ANDROID: Revert "cpuidle, dt: Push RCU-idle into driver"

This reverts commit 0c5ffc3.

Commit causes trigger of debug reboot timer timeout on simple
reboots from android userspace or on reboots from fastbootd mode.
Debug reboot timer is programmed when reboot sequence is initiated
and if reboot doesn't happen in 15 seconds the timer callback
causes a fatal exception in the interrupt using BRK.
This also leads to ramdumps which consume some amount of time
which in its turn leads to longer reboots.

[   27.362551][    C4] debug-reboot: Reboot timer (15 seconds) timeout - Show All Blocked State
	...
[   27.365871][    C4] debug-reboot: Trigger a panic
[   27.365959][    C4] Unexpected kernel BRK exception at EL1
	...
[   27.378991][    C4] CPU: 4 PID: 0 Comm: swapper/4 Tainted: G        W  OE      6.2.0-mainline-maybe-dirty #1
[   27.379363][    C4] Hardware name: Oriole DVT (DT)
[   27.379546][    C4] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[   27.379839][    C4] pc : reboot_timeout+0x38/0x40 [debug_reboot]
[   27.380068][    C4] lr : reboot_timeout+0x38/0x40 [debug_reboot]
[   27.380298][    C4] sp : ffffffc008023e40
[   27.380451][    C4] x29: ffffffc008023e40 x28: dead000000000122 x27: 0000000000000000
[   27.380751][    C4] x26: ffffffc008023ea0 x25: 0000000000000001 x24: ffffff894f18f270
[   27.381050][    C4] x23: ffffffd56e436000 x22: ffffff880022c600 x21: ffffffd56e7d7008
[   27.381349][    C4] x20: ffffffd56e7d4088 x19: 0000000000000101 x18: ffffffc008025030
[   27.381648][    C4] x17: 0000000022b7e063 x16: ffffffffffffffff x15: 0000000000000004
[   27.381948][    C4] x14: 0000000000007fff x13: ffffff894ed58000 x12: 0000000000000003
[   27.382247][    C4] x11: 0000000000000003 x10: c0000000ffff7fff x9 : 14b04a95e2f58a00
[   27.382546][    C4] x8 : 14b04a95e2f58a00 x7 : 205b5d3137383536 x6 : 332e37322020205b
[   27.382846][    C4] x5 : ffffffd56e62b90f x4 : 0000000000000001 x3 : 0000000000000000
[   27.383145][    C4] x2 : 0000000000000000 x1 : ffffffc008023c10 x0 : 000000000000001d
[   27.383445][    C4] Call trace:
[   27.383564][    C4]  reboot_timeout+0x38/0x40 [debug_reboot]
[   27.383780][    C4]  call_timer_fn+0x54/0x268
[   27.383946][    C4]  __run_timers+0x1cc/0x334
[   27.384113][    C4]  run_timer_softirq+0x2c/0x58
[   27.384289][    C4]  __do_softirq+0x104/0x3f0
[   27.384456][    C4]  ____do_softirq+0x18/0x2c
[   27.384622][    C4]  call_on_irq_stack+0x40/0x74
[   27.384798][    C4]  do_softirq_own_stack+0x24/0x38
[   27.384985][    C4]  __irq_exit_rcu+0xa0/0x100
[   27.385154][    C4]  irq_exit_rcu+0x18/0x28
[   27.385314][    C4]  el1_interrupt+0xac/0xe8
[   27.385477][    C4]  el1h_64_irq_handler+0x20/0x30
[   27.385659][    C4]  el1h_64_irq+0x68/0x6c
[   27.385816][    C4]  arch_local_irq_enable+0xc/0x14
[   27.386002][    C4]  cpuidle_enter+0x40/0x60
[   27.386165][    C4]  do_idle+0x1e0/0x2a0
[   27.386315][    C4]  cpu_startup_entry+0x2c/0x34
[   27.386492][    C4]  secondary_start_kernel+0x148/0x16c
[   27.386690][    C4]  __secondary_switched+0xb4/0xb8
[   27.386879][    C4] Code: 9791bb54 b0000000 9106f400 97b1739f (d4200020)
[   27.387137][    C4] ---[ end trace 0000000000000000 ]---
[   27.387341][    C4] Kernel panic - not syncing: BRK handler: Fatal exception in interrupt

Reverting while investigating a proper fix.

Bug: 272060410
Change-Id: Ib7b33586f7670066738c267f497f9a7c2332c3f6
Signed-off-by: Alexey Klimov <klimova@google.com>

Author: Alexey Klimov

drivers/acpi/processor_idle.c

@@ -1223,8 +1223,6 @@ static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
 		state->target_residency = lpi->min_residency;
 		if (lpi->arch_flags)
 			state->flags |= CPUIDLE_FLAG_TIMER_STOP;
-		if (i != 0 && lpi->entry_method == ACPI_CSTATE_FFH)
-			state->flags |= CPUIDLE_FLAG_RCU_IDLE;
 		state->enter = acpi_idle_lpi_enter;
 		drv->safe_state_index = i;
 	}

drivers/cpuidle/cpuidle-big_little.c

@@ -64,8 +64,7 @@ static struct cpuidle_driver bl_idle_little_driver = {
 		.enter			= bl_enter_powerdown,
 		.exit_latency		= 700,
 		.target_residency	= 2500,
-		.flags			= CPUIDLE_FLAG_TIMER_STOP |
-					  CPUIDLE_FLAG_RCU_IDLE,
+		.flags			= CPUIDLE_FLAG_TIMER_STOP,
 		.name			= "C1",
 		.desc			= "ARM little-cluster power down",
 	},
@@ -86,8 +85,7 @@ static struct cpuidle_driver bl_idle_big_driver = {
 		.enter			= bl_enter_powerdown,
 		.exit_latency		= 500,
 		.target_residency	= 2000,
-		.flags			= CPUIDLE_FLAG_TIMER_STOP |
-					  CPUIDLE_FLAG_RCU_IDLE,
+		.flags			= CPUIDLE_FLAG_TIMER_STOP,
 		.name			= "C1",
 		.desc			= "ARM big-cluster power down",
 	},
@@ -122,17 +120,15 @@ static int notrace bl_powerdown_finisher(unsigned long arg)
  * Called from the CPUidle framework to program the device to the
  * specified target state selected by the governor.
  */
-static __cpuidle int bl_enter_powerdown(struct cpuidle_device *dev,
-					struct cpuidle_driver *drv, int idx)
+static int bl_enter_powerdown(struct cpuidle_device *dev,
+				struct cpuidle_driver *drv, int idx)
 {
 	cpu_pm_enter();
-	ct_cpuidle_enter();
 
 	cpu_suspend(0, bl_powerdown_finisher);
 
 	/* signals the MCPM core that CPU is out of low power state */
 	mcpm_cpu_powered_up();
-	ct_cpuidle_exit();
 
 	cpu_pm_exit();
 

drivers/cpuidle/dt_idle_states.c

@@ -77,7 +77,7 @@ static int init_state_node(struct cpuidle_state *idle_state,
 	if (err)
 		desc = state_node->name;
 
-	idle_state->flags = CPUIDLE_FLAG_RCU_IDLE;
+	idle_state->flags = 0;
 	if (of_property_read_bool(state_node, "local-timer-stop"))
 		idle_state->flags |= CPUIDLE_FLAG_TIMER_STOP;
 	/*