Hi,
On Wed, Apr 03, 2019 at 04:33:15AM +0100, Mark Rutland wrote:
> On Mon, Apr 01, 2019 at 09:14:43PM +0300, Aaro Koskinen wrote:
> > From: Aaro Koskinen <[email protected]>
> >
> > Add support for warm reset using SYSTEM_RESET2 introduced in PSCI
> > 1.1 specification.
>
> For reference, how do you intend to use this?
The reboot mode is set using the kernel command line. One use case for warm
reset is pstore/ramoops.
> > @@ -256,6 +257,14 @@ static void psci_sys_reset(enum reboot_mode
> > reboot_mode, const char *cmd)
> > invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
> > }
> >
> > +static void psci_sys_reset2(enum reboot_mode reboot_mode, const char *cmd)
> > +{
> > + if (reboot_mode == REBOOT_WARM)
> > + invoke_psci_fn(psci_function_id[PSCI_FN_SYSTEM_RESET2], 0, 0,
> > 0);
> > + else
> > + psci_sys_reset(reboot_mode, cmd);
> > +}
>
> What happens when RESET2 isn't available, but the user requests s REBOOT_WARM
> reset? It looks like we'd invoke a bogus SMC.
This function is only called through arm_pm_restart. If the feature is
not available, then arm_pm_restart points to the default psci_sys_reset.
> Could we please add a preprocessor definition for SYSTEM_RESET_WARM so that
> it's clear that we're passing a parameter here?
OK, will add.
> > /*
> > * Probe function for PSCI firmware versions >= 0.2
> > */
> > @@ -588,6 +611,8 @@ static int __init psci_probe(void)
> > psci_init_smccc();
> > psci_init_cpu_suspend();
> > psci_init_system_suspend();
> > + if (PSCI_VERSION_MINOR(ver) >= 1)
> > + psci_1_1_set_functions();
> > }
>
> If we're going to add more things to this chain, can we please refactor this
> as:
>
> if (ver < PSCI_VERSION(1, 0))
> return;
>
> /* PSCI 1.0 setup here */
>
> if (ver < PSCI_VERSION(1,1))
> return;
>
> /* PSCI 1.1 setup here */
>
> ... as that saves on indentation and is easier to extend in future.
OK, makes sense, I will do that.
Thanks,
A.
