2022-04-29 10:43:12

by Stafford Horne

[permalink] [raw]
Subject: Re: [PATCH] openrisc: define nop command for simulator reboot

On Thu, Apr 28, 2022 at 01:11:39PM +0200, Jason A. Donenfeld wrote:
> The simulator defines `l.nop 1` for shutdown, but doesn't have anything
> for reboot. Use 13 for this, which is currently unused, dubbed
> `NOP_REBOOT`.
>
> Cc: Stafford Horne <[email protected]>
> Cc: Peter Maydell <[email protected]>
> Link: https://lore.kernel.org/all/[email protected]/
> Signed-off-by: Jason A. Donenfeld <[email protected]>
> ---
> arch/openrisc/kernel/process.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/openrisc/kernel/process.c b/arch/openrisc/kernel/process.c
> index 3c0c91bcdcba..4cce95fa6eb5 100644
> --- a/arch/openrisc/kernel/process.c
> +++ b/arch/openrisc/kernel/process.c
> @@ -52,6 +52,8 @@ void machine_restart(char *cmd)
> {
> do_kernel_restart(cmd);
>
> + __asm__("l.nop 13");
> +
> /* Give a grace period for failure to restart of 1s */
> mdelay(1000);
>
> --
> 2.35.1

This seems fair, probably it would be good to have a comment mentioninmg what
the nop is for, fyi for context these are the nop numbers used to control
simulations.

#define NOP_NOP 0x0000 /* Normal nop instruction */
#define NOP_EXIT 0x0001 /* End of simulation */
#define NOP_REPORT 0x0002 /* Simple report */
/*#define NOP_PRINTF 0x0003 Simprintf instruction (obsolete)*/
#define NOP_PUTC 0x0004 /* JPB: Simputc instruction */
#define NOP_CNT_RESET 0x0005 /* Reset statistics counters */
#define NOP_GET_TICKS 0x0006 /* JPB: Get # ticks running */
#define NOP_GET_PS 0x0007 /* JPB: Get picosecs/cycle */
#define NOP_TRACE_ON 0x0008 /* Turn on tracing */
#define NOP_TRACE_OFF 0x0009 /* Turn off tracing */
#define NOP_RANDOM 0x000a /* Return 4 random bytes */
#define NOP_OR1KSIM 0x000b /* Return non-zero if this is Or1ksim */
#define NOP_EXIT_SILENT 0x000c /* End of simulation, quiet version */
/* New! */
#define NOP_RESET 0x000d /* Reset the cpu */

I will queue this once we update the spec to define some of these, I am thinking
if qemu should allow for the shutdown to work in user mode.

BTW, are you working specifically on openrisc? Or just setting up test
environments for all architectures?

Acked-by: Stafford Horne <[email protected]>


2022-04-29 11:28:32

by Jason A. Donenfeld

[permalink] [raw]
Subject: Re: [PATCH] openrisc: define nop command for simulator reboot

On Thu, Apr 28, 2022 at 08:55:51PM +0900, Stafford Horne wrote:
> On Thu, Apr 28, 2022 at 01:11:39PM +0200, Jason A. Donenfeld wrote:
> > The simulator defines `l.nop 1` for shutdown, but doesn't have anything
> > for reboot. Use 13 for this, which is currently unused, dubbed
> > `NOP_REBOOT`.
> >
> > Cc: Stafford Horne <[email protected]>
> > Cc: Peter Maydell <[email protected]>
> > Link: https://lore.kernel.org/all/[email protected]/
> > Signed-off-by: Jason A. Donenfeld <[email protected]>
> > ---
> > arch/openrisc/kernel/process.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/arch/openrisc/kernel/process.c b/arch/openrisc/kernel/process.c
> > index 3c0c91bcdcba..4cce95fa6eb5 100644
> > --- a/arch/openrisc/kernel/process.c
> > +++ b/arch/openrisc/kernel/process.c
> > @@ -52,6 +52,8 @@ void machine_restart(char *cmd)
> > {
> > do_kernel_restart(cmd);
> >
> > + __asm__("l.nop 13");
> > +
> > /* Give a grace period for failure to restart of 1s */
> > mdelay(1000);
> >
> > --
> > 2.35.1
>
> This seems fair, probably it would be good to have a comment mentioninmg what
> the nop is for, fyi for context these are the nop numbers used to control
> simulations.
>
> #define NOP_NOP 0x0000 /* Normal nop instruction */
> #define NOP_EXIT 0x0001 /* End of simulation */
> #define NOP_REPORT 0x0002 /* Simple report */
> /*#define NOP_PRINTF 0x0003 Simprintf instruction (obsolete)*/
> #define NOP_PUTC 0x0004 /* JPB: Simputc instruction */
> #define NOP_CNT_RESET 0x0005 /* Reset statistics counters */
> #define NOP_GET_TICKS 0x0006 /* JPB: Get # ticks running */
> #define NOP_GET_PS 0x0007 /* JPB: Get picosecs/cycle */
> #define NOP_TRACE_ON 0x0008 /* Turn on tracing */
> #define NOP_TRACE_OFF 0x0009 /* Turn off tracing */
> #define NOP_RANDOM 0x000a /* Return 4 random bytes */
> #define NOP_OR1KSIM 0x000b /* Return non-zero if this is Or1ksim */
> #define NOP_EXIT_SILENT 0x000c /* End of simulation, quiet version */
> /* New! */
> #define NOP_RESET 0x000d /* Reset the cpu */

Right, that's where I got 13 from. By the way, the .tex file only
mentions ones up to 11, so at first I chose 12, and then saw this file.

>
> I will queue this once we update the spec to define some of these, I am thinking
> if qemu should allow for the shutdown to work in user mode.
>
> BTW, are you working specifically on openrisc? Or just setting up test
> environments for all architectures?

Trying to get OpenRISC up on https://build.wireguard.com/ . The other
architectures were simple, but OpenRISC is requiring some work...

Jason

2022-05-03 00:06:37

by Stafford Horne

[permalink] [raw]
Subject: Re: [PATCH] openrisc: define nop command for simulator reboot

On Thu, Apr 28, 2022 at 02:42:20PM +0200, Jason A. Donenfeld wrote:
> On Thu, Apr 28, 2022 at 08:55:51PM +0900, Stafford Horne wrote:
> > On Thu, Apr 28, 2022 at 01:11:39PM +0200, Jason A. Donenfeld wrote:
> > > The simulator defines `l.nop 1` for shutdown, but doesn't have anything
> > > for reboot. Use 13 for this, which is currently unused, dubbed
> > > `NOP_REBOOT`.
> > >
> > > Cc: Stafford Horne <[email protected]>
> > > Cc: Peter Maydell <[email protected]>
> > > Link: https://lore.kernel.org/all/[email protected]/
> > > Signed-off-by: Jason A. Donenfeld <[email protected]>
> > > ---
> > > arch/openrisc/kernel/process.c | 2 ++
> > > 1 file changed, 2 insertions(+)
> > >
> > > diff --git a/arch/openrisc/kernel/process.c b/arch/openrisc/kernel/process.c
> > > index 3c0c91bcdcba..4cce95fa6eb5 100644
> > > --- a/arch/openrisc/kernel/process.c
> > > +++ b/arch/openrisc/kernel/process.c
> > > @@ -52,6 +52,8 @@ void machine_restart(char *cmd)
> > > {
> > > do_kernel_restart(cmd);
> > >
> > > + __asm__("l.nop 13");
> > > +
> > > /* Give a grace period for failure to restart of 1s */
> > > mdelay(1000);
> > >
> > > --
> > > 2.35.1
> >
> > This seems fair, probably it would be good to have a comment mentioninmg what
> > the nop is for, fyi for context these are the nop numbers used to control
> > simulations.
> >
> > #define NOP_NOP 0x0000 /* Normal nop instruction */
> > #define NOP_EXIT 0x0001 /* End of simulation */
> > #define NOP_REPORT 0x0002 /* Simple report */
> > /*#define NOP_PRINTF 0x0003 Simprintf instruction (obsolete)*/
> > #define NOP_PUTC 0x0004 /* JPB: Simputc instruction */
> > #define NOP_CNT_RESET 0x0005 /* Reset statistics counters */
> > #define NOP_GET_TICKS 0x0006 /* JPB: Get # ticks running */
> > #define NOP_GET_PS 0x0007 /* JPB: Get picosecs/cycle */
> > #define NOP_TRACE_ON 0x0008 /* Turn on tracing */
> > #define NOP_TRACE_OFF 0x0009 /* Turn off tracing */
> > #define NOP_RANDOM 0x000a /* Return 4 random bytes */
> > #define NOP_OR1KSIM 0x000b /* Return non-zero if this is Or1ksim */
> > #define NOP_EXIT_SILENT 0x000c /* End of simulation, quiet version */
> > /* New! */
> > #define NOP_RESET 0x000d /* Reset the cpu */
>
> Right, that's where I got 13 from. By the way, the .tex file only
> mentions ones up to 11, so at first I chose 12, and then saw this file.

BTW, I have queued this for 5.19.

> >
> > I will queue this once we update the spec to define some of these, I am thinking
> > if qemu should allow for the shutdown to work in user mode.
> >
> > BTW, are you working specifically on openrisc? Or just setting up test
> > environments for all architectures?
>
> Trying to get OpenRISC up on https://build.wireguard.com/ . The other
> architectures were simple, but OpenRISC is requiring some work...

Thanks, any work is appreciated. Now, I am going to go and replace my openVPN
setup with wireguard.

-Stafford