On Wed, Jun 20, 2018 at 11:39:38PM -0700, Christoph Hellwig wrote:
> > +ifeq ($(CONFIG_FPU),y)
> > KBUILD_AFLAGS += -march=$(KBUILD_MARCH)$(KBUILD_ARCH_A)fd$(KBUILD_ARCH_C)
> > +else
> > +KBUILD_AFLAGS += -march=$(KBUILD_MARCH)$(KBUILD_ARCH_A)$(KBUILD_ARCH_C)
> > +endif
>
> Can we refactor that KBUILD_ARCH code into something like
>
> riscv-march-y :=
> riscv-march-$(CONFIG_ARCH_RV32I) += rv32im
> riscv-march-$(CONFIG_ARCH_RV64I) += rv64im
> riscv-march-$(CONFIG_RISCV_ISA_A) += a
> riscv-march-$(CONFIG_FPU) += fd
> riscv-march-$(CONFIG_RISCV_ISA_C) += c
>
> KBUILD_CFLAGS += -march=$(riscv-march-y)
>
That's neat, sure.
> > +#ifdef CONFIG_FPU
> > regs->sstatus = SR_SPIE /* User mode, irqs on */ | SR_FS_INITIAL;
> > +#else
> > + regs->sstatus = SR_SPIE | SR_FS_OFF;
> > +#endif
>
> Having the comment in one branch, but not the other is odd. I'd be
> tempted to just remove t entirely, but if not it should be move up
> or duplicated.
>
I'll move that comment up.
> > int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
> > {
> > +#ifdef CONFIG_FPU
> > fstate_save(src, task_pt_regs(src));
> > +#endif
>
> Please provide a !CONFIG_FPU stub for fstate_save, please.
>
> > }
It's OK to do this to fstate_save/restore, and
> > +#endif
> >
> > static long restore_sigcontext(struct pt_regs *regs,
> > struct sigcontext __user *sc)
> > @@ -63,6 +65,7 @@ static long restore_sigcontext(struct pt_regs *regs,
> > err = __copy_from_user(regs, &sc->sc_regs, sizeof(sc->sc_regs));
> > if (unlikely(err))
> > return err;
> > +#ifdef CONFIG_FPU
> > /* Restore the floating-point state. */
> > err = restore_d_state(regs, &sc->sc_fpregs.d);
> > if (unlikely(err))
> > @@ -76,6 +79,7 @@ static long restore_sigcontext(struct pt_regs *regs,
> > if (value != 0)
> > return -EINVAL;
> > }
> > +#endif
>
> Same here.
>
it's also OK to do so to restore_d_state/save_d_state. But what to do with the
following __get_user/__put_user calls?
Can I rename existing restore_d_state to __restore_d_state, and create a new
function restore_d_state which includes the original restore_d_state/__get_user
pair, and the same to save_d_state?
> > @@ -127,11 +131,13 @@ static long setup_sigcontext(struct rt_sigframe
> > __user *frame,
> > size_t i;
> > /* sc_regs is structured the same as the start of pt_regs */
> > err = __copy_to_user(&sc->sc_regs, regs, sizeof(sc->sc_regs));
> > +#ifdef CONFIG_FPU
> > /* Save the floating-point state. */
> > err |= save_d_state(regs, &sc->sc_fpregs.d);
> > /* We support no other extension state at this time. */
> > for (i = 0; i < ARRAY_SIZE(sc->sc_fpregs.q.reserved); i++)
> > err |= __put_user(0, &sc->sc_fpregs.q.reserved[i]);
> > +#endif
>
> Same here.
>
Thanks,
Alan
