Re: [Qemu-riscv] [PATCH] riscv: sifive_test: Add reset functionality

[Bin Meng]

On Tue, Jul 30, 2019 at 3:47 AM Palmer Dabbelt <address@hidden> wrote:
>
> On Mon, 22 Jul 2019 22:30:15 PDT (-0700), address@hidden wrote:
> > Hi Palmer,
> >
> > On Sat, Jul 20, 2019 at 9:47 AM Palmer Dabbelt <address@hidden> wrote:
> >>
> >> On Fri, 14 Jun 2019 08:15:51 PDT (-0700), address@hidden wrote:
> >> > This adds a reset opcode for sifive_test device to trigger a system
> >> > reset for testing purpose.
> >> >
> >> > Signed-off-by: Bin Meng <address@hidden>
> >> > ---
> >> >
> >> >  hw/riscv/sifive_test.c         | 4 ++++
> >> >  include/hw/riscv/sifive_test.h | 3 ++-
> >> >  2 files changed, 6 insertions(+), 1 deletion(-)
> >> >
> >> > diff --git a/hw/riscv/sifive_test.c b/hw/riscv/sifive_test.c
> >> > index 24a04d7..cd86831 100644
> >> > --- a/hw/riscv/sifive_test.c
> >> > +++ b/hw/riscv/sifive_test.c
> >> > @@ -21,6 +21,7 @@
> >> >  #include "qemu/osdep.h"
> >> >  #include "hw/sysbus.h"
> >> >  #include "qemu/module.h"
> >> > +#include "sysemu/sysemu.h"
> >> >  #include "target/riscv/cpu.h"
> >> >  #include "hw/riscv/sifive_test.h"
> >> >
> >> > @@ -40,6 +41,9 @@ static void sifive_test_write(void *opaque, hwaddr 
> >> > addr,
> >> >              exit(code);
> >> >          case FINISHER_PASS:
> >> >              exit(0);
> >> > +        case FINISHER_RESET:
> >> > +            qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
> >> > +            return;
> >> >          default:
> >> >              break;
> >> >          }
> >> > diff --git a/include/hw/riscv/sifive_test.h 
> >> > b/include/hw/riscv/sifive_test.h
> >> > index 71d4c9f..c186a31 100644
> >> > --- a/include/hw/riscv/sifive_test.h
> >> > +++ b/include/hw/riscv/sifive_test.h
> >> > @@ -34,7 +34,8 @@ typedef struct SiFiveTestState {
> >> >
> >> >  enum {
> >> >      FINISHER_FAIL = 0x3333,
> >> > -    FINISHER_PASS = 0x5555
> >> > +    FINISHER_PASS = 0x5555,
> >> > +    FINISHER_RESET = 0x7777
> >> >  };
> >> >
> >> >  DeviceState *sifive_test_create(hwaddr addr);
> >>
> >> Reviewed-by: Palmer Dabbelt <address@hidden>
> >
> > Thanks a lot!
> >
> >> Sorry this took a while, but it's in the hardware now.  I'll merge this, 
> >> but
> >> I'm considering it a new feature so it'll be held off a bit.
> >
> > "but it's in the hardware now", do you mean the code I added (0x7777)
> > is now supported by a newer version SiFive test device with compatible
> > string "sifive,test1", and can actually do the system wide reset?
>
> No, the hardware is still a "sifive,test0" as plumbing through the reset is
> trickier than I wanted to take on.  I just reserved the 0x7777 code and
> implemented it by triggering an unsupported function error, so we don't
> accidentally use it for something else later.

OK, thanks for the clarifications!

Regards,
Bin