[v4] Add Counter delegation ISA extension support

[PATCH v4 09/21] RISC-V: Add Ssccfg ISA extension definition and parsing

Posted by Atish Patra 3 weeks, 5 days ago

Ssccfg (‘Ss’ for Privileged architecture and Supervisor-level
extension, ‘ccfg’ for Counter Configuration) provides access to
delegated counters and new supervisor-level state.

This patch just enables the definitions and enable parsing.

Signed-off-by: Atish Patra <atishp@rivosinc.com>
---
 arch/riscv/include/asm/hwcap.h | 2 ++
 arch/riscv/kernel/cpufeature.c | 2 ++
 2 files changed, 4 insertions(+)

diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
index b4eddcb57842..fa5e01bcb990 100644
--- a/arch/riscv/include/asm/hwcap.h
+++ b/arch/riscv/include/asm/hwcap.h
@@ -103,6 +103,8 @@
 #define RISCV_ISA_EXT_SSCSRIND		94
 #define RISCV_ISA_EXT_SMCSRIND		95
 #define RISCV_ISA_EXT_SMCNTRPMF         96
+#define RISCV_ISA_EXT_SSCCFG            97
+#define RISCV_ISA_EXT_SMCDELEG          98
 
 #define RISCV_ISA_EXT_XLINUXENVCFG	127
 
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index 8f225c9c3055..3cb208d4913e 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -390,12 +390,14 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
 	__RISCV_ISA_EXT_BUNDLE(zvksg, riscv_zvksg_bundled_exts),
 	__RISCV_ISA_EXT_DATA(zvkt, RISCV_ISA_EXT_ZVKT),
 	__RISCV_ISA_EXT_DATA(smaia, RISCV_ISA_EXT_SMAIA),
+	__RISCV_ISA_EXT_DATA(smcdeleg, RISCV_ISA_EXT_SMCDELEG),
 	__RISCV_ISA_EXT_DATA(smcntrpmf, RISCV_ISA_EXT_SMCNTRPMF),
 	__RISCV_ISA_EXT_DATA(smcsrind, RISCV_ISA_EXT_SMCSRIND),
 	__RISCV_ISA_EXT_DATA(smmpm, RISCV_ISA_EXT_SMMPM),
 	__RISCV_ISA_EXT_SUPERSET(smnpm, RISCV_ISA_EXT_SMNPM, riscv_xlinuxenvcfg_exts),
 	__RISCV_ISA_EXT_DATA(smstateen, RISCV_ISA_EXT_SMSTATEEN),
 	__RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA),
+	__RISCV_ISA_EXT_DATA(ssccfg, RISCV_ISA_EXT_SSCCFG),
 	__RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF),
 	__RISCV_ISA_EXT_DATA(sscsrind, RISCV_ISA_EXT_SSCSRIND),
 	__RISCV_ISA_EXT_SUPERSET(ssnpm, RISCV_ISA_EXT_SSNPM, riscv_xlinuxenvcfg_exts),

-- 
2.43.0

Re: [PATCH v4 09/21] RISC-V: Add Ssccfg ISA extension definition and parsing

Posted by Clément Léger 3 weeks, 4 days ago


On 06/02/2025 08:23, Atish Patra wrote:
> Ssccfg (‘Ss’ for Privileged architecture and Supervisor-level
> extension, ‘ccfg’ for Counter Configuration) provides access to
> delegated counters and new supervisor-level state.
> 
> This patch just enables the definitions and enable parsing.
> 
> Signed-off-by: Atish Patra <atishp@rivosinc.com>
> ---
>  arch/riscv/include/asm/hwcap.h | 2 ++
>  arch/riscv/kernel/cpufeature.c | 2 ++
>  2 files changed, 4 insertions(+)
> 
> diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
> index b4eddcb57842..fa5e01bcb990 100644
> --- a/arch/riscv/include/asm/hwcap.h
> +++ b/arch/riscv/include/asm/hwcap.h
> @@ -103,6 +103,8 @@
>  #define RISCV_ISA_EXT_SSCSRIND		94
>  #define RISCV_ISA_EXT_SMCSRIND		95
>  #define RISCV_ISA_EXT_SMCNTRPMF         96
> +#define RISCV_ISA_EXT_SSCCFG            97
> +#define RISCV_ISA_EXT_SMCDELEG          98
>  
>  #define RISCV_ISA_EXT_XLINUXENVCFG	127
>  
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index 8f225c9c3055..3cb208d4913e 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
> @@ -390,12 +390,14 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
>  	__RISCV_ISA_EXT_BUNDLE(zvksg, riscv_zvksg_bundled_exts),
>  	__RISCV_ISA_EXT_DATA(zvkt, RISCV_ISA_EXT_ZVKT),
>  	__RISCV_ISA_EXT_DATA(smaia, RISCV_ISA_EXT_SMAIA),
> +	__RISCV_ISA_EXT_DATA(smcdeleg, RISCV_ISA_EXT_SMCDELEG),

Hi Atish,

based on your dt-binding commit, if smcdeleg depends on Sscsrind, Zihpm,
Zicntr, then you could add a validation callback here:

static int riscv_smcdeleg_validate(const struct riscv_isa_ext_data
*data, const unsigned long *isa_bitmap)
{
	if (__riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_SSCSRIND) &&
	    __riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_ZIHPM) &&
	    __riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_ZICNTR))
		return 0;

	return -EPROBE_DEFER;
}

__RISCV_ISA_EXT_DATA_VALIDATE(smcdeleg, RISCV_ISA_EXT_SMCDELEG,
riscv_smcdeleg_validate),

>  	__RISCV_ISA_EXT_DATA(smcntrpmf, RISCV_ISA_EXT_SMCNTRPMF),
>  	__RISCV_ISA_EXT_DATA(smcsrind, RISCV_ISA_EXT_SMCSRIND),
>  	__RISCV_ISA_EXT_DATA(smmpm, RISCV_ISA_EXT_SMMPM),
>  	__RISCV_ISA_EXT_SUPERSET(smnpm, RISCV_ISA_EXT_SMNPM, riscv_xlinuxenvcfg_exts),
>  	__RISCV_ISA_EXT_DATA(smstateen, RISCV_ISA_EXT_SMSTATEEN),
>  	__RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA),
> +	__RISCV_ISA_EXT_DATA(ssccfg, RISCV_ISA_EXT_SSCCFG),

Ditto for this one with Smcdeleg, Sscsrind, Zihpm, Zicntr, Sscofpmf,
Smcntrpmf.

Thanks,

Clément

>  	__RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF),
>  	__RISCV_ISA_EXT_DATA(sscsrind, RISCV_ISA_EXT_SSCSRIND),
>  	__RISCV_ISA_EXT_SUPERSET(ssnpm, RISCV_ISA_EXT_SSNPM, riscv_xlinuxenvcfg_exts),
>

Re: [PATCH v4 09/21] RISC-V: Add Ssccfg ISA extension definition and parsing

Posted by Atish Kumar Patra 5 days, 22 hours ago

On Fri, Feb 7, 2025 at 12:13 AM Clément Léger <cleger@rivosinc.com> wrote:
>
>
>
> On 06/02/2025 08:23, Atish Patra wrote:
> > Ssccfg (‘Ss’ for Privileged architecture and Supervisor-level
> > extension, ‘ccfg’ for Counter Configuration) provides access to
> > delegated counters and new supervisor-level state.
> >
> > This patch just enables the definitions and enable parsing.
> >
> > Signed-off-by: Atish Patra <atishp@rivosinc.com>
> > ---
> >  arch/riscv/include/asm/hwcap.h | 2 ++
> >  arch/riscv/kernel/cpufeature.c | 2 ++
> >  2 files changed, 4 insertions(+)
> >
> > diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
> > index b4eddcb57842..fa5e01bcb990 100644
> > --- a/arch/riscv/include/asm/hwcap.h
> > +++ b/arch/riscv/include/asm/hwcap.h
> > @@ -103,6 +103,8 @@
> >  #define RISCV_ISA_EXT_SSCSRIND               94
> >  #define RISCV_ISA_EXT_SMCSRIND               95
> >  #define RISCV_ISA_EXT_SMCNTRPMF         96
> > +#define RISCV_ISA_EXT_SSCCFG            97
> > +#define RISCV_ISA_EXT_SMCDELEG          98
> >
> >  #define RISCV_ISA_EXT_XLINUXENVCFG   127
> >
> > diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> > index 8f225c9c3055..3cb208d4913e 100644
> > --- a/arch/riscv/kernel/cpufeature.c
> > +++ b/arch/riscv/kernel/cpufeature.c
> > @@ -390,12 +390,14 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
> >       __RISCV_ISA_EXT_BUNDLE(zvksg, riscv_zvksg_bundled_exts),
> >       __RISCV_ISA_EXT_DATA(zvkt, RISCV_ISA_EXT_ZVKT),
> >       __RISCV_ISA_EXT_DATA(smaia, RISCV_ISA_EXT_SMAIA),
> > +     __RISCV_ISA_EXT_DATA(smcdeleg, RISCV_ISA_EXT_SMCDELEG),
>
> Hi Atish,
>
> based on your dt-binding commit, if smcdeleg depends on Sscsrind, Zihpm,
> Zicntr, then you could add a validation callback here:
>

Sure.

> static int riscv_smcdeleg_validate(const struct riscv_isa_ext_data
> *data, const unsigned long *isa_bitmap)
> {
>         if (__riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_SSCSRIND) &&
>             __riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_ZIHPM) &&
>             __riscv_isa_extension_available(isa_bitmap, RISCV_ISA_EXT_ZICNTR))
>                 return 0;
>
>         return -EPROBE_DEFER;
> }
>
> __RISCV_ISA_EXT_DATA_VALIDATE(smcdeleg, RISCV_ISA_EXT_SMCDELEG,
> riscv_smcdeleg_validate),
>
> >       __RISCV_ISA_EXT_DATA(smcntrpmf, RISCV_ISA_EXT_SMCNTRPMF),
> >       __RISCV_ISA_EXT_DATA(smcsrind, RISCV_ISA_EXT_SMCSRIND),
> >       __RISCV_ISA_EXT_DATA(smmpm, RISCV_ISA_EXT_SMMPM),
> >       __RISCV_ISA_EXT_SUPERSET(smnpm, RISCV_ISA_EXT_SMNPM, riscv_xlinuxenvcfg_exts),
> >       __RISCV_ISA_EXT_DATA(smstateen, RISCV_ISA_EXT_SMSTATEEN),
> >       __RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA),
> > +     __RISCV_ISA_EXT_DATA(ssccfg, RISCV_ISA_EXT_SSCCFG),
>
> Ditto for this one with Smcdeleg, Sscsrind, Zihpm, Zicntr, Sscofpmf,
> Smcntrpmf.
>

Smcdeleg is dependent on Sscofpmf/Smcntrpmf only for some of the registers.
For example, Sscofpmf dependancy is only for sireg2 (hpmevent3h-hpmevent31h)
while Smcntrpmf is only for cyclecfg/instretcfg[1].

So we can't include those for validation but I will include other
extensions which are always required.

[1] https://github.com/riscvarchive/riscv-smcdeleg-ssccfg/blob/main/body.adoc
> Thanks,
>
> Clément
>
> >       __RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF),
> >       __RISCV_ISA_EXT_DATA(sscsrind, RISCV_ISA_EXT_SSCSRIND),
> >       __RISCV_ISA_EXT_SUPERSET(ssnpm, RISCV_ISA_EXT_SSNPM, riscv_xlinuxenvcfg_exts),
> >
>

Re: [PATCH v4 09/21] RISC-V: Add Ssccfg ISA extension definition and parsing

Posted by Clément Léger 3 weeks, 4 days ago


On 06/02/2025 08:23, Atish Patra wrote:
> Ssccfg (‘Ss’ for Privileged architecture and Supervisor-level
> extension, ‘ccfg’ for Counter Configuration) provides access to
> delegated counters and new supervisor-level state.

Hi Atish,

The spec seems to primarly use Smcdeleg rather than Ssccfg. This commits
adds both but only mention Ssccfg in the commit title/description. Maybe
it could be nice to mention both as well.

Thanks,

Clément

> 
> This patch just enables the definitions and enable parsing.
> 
> Signed-off-by: Atish Patra <atishp@rivosinc.com>
> ---
>  arch/riscv/include/asm/hwcap.h | 2 ++
>  arch/riscv/kernel/cpufeature.c | 2 ++
>  2 files changed, 4 insertions(+)
> 
> diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
> index b4eddcb57842..fa5e01bcb990 100644
> --- a/arch/riscv/include/asm/hwcap.h
> +++ b/arch/riscv/include/asm/hwcap.h
> @@ -103,6 +103,8 @@
>  #define RISCV_ISA_EXT_SSCSRIND		94
>  #define RISCV_ISA_EXT_SMCSRIND		95
>  #define RISCV_ISA_EXT_SMCNTRPMF         96
> +#define RISCV_ISA_EXT_SSCCFG            97
> +#define RISCV_ISA_EXT_SMCDELEG          98
>  
>  #define RISCV_ISA_EXT_XLINUXENVCFG	127
>  
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index 8f225c9c3055..3cb208d4913e 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
> @@ -390,12 +390,14 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
>  	__RISCV_ISA_EXT_BUNDLE(zvksg, riscv_zvksg_bundled_exts),
>  	__RISCV_ISA_EXT_DATA(zvkt, RISCV_ISA_EXT_ZVKT),
>  	__RISCV_ISA_EXT_DATA(smaia, RISCV_ISA_EXT_SMAIA),
> +	__RISCV_ISA_EXT_DATA(smcdeleg, RISCV_ISA_EXT_SMCDELEG),
>  	__RISCV_ISA_EXT_DATA(smcntrpmf, RISCV_ISA_EXT_SMCNTRPMF),
>  	__RISCV_ISA_EXT_DATA(smcsrind, RISCV_ISA_EXT_SMCSRIND),
>  	__RISCV_ISA_EXT_DATA(smmpm, RISCV_ISA_EXT_SMMPM),
>  	__RISCV_ISA_EXT_SUPERSET(smnpm, RISCV_ISA_EXT_SMNPM, riscv_xlinuxenvcfg_exts),
>  	__RISCV_ISA_EXT_DATA(smstateen, RISCV_ISA_EXT_SMSTATEEN),
>  	__RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA),
> +	__RISCV_ISA_EXT_DATA(ssccfg, RISCV_ISA_EXT_SSCCFG),
>  	__RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF),
>  	__RISCV_ISA_EXT_DATA(sscsrind, RISCV_ISA_EXT_SSCSRIND),
>  	__RISCV_ISA_EXT_SUPERSET(ssnpm, RISCV_ISA_EXT_SSNPM, riscv_xlinuxenvcfg_exts),
>