cpuidle: riscv-sbi: Add cpuidle_disabled() check

The consumer devices that inside the cpu/cluster power domain may register
the genpd notifier where their power domains point to the pd nodes under
'/cpus/power-domains'. If the cpuidle.off==1, the genpd notifier will fail
due to sbi_cpuidle_pd_allow_domain_state is not set. We also need the
sbi_cpuidle_cpuhp_up/down to invoke the callbacks. Therefore adding a
cpuidle_disabled() check before cpuidle_register() to address the issue.

Signed-off-by: Nick Hu <nick.hu@sifive.com>
Reviewed-by: Anup Patel <anup@brainfault.org>
Link: https://lore.kernel.org/r/20240814054434.3563453-3-nick.hu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>

Author: nick650823

drivers/cpuidle/cpuidle-riscv-sbi.c

@@ -25,6 +25,7 @@
 #include <asm/smp.h>
 #include <asm/suspend.h>
 
+#include "cpuidle.h"
 #include "dt_idle_states.h"
 #include "dt_idle_genpd.h"
 
@@ -336,6 +337,9 @@ static int sbi_cpuidle_init_cpu(struct device *dev, int cpu)
 		return ret;
 	}
 
+	if (cpuidle_disabled())
+		return 0;
+
 	ret = cpuidle_register(drv, NULL);
 	if (ret)
 		goto deinit;
@@ -548,7 +552,10 @@ static int sbi_cpuidle_probe(struct platform_device *pdev)
 	/* Setup CPU hotplut notifiers */
 	sbi_idle_init_cpuhp();
 
-	pr_info("idle driver registered for all CPUs\n");
+	if (cpuidle_disabled())
+		pr_info("cpuidle is disabled\n");
+	else
+		pr_info("idle driver registered for all CPUs\n");
 
 	return 0;