Messages in this thread | | | Date | Wed, 3 Apr 2019 04:33:15 +0100 | From | Mark Rutland <> | Subject | Re: [PATCH] drivers: firmware: psci: add support for warm reset |
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On Mon, Apr 01, 2019 at 09:14:43PM +0300, Aaro Koskinen wrote: > From: Aaro Koskinen <aaro.koskinen@nokia.com> > > Add support for warm reset using SYSTEM_RESET2 introduced in PSCI > 1.1 specification.
For reference, how do you intend to use this?
> > Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com> > --- > drivers/firmware/psci.c | 25 +++++++++++++++++++++++++ > include/uapi/linux/psci.h | 3 +++ > 2 files changed, 28 insertions(+) > > diff --git a/drivers/firmware/psci.c b/drivers/firmware/psci.c > index c80ec1d03274..1d95b5f6d403 100644 > --- a/drivers/firmware/psci.c > +++ b/drivers/firmware/psci.c > @@ -73,6 +73,7 @@ enum psci_function { > PSCI_FN_CPU_ON, > PSCI_FN_CPU_OFF, > PSCI_FN_MIGRATE, > + PSCI_FN_SYSTEM_RESET2, > PSCI_FN_MAX, > }; > > @@ -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.
Could we please add a preprocessor definition for SYSTEM_RESET_WARM so that it's clear that we're passing a parameter here?
> + > static void psci_sys_poweroff(void) > { > invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0); > @@ -564,6 +573,20 @@ static void __init psci_0_2_set_functions(void) > pm_power_off = psci_sys_poweroff; > } > > +static void __init psci_1_1_set_functions(void) > +{ > + int sys_reset2; > + int feature; > + > + sys_reset2 = PSCI_FN_NATIVE(1_1, SYSTEM_RESET2); > + feature = psci_features(sys_reset2); > + > + if (feature != PSCI_RET_NOT_SUPPORTED) { > + psci_function_id[PSCI_FN_SYSTEM_RESET2] = sys_reset2; > + arm_pm_restart = psci_sys_reset2; > + } > +} > + > /* > * 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.
Thanks, Mark
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