Quoting Elliot Berman (2024-10-18 12:39:48)
> diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c
> index 2328ca58bba6..60bc285622ce 100644
> --- a/drivers/firmware/psci/psci.c
> +++ b/drivers/firmware/psci/psci.c
> @@ -29,6 +29,8 @@
> #include <asm/smp_plat.h>
> #include <asm/suspend.h>
>
> +#define REBOOT_PREFIX "mode-"
Maybe move this near the function that uses it.
> +
> /*
> * While a 64-bit OS can make calls with SMC32 calling conventions, for some
> * calls it is necessary to use SMC64 to pass or return 64-bit values.
> @@ -305,9 +315,29 @@ static int get_set_conduit_method(const struct device_node *np)
> return 0;
> }
>
> +static void psci_vendor_sys_reset2(unsigned long action, void *data)
> +{
> + const char *cmd = data;
> + unsigned long ret;
> + size_t i;
> +
> + for (i = 0; i < num_psci_reset_params; i++) {
> + if (!strcmp(psci_reset_params[i].mode, cmd)) {
> + ret = invoke_psci_fn(PSCI_FN_NATIVE(1_1, SYSTEM_RESET2),
> + psci_reset_params[i].reset_type,
> + psci_reset_params[i].cookie, 0);
> + pr_err("failed to perform reset \"%s\": %ld\n",
> + cmd, (long)ret);
Do this intentionally return? Should it be some other function that's
__noreturn instead and a while (1) if the firmware returns back to the
kernel?
> + }
> + }
> +}
> +
> static int psci_sys_reset(struct notifier_block *nb, unsigned long action,
> void *data)
> {
> + if (data && num_psci_reset_params)
> + psci_vendor_sys_reset2(action, data);
> +
> if ((reboot_mode == REBOOT_WARM || reboot_mode == REBOOT_SOFT) &&
> psci_system_reset2_supported) {
> /*
> @@ -750,6 +780,68 @@ static const struct of_device_id psci_of_match[] __initconst = {
> {},
> };
>
> +static int __init psci_init_system_reset2_modes(void)
> +{
> + const size_t len = strlen(REBOOT_PREFIX);
> + struct psci_reset_param *param;
> + struct device_node *psci_np __free(device_node) = NULL;
> + struct device_node *np __free(device_node) = NULL;
> + struct property *prop;
> + size_t count = 0;
> + u32 magic[2];
> + int num;
> +
> + if (!psci_system_reset2_supported)
> + return 0;
> +
> + psci_np = of_find_matching_node(NULL, psci_of_match);
> + if (!psci_np)
> + return 0;
> +
> + np = of_find_node_by_name(psci_np, "reset-types");
> + if (!np)
> + return 0;
> +
> + for_each_property_of_node(np, prop) {
> + if (strncmp(prop->name, REBOOT_PREFIX, len))
> + continue;
> + num = of_property_count_elems_of_size(np, prop->name, sizeof(magic[0]));
Use of_property_count_u32_elems()?
> + if (num != 1 && num != 2)
> + continue;
> +
> + count++;
> + }
> +
> + param = psci_reset_params = kcalloc(count, sizeof(*psci_reset_params), GFP_KERNEL);
> + if (!psci_reset_params)
> + return -ENOMEM;
> +
> + for_each_property_of_node(np, prop) {
> + if (strncmp(prop->name, REBOOT_PREFIX, len))
> + continue;
> +
> + param->mode = kstrdup_const(prop->name + len, GFP_KERNEL);
> + if (!param->mode)
> + continue;
> +
> + num = of_property_read_variable_u32_array(np, prop->name, magic, 1, 2);
ARRAY_SIZE(magic)?
> + if (num < 0) {
Should this be less than 1?
> + pr_warn("Failed to parse vendor reboot mode %s\n", param->mode);
> + kfree_const(param->mode);
> + continue;
> + }
> +
> + /* Force reset type to be in vendor space */
> + param->reset_type = PSCI_1_1_RESET_TYPE_VENDOR_START | magic[0];
> + param->cookie = num == 2 ? magic[1] : 0;
ARRAY_SIZE(magic)?
> + param++;
> + num_psci_reset_params++;
> + }
> +
> + return 0;
