[PATCH Zisslpcfi 2/2] lib: sbi: zsslpcfi detection and elp cfi state reflect back in status

[Deepak Gupta]

On Wed, Dec 21, 2022 at 5:43 AM Bin Meng <bmeng.cn at gmail.com> wrote:
>
> > @@ -87,6 +87,7 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs,
> >                       struct sbi_trap_info *trap)
> >  {
> >         ulong hstatus, vsstatus, prev_mode;
> > +       bool elp = FALSE;
>
> s/FALSE/false

I followed whatever rest of the code is following. In the same function

"
int sbi_trap_redirect(struct sbi_trap_regs *regs,
                      struct sbi_trap_info *trap)
{
        ulong hstatus, vsstatus, prev_mode;
        bool elp = FALSE;
#if __riscv_xlen == 32
        bool prev_virt = (regs->mstatusH & MSTATUSH_MPV) ? TRUE : FALSE;
#else
        bool prev_virt = (regs->mstatus & MSTATUS_MPV) ? TRUE : FALSE;
#endif
        /* By default, we redirect to HS-mode */
        bool next_virt = FALSE;
"
I can change it to false but it'll look ugly because at other places
we're using upper case FALSE.
Let me know what needs to be done.

>
> >  #if __riscv_xlen == 32
> >         bool prev_virt = (regs->mstatusH & MSTATUSH_MPV) ? TRUE : FALSE;
> >  #else
> > @@ -100,6 +101,13 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs,
> >         if (prev_mode != PRV_S && prev_mode != PRV_U)
> >                 return SBI_ENOTSUPP;
> >
> > +       /* If extension has support for CFI, clear MPELP because redirecting to VS or (H)S */
> > +       if (sbi_hart_has_extension(sbi_scratch_thishart_ptr(), SBI_HART_EXT_SSLPCFI)) {
> > +               elp = (regs->mstatus & MSTATUS_MPELP)? TRUE: FALSE;
> > +               /* Since redirecting, clear mpelp unconditionally */
> > +               regs->mstatus &= ~MSTATUS_MPELP;
> > +       }
> > +
> >         /* If exceptions came from VS/VU-mode, redirect to VS-mode if
> >          * delegated in hedeleg
> >          */
> > @@ -153,6 +161,11 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs,
> >                 /* Get VS-mode SSTATUS CSR */
> >                 vsstatus = csr_read(CSR_VSSTATUS);
> >
> > +               /*if elp was set, set it back in vsstatus */
>
> need space after /*
>
> > +               if (elp) {
> > +                       vsstatus |= MSTATUS_SPELP;
> > +               }
> > +
> >                 /* Set SPP for VS-mode */
> >                 vsstatus &= ~SSTATUS_SPP;
> >                 if (prev_mode == PRV_S)
> > @@ -193,6 +206,11 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs,
> >
> >                 /* Clear SIE for S-mode */
> >                 regs->mstatus &= ~MSTATUS_SIE;
> > +
> > +               /* if elp was set, set it back in mstatus */
> > +               if (elp) {
> > +                       regs->mstatus |= MSTATUS_SPELP;
> > +               }
> >         }
> >
>
> Regards,
> Bin