Message ID | 20190515013725.2198-1-shawn@git.icu (mailing list archive) |
---|---|
State | Superseded |
Headers | show |
Series | [v4,1/2,PowerPC] Add simd.h implementation | expand |
Context | Check | Description |
---|---|---|
snowpatch_ozlabs/apply_patch | success | Successfully applied on branch next (8150a153c013aa2dd1ffae43370b89ac1347a7fb) |
snowpatch_ozlabs/checkpatch | warning | total: 0 errors, 0 warnings, 1 checks, 53 lines checked |
Le 15/05/2019 à 03:37, Shawn Landden a écrit : > Based off the x86 one. > > WireGuard really wants to be able to do SIMD in interrupts, > so it can accelerate its in-bound path. > > Signed-off-by: Shawn Landden <shawn@git.icu> > --- Could you please as usual list here the changes provided by each version to ease the review ? Thanks Christophe > arch/powerpc/include/asm/simd.h | 17 +++++++++++++++++ > arch/powerpc/kernel/process.c | 30 ++++++++++++++++++++++++++++++ > 2 files changed, 47 insertions(+) > create mode 100644 arch/powerpc/include/asm/simd.h > > diff --git a/arch/powerpc/include/asm/simd.h b/arch/powerpc/include/asm/simd.h > new file mode 100644 > index 000000000..2fe26f258 > --- /dev/null > +++ b/arch/powerpc/include/asm/simd.h > @@ -0,0 +1,17 @@ > +/* SPDX-License-Identifier: GPL-2.0+ */ > + > +/* > + * may_use_simd - whether it is allowable at this time to issue SIMD > + * instructions or access the SIMD register file > + * > + * It's always ok in process context (ie "not interrupt") > + * but it is sometimes ok even from an irq. > + */ > +#ifdef CONFIG_PPC_FPU > +extern bool may_use_simd(void); > +#else > +static inline bool may_use_simd(void) > +{ > + return false; > +} > +#endif > diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c > index dd9e0d538..ef534831f 100644 > --- a/arch/powerpc/kernel/process.c > +++ b/arch/powerpc/kernel/process.c > @@ -345,6 +345,36 @@ static int restore_altivec(struct task_struct *tsk) > } > return 0; > } > + > +/* > + * Were we in user mode when we were > + * interrupted? > + * > + * Doing kernel_altivec/vsx_begin/end() is ok if we are running > + * in an interrupt context from user mode - we'll just > + * save the FPU state as required. > + */ > +static bool interrupted_user_mode(void) > +{ > + struct pt_regs *regs = get_irq_regs(); > + > + return regs && user_mode(regs); > +} > + > +/* > + * Can we use FPU in kernel mode with the > + * whole "kernel_fpu/altivec/vsx_begin/end()" sequence? > + * > + * It's always ok in process context (ie "not interrupt") > + * but it is sometimes ok even from an irq. > + */ > +bool may_use_simd(void) > +{ > + return !in_interrupt() || > + interrupted_user_mode(); > +} > +EXPORT_SYMBOL(may_use_simd); > + > #else > #define loadvec(thr) 0 > static inline int restore_altivec(struct task_struct *tsk) { return 0; } >
On Wed, May 15, 2019 at 1:27 AM Christophe Leroy <christophe.leroy@c-s.fr> wrote: > Could you please as usual list here the changes provided by each version > to ease the review ? A bunch of embarrassing stuff that caused it not to build on some set-ups (the functions were under the wrong include guards), and I added include guards on simd.h so that you can use may_use_simd() even if you don't have the FPU enabled (ARM's simd.h does this).
diff --git a/arch/powerpc/include/asm/simd.h b/arch/powerpc/include/asm/simd.h new file mode 100644 index 000000000..2fe26f258 --- /dev/null +++ b/arch/powerpc/include/asm/simd.h @@ -0,0 +1,17 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ + +/* + * may_use_simd - whether it is allowable at this time to issue SIMD + * instructions or access the SIMD register file + * + * It's always ok in process context (ie "not interrupt") + * but it is sometimes ok even from an irq. + */ +#ifdef CONFIG_PPC_FPU +extern bool may_use_simd(void); +#else +static inline bool may_use_simd(void) +{ + return false; +} +#endif diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index dd9e0d538..ef534831f 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -345,6 +345,36 @@ static int restore_altivec(struct task_struct *tsk) } return 0; } + +/* + * Were we in user mode when we were + * interrupted? + * + * Doing kernel_altivec/vsx_begin/end() is ok if we are running + * in an interrupt context from user mode - we'll just + * save the FPU state as required. + */ +static bool interrupted_user_mode(void) +{ + struct pt_regs *regs = get_irq_regs(); + + return regs && user_mode(regs); +} + +/* + * Can we use FPU in kernel mode with the + * whole "kernel_fpu/altivec/vsx_begin/end()" sequence? + * + * It's always ok in process context (ie "not interrupt") + * but it is sometimes ok even from an irq. + */ +bool may_use_simd(void) +{ + return !in_interrupt() || + interrupted_user_mode(); +} +EXPORT_SYMBOL(may_use_simd); + #else #define loadvec(thr) 0 static inline int restore_altivec(struct task_struct *tsk) { return 0; }
Based off the x86 one. WireGuard really wants to be able to do SIMD in interrupts, so it can accelerate its in-bound path. Signed-off-by: Shawn Landden <shawn@git.icu> --- arch/powerpc/include/asm/simd.h | 17 +++++++++++++++++ arch/powerpc/kernel/process.c | 30 ++++++++++++++++++++++++++++++ 2 files changed, 47 insertions(+) create mode 100644 arch/powerpc/include/asm/simd.h