From: Aaro Koskinen <[email protected]>
Add support for warm reset using SYSTEM_RESET2 introduced in PSCI
1.1 specification.
Signed-off-by: Aaro Koskinen <[email protected]>
---
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);
+}
+
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();
}
return 0;
diff --git a/include/uapi/linux/psci.h b/include/uapi/linux/psci.h
index b3bcabe380da..f36e616c3b3f 100644
--- a/include/uapi/linux/psci.h
+++ b/include/uapi/linux/psci.h
@@ -52,6 +52,9 @@
#define PSCI_1_0_FN64_SYSTEM_SUSPEND PSCI_0_2_FN64(14)
+#define PSCI_1_1_FN_SYSTEM_RESET2 PSCI_0_2_FN(18)
+#define PSCI_1_1_FN64_SYSTEM_RESET2 PSCI_0_2_FN64(18)
+
/* PSCI v0.2 power state encoding for CPU_SUSPEND function */
#define PSCI_0_2_POWER_STATE_ID_MASK 0xffff
#define PSCI_0_2_POWER_STATE_ID_SHIFT 0
--
2.17.0
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?
>
> Signed-off-by: Aaro Koskinen <[email protected]>
> ---
> 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
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.