On Mon, Feb 24, 2020 at 12:57:37PM -0800, Elliot Berman wrote:
> Some implementors of PSCI may relax the requirements of the PSCI
> architectural warm reset. In order to comply with PSCI specification, a
> different reset_type value must be used. The alternate PSCI
> SYSTEM_RESET2 may be used in all warm/soft reboot scenarios, replacing
> the architectural warm reset.
As with the binding patch, this sounds like a workaround for a firmware
bug. Can you please elaborate on what exactly your firmware does in this
case?
Thanks,
Mark.
>
> Signed-off-by: Elliot Berman <eberman@xxxxxxxxxxxxxx>
> ---
> drivers/firmware/psci/psci.c | 22 ++++++++++++++++++----
> include/uapi/linux/psci.h | 2 ++
> 2 files changed, 20 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
> index 2937d44..8f4609c 100644
> --- a/drivers/firmware/psci/psci.c
> +++ b/drivers/firmware/psci/psci.c
> @@ -90,6 +90,8 @@ static u32 psci_function_id[PSCI_FN_MAX];
>
> static u32 psci_cpu_suspend_feature;
> static bool psci_system_reset2_supported;
> +static u32 psci_sys_reset2_reset_param =
> + PSCI_1_1_SYSTEM_RESET2_SYSTEM_WARM_RESET;
>
> static inline bool psci_has_ext_power_state(void)
> {
> @@ -272,11 +274,10 @@ static void psci_sys_reset(enum reboot_mode reboot_mode, const char *cmd)
> if ((reboot_mode == REBOOT_WARM || reboot_mode == REBOOT_SOFT) &&
> psci_system_reset2_supported) {
> /*
> - * reset_type[31] = 0 (architectural)
> - * reset_type[30:0] = 0 (SYSTEM_WARM_RESET)
> * cookie = 0 (ignored by the implementation)
> */
> - invoke_psci_fn(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2), 0, 0, 0);
> + invoke_psci_fn(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2),
> + psci_sys_reset2_reset_param, 0, 0);
> } else {
> invoke_psci_fn(PSCI_0_2_FN_SYSTEM_RESET, 0, 0, 0);
> }
> @@ -493,6 +494,7 @@ typedef int (*psci_initcall_t)(const struct device_node *);
> static int __init psci_0_2_init(struct device_node *np)
> {
> int err;
> + u32 param;
>
> err = get_set_conduit_method(np);
> if (err)
> @@ -505,7 +507,19 @@ static int __init psci_0_2_init(struct device_node *np)
> * can be carried out according to the specific version reported
> * by firmware
> */
> - return psci_probe();
> + err = psci_probe();
> + if (err)
> + return err;
> +
> + if (psci_system_reset2_supported &&
> + !of_property_read_u32(np, "arm,psci-sys-reset2-param", ¶m)) {
> + if ((s32)param > 0)
> + pr_warn("%08x is an invalid architectural reset type.\n",
> + param);
> + psci_sys_reset2_reset_param = param;
> + }
> +
> + return 0;
> }
>
> /*
> diff --git a/include/uapi/linux/psci.h b/include/uapi/linux/psci.h
> index 2fcad1d..d786ec8 100644
> --- a/include/uapi/linux/psci.h
> +++ b/include/uapi/linux/psci.h
> @@ -55,6 +55,8 @@
> #define PSCI_1_0_FN64_SYSTEM_SUSPEND PSCI_0_2_FN64(14)
> #define PSCI_1_1_FN64_SYSTEM_RESET2 PSCI_0_2_FN64(18)
>
> +#define PSCI_1_1_SYSTEM_RESET2_SYSTEM_WARM_RESET 0
> +
> /* 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
> --
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
