| Message ID | 20210301182830.478145-2-imbrenda@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | s390x: mvpg test | expand |
On 01/03/2021 19.28, Claudio Imbrenda wrote: > In most testcases, we enter problem state (userspace) just to test if a > privileged instruction causes a fault. In some cases, though, we need > to test if an instruction works properly in userspace. This means that > we do not expect a fault, and we need an orderly way to leave problem > state afterwards. > > This patch introduces a simple system based on the SVC instruction. > > Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> > Acked-by: David Hildenbrand <david@redhat.com> > Reviewed-by: Cornelia Huck <cohuck@redhat.com> > Reviewed-by: Janosch Frank <frankja@linux.ibm.com> > --- > lib/s390x/asm/arch_def.h | 7 +++++++ > lib/s390x/interrupt.c | 12 ++++++++++-- > 2 files changed, 17 insertions(+), 2 deletions(-) > > diff --git a/lib/s390x/asm/arch_def.h b/lib/s390x/asm/arch_def.h > index 9c4e330a..4cf8eb11 100644 > --- a/lib/s390x/asm/arch_def.h > +++ b/lib/s390x/asm/arch_def.h > @@ -173,6 +173,8 @@ struct cpuid { > uint64_t reserved : 15; > }; > > +#define SVC_LEAVE_PSTATE 1 > + > static inline unsigned short stap(void) > { > unsigned short cpu_address; > @@ -276,6 +278,11 @@ static inline void enter_pstate(void) > load_psw_mask(mask); > } > > +static inline void leave_pstate(void) > +{ > + asm volatile(" svc %0\n" : : "i" (SVC_LEAVE_PSTATE)); > +} > + > static inline int stsi(void *addr, int fc, int sel1, int sel2) > { > register int r0 asm("0") = (fc << 28) | sel1; > diff --git a/lib/s390x/interrupt.c b/lib/s390x/interrupt.c > index 1ce36073..d0567845 100644 > --- a/lib/s390x/interrupt.c > +++ b/lib/s390x/interrupt.c > @@ -188,6 +188,14 @@ int unregister_io_int_func(void (*f)(void)) > > void handle_svc_int(void) > { > - report_abort("Unexpected supervisor call interrupt: on cpu %d at %#lx", > - stap(), lc->svc_old_psw.addr); > + uint16_t code = lc->svc_int_code; > + > + switch (code) { > + case SVC_LEAVE_PSTATE: > + lc->svc_old_psw.mask &= ~PSW_MASK_PSTATE; > + break; > + default: > + report_abort("Unexpected supervisor call interrupt: code %#x on cpu %d at %#lx", > + code, stap(), lc->svc_old_psw.addr); > + } > } > Reviewed-by: Thomas Huth <thuth@redhat.com>
diff --git a/lib/s390x/asm/arch_def.h b/lib/s390x/asm/arch_def.h index 9c4e330a..4cf8eb11 100644 --- a/lib/s390x/asm/arch_def.h +++ b/lib/s390x/asm/arch_def.h @@ -173,6 +173,8 @@ struct cpuid { uint64_t reserved : 15; }; +#define SVC_LEAVE_PSTATE 1 + static inline unsigned short stap(void) { unsigned short cpu_address; @@ -276,6 +278,11 @@ static inline void enter_pstate(void) load_psw_mask(mask); } +static inline void leave_pstate(void) +{ + asm volatile(" svc %0\n" : : "i" (SVC_LEAVE_PSTATE)); +} + static inline int stsi(void *addr, int fc, int sel1, int sel2) { register int r0 asm("0") = (fc << 28) | sel1; diff --git a/lib/s390x/interrupt.c b/lib/s390x/interrupt.c index 1ce36073..d0567845 100644 --- a/lib/s390x/interrupt.c +++ b/lib/s390x/interrupt.c @@ -188,6 +188,14 @@ int unregister_io_int_func(void (*f)(void)) void handle_svc_int(void) { - report_abort("Unexpected supervisor call interrupt: on cpu %d at %#lx", - stap(), lc->svc_old_psw.addr); + uint16_t code = lc->svc_int_code; + + switch (code) { + case SVC_LEAVE_PSTATE: + lc->svc_old_psw.mask &= ~PSW_MASK_PSTATE; + break; + default: + report_abort("Unexpected supervisor call interrupt: code %#x on cpu %d at %#lx", + code, stap(), lc->svc_old_psw.addr); + } }