2023-09-22 10:18:09

by Yong-Xuan Wang

Subject: [PATCH v2 1/3] RISC-V: Detect and Enable Svadu Extension Support

We detect Svadu extension support from DTB and add arch_has_hw_pte_young()
to enable optimization in MGLRU and __wp_page_copy_user() if Svadu
extension is available.

Co-developed-by: Jinyu Tang <[email protected]>
Signed-off-by: Jinyu Tang <[email protected]>
Signed-off-by: Yong-Xuan Wang <[email protected]>
---
arch/riscv/include/asm/csr.h | 1 +
arch/riscv/include/asm/hwcap.h | 1 +
arch/riscv/include/asm/pgtable.h | 6 ++++++
arch/riscv/kernel/cpufeature.c | 1 +
4 files changed, 9 insertions(+)

diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h
index 777cb8299551..10648b372a2a 100644
--- a/arch/riscv/include/asm/csr.h
+++ b/arch/riscv/include/asm/csr.h
@@ -194,6 +194,7 @@
/* xENVCFG flags */
#define ENVCFG_STCE (_AC(1, ULL) << 63)
#define ENVCFG_PBMTE (_AC(1, ULL) << 62)
+#define ENVCFG_HADE (_AC(1, ULL) << 61)
#define ENVCFG_CBZE (_AC(1, UL) << 7)
#define ENVCFG_CBCFE (_AC(1, UL) << 6)
#define ENVCFG_CBIE_SHIFT 4
diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
index b7b58258f6c7..1013661d6516 100644
--- a/arch/riscv/include/asm/hwcap.h
+++ b/arch/riscv/include/asm/hwcap.h
@@ -58,6 +58,7 @@
#define RISCV_ISA_EXT_ZICSR 40
#define RISCV_ISA_EXT_ZIFENCEI 41
#define RISCV_ISA_EXT_ZIHPM 42
+#define RISCV_ISA_EXT_SVADU 43

#define RISCV_ISA_EXT_MAX 64

diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index b2ba3f79cfe9..028b700cd27b 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -629,6 +629,12 @@ static inline pgprot_t pgprot_writecombine(pgprot_t _prot)
return __pgprot(prot);
}

+#define arch_has_hw_pte_young arch_has_hw_pte_young
+static inline bool arch_has_hw_pte_young(void)
+{
+ return riscv_has_extension_unlikely(RISCV_ISA_EXT_SVADU);
+}
+
/*
* THP functions
*/
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index 1cfbba65d11a..ead378c04991 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -178,6 +178,7 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
__RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA),
__RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF),
__RISCV_ISA_EXT_DATA(sstc, RISCV_ISA_EXT_SSTC),
+ __RISCV_ISA_EXT_DATA(svadu, RISCV_ISA_EXT_SVADU),
__RISCV_ISA_EXT_DATA(svinval, RISCV_ISA_EXT_SVINVAL),
__RISCV_ISA_EXT_DATA(svnapot, RISCV_ISA_EXT_SVNAPOT),
__RISCV_ISA_EXT_DATA(svpbmt, RISCV_ISA_EXT_SVPBMT),
--
2.17.1

2023-09-27 10:51:13

by Matthew Wilcox

Subject: Re: [PATCH v2 1/3] RISC-V: Detect and Enable Svadu Extension Support

On Fri, Sep 22, 2023 at 08:56:47AM +0000, Yong-Xuan Wang wrote:
> We detect Svadu extension support from DTB and add arch_has_hw_pte_young()
> to enable optimization in MGLRU and __wp_page_copy_user() if Svadu
> extension is available.

If you're going to cc people outside the RiscV space, you should probably
explain what Svadu is. To me, it sounds like a Great Old One, maybe a
friend of Cthulhu?

2023-09-27 15:24:32

by Andrew Jones

Subject: Re: [PATCH v2 1/3] RISC-V: Detect and Enable Svadu Extension Support

On Fri, Sep 22, 2023 at 08:56:47AM +0000, Yong-Xuan Wang wrote:
> We detect Svadu extension support from DTB and add arch_has_hw_pte_young()
> to enable optimization in MGLRU and __wp_page_copy_user() if Svadu
> extension is available.
>
> Co-developed-by: Jinyu Tang <[email protected]>
> Signed-off-by: Jinyu Tang <[email protected]>
> Signed-off-by: Yong-Xuan Wang <[email protected]>
> ---
> arch/riscv/include/asm/csr.h | 1 +
> arch/riscv/include/asm/hwcap.h | 1 +
> arch/riscv/include/asm/pgtable.h | 6 ++++++
> arch/riscv/kernel/cpufeature.c | 1 +
> 4 files changed, 9 insertions(+)
>
> diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h
> index 777cb8299551..10648b372a2a 100644
> --- a/arch/riscv/include/asm/csr.h
> +++ b/arch/riscv/include/asm/csr.h
> @@ -194,6 +194,7 @@
> /* xENVCFG flags */
> #define ENVCFG_STCE (_AC(1, ULL) << 63)
> #define ENVCFG_PBMTE (_AC(1, ULL) << 62)
> +#define ENVCFG_HADE (_AC(1, ULL) << 61)

This bit is named 'ADUE' in the spec. Why are we calling it HADE?

> #define ENVCFG_CBZE (_AC(1, UL) << 7)
> #define ENVCFG_CBCFE (_AC(1, UL) << 6)
> #define ENVCFG_CBIE_SHIFT 4
> diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
> index b7b58258f6c7..1013661d6516 100644
> --- a/arch/riscv/include/asm/hwcap.h
> +++ b/arch/riscv/include/asm/hwcap.h
> @@ -58,6 +58,7 @@
> #define RISCV_ISA_EXT_ZICSR 40
> #define RISCV_ISA_EXT_ZIFENCEI 41
> #define RISCV_ISA_EXT_ZIHPM 42
> +#define RISCV_ISA_EXT_SVADU 43
>
> #define RISCV_ISA_EXT_MAX 64
>
> diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> index b2ba3f79cfe9..028b700cd27b 100644
> --- a/arch/riscv/include/asm/pgtable.h
> +++ b/arch/riscv/include/asm/pgtable.h
> @@ -629,6 +629,12 @@ static inline pgprot_t pgprot_writecombine(pgprot_t _prot)
> return __pgprot(prot);
> }
>
> +#define arch_has_hw_pte_young arch_has_hw_pte_young
> +static inline bool arch_has_hw_pte_young(void)
> +{
> + return riscv_has_extension_unlikely(RISCV_ISA_EXT_SVADU);
> +}
> +
> /*
> * THP functions
> */
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index 1cfbba65d11a..ead378c04991 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
> @@ -178,6 +178,7 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
> __RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA),
> __RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF),
> __RISCV_ISA_EXT_DATA(sstc, RISCV_ISA_EXT_SSTC),
> + __RISCV_ISA_EXT_DATA(svadu, RISCV_ISA_EXT_SVADU),
> __RISCV_ISA_EXT_DATA(svinval, RISCV_ISA_EXT_SVINVAL),
> __RISCV_ISA_EXT_DATA(svnapot, RISCV_ISA_EXT_SVNAPOT),
> __RISCV_ISA_EXT_DATA(svpbmt, RISCV_ISA_EXT_SVPBMT),
> --
> 2.17.1
>

Thanks,
drew

2023-09-27 18:09:09

by Yong-Xuan Wang

Subject: Re: [PATCH v2 1/3] RISC-V: Detect and Enable Svadu Extension Support

Hi drew,

On Wed, Sep 27, 2023 at 3:03 PM Andrew Jones <[email protected]> wrote:
>
> On Fri, Sep 22, 2023 at 08:56:47AM +0000, Yong-Xuan Wang wrote:
> > We detect Svadu extension support from DTB and add arch_has_hw_pte_young()
> > to enable optimization in MGLRU and __wp_page_copy_user() if Svadu
> > extension is available.
> >
> > Co-developed-by: Jinyu Tang <[email protected]>
> > Signed-off-by: Jinyu Tang <[email protected]>
> > Signed-off-by: Yong-Xuan Wang <[email protected]>
> > ---
> > arch/riscv/include/asm/csr.h | 1 +
> > arch/riscv/include/asm/hwcap.h | 1 +
> > arch/riscv/include/asm/pgtable.h | 6 ++++++
> > arch/riscv/kernel/cpufeature.c | 1 +
> > 4 files changed, 9 insertions(+)
> >
> > diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h
> > index 777cb8299551..10648b372a2a 100644
> > --- a/arch/riscv/include/asm/csr.h
> > +++ b/arch/riscv/include/asm/csr.h
> > @@ -194,6 +194,7 @@
> > /* xENVCFG flags */
> > #define ENVCFG_STCE (_AC(1, ULL) << 63)
> > #define ENVCFG_PBMTE (_AC(1, ULL) << 62)
> > +#define ENVCFG_HADE (_AC(1, ULL) << 61)
>
> This bit is named 'ADUE' in the spec. Why are we calling it HADE?

This bit was called HADE in v0.1 spec. I will update it to ADUE in
patch v3. Thank you!

Regards,
Yong-Xuan


>
> > #define ENVCFG_CBZE (_AC(1, UL) << 7)
> > #define ENVCFG_CBCFE (_AC(1, UL) << 6)
> > #define ENVCFG_CBIE_SHIFT 4
> > diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h
> > index b7b58258f6c7..1013661d6516 100644
> > --- a/arch/riscv/include/asm/hwcap.h
> > +++ b/arch/riscv/include/asm/hwcap.h
> > @@ -58,6 +58,7 @@
> > #define RISCV_ISA_EXT_ZICSR 40
> > #define RISCV_ISA_EXT_ZIFENCEI 41
> > #define RISCV_ISA_EXT_ZIHPM 42
> > +#define RISCV_ISA_EXT_SVADU 43
> >
> > #define RISCV_ISA_EXT_MAX 64
> >
> > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> > index b2ba3f79cfe9..028b700cd27b 100644
> > --- a/arch/riscv/include/asm/pgtable.h
> > +++ b/arch/riscv/include/asm/pgtable.h
> > @@ -629,6 +629,12 @@ static inline pgprot_t pgprot_writecombine(pgprot_t _prot)
> > return __pgprot(prot);
> > }
> >
> > +#define arch_has_hw_pte_young arch_has_hw_pte_young
> > +static inline bool arch_has_hw_pte_young(void)
> > +{
> > + return riscv_has_extension_unlikely(RISCV_ISA_EXT_SVADU);
> > +}
> > +
> > /*
> > * THP functions
> > */
> > diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> > index 1cfbba65d11a..ead378c04991 100644
> > --- a/arch/riscv/kernel/cpufeature.c
> > +++ b/arch/riscv/kernel/cpufeature.c
> > @@ -178,6 +178,7 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = {
> > __RISCV_ISA_EXT_DATA(ssaia, RISCV_ISA_EXT_SSAIA),
> > __RISCV_ISA_EXT_DATA(sscofpmf, RISCV_ISA_EXT_SSCOFPMF),
> > __RISCV_ISA_EXT_DATA(sstc, RISCV_ISA_EXT_SSTC),
> > + __RISCV_ISA_EXT_DATA(svadu, RISCV_ISA_EXT_SVADU),
> > __RISCV_ISA_EXT_DATA(svinval, RISCV_ISA_EXT_SVINVAL),
> > __RISCV_ISA_EXT_DATA(svnapot, RISCV_ISA_EXT_SVNAPOT),
> > __RISCV_ISA_EXT_DATA(svpbmt, RISCV_ISA_EXT_SVPBMT),
> > --
> > 2.17.1
> >
>
> Thanks,
> drew