On Wed, Nov 17, 2021 at 10:42 AM LIU Zhiwei <zhiwei_...@c-sky.com> wrote:
>
> 0
>
> On 2021/11/17 上午8:03, Alistair Francis wrote:
> > On Wed, Nov 17, 2021 at 1:12 AM LIU Zhiwei <zhiwei_...@c-sky.com> wrote:
> >> If PMP rules number is zero, it should not influence the TLB entry for
> >> M-mode program.
> > This doesn't sound right. From what I can tell if we have no rules
> > pmp_is_range_in_tlb() shouldn't have an effect on the tlb_size. What
> > error are you seeing?
>
> When address is in [0-4K] and no pmp rule configured, the tlb_size will
> be set to 1.
>
> This is caused by pmp_get_tlb_size return a value 1.
>
> if (pmp_sa >= tlb_sa && pmp_ea <= tlb_ea) {
> return pmp_ea - pmp_sa + 1;
>
> }
>
> Here pmp_sa == 0 and pmp_ea == 0.
Ah ok. Do you mind adding that to the commit message.
Also, do you think it would be better to add the check to
pmp_is_range_in_tlb() instead?
Alistair
>
> Thanks,
> Zhiwei
>
> > Alistair
> >
> >> Signed-off-by: LIU Zhiwei <zhiwei_...@c-sky.com>
> >> ---
> >> target/riscv/cpu_helper.c | 2 +-
> >> 1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
> >> index 9eeed38c7e..48da872d39 100644
> >> --- a/target/riscv/cpu_helper.c
> >> +++ b/target/riscv/cpu_helper.c
> >> @@ -376,7 +376,7 @@ static int get_physical_address_pmp(CPURISCVState
> >> *env, int *prot,
> >> }
> >>
> >> *prot = pmp_priv_to_page_prot(pmp_priv);
> >> - if (tlb_size != NULL) {
> >> + if ((tlb_size != NULL) && pmp_get_num_rules(env)) {
> >> if (pmp_is_range_in_tlb(env, addr & ~(*tlb_size - 1),
> >> &tlb_size_pmp)) {
> >> *tlb_size = tlb_size_pmp;
> >> }
> >> --
> >> 2.25.1
> >>
> >>
