0 siblings, 0 replies; 16+ messages in thread
From: Palmer Dabbelt @ 2022-01-20 16:58 UTC (permalink / raw)
To: heinrich.schuchardt
Cc: Paul Walmsley, aou, linux-riscv, linux-kernel, heinrich.schuchardt
On Thu, 16 Dec 2021 04:35:38 PST (-0800), heinrich.schuchardt@canonical.com wrote:
> The SBI 0.1 specification is obsolete. The current version is 0.3.
> Hence we should not rely by default on SBI 0.1 being implemented.
>
> Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
> ---
> arch/riscv/Kconfig | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 09abf62ae0ad..f177ad3bee0f 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -396,7 +396,6 @@ source "kernel/Kconfig.hz"
>
> config RISCV_SBI_V01
> bool "SBI v0.1 support"
> - default y
> depends on RISCV_SBI
> help
> This config allows kernel to use SBI v0.1 APIs. This will be
Thanks, this is on for-next.
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^ permalink raw reply [flat|nested] 16+ messages in thread
end of thread, other threads:[~2022-01-20 16:58 UTC | newest]
Thread overview: 16+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-12-16 12:35 [PATCH 1/1] riscv: default to CONFIG_RISCV_SBI_V01=n Heinrich Schuchardt
2021-12-16 12:35 ` Heinrich Schuchardt
2021-12-16 13:49 ` Jessica Clarke
2021-12-16 13:49 ` Jessica Clarke
2021-12-16 14:17 ` Heinrich Schuchardt
2021-12-16 14:17 ` Heinrich Schuchardt
2021-12-16 16:51 ` Jessica Clarke
2021-12-16 16:51 ` Jessica Clarke
2021-12-17 10:42 ` Heinrich Schuchardt
2021-12-17 10:42 ` Heinrich Schuchardt
2021-12-17 12:09 ` Anup Patel
2021-12-17 12:09 ` Anup Patel
2021-12-17 18:35 ` Palmer Dabbelt
2021-12-17 18:35 ` Palmer Dabbelt
2022-01-20 16:58 ` Palmer Dabbelt
2022-01-20 16:58 ` Palmer Dabbelt
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