[PATCH] lib: sbi: sbi_ecall: Improve return SBI error

[Anup Patel]

On Tue, Feb 21, 2023 at 10:51 PM Andrew Jones <ajones at ventanamicro.com> wrote:
>
> On Tue, Feb 21, 2023 at 06:47:56PM +0800, Yu Chien Peter Lin wrote:
> > We should also check if the return error code is greater than 0
> > (SBI_SUCCESS), as this is an invalid error.
> >
> > Also rename the variable returned via a0 to 'out_err' and use
> > SBI_ERR_NOT_SUPPORTED when the extension does not have a handler
> > for consistency with the standard SBI errors defined in Table 1
> > of the SBI specification.
>
> It's best to do renames separate from functional changes, and, in
> this case, the ret -> out_err rename feels like unnecessary churn.

Maybe we can do something similar to KVM RISC-V ?

Regards,
Anup

>
> Thanks,
> drew
>
> >
> > Signed-off-by: Yu Chien Peter Lin <peterlin at andestech.com>
> > ---
> >  lib/sbi/sbi_ecall.c | 18 +++++++++---------
> >  1 file changed, 9 insertions(+), 9 deletions(-)
> >
> > diff --git a/lib/sbi/sbi_ecall.c b/lib/sbi/sbi_ecall.c
> > index 27ce5d49..8accf675 100644
> > --- a/lib/sbi/sbi_ecall.c
> > +++ b/lib/sbi/sbi_ecall.c
> > @@ -97,34 +97,34 @@ void sbi_ecall_unregister_extension(struct sbi_ecall_extension *ext)
> >
> >  int sbi_ecall_handler(struct sbi_trap_regs *regs)
> >  {
> > -     int ret = 0;
> > +     int out_err = 0;
> > +     unsigned long out_val = 0;
> >       struct sbi_ecall_extension *ext;
> >       unsigned long extension_id = regs->a7;
> >       unsigned long func_id = regs->a6;
> >       struct sbi_trap_info trap = {0};
> > -     unsigned long out_val = 0;
> >       bool is_0_1_spec = 0;
> >
> >       ext = sbi_ecall_find_extension(extension_id);
> >       if (ext && ext->handle) {
> > -             ret = ext->handle(extension_id, func_id,
> > +             out_err = ext->handle(extension_id, func_id,
> >                                 regs, &out_val, &trap);
> >               if (extension_id >= SBI_EXT_0_1_SET_TIMER &&
> >                   extension_id <= SBI_EXT_0_1_SHUTDOWN)
> >                       is_0_1_spec = 1;
> >       } else {
> > -             ret = SBI_ENOTSUPP;
> > +             out_err = SBI_ERR_NOT_SUPPORTED;
> >       }
> >
> > -     if (ret == SBI_ETRAP) {
> > +     if (out_err == SBI_ETRAP) {
> >               trap.epc = regs->mepc;
> >               sbi_trap_redirect(regs, &trap);
> >       } else {
> > -             if (ret < SBI_LAST_ERR) {
> > +             if (out_err < SBI_LAST_ERR || SBI_SUCCESS < out_err) {
> >                       sbi_printf("%s: Invalid error %d for ext=0x%lx "
> > -                                "func=0x%lx\n", __func__, ret,
> > +                                "func=0x%lx\n", __func__, out_err,
> >                                  extension_id, func_id);
> > -                     ret = SBI_ERR_FAILED;
> > +                     out_err = SBI_ERR_FAILED;
> >               }
> >
> >               /*
> > @@ -136,7 +136,7 @@ int sbi_ecall_handler(struct sbi_trap_regs *regs)
> >                * case should be handled differently.
> >                */
> >               regs->mepc += 4;
> > -             regs->a0 = ret;
> > +             regs->a0 = out_err;
> >               if (!is_0_1_spec)
> >                       regs->a1 = out_val;
> >       }
> > --
> > 2.34.1
> >
> >
> > --
> > opensbi mailing list
> > opensbi at lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/opensbi
>
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