| Message ID | 4446ff53a13d4feca0d17f84efd06b22@MSX-L201.msx.ad.zih.tu-dresden.de |
|---|---|
| State | Accepted |
| Headers | show |
| Series | lib: sbi_trap: Fix hstatus.SPVP update in sbi_trap_redirect() | expand |
> -----Original Message----- > From: opensbi <opensbi-bounces@lists.infradead.org> On Behalf Of Georg > Kotheimer > Sent: 15 August 2020 02:31 > To: opensbi@lists.infradead.org > Cc: Georg Kotheimer <georg.kotheimer@tu-dresden.de> > Subject: [PATCH] lib: sbi_trap: Fix hstatus.SPVP update in sbi_trap_redirect() > > When redirecting from VS/VU-mode to HS-mode, hstatus.SPVP was set to > the value of mstatus.SPP, as according to the specification both flags should > be set to the same value. > However, the assignment of SPVP takes place before SPP itself is updated, > which results in SPVP having an outdated value. > > Signed-off-by: Georg Kotheimer <georg.kotheimer@tu-dresden.de> > --- > lib/sbi/sbi_trap.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/lib/sbi/sbi_trap.c b/lib/sbi/sbi_trap.c index 930119d..c2bd061 > 100644 > --- a/lib/sbi/sbi_trap.c > +++ b/lib/sbi/sbi_trap.c > @@ -123,7 +123,7 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs, > /* Update HSTATUS SPVP and SPV bits */ > hstatus = csr_read(CSR_HSTATUS); > hstatus &= ~HSTATUS_SPVP; > - hstatus |= (regs->mstatus & MSTATUS_SPP) ? > HSTATUS_SPVP : 0; > + hstatus |= (prev_mode == PRV_S) ? HSTATUS_SPVP : 0; > hstatus &= ~HSTATUS_SPV; > hstatus |= (prev_virt) ? HSTATUS_SPV : 0; > csr_write(CSR_HSTATUS, hstatus); > -- > 2.25.1 > > > -- > opensbi mailing list > opensbi@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/opensbi Nice catch. Looks good to me. Reviewed-by: Anup Patel <anup.patel@wdc.com> Regards, Anup
> -----Original Message----- > From: Anup Patel > Sent: 15 August 2020 22:38 > To: Georg Kotheimer <georg.kotheimer@tu-dresden.de>; > opensbi@lists.infradead.org > Subject: RE: [PATCH] lib: sbi_trap: Fix hstatus.SPVP update in > sbi_trap_redirect() > > > > > -----Original Message----- > > From: opensbi <opensbi-bounces@lists.infradead.org> On Behalf Of Georg > > Kotheimer > > Sent: 15 August 2020 02:31 > > To: opensbi@lists.infradead.org > > Cc: Georg Kotheimer <georg.kotheimer@tu-dresden.de> > > Subject: [PATCH] lib: sbi_trap: Fix hstatus.SPVP update in > > sbi_trap_redirect() > > > > When redirecting from VS/VU-mode to HS-mode, hstatus.SPVP was set to > > the value of mstatus.SPP, as according to the specification both flags > > should be set to the same value. > > However, the assignment of SPVP takes place before SPP itself is > > updated, which results in SPVP having an outdated value. > > > > Signed-off-by: Georg Kotheimer <georg.kotheimer@tu-dresden.de> > > --- > > lib/sbi/sbi_trap.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/lib/sbi/sbi_trap.c b/lib/sbi/sbi_trap.c index > > 930119d..c2bd061 > > 100644 > > --- a/lib/sbi/sbi_trap.c > > +++ b/lib/sbi/sbi_trap.c > > @@ -123,7 +123,7 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs, > > /* Update HSTATUS SPVP and SPV bits */ > > hstatus = csr_read(CSR_HSTATUS); > > hstatus &= ~HSTATUS_SPVP; > > - hstatus |= (regs->mstatus & MSTATUS_SPP) ? > > HSTATUS_SPVP : 0; > > + hstatus |= (prev_mode == PRV_S) ? HSTATUS_SPVP : 0; > > hstatus &= ~HSTATUS_SPV; > > hstatus |= (prev_virt) ? HSTATUS_SPV : 0; > > csr_write(CSR_HSTATUS, hstatus); > > -- > > 2.25.1 > > > > > > -- > > opensbi mailing list > > opensbi@lists.infradead.org > > http://lists.infradead.org/mailman/listinfo/opensbi > > Nice catch. Looks good to me. > > Reviewed-by: Anup Patel <anup.patel@wdc.com> Applied this patch to the riscv/opensbi repo. Thanks, Anup
diff --git a/lib/sbi/sbi_trap.c b/lib/sbi/sbi_trap.c index 930119d..c2bd061 100644 --- a/lib/sbi/sbi_trap.c +++ b/lib/sbi/sbi_trap.c @@ -123,7 +123,7 @@ int sbi_trap_redirect(struct sbi_trap_regs *regs, /* Update HSTATUS SPVP and SPV bits */ hstatus = csr_read(CSR_HSTATUS); hstatus &= ~HSTATUS_SPVP; - hstatus |= (regs->mstatus & MSTATUS_SPP) ? HSTATUS_SPVP : 0; + hstatus |= (prev_mode == PRV_S) ? HSTATUS_SPVP : 0; hstatus &= ~HSTATUS_SPV; hstatus |= (prev_virt) ? HSTATUS_SPV : 0; csr_write(CSR_HSTATUS, hstatus);
When redirecting from VS/VU-mode to HS-mode, hstatus.SPVP was set to the value of mstatus.SPP, as according to the specification both flags should be set to the same value. However, the assignment of SPVP takes place before SPP itself is updated, which results in SPVP having an outdated value. Signed-off-by: Georg Kotheimer <georg.kotheimer@tu-dresden.de> --- lib/sbi/sbi_trap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)